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Jura’s ‘jurassic’ journeys of discovery to and from sorghum’s ‘seven seas sede’

 Africa, Asia, Comparative genomics in cereals, Genetics, Genomics, Latin America, Researchers, Sorghum  No Responses »
Jan 082015
 

Welcome to Brazil! Journey by road six hours northwest from Rio de Janeiro and you’ll arrive to Sete Lagoas,  a city whose name means ‘Seven Lagoons’ in Portuguese. Although cloistered in farmlands, the city is largely a commercial centre, but also the seat of Embrapa Milho e Sorgo, the nerve centre of EMBRAPA’s maize and sorghum research, and so could pass for the ‘sede’ (Portuguese for headquarters) of the these two cereals. EMBRAPA is the Portuguese acronym for Empresa Brasileira de Pesquisa Agropecuária; the Brazilian Agricultural Research Corporation. EMBRAPA is a GCP Consortium member, and contributed to the proposal that founded GCP.

Photo provided by J MagalhãesJurandir Magalhães (pictured), or Jura, as he likes to be referred to in informal settings such as our story today, is a cereal molecular geneticist who has been working at the Embrapa Milho e Sorgo centre since 2002. “The centre develops projects and research to produce, adapt and diffuse knowledge and technologies in maize and sorghum production by the efficient and rational use of natural resources,” Jura explains.

Such qualities are exactly what appeal to GCP, which has supported Jura as a Principal Investigator since 2004. Beyond science and on to governance and advisory issues, Jura is also EMBRAPA’s representative on the GCP Consortium Committee.

Home and away, on a journey of discovery in sorghum
Hailing from Belo Horizonte, Minas Gerais State, where he was born, Jura attended the Federal University of Viçosa in his home state. Upon completing his Master’s degree at the university in 1995, he proceeded to USA’s Cornell University in 1998 for his PhD, under the watchful eye of Leon Kochian, another GCP Principal Investigator.

Sorghum rainbow_A Borrell

No, it’s not photo-shopped. This Australian sorghum-and-double-rainbows shot is from Supa Snappa, Andy Borrell, also a GCP sorghum Principal Investigator. See http://bit.ly/1tBAOMW

At Cornell, Jura worked with Leon on identifying the genes associated with aluminium tolerance in sorghum. “At the time, genes associated with aluminium tolerance were known for cereals in the Triticeae family (wheat, barley and rye). But the same genes were not found in the Poaceae family (sorghum, rice and maize). This suggested that there were different aluminium-tolerance genes at play, so it was a really pioneering project.” Continuing with the Cornell team after his PhD, Jura worked with Leon to  map the location of a major aluminium-tolerance genetic ‘hotspot’ in sorghum, which the project team contracted to  AltSB  for short (aluminium-tolerance gene or locus in Sorghum bicolor). The mapping also marked the next chapter  of what was to be a long-term professional relationship for the pair.

Brazil beckons, joining GCP, leadership and enduring partnerships
But in between, Brazil broke in and beckoned her native son home. And so it was that in 2002, Jura packed his bags and accepted a position with EMBRAPA’s maize and sorghum research centre. And despite the geographical distance, it wasn’t long before he and Leon teamed up again. “When I left Cornell, Leon and I had finished mapping AltSB and we were keen to clone it so we could then develop aluminium-tolerant sorghum varieties more efficiently,” says Jura.

Two years after his return to Brazil,  Leon and Jura – in 2004 – submitted a joint proposal for a competitive grant for their first GCP project on aluminium tolerance in cereals, premised on AltSB. This project contributed to GCP’s foundation work on sorghum in this and other projects, the common goal being a bid to provide farmers in the developing world with sorghum crops that would be able to tolerate harsh soils. But the project contributed much more with a deep taproot in pre-history, as that which we today call ‘sorghum’, ‘maize’ and ‘rice’ were once one millions of ‘Jurassic’ years ago. More on that interesting side-story.

And since this first project, EMBRAPA and Cornell University have collaborated with several other research institutes around the world, particularly in Africa.

Left to right (foreground): Leon Kochian, Jurandir Magalhães (both EMBRAPA) and Sam Gudu (Moi University) examine crosses between Kenyan and Brazilian maize, at the Kenya Agricultural Research Institute (KARI), Kitale, in May 2010.

Left to right (foreground): Leon, Jura and Sam Gudu (Moi University) examine crosses between Kenyan and Brazilian maize, at the Kenya Agricultural Research Institute (KARI), Kitale, in May 2010.

Jura leads several EMBRAPA and GCP collaborative projects across three continents (Africa, Asia and the Americas). The partnerships forged by and through these projects go well beyond project life and frame, and will therefore continue after GCP’s sunset. Jura is both team leader and team player. And a couple of GCP projects in which Jura is part of the project team will run on in 2015 (see page 10), after GCP’s closure in December 2014.

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Decoding disease resistance in maize and rice

 Africa, Asia, Crop breeding, Genetics, Genomics, Maize, Women in science  No Responses »
Aug 312014
 

 Crop disease costs farmers billions of dollars each year in lost yields and inputs. For farming communities in developing countries, such losses can mean deepening poverty, food insecurity, and the resulting poor nutrition and health. 

In Africa alone, it is estimated that crop pests and diseases lead to losing more than half the crops planted. Added to this, some fungal pathogens cause toxic compounds to accumulate in food. In extreme cases, crop diseases have led to widespread famine, social disruption and loss of life – the Irish Potato Famine in the 19th century is a case in point.

Overcoming this reality is what motivates plant pathologists like Rebecca Nelson (pictured below, and profiled here), of Cornell University, USA. For the past quarter century, Rebecca has worked across four continents to understand the ways in which plants defend themselves against diseases.

Rebecca Nelson

Rebecca Nelson

“Pesticides are the dominant way in which pests and diseases are managed, in spite of the many downsides to this approach,” says Rebecca. “For resource-limited farmers, this is often not an option. For those who use pesticides, the health impacts hit harder in the tropics, where protective clothing is not the norm. That’s why we’re trying to understand how plants naturally defend themselves, so that we can then tap into this, and learn from nature to breed crops that are resistant to disease.”

With this premise and funding from GCP, Rebecca collaborated with an interdisciplinary international team from USA, The Philippines, Indonesia and Kenya to identify genes associated with disease resistance in maize and rice. Although the project itself ended in 2009, that was far from the end of the story. In many ways, the end of the GCP project was in fact the beginning of life-changing chapters that followed. Thus far, the project has led to several locally developed disease-resistant varieties of rice in Indonesia and maize in Kenya.

We now already know quite a lot about the genetic architecture of several critical diseases, and this knowledge is enough for us to get started on improving the efficiency of resistance breeding”

Dissecting resistance – the genie in the genes
To understand the genetic reason behind resistance, Rebecca and her team used a range of genetic tools to dissect various forms of genetic resistance, understand the mechanisms that the plants use to reduce pathogen success, and identify the genes that provide resistance.

To create a near isogenic line, an organism with the phenotype of interest, often a plant, is crossed with a standard line of the same plant. The F1 generation is selfed to produce the F2 generation.

NILS explained: To create a near-isogenic line, a plant with the phenotype of interest is crossed with a standard line of the same plant. The F1 (1st filial) generation is thereafter selfed (ie, crossbred within itself) to produce the F2 (2nd filial) generation.

“There has been a lot of work done on sequencing the genomes of rice and maize, so we tapped into this work and combined our team expertise in genetics, pathology and plant breeding to help identify these disease-resistance genes,” says Rebecca. “We used recombination breeding and other genetic techniques to dissect the genomes and identify specific regions that convey disease resistance. We now already know quite a lot about the genetic architecture of several critical diseases, and this knowledge is enough for us to get started on improving the efficiency of resistance breeding. In addition, we’re identifying the genes and the ways they work, so as to interrupt pathogenesis [the manner in which a disease develops]. This involved breeding near-isogenic lines of rice and maize with the genes of interest, infecting these plants with a disease of interest, and monitoring their resistance in the field.”

Identifying genes responsible for resistance
Through this process, the team identified several genomic regions and specific genes responsible for protecting resistant rice plants against rice blast and sheath blight and resistant maize plants against northern and southern leaf blight, grey leaf spot and ear rot.

An underlying objective of the project was to also investigate if some of these genes were responsible not for just one specific disease, but for multiple diseases.

“We were intrigued by the idea of multiple disease resistance, because farmers face a range of diseases in their fields. In maize, we identified a gene associated with resistance to three diseases – southern leaf blight, northern leaf blight and grey leaf spot.”

While the team found several gene loci in both maize and rice that provide resistance to more than one disease, they have so far found little cross-benefit from the work on the two crops. But from their research they have ‘handles’ on the rich diversity of resistance loci in each of the two crops.

“Plant breeders will be able to use this information to breed crops for multiple disease resistance, increasing the security of the crop and farmers’ livelihoods,” says Rebecca.

A 2008 update: A slide from Rebecca's presentation at the GCP General Research Meeting in September of that year.

A 2008 update: a slide from Rebecca’s presentation at the GCP General Research Meeting in September of that year.

Working with that great group of people and being a part of the larger GCP family, which comprises of an amazing talent pool, was really valuable.”

Collaborating with old friends, and new
Rebecca credits her collaborators and support from the GCP family for the success of the project, saying none of the outcomes could have been achieved without everyone playing their part.  “Working with that great group of people and being a part of the larger GCP family, which comprises of an amazing talent pool, was really valuable. I really appreciated that GCP supported my work at a time when I was making a transition in my career. GCP gave me and my team time and inspiration to find our feet. All of our labs are now well established, and we have since been able to diversify our funding sources.”

Project scientists from the Kenya Agricultural Research Institute (KARI) and the Indonesian Centre for Agricultural Resources Research and Development (ICABIOGRAD) reflect the involvement of country agricultural research programmes. Other partners included the International Rice Research Institute (IRRI) and four universities: Bogor Agriculture University in Indonesia and Colorado State, Cornell and North Carolina State Universities, all in USA.

Masdiar Bustamam

A highlight of the project for Rebecca was reconnecting with old colleagues at IRRI, where she had previously worked for eight years. “It was great to involve my IRRI mentor, Hei Leung, and our collaborator Jan Leach, as well as several other IRRI people whom I worked with on several rice disease-resistance projects. It was also great to involve Masdiar Bustamam of ICABIOGRAD. My team at IRRI had worked with her laboratory as she was getting it started. It was such a pleasure to see how far she and her lab had come since our earlier collaboration. They were able to make a significant contribution to the project in advancing the understanding of inheritance of rice blast and sheath blast resistance, and they developed germplasm that has really good resistance to these diseases.”

Having a limited background in maize research before the project began, Rebecca was grateful for her close collaboration with KARI’s James Gethi, who was a lead researcher in Kenya. At the time of the proposal, James was a recent Cornell graduate who was returning home to contribute to his nation’s crop-research capabilities.

“James and I were both getting our maize programmes going and the support was terrific for our labs and for our collaboration. We’ve continued to work together since our GCP project wrapped up.”

Rebecca (left) on a field visit to Kenya in September 2006. On the left is John Okalembo of Moi University, with James Gethi behind the camera.

A partnership of long standing: Rebecca (left) on a field visit to Kenya in September 2006. On the right is John Okalembo of Moi University, with James Gethi behind the camera.

You can’t see it, you can’t taste it, you can’t feel it. The population is being poisoned without knowing about it.”

Continuing projects, tracking a silent cereal killer, and spreading a positive epidemic
One such project, which Rebecca and James have worked tirelessly on, is understanding genetic resistance to aflatoxins in maize. “We were travelling through Kenya together in 2005 when there was an aflatoxin outbreak,” remembers Rebecca. “Ever since, we’ve been obsessed with the problem.”

Aflatoxin is the most carcinogenic natural substance known. It is produced by species of fungi, especially Aspergillus flavus, which can colonise and contaminate grain before harvest or during storage. Maize is particularly susceptible to infection during drought, or when it is attacked by insects, or improperly stored. In 2004, 125 people died in Kenya after eating maize with very high aflatoxin levels.

“This food-safety problem is rigorously and carefully managed in developed countries but less so in cash-strapped developing nations,” says Rebecca. “In tropical countries where maize and groundnuts are often grown under stress and stored under suboptimal conditions, it is a huge problem. Yet you can’t see it, you can’t taste it, you can’t feel it. The population is being poisoned without knowing about it.”

Rebecca and James spent years trying to get support for their work on aflatoxin – the silent cereal killer – and trying to get funding for a graduate student who could take a lead. They made headway while Rebecca was on sabbatical at the Biosciences eastern and central Africa (BecA) Hub in Nairobi. BecA eventually received a major grant from Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), and Rebecca says a strong team is now tackling the issue.

We’re indebted to GCP for bringing us together to tackle cereal diseases”

“One of our big goals was to support a promising young talent named Samuel Mutiga. I’m delighted to say that he is just finishing his PhD at Cornell now, and has done some terrific work on aflatoxin in collaboration with James and BecA.”

Samuel is one of several PhD students at Cornell who are passionate about improving food safety in Africa by beating the aflatoxin problem. “One American students is working with a Kenyan student in Nairobi to develop an improved spectroscopic grain sorter for people processing their maize at small grain mills. This will allow them to remove the toxic kernels before they mill and eat the grain, something that cannot be done visually.”

Rebecca says it’s “exciting to see this new generation take on this huge challenge. There are more scientists who are coming on board and sharing their expertise. James and I are gratified that we helped ‘infect’ these people with the conviction that something needs to be done and can be done. We’re indebted to GCP for bringing us together to tackle cereal diseases.”

 Links

 

Lively Leon: a never-grow-old researcher, and his biological rebirths

 Comparative genomics in cereals, Genomics, Maize, Researchers, Sorghum  No Responses »
Aug 272014
 
Leon Kochian

Leon Kochian

“By being involved with GCP, I’ve had more opportunities to travel to the developing world and witness the problems that local farmers in these countries are facing, as well as to meet with the local researchers who are trying to overcome these problems. It has made me appreciate that these  researchers also need the capacity to sustainably deal with agricultural problems once the project money starts to dry up.” – Leon Kochian (pictured), Professor, Cornell University, USA; and Director of Robert W Holley Center for Agriculture and Health, United States Department of Agriculture – Agricultural Research Service. Also Product Delivery Leader for GCP’s Comparative Genomics Research Initiative.

Bright and early beginnings in biology
For as long as Leon Kochian can remember, he’d always wanted to be a biologist.

“I remember my second-grade teacher reading a story to us about the white cliffs of Dover and thinking to myself ‘They’re white because they’re covered in the prehistoric remains of dead protozoan’,”’ says Leon with a chuckle. “Yes, I was a weird kid and that sort of stuff [biology] has always interested me.”

Having completed a Bachelor’s Degree in Botany at the University of California, Berkeley, and a PhD in Plant Physiology at the University of California, Davis (both in USA), Leon joined the United States Department of Agriculture based at Cornell University.

For 30 years, he has combined lecturing and supervising duties at Cornell, with his quest to understand the genetic and physiological mechanisms that allow some cereals to tolerate acidic soils.

The GCP model has always attracted me, particularly its focus on making an impact on farmers’ lives… I had already been a successful researcher having published more than 250 papers, but I felt little of that had made any real impact on the world.”

Identifying genes and breeding tolerant crops for African farmers
Leon and Cornell University have been involved with GCP since the Programme’s inception in 2004, playing a lead role in GCP’s Comparative Genomics Research Initiative, of which Leon is the Product Delivery Coordinator. Cornell University is a member of the GCP Consortium, with Leon as Cornell’s representative in the GCP Consortium Committee.

“The GCP model has always attracted me, particularly its focus on making an impact on farmers’ lives,” says Leon, who has been a Principal Investigator for several Comparative Genomics Research Initiative projects. “I had already been a successful researcher having published more than 250 papers, but I felt little of that had made any real impact on the world.”

During the first phase of the project, Leon led a team comprising of researchers from Cornell, EMBRAPA in Brazil and Moi University in Kenya.

In the foreground, left to right, Leon, Jura and Sam in a maize field in Kenya.

Leon (left) with project colleagues, Jurandir Magalhães (EMBRAPA) and Sam Gudu (Moi University) in a maize field in Kenya in May 2010.

“We had been working for many years with both EMBRAPA and Moi University to identify the genes associated with aluminium tolerance in sorghum and maize and saw the potential to apply our research and expand it to explore other cereals such as rice and wheat,” explains Leon.

During GCP Phase I (2004–2008), the team successfully identified and cloned the major sorghum aluminium tolerance gene (AltSB). In Phase II (2009–2014), they are working towards breeding aluminium-tolerant sorghum lines for sub-Saharan Africa as well as applying what they have learnt to discover similar genes in rice and maize.

“Aluminium toxicity is a problem all over the world, but more so in Africa, as most farmers don’t have the money to manage it,” says Leon “These new aluminium-tolerant crops will improve African farmers’ yields, and, in turn, improve their quality of life.”

It’s like match.com for collaborative research and will hopefully foster greater collaboration between the two continents.”

Insights, connections and matchmaking
According to Leon, the funding from GCP has been very beneficial in making significant research progress on the projects he’s been involved with so far, and he is also quick to note the unexpected and very welcome non-monetary benefits from being involved with GCP.

“By being involved with GCP, I’ve had more opportunities to travel to the developing world and witness the problems that local farmers in these countries are facing, as well as to meet with the local researchers who are trying to overcome these problems. It has made me appreciate that these  researchers also need the capacity to sustainably deal with agricultural problems once the project money starts to dry up.”

Working with GCP, Leon has designed and run workshops to train African scientists on molecular breeding techniques and hosted several postgraduate researchers at Cornell. He is now working with GCP collaborators to develop a database that will help African scientists find potential collaborators in USA and the rest of the Americas. “It’s like match.com for collaborative research and will hopefully foster greater collaboration between the two continents,” says Leon.

Research is such a fun and social experience! … I still love getting into the lab and discovering new things. I’ve also learnt to enjoy being the old guy in the lab!”

Growing greyer, growing wiser
Leon says his passion for biology and research is steadfast and has not waned through the years. Although he doesn’t get to do much of the hands-on work these days, it still remains the most enjoyable part of his job. “Research is such a fun and social experience! I still love getting into the lab and discovering new things. I’ve also learnt to enjoy being the old guy in the lab! Just watching and helping young researchers grow and develop their skills is really rewarding. Each of the 13 PhD students I’ve supervised is like one of my kids and I still keep in touch with all of them, as I do with my own PhD supervisor, 30 years on!”

Having recently celebrated his 60th birthday, Leon has no plans on slowing down anytime soon. “I’m currently Director of the Robert W Holley Center for Agriculture and Health, lecturing undergraduate and postgraduate students, supervising two PhD students and sitting on several boards, all the while trying to find time to write papers and do some research. It’s hard work but I enjoy it.”

The three faces of Leon: (1) in the lab in Cornell; (2) in the field courtesy of USDA-ARS; and, (3) delivering opening remarks as Director of the Robert W Holley Center

The three faces of Leon: (1) in the lab in Cornell; (2) in the field, courtesy of USDA–ARS; and, (3) delivering opening remarks as Director of the Robert W Holley Center.

Leon tries to impart this philosophy to his students, believing scientists need to enjoy what they are doing, work hard at it, be flexible and creative, and, most importantly, not have ‘fear of failure’. “I don’t care how smart you are. If you’re not willing to work really hard and learn to improve yourself, then you’re not going to succeed.”

With regard to his GCP projects soon coming to a close when GCP sunsets in December 2014, Leon hopes he and team will succeed in meeting all their goals, but even if they don’t, he’s sure they’ll continue the research and try to discover more about aluminium tolerance. More power to them!

Leon’s slides, with links to more supplementary material after the slides

Links

Super Sam: Kenya’s nurturing geneticist, and the fruits of his labour

 Africa, Capacity building, Comparative genomics in cereals, Crop breeding, Genetics, Genomics, Maize, Researchers  3 Responses »
Aug 152014
 

 

Samuel Gudu

Samuel Gudu

“Having funding to support PhD students and provide them with the resources they need to complete their research is very fulfilling and will go a long way to enhance the long-term success of our goal: to provide Kenyan farmers with cereal varieties that will improve their yields and make their livelihood more secure and sustainable.” – Samuel Gudu, Professor and Deputy Vice-Chancellor (Planning & Development) at Moi University, and now Principal, Rongo University College: a Constituent College of Moi University, Kenya.

Growing up, and getting dirty
Learner, teacher and leader. Sam Gudu has been all these, but this doesn’t mean he doesn’t like to get his hands dirty.

Growing up in a small fishing village on the banks of Lake Victoria, in Western Kenya, Sam was always helping his parents to fish and garden, or his grandparents to muster cattle.

“I remember spending long hours before and after school either on the lake or in the field helping to catch, harvest and produce enough food to eat and support our family,” reminisces Sam.

He attributes this “hard and honest” work to why he still enjoys being in the field.

“Even though I now spend most of my days doing administration work, I’m always trying to get out into the field to get my hands dirty and see how our research is helping to make the lives of Kenyan farmers a lot more profitable and sustainable,” he says.

Sam in a maize field in Kenya.

Doing what he likes to do best: Sam in a maize field in Kenya.

I was… captivated by the study of genetics as it focused on what controlled life.”

Taking control: bonded to genetics, at home and away
Sam says his love for the land transferred to an interest and then passion in the classroom during high school. “I became very interested in Biology as I wanted to know how nature worked,” says Sam. “I was particularly captivated by the study of genetics as it focused on what controlled life.”

This interest grew during his undergraduate years at the University of Nairobi where he completed a Bachelor of Science in Agriculture and a Master’s of Science in Agriculture, focusing on genetics and plant breeding.

“I fondly remember a lecturer during my master’s degree studies who would continually give us challenges to test in the field and in the lab. If you had a viable idea he supported you to design an experiment to test your theory. I like to use the same method in teaching my students. I discuss quite a lot with my students and I encourage them to disagree if they use scientific process.”

Driven by an ever-growing passion and enthusiasm, Sam secured a scholarship to travel to Canada to undertake a PhD in Plant Genetics and Biotechnology at the University of Guelph.

[There has been an] influx of young Kenyans who are choosing degrees in science. The Kenyan Government has recently increased its funding for science and research…”

Nurturing the next breed of geneticists
After graduating from Guelph in 1993, Sam returned to Kenya to lecture at Moi University where he initiated and helped expand teaching and research in the disciplines of Genetic Engineering, Biotechnology and Molecular Biology.

In the past two decades, he has recruited young talented graduates in genetics and helped acquire advanced laboratory equipment that has enabled practical teaching and research in molecular biology.

“I wouldn’t be where I am now were it not for all the assistance I received from my teachers, lecturers and supervisors; notably my PhD supervisor – Prof Ken Kasha of the University of Guelph. So I’ve always tried my best to give the same assistance to my students. It’s been hard work but very rewarding, especially when you see your students graduate to become peers and colleagues.” (Meet some of Sam’s students)

Sam (2nd right), with some of his young charges: Thomas Matonyei (far left) , Edward Saina (2nd left) and Evans Ouma (far right)

Sam (2nd right), with some of his young charges: Thomas Matonyei (far left), Edward Saina (2nd left) and Evans Ouma (far right).

Sam is particularly buoyed by the influx of young Kenyans who are choosing degrees in science.

“The Kenyan Government has recently increased its funding for science and research to two percent of GDP,” explains Sam. “This has not only helped us compete in the world of research but has helped raise the profile of science as a career.”

Knowing which genes are responsible for aluminium tolerance will allow us to more precisely select for aluminium tolerance in our breeding programmes, reducing the time it takes for us to breed varieties that will have improved yields in acidic soils without the use of costly inputs such as lime or fertiliser.” (See the work that Sam does in this area with other partners outside Kenya)

So far we have produced 10 inbred lines that are outstanding for phosphorus efficiency, and two that were outstanding for aluminium toxicity. We are now testing unique verities developed for acid soils of Kenya.”

Slashing costs, increasing yields and resilience: genes to the rescue
Currently, Sam and his team of young researchers at Moi University are working with several other research facilities around the world (Brazilian Agricultural Research Corporation, EMBRAPA; Cornell University, USA; the International Rice Research Institute (IRRI); Japan’s International Research Center for Agricultural Sciences, JIRCAS; and the Kenya Agricultural Research Institute, KARI–Kitale) to develop high-yielding maize varieties adapted to acid soils in East Africa, using molecular and conventional breeding approaches.

Can you spot Sam? It’s a dual life. Here, he sheds his field clothes in this 2011 suit-and-tie moment with Moi University and other colleagues involved in the projects he leads. Left to right: P Kisinyo, J Agalo, V Mugalavai, B Were, D Ligeyo, S Gudu, R Okalebo and A Onkware.

Acid soils cover almost 13 per cent of arable land in Kenya, and most of the maize-growing areas in Kenya. In most of these areas, maize yields are reduced by almost 60 per cent. Aluminium toxicity is partly responsible for the low and declining yields.

“We found that most local maize varieties and landraces grown in acid soils are sensitive to aluminium toxicity. The aluminium reduces root growth and as such the plant cannot efficiently tap into native soil phosphorus, or even added phosphorus fertiliser. However, there are some varieties of maize that are suited to the conditions even if you don’t use lime to improve the soil’s pH. So far we have produced 10 inbred lines that are outstanding for phosphorus efficiency, and two that were outstanding for aluminium toxicity. We are now testing unique varieties developed for acid soils of Kenya.”

Sam (left) a group of farmers and alking to farmers and researchers at Sega, Western Kenya, in June 2009

Sam (left) addressing a mixed group of farmers and researchers at Sega, Western Kenya, in June 2009.

In a related project, Sam is working with the same partners to understand the molecular and genetic basis for aluminium tolerance.

“Knowing which genes are responsible for aluminium tolerance will allow us to more precisely select for aluminium tolerance in our breeding programmes, reducing the time it takes for us to breed varieties that will have improved yields in acidic soils without the use of costly inputs such as lime or fertiliser.”

 … my greatest achievements thus far have been those which have benefited farmers and my students.”

 Summing up success
For Sam, the greatest two successes in his career have not been personal.

“If I’m honest, I have to say my greatest achievements thus far have been those which have benefited farmers and my students. Having funding to support PhD students and provide them with the resources they need to complete their research is very fulfilling and will go a long way to enhance the long-term success of our goal: to provide Kenyan farmers with cereal varieties that will improve their yields and make their livelihoods more secure and sustainable.”

With a dozen aluminium-tolerant and phosphorus-efficient breeding lines under their belt already, and two lines submitted for National Variety Trials (a pre-requisite step to registration and release to farmers), Sam and his team seem well on their way towards their goal, and we wish them well in their quest and labour.

Links:

 

Sugarcane, sorghum, students and maize: Claudia’s colourful and contrasting crop science career

 Comparative genomics in cereals, Genomics, Latin America, Maize, Researchers, Women in science  No Responses »
Jul 242014
 

Read how this cocktail blends in a comparative genomics crucible, where both family genes and crop genes come into play in Brazil. Nothing whatsoever to do with the World Cup. It’s all about a passionate love affair with plant science – specifically a quest for aluminium-resilient maize – spanning a decade-and-a-half, and still counting…

Claudia

Claudia Guimarães

 

“I love the whole process of science; from identifying a problem, developing a method, conducting the experiments, analysing the data and evaluating the findings.” – Claudia Guimarães (pictured), Researcher at EMBRAPA Milho e Sorgo, Sete Lagoas, Brazil

I always enjoyed looking after the cattle and horses as well as planting and harvesting different crops.”

Forged on family farm, federal institute and foreign land
Claudia Guimarães is a plant molecular geneticist, with a pronounced passion for science. At the Federal University of Viçosa, Claudia studied agronomy because it provided a wide range of possibilities career-wise. She also believes her family’s farming background too had a part to play in her study and career choice. “My father has a farm in a small village 200 km north of Sete Lagoas. My whole family used to go there during our school holidays. I always enjoyed looking after the cattle and horses as well as planting and harvesting different crops.”

During her bachelor’s degrees, Claudia was increasingly drawn to plant genetics. She decided to pursue this field further and completed a Master’s degree in Genetics and Breeding, focusing on maize. She then completed a PhD in Comparative Genomics where she split her time between California and Brazil. “For my PhD, I got a scholarship from the Brazilian Council for Scientific and Technological Development which included international training in San Diego, California. During my PhD, I focused on comparative genomics for sugarcane, maize and sorghum, which involved genetic mapping and markers,” Claudia reveals.

Returning to Brazil after two years in California, Claudia joined the Brazilian Agricultural Research Corporation, commonly referred to as EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária), where she has worked for the last 15 years, since 1999.

bCIMMYTmaizeField_w

Preparing to put her shoulder to the wheel, literally? Claudia in a maize field at the International Maize and Wheat Improvement Center (CIMMYT), Tlaltizapan, Mexico, in January 2010.

dNutrientSolutionEmbrapa_w

Maize plantlets cultivated in nutrient solution, the methodology Claudia and her team use to evaluate aluminium tolerance.

Our next challenge is to develop specific markers for a wider marker-assisted selection of aluminium tolerance in maize.”

Long-term allies in aluminium tolerance
EMBRAPA first became involved with GCP through one of its foundation programmes headed by Leon Kochian and his former PhD student Jurandir Magalhães. “Jura has been a really close friend for a long time,” explains Claudia. “We went to university together and have ended up working together here at EMBRAPA. I was involved in Jura’s project, which sought to clone a sorghum aluminium-tolerance gene.”

This gene is called SbMATE. Claudia continues, “EMBRAPA had a long-term aluminium-tolerance programme on maize and sorghum, within which there was a QTL mapping project for aluminium tolerance in maize, in which we started to look for a similar gene as the sorghum team.”

[Editor’s note: QTL stands for quantitative trait locus or loci – gene loci where allelic variation is associated with variation in a quantitative trait. An allele is a variant (different version) of a gene, that leads to variation in a trait, eg different colour for hair and eyes in human beings.]

Working with Leon Kochian at Cornell University, USA, Claudia and her team were able to find an important aluminium-tolerance gene homologue (loosely meaning a relative or counterpart) to the sorghum SbMATE, which they named ZmMATE. This gene is responsible for a major aluminium tolerance QTL that improves yield in acidic soil in maize breeding lines and hybrids. (see why scientists work jointly on closely related cereals)

“Identifying and then validating ZmMATE as the primary aluminium tolerance QTL in maize was a great project,” says Claudia. “Our next challenge is to develop specific markers for a wider marker-assisted selection of aluminium tolerance in maize.”

1: Rhyzobox containing two layers of Cerrado soil – a corrected top-soil and lower soils with 15 percent of aluminium saturation. We can see that near-isogenic lines (NILs) introgressed with the Al tolerance QTL (qALT6) that encompasses ZmMATE1 show deeper roots and longer secondary roots in acid soils, whereas the roots of L53 are mainly confined in the corrected top soil. 2: Maize ears, representing the improved yield stability in acid soils of a NIL per se and crossed with L3. NILs have the genetic background of L53 introgressed with qALT6, the major aluminium-tolerance QTL.

March 2014. Photo 1: Rhyzobox containing two layers of Cerrado soil – a corrected top-soil and lower soils with 15 percent aluminium saturation. We can see that near-isogenic lines (NILs) introgressed with the aluminium-tolerance QTL (qALT6) that encompasses ZmMATE1 show deeper roots and longer secondary roots in acidic soils, whereas the roots of L53 are mainly confined in the corrected top soil. Photo 2: Maize ears, representing the improved yield stability in acidic soils of a NIL per se and crossed with L3. NILs have the genetic background of L53 introgressed with qALT6, the major aluminium-tolerance QTL.

 

 …the students have really become my arms…  helping me a lot with the experiments…

Giving and receiving: students step in, partners in print
Supervising students has become a larger part of Claudia’s life since becoming a member of the Genetics Graduate Programme at Universidade Federal de Minas Gerais, in 2004. Because of this, she credits the students for helping her with her research. “I don’t have as much time as I used to in the lab, so the students have really become my arms in that area, helping me a lot with the experiments,” Claudia reveals. “This isn’t to say that they don’t have to think about what they are doing. I encourage them to always be thinking about why they are doing an experiment and what the result means. At the end of the day, they need to know more about what they are doing than I do, so they can identify indiscretions and successes.”

Claudia says she is always preaching three simple instructions to her students – work hard, always continue to learn and like what you do. “The last instruction is particularly important because as a scientist you need to dedicate a lot of time to what you do, so it helps if you like it. If you don’t like it then it becomes frustrating and no fun at all. I don’t think of my work as a job, rather as a passion. I just enjoy it so much!”

Claudia’s passion is not just a matter of the heart but also of the head, expressing itself in print. Her latest publication reflects the most current results on maize aluminium tolerance, highlighting GCP support, partnerships within and beyond EMBRAPA embracing Cornell University and the Agricultural Research Services of the United States Department of Agriculture (USDA–ARS) , as well as the strong presence of students. Check it out

Links:

SLIDES

Science enlists nature and collaboration to ‘neutralise’ acidic soils

 Africa, Asia, Comparative genomics in cereals, Genomics, Latin America, Maize, Rice, Sorghum  No Responses »
Jul 232014
 

 

DNA spiral

DNA spiral

Crop researchers including plant breeders across five continents are collaborating on several GCP projects to develop local varieties of sorghum, maize and rice, which can withstand phosphorus deficiency and aluminium toxicity – two of the most widespread constraints leading to poor crop productivity in acidic soils. These soils account for nearly half the world’s arable soils, with the problem particularly pronounced in the tropics, where few smallholder farmers can afford the costly farm inputs to mitigate the problems. Fortunately, science has a solution, working with nature and the plants’ own defences, and capitalising on cereal ‘family history’ from 65 million years ago. Read on in this riveting story related by scientists, that will carry you from USA to Africa and Asia with a critical stopover in Brazil and back again, so ….

… welcome to Brazil, where there is more going than the 2014 football World Cup! Turning from sports to matters cerebral and science, drive six hours northwest from Rio de Janeiro and you’ll arrive in Sete Lagoas, nerve centre of the EMBRAPA Maize and Sorghum Research Centre. EMBRAPA stands for Empresa Brasileira de Pesquisa Agropecuária  ‒  in  English, the Brazilian Agricultural Research Corporation.

Jura_w

Jurandir Magalhães

Jurandir Magalhães (pictured), or Jura as he prefers to be called, is a cereal molecular geneticist and principal scientist who’s been at EMBRAPA since 2002.

“EMBRAPA develops projects and research to produce, adapt and diffuse knowledge and technologies in maize and sorghum production by the efficient and rational use of natural resources,” Jura explains.

Such business is also GCP’s bread and butter. So when in 2004, Jura and his former PhD supervisor at Cornell University, Leon Kochian, submitted their first GCP project proposal to clone a major aluminium tolerance gene in sorghum they had been searching for, GCP approved the proposal.

“We were already in the process of cloning the AltSB gene,” remembers Jura, “So when this opportunity came along from GCP, we thought it would provide us with the appropriate conditions to carry this out and complete the work.”

Cloning the AltSB gene would prove to be one of the first steps in GCP’s foundation sorghum and maize projects, both of which seek to provide farmers in the developing world with crops that will not only survive but thrive in the acidic soils that make up more than half of the world’s arable soils (see map below).

More than half of world’s potentially arable soils are highly acidic.

More than half of world’s potentially arable soils are highly acidic.

… identifying the AltSB gene was a significant achievement which brought the project closer to their final objective, which is to breed aluminium-tolerant crops that will improve yields in harsh environments, in turn improving the quality of life for farmers.”

A star is born: identifying and cloning AltSB
For 30 years, Leon Kochian (pictured below) has combined lecturing and supervising duties at Cornell University and the United States Department of Agriculture, with his quest to understand the genetic and physiological mechanisms behind the ability of some cereals to withstand acidic soils. Leon is also the Product Delivery Coordinator for GCP’s Comparative Genomics Research Initiative.

Leon Kochian

Leon Kochian

Aluminium toxicity is associated with acidic soils and is the primary limitation on crop production for more than 30 percent of farmland in Southeast Asia and Latin America, and approximately 20 percent in East Asia, sub-Saharan Africa and North America. Aluminium ions damage roots and impair their growth and function. This results in reduced nutrient and water uptake, which in turn depresses yield.

“These effects can be limited by applying lime to increase the soil’s pH. However, this isn’t a viable option for farmers in developing countries,” says Leon, who was the Principal Investigator for the premier AltSB project and is currently involved in several off-shoot projects.

Working on the understanding that grasses like barley and wheat use membrane transporters to insulate themselves against subsoil aluminium, Leon and Jura searched for a similar transporter in sorghum varieties that were known to tolerate aluminium.

“In wheat, when aluminium levels are high, these membrane transporters prompt organic acid release from the tip of the root,” explains Leon. “The organic acid binds with the aluminium ion, preventing it from entering the root. We found that in certain sorghum varieties, AltSB is the gene that encodes a specialised organic acid transport protein – SbMATE*  –  which mediates the release of citric acid. From cloning the gene, we found it is highly expressed in aluminium-tolerant sorghum varieties. We also found that the expression increases the longer the plant is exposed to high levels of aluminium.”

[*Editor’s note: different from the gene with the same name, hence not in italics]

Leon says identifying the AltSB gene and then cloning it was a significant achievement and it brought the project closer to their final objective, which he says is “to breed aluminium-tolerant crops that will improve yields in harsh environments, in turn improving the quality of life for farmers.”

This research was long and intensive, but it set a firm foundation for the work in GCP Phase II, which seeks to use what we have learnt in the laboratory and apply it to breed crops that are tolerant to biotic or abiotic stress such as aluminium toxicity and phosphorus deficiency.”

Comparative genomics: finding similar genes in different crops
Wheat, maize, sorghum and rice are all part of the Poaceae (grasses) family, evolving from a common grass ancestor 65 million years ago. Over this time they have become very different from each other. However, at a genetic level they still have a lot in common.

Over the last 20 years, genetic researchers all over the world have been mapping these cereals’ genomes. These maps are now being used by geneticists and plant breeders to identify similarities and differences between the genes of different cereal species. This process is termed comparative genomics and is a fundamental research theme for GCP research as part of its second phase.

rajeev-varshney_1332450938

Rajeev Varshney

“The objective during GCP Phase I was to study the genomes of important crops and identify genes conferring resistance or tolerance to biotic or abiotic stresses,” says Rajeev Varshney (pictured), Director, Center of Excellence in Genomics and Principal Scientist in applied genomics at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). “This research was long and intensive, but it set a firm foundation for the work in GCP Phase II, which seeks to use what we have learnt in the laboratory and apply it to breed crops that are tolerant to biotic or abiotic stress such as aluminium toxicity and phosphorus deficiency.”

Until August 2013, Rajeev had oversight on GCP’s comparative genomics research projects on aluminium tolerance and phosphorus deficiency is sorghum, maize and rice, as part of his GCP role as Leader of the Comparative and Applied Genomics Theme.

“Phosphorus deficiency and aluminium toxicity are soil problems that typically coincide in acidic soils,” says Rajeev. “They are two of the most critical constraints responsible for low crop productivity on acid soils worldwide. These projects are combining the aluminium tolerance work done by EMBRAPA and Cornell University with the phosphorus efficiency work done by IRRI [International Rice Research Institute] and JIRCAS [Japan International Research Centre for Agricultural Sciences] to first identify and validate similar aluminium-tolerance and phosphorus-efficient genes in sorghum, maize and rice, and then, secondly, breed crops with these combined improvements.”

These collaborations are really exciting! They make it possible to answer questions that we could not answer ourselves, or that we would have overlooked, were it not for the partnerships.”

When AltSB met Pup1…
Having spent more than a decade identifying and cloning AltSB, Jura and Leon have recently turned their attention to identifying and cloning the genes responsible for phosphorus efficiency in sorghum. Luckily, they weren’t starting from scratch this time, as another GCP project on the other side of the world was well on the way to identifying a phosphorus-efficiency gene in rice.

Led by Matthias Wissuwa at JIRCAS and Sigrid Heuer at IRRI, the Asian base GCP project had identified a gene locus, which encoded a particular protein kinase that allowed varieties with this gene to grow successfully in low-phosphorous conditions. They termed the region of the rice genome where this gene resides as ‘phosphorus uptake 1’ or Pup1 as it is commonly referred to in short.

“In phosphorus-poor soils, this protein kinase instructs the plant to grow larger, longer roots, which are able to forage through more soil to absorb and store more nutrients,” explains Sigrid. “By having a larger root surface area, plants can explore a greater area in the soil and find more phosphorus than usual. It’s like having a larger sponge to absorb more water!”

Read more about the mechanics of Pup-1 and the evolution of the project.

Jura and Leon are working on the same theory as IRRI and JIRCAS, that larger and longer roots enhance phosphorus efficiency. They are identifying sorghum with these traits, using comparative genomics to identify a locus similar to Pup1 in these low-phosphorus-tolerant varieties, and then verify whether the genes at this locus are responsible for the trait.

“So far, the results are promising and we have evidence that Pup1 homologues may underlie a major QTL for phosphorous uptake in sorghum,” says Jura who is leading the project to identify and validate Pup1 and other phosphorus-efficiency QTLs in sorghum.  QTL stands for ‘quantitative trait locus’ which refers to stretches of DNA containing ‒ or linked to ‒ the genes responsible for a quantitative trait  “What we have to do now is to see if this carries over in the field, leading to enhanced phosphorus uptake and grain yield in low-phosphorus soils,” he adds.

Jura and Leon are also returning the favour to IRRI and JIRCAS and are collaborating with both institutes to identify and clone in rice similar genes to the AltSB gene in sorghum.

“These collaborations are really exciting! They make it possible to answer questions that we could not answer ourselves, or that we would have overlooked, were it not for the partnerships,” says Sigrid.

To make a difference in rural development, to truly contribute to improved food security through crop improvement and incomes for poor farmers, we knew that capacity development had to be a continuing cornerstone in our strategy.”

Building capacity in Africa
In GCP Phase II which is more application oriented, projects must have objectives that deliver products and build capacity in developing-world breeding programmes.

Jean-Marcel Ribaut

Jean-Marcel Ribaut

“The thought behind the latter requirement is that GCP is not going to be around after 2014 so we need to facilitate these country breeding programmes to take ownership of the science and products so they can continue it locally,” says Jean-Marcel Ribaut, GCP Director (pictured). “To make a difference in rural development, to truly contribute to improved food security through crop improvement and incomes for poor farmers, we knew that capacity development had to be a continuing cornerstone in our strategy.”

Back to Brazil: Jura says this requirement is not uncommon for EMBRAPA projects as the Brazilian government seeks to become a world leader in science and agriculture. “Before GCP started, we had been working with African partners for five to six years through the McKnight Project. It was great when GCP came along as we were able to continue these collaborations.”

Samuel Gudu

Samuel Gudu

One collaboration Jura was most pleased to continue was with his colleague and friend, Sam Gudu (pictured), from Moi University, Kenya. Sam has been collaborating with Jura and Leon on several GCP projects and is the only African Principal Investigator in the Comparative Genomics Research Initiative.

“Our relationship with EMBRAPA and Cornell University has been very fruitful,” says Sam. “We wouldn’t have been able to do as much as we have done without these collaborations or without our other international collaborators at IRRI, JIRCAS, ICRISAT or Niger’s National Institute of Agricultural Research [INRAN].”

Sam is currently working on several projects with these partners looking at validating the genes underlying major aluminium-tolerance and phosphorus-efficiency traits in local sorghum and maize varieties in Kenya, as well as establishing a molecular breeding programme.

“The molecular-marker work has been very interesting. We have selected the best phosphorus-efficient lines from Brazil and Kenya, and have crossed them with local varieties to produce several really good hybrids which we are currently field-testing in Kenya,” explains Sam. “Learning and using these new breeding techniques will enable us to select for and breed new varieties faster.”

Sam is also grateful to both EMBRAPA and Cornell University for hosting several PhD students as part of the project. “This has been a significant outcome as these PhD students are returning to Kenya with a far greater understanding of molecular breeding which they are sharing with us to advance our national breeding programme.”

We’ve used the knowledge that Jura’s and Leon’s AltSB projects have produced to discover and validate similar genes in maize…We identified Kenyan lines carrying the superior allele of ZmMATE …This work will also improve our understanding of what other mechanisms may be working in the Brazilian lines too.” 

‘Everyone’ benefits! Applying the AltSB gene to maize
Claudia Guimarães (pictured) is a maize geneticist at EMBRAPA. But unlike Jura, her interest lies in maize.

Claudia

Claudia Guimarães

Working on the same comparative genomics principle used to identify Pup1 in sorghum, Claudia has been leading a GCP project replicating the sorghum aluminium tolerance work in maize.

“We’ve used the knowledge that Jura’s and Leon’s AltSBprojects have produced to discover and validate similar genes in maize,” explains Claudia. “From our mapping work we identified ZmMATE as the gene underlying a major aluminium tolerance QTL in maize. It has a similar sequence as the gene found in sorghum and it encodes a similar protein membrane transporter that is responsible for citrate extradition.”

A maize field at EMBRAPA. Maize on the left is aluminum-tolerant while the maize on the right is not.

A maize field at EMBRAPA. Maize on the left is aluminium-tolerant while the maize on the right is not.

Using molecular markers, Claudia and her team of researchers from EMBRAPA, Cornell University and Moi University have developed near-isogenic lines from Brazilian and Kenyan maize varieties that show aluminium tolerance, with ZmMATE present. From preliminary field tests, the Brazilian lines have had improved yields in acidic soils.

“We identified a few Kenyan lines carrying the superior allele of ZmMATE that can be used as donors to develop maize varieties with improved aluminium tolerance,” says Claudia.  “This work will also improve our understanding of what other mechanisms may be working in the Brazilian lines too.”

What has pleased Jura and other Principal Investigators the most is the leadership that African partners have taken in GCP projects.

Cherry on the cereal cake
With GCP coming to an end in December 2014, Jura is hopeful that his and other offshoot projects dealing with aluminium tolerance and phosphorus efficiency will deliver on what they set out to do.

“For me, the cherry on the cake for the aluminium-tolerance projects would be if we show that AltSB improves tolerance in acidic soils in Africa. If everything goes well, I think this will be possible as we have already developed molecular markers for AltSB.”

What has pleased Jura and other Principal Investigators the most is the leadership that African partners have taken in GCP projects.

“This has been a credit to them and all those involved to help build their capacity and encourage them to take the lead. I feel this will help sustain the projects into the future and one day help these developing countries produce varieties of sorghum and maize for their farmers that are able to yield just as well in acidic soils as they do in non-acidic soils.”

In the foreground, left to right, Leon, Jura and Sam in a maize field in Kenya.

In the foreground, left to right, Leon, Jura and Sam in a maize field at the Kenya Agricultural Research Institute (KARI), Kitale, in May 2010. They are examining crosses between Kenyan and Brazilian maize germplasm.

Links

 

 

♫We’ll rock your world!♫

 Comparative genomics in cereals, Crop breeding, Genomics, Researchers, Rice  No Responses »
Sep 072012
 

“It is very rare that scientists can take their projects wherever they go. I’ve been very lucky to be able to do this, and much of this has to do with the support I’ve received from GCP.” – Matthias Wissuwa

In the world of phosphorus, Matthias (pictured) is somewhat of a ‘rock star, not that he would admit to it. We don’t understand why not, since to borrow his words, the project he’s involved has becoming something of a ‘celebrity project’ in the scientific community.

For  a decade-and-a-half, he has searched tirelessly for a rice gene that could improve the crop’s yield in phosphorus-deficient soils –which make up half of the world’s soils. Last month, his transnational team published in Nature that their 15-year quest had ended, having finally found the elusive gene – Pup1.

We celebrate this happy ending, especially as we had the added pleasure of talking to Matthias recently: it was delightful in listening to the modest German recount the long journey which has taken him from his home town of Hamburg, to USA, Japan, The Philippines and back to Japan, all this while,  faithfully ‘carrying’ Pup1 with him as he switched employers. As you’ve seen, Japan scores a double strike, so our ‘rock star’ is also ‘big on Japan’! 

Talking to Matthias, we could sense the achievement was only just sinking in – that he and his team’s years of laboratory work was becoming a practical reality that will aid rice-growing farmers from Africa to Asia,  and hopefully other grain growers in years to come. Here’s what Matthias had to say…

You started this project back in 1997. Tell us how you became interested in phosphorus deficiency and rice.

After completing my PhD in the United States, I accepted a postdoc position in Tsukuba, Japan, with the National Institute of Agro-Environmental Sciences (NIAES). It was an easy decision because my wife is Japanese.

My postdoc host, Dr Ae was interested in phosphorus, particularly in legumes. I originally started work on tolerance to phosphorus deficiency in groundnuts, but soon changed to rice to take advantage of the molecular tools available for rice.

Tsukuba is a very new city. It’s called The Science City in Japan because the Japanese government built it to house all the national research institutes. This was great for me as I became interested in QTL mapping, which was pioneered by scientists in Tsukuba. I got talking to people in the rice research community in Tsukuba and was introduced to Dr Yano, who was developing mapping populations for rice at the National Institute of Agrobiological Sciences. He kindly gave me his populations and that’s how I started to map QTL for phosphorus-deficiency tolerance in rice.

Dr Ae was perplexed by my decision, believing that studying legumes was far more challenging than rice. He always told me: “Rice is boring. They just make long, fine roots to capture phosphorus.” That was 15 years ago and he turned out to be right. Long roots are the secret for phosphorus uptake in rice, particular in Kasalath and varieties like that.

Field trials for phosporus-efficient rice in The Philippines.

Did you share Dr Ae’s hypothesis that longer roots were the secret to some rice varieties being able to tolerate phosphorus-deficient soils?

For a long time, I was not sure if it was just long roots. It was a real chicken-and-egg scenario – does strong phosphorus uptake spur root growth, or the other way around?

As it turns out, it is the latter – plants growing longer roots help with the uptake of more phosphorus – and Pup1 is responsible for this.

We have now shifted our aim and are looking for varieties of rice tolerant to phosphorus-deficient soils that either:

  • release organic acids, phosphatases or some other compound that makes phosphorus more readily available for the plant to absorb, or
  • manipulate soil microorganisms to favour those that can aid in making phosphorus more soluble, or
  • very efficiently utilise phosphorus once it is taken up.

All three mechanisms are found in legumes, so there is reason to believe that they exist in rice and we are now working on finding them.

GCP has been interested in the project since 2004 as its outcome aligns with GCP’s goals to improve crop yields and security in developing countries… It has become something of a ‘celebrity project’ in the scientific community, attracting researchers to work on the project or collaborate with us.

In 2002 you left NIAES and accepted a position with the International Rice Research Institute (IRRI), and were encouraged to continue your work on Pup1. When you moved back to Tsukuba in 2005 to accept the position you currently hold with the Japan International Research Center for Agricultural Sciences (JIRCAS), you were again encouraged to continue your Pup1 project, collaborating with your successor at IRRI, Dr Sigrid Heuer. How important has it been to you and the project to have the support of your institutes?

It is very rare that scientists can take their projects wherever they go. I’ve been very lucky to be able to do this, and much of this has to do with the support I’ve received from GCP. They’ve been interested in the project since 2004 as its outcome aligns with GCP’s goals to improve crop yields and security in developing countries.

When I left IRRI, Sigrid was just starting and was more or less free to take on the project, so I asked her if she’d be interested in continuing my work with Pup1 at IRRI and collaborate with me in Japan. She was actually the perfect person for the project because her background in molecular biology complemented my background as a plant breeder.

Over the past seven years, we have worked together very well, and with the addition of Rico Gamuyao, a PhD student supervised by Sigrid, things have recently progressed quite quickly to the point that we were able to pinpoint Pup1.

So GCP has played a major role along your journey?

Yes, definitely. The support from GCP on the Pup1 project, now in its 8th year, was instrumental at getting this project to where it is.

Quite simply, the funding from GCP allowed us to hire Rico as well as Juan Pariasca-Tanaka, a project scientist with me at JIRCAS. Neither Sigrid nor myself had the time to do all the hands-on work so having both Rico and Juan has been hugely helpful.

How important has the collaboration between IRRI and JIRCAS been for the project?

Are they playing with mud? Not at all! Working. Matthias (L) and Rico (R) have zipped up their boots and gone back to their bee…er…. we mean, roots, mucking mud here as they do some fieldwork related to the search for PSTOL1.

Tremendously important. Sigrid’s group at IRRI is relatively small as is mine in Japan, so we rely on each other’s complementary expertise when working on complicated projects.

We have also been fortunate to have constant interest in the project from the scientific community. It has become something of a ‘celebrity project’, and as such, attracted researchers to work on the project or collaborate with us.

For example, we are working with two US groups at Cornell University and Penn State, that are also funded by GCP, trying to track down Pup1 in other crops and identifying genes that control root architecture, and how different architectures may affect P uptake.

These collaborations are really exciting, and make it possible to answer questions that we could not answer ourselves, or that we would have overlooked, were it not for the partnerships.

It really has been a team effort and we wouldn’t have got to where we are now without all the help of everyone involved

You’ve been described as the Godfather and Guru of Pup1. How do compliments like this make you feel?

It makes me laugh but of course it’s a very well-meant comment, and to some extent, considering I’ve worked on it for 15 years, you could say that there is some truth to it.

I’ve done all the original work, but Sigrid has been just as instrumental. She did the part where my expertise was no longer adequate – the molecular side, looking at genes and thinking about the function of a gene and testing for its function.

It really has been a team effort and we wouldn’t have got to where we are now without all the help of everyone involved, which also includes the support of Dr Yano over the years.

…phosphorus deficiency is a worldwide problem that has recently gained public attention because of how expensive phosphate fertilisers have become…Farmers are always interested in saving money and improving yields and we believe this discovery will help with both.

Have you been surprised by the attention this project has received?

As I said, the project has always been in the scientific spotlight because it was the first to map a major QTL for phosphorus uptake.

We knew from the Sub1 story – the submergence tolerance gene, which was published in Nature 4–5 years ago – that the media would probably be interested in this similar discovery. I’m still very surprised that this unsexy story has caused such interest.

You have to remember though, phosphorus deficiency is a worldwide problem that has recently gained public attention because of how expensive phosphate fertilisers have become. About four years ago, the price almost tripled and continues to stay high.

Farmers are always interested in saving money and improving yields and we believe this discovery will help with both.

Phosphorus deficiency is probably even more critical in Africa than it is in Asia… This means Pup1 may have its biggest impact in Africa.

How will the research continue?

Having focused so much on the basic research, we now want to turn our attention to the application. IRRI and JIRCAS will train national breeding programmes to use marker-assisted selection and help them breed their own rice varieties with Pup1.

Sigrid and IRRI are mainly working with Asian national breeding programmes and we at JIRCAS focus more on African programmes such as the Africa Rice Center. Phosphorus deficiency is probably even more critical in Africa than it is in Asia, as phosphate fertilisers aren’t used nearly as much as they are in Asia. This means Pup1 may have its biggest impact in Africa.

We are also looking for new sources of tolerance to phosphorus-deficiency. One very exciting project involves West African rice (Oryza glaberrima) the father of the Nerica ™ (New Rice for Africa) varieties.

So far, we have found that this rice is very tolerant to phosphorus-deficient soils. It does have Pup1, but in addition harbours novel genes that also enhance performance on phosphorus-deficient soils.

We hope to discover a Pup2 in the years to come.

Links

 

Rooting for the key to more phosphorus for rice

 Comparative genomics in cereals, Crop breeding, Genetics, Genomics, Rice  3 Responses »
Sep 072012
 

Preparing rice root samples (Photo: IRRI)ALL IN THE ROOTS: A plant’s roots are a marvellously multitalented organ. They act as fingers and mouths helping plants forage and absorb water and nutrients. They act like arms and legs offering a sturdy base of support so a plant doesn’t keel over. They help store food and water, like our stomach and fat cells. And in some plants, can spawn new life – we leave that to your imagination!

That is why it is of little surprise that this multitalented organ was the key to discovering why some rice lines yield better in phosphorus-poor soils, a puzzle whose answer has eluded farmers and researchers… until now.  And even better, the findings hold promise for sorghum, maize and wheat too. Please read on!

 In search of the key – The Gene Trackers
In 1999, Dr Matthias Wissuwa, now with the Japan International Research Centre for Agricultural Sciences (JIRCAS), deduced that Kasalath, a northern Indian rice variety, contained one or more genes that allowed it to grow successfully in low-phosphorus conditions.

For years, Matthias made it his mission to find these genes, only to find it was as easy as finding a needle in a genetic haystack. He teamed up with the International Rice Research Institute (IRRI), and with GCP’s support, the gene trackers were able to narrow the search down to five genes of interest.

“We had started with 68 genes and within three years, we had narrowed in on these five candidate genes. And then, one-by-one, we checked whether they were related to phosphorous uptake,” recollects Dr Sigrid Heuer, senior scientist at IRRI and leader of the team that published the discovery in Nature in August 2012.

Sigrid Heuer at a rice phosphorus uptake demonstration field in The Philippines.

“In the end we found that if a certain protein kinase gene was turned on in tolerant plants like Kasalath, then those plants would perform better in phosphorus-deficient soils.”

They named this protein kinase gene PSTOL1, which stands for Phosphorus Starvation Tolerance. “When we put this gene into intolerant rice varieties that did not have this gene, they performed better in phosphorus-deficient soils.”

The importance of phosphorus
Rice, like all plants, needs phosphorus to survive and thrive. It’s a key element in plant metabolism, root growth, maturity and yield. Plants deficient in phosphorus are often stunted.

Sigrid explains that whereas phosphorus is abundant in most soils, it is however not always easily accessible by plants. “Many soil types bond tightly to phosphorus, surrendering only a tiny amount to plant roots. This is why more than half of the world’s rice lands are phosphorus-deficient.”

Farmers can get around this by applying phosphate fertilisers. However this is a very expensive exercise and is not an option for the majority of the world’s rice growers, especially the poorer ones –the price of rock phosphate has more than doubled since 2007. The practice is also not sustainable since it is a finite resource.

By selecting for rice varieties with PSTOL1, growers will be less reliant on phosphate fertilisers.

How it works: unravelling PSTOL1 mechanics
In phosphorus-poor soils, PSTOL1 switches on during the early stage of root development. The gene tells the plant to grow larger longer roots, which are able to forage through more soil to absorb and store more nutrients.

“By having a larger root surface area, plants can explore a greater area in the soil and find more phosphorus than usual,” says Sigrid. “It’s like having a larger sponge to absorb more water.”

A rice variety — IR-74 — with Pup1 (left) and without Pup1 (right).

Although the researchers focussed on this one key nutrient, they found the extra root growth helped with other vital elements like nitrogen and potassium.

Another by-chance discovery was that phosphorus uptake 1 (Pup1), the collection of genes (locus) where PSTOL1 is found, is present within a large group of rice varieties.

“We found that in upland rice varieties – those bred for drought-prone environments – most have Pup1,” says Sigrid. “So the breeders in these regions have, without knowing it, been selecting for phosphorus tolerance.”

“When thinking about it, it makes sense as phosphorus is very immobile in dry soils, therefore these plants would have had to adapt to grow longer roots to reach water deeper in the soil and this, at the same time, helps to access more reservoirs of phosphorous .”

Breeding for phosphorus tolerance, and going beyond rice
Using conventional breeding methods, Sigrid says that her team introduced PSTOL1 into two irrigated rice varieties and three Indonesian upland varieties, and found that this increased yields by up to 20 percent.

“In our pot experiments,” she added, “when we use soil that is really low in phosphorus, we see yield increases of 60 percent and more. This will mean growers of upland rice varieties will probably benefit the most from these new lines, which is pleasing given they are among the poorest rice growers in the world.”

Read how Indonesian researchers are developing their own breeds of upland rice with the PSTOL1 gene

Sigrid also sheds light on broadening the research to other crop varieties: “The project team is currently looking at Pup1 in sorghum and maize and we are just about to start on wheat.”

Building capacity and ensuring impact
Like all GCP projects, this one invests as much time in building capacity for country breeding programmes as on research.

Sigrid and her team are currently conducting the first Pup1 workshop to train researchers from Bangladesh, India, Indonesia, Nepal, Philippines, Thailand and Vietnam. They will share molecular markers that indicate the presence of PSTOL1, techniques to select for the gene, as well as for new phosphorus-efficient varieties.

Breeding for phosphorus-efficient rice in the Philippines.

“The aim of these workshops is to take these important tools to where they are most needed and allow them to evolve according to the needs and requirements of each country,” says Dr Rajeev Varshney, GCP’s Comparative and Applied Genomics Leader. “Breeders will be able to breed new rice varieties faster and more easily, and with 100 percent certainty that their rice plants will have the gene. Within three to five years, each country will be able to breed varieties identical to those that growers know and trust except that they will now have the Pup1 gene and an improved ability to unlock and take up soil phosphorus.”

Joining hands in collaboration
This IRRI-led project was conducted in collaboration with JIRCAS and the Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development (ICABIOGRAD) working with the Indonesian Centre for Rice Research. Other partners included: Italy’s University of Milano, Germany’s Max Planck Institute in Golm, the University of The Philippines at Los Baños, USA’s Cornell University and University of California (Davis and Riverside), Brazil’s EMBRAPA, Africa Rice Center, Iran’s Agricultural Biotechnology Research Institute, Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) and University of Dhaka in Bangladesh.

Links

Sigrid’s presentation at the GCP General Research Meeting 2011

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