Reflections from the “Feed the Future” conference in Burkina Faso

By Atsuko Kanazawa, Igor Houwat, Cynthia Donovan

This article is reposted with permission from the Michigan State University team. You can find the original post here: MSU-DOE Plant Research Laboratory

By Atsuko Kanazawa

Atsuko Kanazawa is a plant scientist in the lab of David Kramer. Her main focus is on understanding the basics of photosynthesis, the process by which plants capture solar energy to generate our planet’s food supply.

This type of research has implications beyond academia, however, and the Kramer lab is using their knowledge, in addition to new technologies developed in their labs, to help farmers improve land management practices.

One component of the lab’s outreach efforts is its participation in the Legume Innovation Lab (LIL) at Michigan State University, a program which contributes to food security and economic growth in developing countries in Sub-Saharan Africa and Latin America.

Atsuko recently joined a contingent that attended a LIL conference in Burkina Faso to discuss legume management with scientists from West Africa, Central America, Haiti, and the US. The experience was an eye opener, to say the least.

To understand some of the challenges faced by farmers in Africa, take a look at this picture, Atsuko says.

Rows of corn crops in Burkina Faso

Corn crops in Burkina Faso. By Atsuko Kanazawa

“When we look at corn fields in the Midwest, the corn stalks grow uniformly and are usually about the same height,” Atsuko says. “As you can see in this photo from Burkina Faso, their growth is not even.”

“Soil scientists tell us that much farmland in Africa suffers from poor nutrient content. In fact, farmers sometimes rely on finding a spot of good growth where animals have happened to fertilize the soil.”

Even if local farmers understand their problems, they often find that the appropriate solutions are beyond their reach. For example, items like fertilizer and pesticides are very expensive to buy.

That is where USAID’s Feed the Future and LIL step in, bringing economists, educators, nutritionists, and scientists to work with local universities, institutions, and private organizations towards designing best practices that improve farming and nutrition.

Atsuko says, “LIL works with local populations to select the most suitable crops for local conditions, improve soil quality, and manage pests and diseases in financially and environmentally sustainable ways.”

Unearthing sources of protein

At the Burkina Faso conference, the Kramer lab reported how a team of US and Zambian researchers are mapping bean genes and identifying varieties that can sustainably grow in hot and drought conditions.

The team is relying on a new technology platform, called PhotosynQ, which has been designed and developed in the Kramer labs in Michigan.

A user testing a plant leaf with the MultispeQ

PhotosynQ in action: the device collects data. A mobile app  uploads it to an online platform for further analysis. By Harley J Seeley Photography

PhotosynQ includes a hand-held instrument that can measure plant, soil, water, and environmental parameters. The device is relatively inexpensive and easy to use, which solves accessibility issues for communities with weak purchasing power.

The heart of PhotosynQ, however, is its open-source online platform, where users upload collected data so that it can be collaboratively analyzed among a community of 2400+ researchers, educators, and farmers from over 18 countries. The idea is to solve local problems through global collaboration.

Atsuko notes that the Zambia project’s focus on beans is part of the larger context under which USAID and LIL are functioning.

“From what I was told by other scientists, protein availability in diets tends to be a problem in developing countries, and that particularly affects children’s development,” Atsuko says. “Beans are cheaper than meat, and they are a good source of protein. Introducing high quality beans aims to improve nutrition quality.”

Science alone is sometimes not enough

But, as LIL has found, good science and relationships don’t necessarily translate into new crops being embraced by local communities.

Farmers might be reluctant to try a new variety, because they don’t know how well it will perform or if it will cook well or taste good. They also worry that if a new crop is popular, they won’t have ready access to seed quantities that meet demand.

Sometimes, as Atsuko learned at the conference, the issue goes beyond farming or nutrition considerations. In one instance, local West African communities were reluctant to try out a bean variety suggested by LIL and its partners.

The issue was its color.

“One scientist reported that during a recent famine, West African countries imported cowpeas from their neighbors, and those beans had a similar color to the variety LIL was suggesting. So the reluctance was related to a memory from a bad time.”

This particular story does have a happy ending. LIL and the Burkina Faso governmental research agency, INERA, eventually suggested two varieties of cowpeas that were embraced by farmers. Their given names best translate as, “Hope,” and “Money,” perhaps as anticipation of the good life to come.

A gathering at a women's experimental farm.

Visiting the women-run farms. By Atsuko Kanazawa

 

Another fruitful, perhaps more direct, approach of working with local communities has been supporting women-run cowpea seed and grain farms. These ventures are partnerships between LIL, the national research institute, private institutions, and Burkina Faso’s state and local governments.

Atsuko and other conference attendees visited two of these farms in person. The Women’s Association Yiye in Lago is a particularly impressive success story. Operating since 2009, it now includes 360 associated producing and processing groups, involving 5642 women and 40 men.

“They have been very active,” Atsuko remarks. “You name it: soil management, bean quality management, pest and disease control, and overall economic management, all these have been implemented by this consortium in a methodical fashion.”

“One of the local farm managers told our visiting group that their crop is wonderful, with high yield and good nutrition quality. Children are growing well, and their families can send them to good schools.”

As the numbers indicate, women are the main force behind the success. The reason is that, usually, men don’t do the fieldwork on cowpeas. “But that local farm manager said that now the farm is very successful, men were going to have to work harder and pitch in!”

Back in Michigan, Atsuko is back to the lab bench to continue her photosynthesis research. She still thinks about her Burkina Faso trip, especially how her participation in LIL’s collaborative framework facilitates the work she and her colleagues pursue in West Africa and other parts of the continent.

“We are very lucky to have technologies and knowledge that can be adapted by working with local populations. We ask them to tell us what they need, because they know what the real problems are, and then we jointly try to come up with tailored solutions.”

“It is a successful model, and I feel we are very privileged to be a part of our collaborators’ lives.”

This article is reposted with permission from the Michigan State University team. You can find the original post here: MSU-DOE Plant Research Laboratory

How diverse is your food?

Dr Colin Khoury

Dr Colin Khoury

This post was written by Dr Colin Khoury. Colin studies diversity in the crops people grow and eat worldwide, and the implications of change in this diversity on human health and environmental sustainability. He is particularly interested in the wild relatives of crops. Colin is a research scientist at the International Center for Tropical Agriculture (CIAT), Colombia, and at the USDA National Laboratory for Genetic Resources Preservation in Fort Collins, Colorado.

 

New Changing Global Diet website explores changes in diets over the past 50 years in countries around the world.

One of the central concepts that unifies those concerned with biodiversity is the understanding that this diversity is being lost, piece by piece, to a greater or lesser degree, globally.

The same goes for the biodiversity of what we eat. Scientists and activists have worried about the loss of crops and their many traditional varieties for at least a hundred years, since botanist N. I. Vavilov traveled the world in search of plants useful for cultivation in his Russian homeland. He noticed that diversity was disappearing in the cradles of agriculture – places where crops had been cultivated continuously for thousands of years. The alarm sounded even louder 50 years ago, during the Green Revolution, when farmers in some of the most diverse regions of the world largely replaced their many locally adapted wheat, rice and other grain varieties with fewer, more uniform, higher yielding professionally bred varieties.

 

Map of crop diversity

Cradles of agriculture: origins and primary regions of diversity of agricultural crops

(Click to magnify)

 

This is ironic, since modern productive crop varieties are bred by wisely mixing and matching diverse genetic resources. The disappearance of old varieties thus reduces the options available to plant breeders, including those working to produce more nutritious or resilient crops.

Being a food biodiversity scientist, I grew up (in the professional sense) with the loss of crop diversity looming over my head, providing both a raison d’être, and an urgency to my efforts. Somewhere along the line, I became interested in understanding its magnitude. That is, counting how many crops and how many varieties have been lost.

That’s where it started to become complicated, and also more interesting. Because, when I went looking for signs of the loss of specific crops, I couldn’t find any. Instead, I found evidence of massive global changes in our food diversity that left me worried, but at the same time hopeful.

A bit of background. Most of the numbers seen in the news on how much crop diversity has been lost go back to a handful of reports and books that reference a few studies: for example, the changing number of vegetable varieties for sale in the U.S. over time. The results are estimations for a few crops at local to national levels, but they somehow have been inflated to generalized statements about the global state of crop diversity, the most common of which being some variation of “75% of diversity in crops has been lost”.

Market stand of fruit and vegetables

Diverse produce, but is it all local? Image credit:  Karyn Christner. Used under license: CC BY 2.0.

Putting true numbers on diversity loss turns out to be a complicated and contested business, with no shortage of strong opinions. One big part of the problem is that there aren’t many good ways to count the diversity that existed before it disappeared. Researchers have done some work to assess the changes in diversity in crop varieties of Green Revolution cereals, and to some degree on the genetic diversity within those varieties. The results indicate that, although diversity on farms decreased when farmers first replaced traditional varieties with modern types, the more recent trends are not so simple to decipher.

It was particularly surprising to me that very little work had been done to understand the changes in what is probably the simplest level to measure: the diversity of crop species in the human diet, that is, how successful is maize versus rice versus potato versus quinoa and so on. I realized that data on the contribution of crops to national food supplies were available for almost all countries worldwide via FAOSTAT, with information for every year since 1961. Perhaps these were the data that could show when a crop fell off the world map.

Fast forward through a couple of years of investigation. To my great surprise, I found that not a single crop was lost over the past 50 years! There was no evidence for extinction. What was going on?

Maize

Maize is a key crop in many countries. Image credit: Erfan A. Setiawan. Used under license: CC BY 2.0.

It turns out that my failure to see any loss of crops was due to the lack of sufficient resolution in the FAO data. Only 52 meaningful crop species-specific commodities are measured and a number of these are general groupings such as “cereals, other”. Because of this lack of specificity, the data couldn’t comprehensively assess the crops that have been most vulnerable to changes in the global food system over the past 50 years. In FAO data, these plants are either thrown into the general categories or they aren’t measured at all, especially if they are produced only on a small scale, for local markets or in home gardens. This is, in itself, sign enough that they may be imperiled. We need better statistics about what people eat (and grow) around the world. But, enough is known to be confident that many locally relevant crops are in decline.

Over the past 50 years, almost all countries’ diets actually became more diverse, not less, for the crops that FAO statistics do report on. We found that traditional diets that were primarily based on singular staples a half century ago, for instance rice in Southeast Asia, had diversified over time to include other staples such as wheat and potatoes. The same was true for maize-based diets in Latin America, sorghum- and millet-based diets in sub-Saharan Africa, and so on.

Not that there weren’t plant winners and losers. Wheat, rice, and maize, the most dominant crops worldwide 50 years ago, became more important globally. Other crops emerged as widespread staples, particularly oilcrops such as soybean, palm oil, sunflower, and rapeseed oil. And, as the winners came to take more precedence in food supplies around the world, alternative staples such as sorghum, millets, rye, cassava, sweet potato, and yam were marginalized. They haven’t disappeared (at least not yet), but they have become less important to what is eaten every day.

As countries’ food supplies became more diverse in the winner crops reported by FAO, and the relative abundance of these crops within diets became more even, food supplies worldwide became much more similar, with an average decrease in variation between diets in different countries of 68.8% over the past 50 years!

This is why, although we could see no absolute loss in crops consumed over the past 50 years, I am concerned. For even in the relatively small list of crops reported in the FAO data, many of these foods are becoming marginalized, day by day, bite by bite. That doesn’t seem like a good thing for the long-term resilience of our agricultural areas, nor for human health, although it’s important to remember that such changes are the collateral damage resulting from the creation of highly productive mega-crop farming systems, which have increased the affordability of these foods worldwide, leading to less stunting and other effects of undernutrition worldwide. On the other hand, global dependence on a few select crops equates to expansive monocultures, with more lives riding on the outcome of the game of cat and mouse between pestilence and uniform varieties grown over large areas. Moreover, cheaply available macronutrients have contributed to the negative effects of the nutrition transition, including obesity, heart disease and diabetes.

So why then am I hopeful? Because the data, and some literature, and my own direct experience also indicate that diets in recent years, in some countries, are beginning to move in different directions, reducing the excessive use of animal products and other energy-dense and environmentally expensive foods, and becoming more diverse, particularly with regard to fruits and vegetables, and even healthy grains. What better evidence than quinoa, which was relatively unknown outside the Andes a couple of decades ago, and is now cultivated in 100 countries and consumed in even more?

When we published our findings of increasing homogeneity in global food supplies, we hadn’t yet found a good way to make the underlying national-level data readily visible to interested readers. This is why I’m tremendously excited to announce the publication of our new Changing Global Diet website, which provides interactive visuals for 152 countries over 50 years of change. We that hope you will enjoy your own investigations of dietary change over time. Perhaps you can tell us where you think the changing global diet is headed.

Check out The Changing Global Diet website


Read the published article: Khoury CK, Bjorkman AD, Dempewolf H, Ramírez-Villegas J, Guarino L, Jarvis A, Rieseberg LH and Struik PC (2014). Increasing homogeneity in global food supplies and the implications for food security. PNAS 111(11): 4001-4006.

Genome editing: an introduction to CRISPR/Cas9

Damiano Martignago

Dr Damiano Martignago, Rothamsted Research

This week’s blog post was written by Dr Damiano Martignago, a genome editing specialist at Rothamsted Research.

 

Genome editing technologies comprise a diverse set of molecular tools that allow the targeted modification of a DNA sequence within a genome. Unlike “traditional” breeding, genome editing does not rely on random DNA recombination; instead it allows the precise targeting of specific DNA sequences of interest. Genome editing approaches induce a double strand break (DSB) of the DNA molecule at specific sites, activating the cell’s DNA repair system. This process could be either error-prone, thus used by scientists to deactivate “undesired” genes, or error-free, enabling target DNA sequences to be “re-written” or the insertion of DNA fragments in a specific genomic position.

The most promising among the genome editing technologies, CRISPR/Cas9, was chosen as Science’s 2015 Breakthrough of the Year. Cas9 is an enzyme able to target a specific position of a genome thanks to a small RNA molecule called guide RNA (gRNA). gRNAs are easy to design and can be delivered to cells along with the gene encoding Cas9, or as a pre-assembled Cas9-gRNA protein-RNA complex. Once inside the cell, Cas9 cuts the target DNA sequence homologous to the gRNAs, producing DSBs.

CRISPR/Cas9

The guide RNA (sgRNA) directs Cas9 to a specific region of the genome, where it induces a double-strand break in the DNA. On the left, the break is repaired by non-homologous-end joining, which can result in insertion/deletion (indel) mutations. On the right, the homologous-directed recombination pathway creates precise changes using a supplied template DNA. Credit: Ran et al. (2013). Nature Protocols.

 

Genome editing in crops

Together with the increased data availability on crop genomes, genome editing techniques such as CRISPR are allowing scientists to carry out ambitious research on crop plants directly, building on the knowledge obtained during decades of investigation in model plants.

The concept of CRISPR was first tested in crops by generating cultivars that are resistant to herbicides, as this is an easy trait to screen for and identify. One of the first genome-edited crops, a herbicide-resistant oilseed rape produced by Cibus, has already been grown and harvested in the USA in 2015.

Wheat powdery mildew

Researchers used CRISPR to engineer a wheat variety resistant to powdery mildew (shown here), a major disease of this crop. Image credit: NY State IPM Program. Used under license: CC BY 2.0.

 

Using CRISPR, scientists from the Chinese Academy of Sciences produced a wheat variety resistant to powdery mildew, one of the major diseases in wheat. Similarly, another Chinese research group exploited CRISPR to produce a rice line with enhanced rice blast resistance that will help to reduce the amount of fungicides used in rice farming. CRISPR/Cas9 has also been already applied to maize, tomato, potato, orange, lettuce, soybean and other legumes.

Genome editing could also revolutionize the management of viral plant disease. The CRISPR/Cas9 system was originally discovered in bacteria, where it provided them with molecular immunity against viruses, but it can also be moved into plants. Scientists can transform plants to produce the Cas9 and gRNAs that target viral DNA, reducing virus accumulation; alternatively, they can suppress those plant genes that are hijacked by the virus to mediate its own diffusion in the plants. Since most plants are defenseless against viruses and there are no chemical controls available for plant viruses, the main method to stop the spread of these diseases is still the destruction of the infected plant. For the first time in history, scientists have an effective weapon to fight back against plant viruses.

Cassava brown streak disease

The cassava brown streak disease virus can destroy cassava crops, threatening the food security of the 300 million people who rely on this crop in Africa. Image credit: Katie Tomlinson (for more on this topic, read her blog here).

 

Genome editing will be particularly useful in the genetic improvement of many crops that are propagated mainly by vegetative reproduction, and so very difficult to improve by traditional breeding methods involving crossing (e.g. cassava, banana, grape, potato). For example, using TALENs, scientists from Cellectis edited a potato line to minimize the accumulation of reducing sugars that may be converted into acrylamide (a possible carcinogen) during cooking.

 

Concerns about off-targets

One of the hypothesized risks of using CRISPR/Cas9 is the potential targeting of undesired DNA regions, called off-targets. It is possible to limit the potential for off-targets by designing very specific gRNAs, and all of the work published so far either did not detect any off-targets or, if detected, they occurred at a very low frequency. The number of off-target mutations produced by CRISPR/Cas9 is therefore minimal, especially if compared with the widely accepted random mutagenesis of crops used in plant breeding since the 1950s.

 

GM or not-GM

Genome editing is interesting from a regulatory point of view too. After obtaining the desired heritable mutation using CRISPR/Cas9, it is possible to remove the CRISPR/Cas9 integrated vectors from the genome using simple genetic segregation, leaving no trace of the genome modification other than the mutation itself. This means that some countries (including the USA, Canada, and Argentina) consider the products of genome editing on a case-by-case basis, ruling that a crop is non-GM when it contains gene combinations that could have been obtained through crossing or random mutation. Many other countries are yet to issue an official statement on CRISPR, however.

Recently, scientists showed that is possible to edit the genome of plants without adding any foreign DNA and without the need for bacteria- or virus-mediated plant transformation. Instead, a pre-assembled Cas9-gRNA ribonucleoprotein (RNP) is delivered to plant cells in vitro, which can edit the desired region of the genome before being rapidly degraded by the plant endogenous proteases and nucleases. This non-GM approach can also reduce the potential of off-target editing, because of the minimal time that the RNP is present inside the cell before being degraded. RNP-based genome editing has been already applied to tobacco plants, rice, and lettuce, as well as very recently to maize.

In conclusion, genome editing techniques, and CRISPR/Cas9 in particular, offers scientists and plant breeders a flexible and relatively easy approach to accelerate breeding practices in a wide variety of crop species, providing another tool that we can use to improve food security in the future.
For more on CRISPR, check out this recent TED Talk from Ellen Jorgensen:


About the author

Dr Damiano Martignago is a plant molecular biologist who graduated from Padua University, Italy, with a degree in Food Biotechnology in 2009. He obtained his PhD in Biology at Roma Tre University in 2014. His experience with CRISPR/Cas9 began in the lab of Prof. Fabio Fornara (University of Milan), where he used CRISPR/Cas9 to target photoperiod genes of interest in rice and generate mutants that were not previously available. He recently moved to Rothamsted Research, UK, where he works as Genome Editing Specialist, transferring CRISPR/Cas9 technology to hexaploid bread wheat with the aim of improving the efficiency of genome editing in this crop. He is actively involved with AIRIcerca (International Association of Italian Scientists), disseminating and promoting scientific news.

Plant Artificial Chromosome Technology

Established GM technologies are far from perfect

The first genetically modified (GM) crops were approved for commercial use in 1994, and GM crops are now grown on over 180 million hectares across 29 countries. The most used forms of genetic modification are systems that result in herbicide resistance or expression of the Bt toxin in maize and cotton to provide protection against pests such as the European corn borer. These systems both require few novel genes to be introduced to the plant, and allow more efficient use of herbicides and pesticides, both of which are harmful to the environment and human health. Current systems of genetic modification usually involve

Agrobacterium tumefaciens is used to genetically engineer plants in the lab. In nature this bacteria uses its ability to alter plant DNA to cause tumours.

Agrobacterium tumefaciens is used to genetically engineer plants in the lab. In nature this bacteria uses its ability to alter plant DNA to cause tumours. Image by Jacinta Lluch Valero used under Creative Commons 2.0.

the use of Agrobacterium vectors, direct transformation by DNA uptake into the plant protoplast, or bombardment with gold particles covered in DNA. However, current systems of transformation are far from perfect. Many beneficial traits such as disease resistance require stacking of multiple genes, something that is difficult with current transformation systems. Furthermore, it is essential that transgenes are positioned correctly within the host genome. Current systems of genetic modification can insert genes into the ‘wrong’ place, disrupting function of endogenous genes or having implications for down or upstream processes. An additional problem is that transfer of transgenes from one line to another requires several generations of backcrossing. However, the past two decades have seen great developments in microbiology. Many new tools and resources are now available that could greatly enhance the biotechnology of the future.

 

New technologies

Many new and emerging technologies are now available that could transform plant genetic engineering. For example, high throughput sequencing and the wide availability of bioinformatics tools now make identifying target genes and traits easier than ever. Technologies such as site-specific recombination (SSR) and genome editing allow specific regions of the genome to be precisely targeted in order to add or remove genes. Artificial chromosome technology is also part of this emerging group that could be of benefit to plant science. Synthetic chromosomes have already been used in yeast, and widely studied in mammalian systems due to their potential use in gene therapy. Although there have so far been no definitive examples in plants, work has been done in maize that shows the potential of the technology for use in GM crops.

 

Building an artificial chromosome

A minichromosomes is a small, synthetic chromosome with no genes of its own. It can be programmed to express any desirable DNA sequence that could encode for one, or a number, of genes. An ideal minichromosome would be small and only contain essential elements such as a centromere, telomeres and origin of replication. Once introduced into the plant the minichromosomes should be designed such that interference with host growth and development is minimal. A key requirement is that the chromosome is stable during both meiosis and mitosis. This would ensure introduced genes do not become disrupted or mutated during cell division and reproduction. Gene expression would therefore remain the same for many generations. Finally, the DNA sequence on the minichromosomes could be designed such that it is amenable to SSR or gene editing systems. This would allow re-design and addition of new traits further down the line.

 

Potential advantages of artificial chromosomes

Plant artificial chromosomes (PACs) have many advantages over traditional transformation systems. For example, to confer complex traits such as disease resistance and tolerance to abiotic stresses such as heat and drought, multiple genes are required. This is not easy with current methods of modification.

PACs could offer a new way to introduce beneficial traits to our crops plants and feed a growing population.

PACs could offer a new way to introduce beneficial traits to our crops plants and feed a growing population.Image by Seattle.Romer. Used under Creative Commons 2.0.

However, PACs allow an almost unlimited number of genes to be integrated into the host system. A further possibility that comes from being able to add multiple genes is the addition of new metabolic pathways into the plant. This could allow us to change the nutrients produced by a plant to benefit our diets. Additionally, in a contained environment, plants could be used as a cheap, sustainable way to produce pharmaceuticals. A second major benefit of PACs is that they avoid linkage drag. This is when a desirable gene is closely linked to a deleterious gene that acts to reduce plant fitness. Where this linkage is very tight even repeated backcrossing cannot separate out the genes. Design of new DNA sequences completely avoids this problem, and could allow us to select out detrimental traits from out crop plants.

 

Regulations for novel biotechnology

Emerging technologies pose new questions to policy makers regarding GM regulation. For example, the use of genome editing, whereby specific sites in the genome are targeted and modified, produces an end product with a phenotype almost identical to one that could be achieved through conventional breeding. This sets genome-edited crops apart from other transgene-containing GM material. For this reason many now argue that genome-edited crops ought not to come under current GM regulations. Much of this argument centres on whether or not to regulate the scientific technique used to produce a crop, or to regulate the end product in the field. For more information on genome editing including current regulations and consensus, see the links at the end of this article.

 

PACs pose a different set of problems entirely. Minichromosomes would be foreign bodies in the plant, and gene stacking within these introduces even more foreign genes than is possible with current technologies. This would require extensive assessment of both environmental and health effects prior to commercialization. Currently regulatory approval costs around $1-15 million per insertion into the genome. These heavy charges may discourage the further development of minichromosomes technology. However, with PACs it is possible that a particular package of genes could be assessed once, and then transferred into numerous cultivars. This would eliminate the requirement to individually engineer and test every cultivar, so perhaps saving time and money in the long term.

 

More information on genome editing:

Sense about science genome editing Q & A

The regulatory status of genome-edited crops

The Guardian article on genome editing regulation

A proposed regulatory network for genome edited crops in Nature

A recent workshop on the CRISPR-CAS system of genome editing was held in September 2015 by GARNet and OpenPlant at the John Innes Centre in Norwich, UK. You can read the full meeting report here.

 

 

 

 

 

 

 

 

 

 

 

Integrated Pest Management Systems

Herbivorous pests can devastate crops, with huge economic and social impacts that threaten global food security. In 2011 scientists warned that biological threats, including pests and pathogens, account for a 40% loss in global production and have the potential for even higher losses in the future.

A farmer sprays pesticides on her crop

A farmer sprays pesticides on her crop. From IFPRI – IMAGES. Used under Creative Commons 2.0.

In the 1950s and 1960s huge amounts of pesticides were being used in agriculture, with negative effects on both humans and ecology. Pests and pathogens were developing resistance to pesticides, and to counteract this chemical companies were developing ever stronger, more expensive chemicals.

Perry Adkisson and Ray Smith, both entomologists, noted the harmful effects on the economy and environment of the overuse of synthetic pesticides. Working together they identified practical approaches to pest control that minimized pesticide use. They developed and popularized integrated pest management (IPM) systems, for which they won the World Food prize in 1997.

 

“Integrated Pest Management (IPM) means the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms.” FAO definition

 

What is IPM?

IPM is an approach to crop production that considers the whole ecosystem, integrating a number of management techniques, rather than focusing all resources on a single practice such as pesticide use. Adkisson and Smith identified a number of principals around which successful IPM should be based:

Firstly, crop varieties should be selected that are appropriate to the culture and local environment. This would ensure the crop species is already adapted to local conditions, and may have some defense mechanisms to protect itself from biotic and abiotic stresses.

Secondly, IPM is based around pest control rather than complete eradication. Therefore, maximum tolerable levels of the pest that still enable good crop yields should be identified and the pests should be allowed to survive at this threshold level, although allowing a number of pests to exist within the crop requires continual monitoring. Good knowledge of pest behavior and lifecycle enables the prediction of where more or less controls are required.

Finally, when choosing a method of control, both mechanical methods, such as traps or barriers, or appropriate biological control are preferential. However, pesticides can be integrated into the plan if necessary, providing use is responsible and not in excess of requirements. Some really cool practices are now emerging that can be used as part of an IPM system around the world.

 

Enhancing biological control

Simply reducing pesticide use can actually lead to increased yields, as farmers in Vietnam discovered when scientists convinced them to try it for themselves. Their nemesis, the brown planthopper (Nilaparvata lugens), is increasingly resistant to insecticides, with devastating outbreaks becoming more common. Rice farmers found that by stopping their typical regular insecticide sprays, the planthopper’s natural predators such as frogs, spiders, wasps and dragonflies were able to survive and remove the pests, giving farmers a 10% increase in harvest income. This improved biological control is a key component of IPM.

Brown Planthopper

The Brown Planthopper (Nilaparvata lumens) on a rice stem. From IRRI photos. Used under Creative Commons 2.0.

 

Push-pull technology

Push-pull agriculture has been very successful in Kenya, where stemborer moths can cause vast yield losses in maize with estimated economic impacts of up to US$ 40.8 million per year. Push-pull technology uses selected species as intercrops between the main crops of interest. Intercrops work in two ways, by pushing pests away from the economically valuable crop, and pulling them towards a less valuable intercrop. The stemborer moth push-pull system uses Desmodium (Desmodium uncinatum) to repel stemborer moths. Desmodium species are small flowering plants that produce secondary metabolites that repel insects. Moths are then attracted to the surrounding napier grass instead.

Aside from controlling the stemborer moth, this system has a number of additional benefits. Desmodium suppresses the growth of Striga grass (a devastating weed that you can read about here) via a number of mechanisms, primarily through interfering with root growth. Additionally, the intercrop species can be used for animal fodder and improve soil fertility. The multiple benefits and success of this system has meant push pull has now been adopted by over 80,000 small-holdings in Kenya and is being rolled out to Uganda, Tanzania and Ethiopia.

 

Stem borer larva feeding on a maize stem.

Stem borer larva feeding on a maize stem. From International Institute of Tropical Agriculture. Used under Creative Commons 2.0.

Abrasive weeding

Abrasive weeding is a relatively new technique that involves firing air-propelled grit at a crop to physically kill any weeds growing between crop rows. One issue with this method is that it indiscriminately damages the stem and leaf tissue of both crops and weeds, but grit applicator nozzles are available to more directly target the base of the stem to minimize collateral damage. A recent study found abrasive weed control reduced weed density by up to 80% in tomato and pepper fields, with 33-44% increases in yield.

Maize cob or walnut shells are currently the most frequently used grits, but the technique offers the exciting possibility of combining fertilization and weed control in one step, which could reduce time and cost to the farmer. For example, soybean meal is able to destroy plant tissues when fired from the gun, and has high nitrogen content that is released slowly into the soil over a period of at least three months, making it an ideal source of fertilizer.

 

Creating stress resilient agricultural systems: Video interviews

The global population is projected to reach 9.6 billion by 2050, and to accommodate this, crop production must increase by 60% in the next 35 years. Furthermore, our global climate is rapidly changing, putting our cropping systems under more strain than ever before. Agriculture will need to adapt to accommodate more extreme weather events and changing conditions that may mean increased instance of drought, heatwaves or flooding. The Global Plant Council Stress Resilience initiative, was created to address these issues.

Back in October the Global Plant Council, in collaboration with the Society for Experimental Biology brought together experts from around the world at a Stress Resilience Forum to identify gaps in current research, and decide how best the plant science community can move forwards in terms of developing more resilient agricultural systems. We interviewed a number of researchers throughout the meeting, asking about their current work and priorities for the future.  Watch the best bits in the video below:

Now That’s What I Call Plant Science 2015

With another year nearly over we recently put out a call for nominations for the Most Influential Plant Science Research of 2015. Suggestions flooded in, and we also trawled through our social media feeds to see which stories inspired the most discussion and engagement. It was fantastic to read about so much amazing research from around the world. Below are our top five, selected based on impact for the plant science research community, engagement on social media, and importance for both policy and potential end product/application.

Choosing the most inspiring stories was not an easy job. If you think we’ve missed something, please let us know in the comments below, or via Twitter! In the coming weeks we’ll be posting a 2015 Plant Science Round Up, which will include other exciting research that didn’t quite make the top five, so watch this space!

  1. Sweet potato is a naturally occurring GM crop
Sweet potato contains genes from bacteria making it a naturally occurring GM crop

Sweet potato contains genes from bacteria making it a naturally occurring GM crop. Image from Mike Licht used under creative commons license 2.0

Scientists at the International Potato Center in Lima, Peru, found that 291 varieties of sweet potato actually contain bacterial genes. This technically means that sweet potato is a naturally occurring genetically modified crop! Alongside all the general discussion about GM regulations, particularly in parts of Europe where regulations about growing GM crops have been decentralized from Brussels to individual EU Member States, this story caused much discussion on social media when it was published in March of this year.

It is thought that ancestors of the modern sweet potato were genetically modified by bacteria in the soil some 8000 years ago. Scientists hypothesize that it was this modification that made consumption and domestication of the crop possible. Unlike the potato, sweet potato is not a tuber but a mere root. The bacteria genes are thought to be responsible for root swelling, giving it the fleshy appearance we recognize today.

This story is incredibly important, firstly because sweet potato is the world’s seventh most important food crop, so knowledge of its genetics and development are essential for future food supply. Secondly, Agrobacterium is frequently used by scientists to artificially genetically modify plants. Evidence that this process occurs in nature opens up the conversation about GM, the methods used in this technology, and the safety of these products for human consumption.

Read the original paper in PNAS here.

  1. RNA-guided Cas9 nuclease creates targetable heritable mutations in Barley and Brassica

Our number two on the list also relates to genetic modification, this time focusing on methods. Regardless of whether or not we want to have genetically modified crops in our food supply, GM is a valuable tool used by researchers to advance knowledge of gene function at the genetic and phenotypic level. Therefore, systems of modification that make the process faster, cheaper, and more accurate provide fantastic opportunities for the plant science community to progress its understanding.

The Cas9 system is a method of genome editing that can make precise changes at specific locations in the genome relatively cheaply. This novel system uses small non-coding RNA to direct Cas9 nuclease to the DNA target site. This type of RNA is small and easy to program, providing a flexible and easily accessible system for genome editing.

Barley in the field

Barley in the field. Image by Moldova_field used under creative commons license 2.0

Inheritance of genome modifications using Cas9 has previously been shown in the model plants, Arabidopsis and rice. However, the efficiency of this inheritance, and therefore potential application in crop plants has been questionable.

The breakthrough study published in November by researchers at The Sainsbury Laboratory and John Innes Centre both in Norwich, UK, demonstrated the mutation of two commercial crop plants, Barley and Brassica oleracea, using the Cas9 system and subsequent inheritance mutations.

This is an incredibly exciting development in the plant sciences and opens up many options in the future in terms of genome editing and plant science research.

Read the full paper in Genome Biology here.

  1. Control of Striga growth

Striga is a parasitic plant that mainly affects parts of Africa. It is a major threat to food crops such as rice and corn, leading to yield losses worth over 10 billion US dollars, and affecting over 100 million people.

Striga infects the host crop plant through its roots, depriving them of their nutrients and water. The plant hormone strigolactone, which is released by host plants, is known to induce Striga germination when host plants are nearby.

In a study published in August of this year the Striga receptors for this hormone, and the proteins responsible for striga germination were identified.

Striga plants are known to wither and die if they cannot find a host plant upon germination. Induction of early germination using synthetic hormones could therefore remove Striga populations before crops are planted. This work is vital in terms of regulating Striga populations in areas where they are hugely damaging to crop plants and people’s livelihoods.

Read the full study in Science here.

Striga, a parasitic plant. Also known as Witchweed.

Striga, a parasitic plant. Also known as Witchweed. Image from the International Institute of Tropical Agriculture used under creative commons license 2.0

  1. Resurrection plants genome harvesting

Resurrection plants are a unique group of flora that can survive extreme water shortages for months or even years. There are more than 130 varieties in the world, and many researchers believe that unlocking the genetic codes of drought-tolerant plants could help farmers working in increasingly hot and dry conditions.

During a drought, the plant acts like a seed, becoming so dry that it appears dead. But as soon as the rains come, the shriveled plant bursts ‘back to life’, turning green and robust in just a few hours.

In November, researchers from the Donald Danforth Plant Science Centre in Missouri, US, published the complete draft genome of Oropetium thomaeum, a resurrection grass species.

O. thomaeum is a small C4 grass species found in Africa and India. It is closely related to major food feed and bioenergy crops. Therefore this work represents a significant step in terms of understanding novel drought tolerance mechanisms that could be used in agriculture.

Read the full paper in Nature here.

  1. Supercomputing overcomes major ecological challenge

Currently, one of the greatest challenges for ecologists is to quantify plant diversity and understand how this affects plant survival. For the last 500 years independent research groups around the world have collected this diversity data, which has made organization and collaboration difficult in the past.

Over the last 500 years, independent research groups have collected a wealth of diversity data. The Botanical Information and Ecology Network (BIEN) are collecting and collating these data together for the Americas using high performance computing (HPC) and data resources, via the iPlant Collaborative and the Texas Advanced Computing Center (TACC). This will allow researchers to draw on data right from the earliest plant collections up to the modern day to understand plant diversity.

There are approximately 120,000 plant species in North and South America, but mapping and determining the hotspots of species richness requires computationally intensive geographic range estimates. With supercomputing the BIEN group could generate and store geographic range estimates for plant species in the Americas.

It also gives ecologists the ability to document continental scale patterns of species diversity, which show where any species of plant might be found. These novel maps could prove a fantastic resource for ecologists working on diversity and conservation.

Read more about this story on the TACC website, here.

Taking Care of Wildlings

By Hannes Dempewolf

We at the Global Crop Diversity Trust care about wildlings! No, not the people beyond The Wall, but the wild cousins of our domesticated crops. By collecting, conserving and using wild crop relatives, we hope to be able to adapt agriculture to climate change. This project is funded by the Government of Norway, in partnership with the Millennium Seed Bank at Kew in the UK, and many national and international research institutes around the world.

The first step of this project was to map and analyze the distribution patterns of hundreds of crop wild relatives. Next, we identified global priorities for collecting, and are now providing support to our national partners to collect these wild species and use them in pre-breeding efforts. An example of a crop we have already started pre-breeding is eggplant (aubergine). This crop, important in developing countries, has many wild relatives, which we are using to develop varieties that can better withstand abiotic stresses and variable environments.

More recently we have started a discussion with the crop science community on how best to share our data and information about these species, and genetic resources more generally. This discourse that was at the heart of what has now become the DivSeek Initiative, a Global Plant Council initiative that you can read more about in this GPC blog post by Gurdev Khush.

Why should you care?

Good question. I couldn’t possibly answer it better than Sandy Knapp, one of the Project’s recent reviewers, who speaks in the video below.

One of the great leaders in the field, Jack Harlan, also recognized their immense value: “When the crop you live by is threatened you will turn to any source of relief you can find. In most cases, it is the wild relatives that salvage the situation, and we can point very specifically to several examples in which genes from wild relatives stand between man and starvation or economic ruin.”

Oryza

Wild rice, Oryza officinalis, is being used to adapt commercial rice cultivars to climate change. Photo credit: IRRI photos, used under Creative Commons License 2.0

Crop wild relatives have indeed been used for many decades to improve crops and their value is well recognized by breeders. This is increasingly true also for abiotic stress tolerances, particularly relevant if we care about adapting our agricultural systems to climate change. One such example is the use of a wild rice (Oryza officinalis) to change the flowering time of the rice cultivar Koshihikari (Oryza sativa) to avoid the hottest part of the day.

Share the care

Fostering the community of those who care about crop wild relatives is an important objective of the project. We make sure that all the germplasm collected by partners is accessible to the global community for research and breeding, within the framework of the International Treaty on Plant Genetic Resources for Food and Agriculture (the ‘Plant Treaty’). The project invests into building capacity into collecting: it’s not as simple a process as it may sound. The following shows the training in collection in Uganda:

We also put a heavy emphasis on technology transfer and the development of lasting partnerships in all of the pre-breeding projects we support.

The only way we can safeguard and reap the benefits of the genetic diversity of crop wild relatives over the long term is by supporting a vibrant, committed community.  We hope you agree, and encourage you to get in touch via [email protected].

To find out more about the Crop Trust and how you can take action to help conserve crop diversity for food security, please visit our webpage. For more information about the Crop Wild Relatives project, please visit www.cwrdiversity.org.

 

Biofortification

Approaches to biofortification

Biofortification is the improvement of the nutritional value of our crops through both traditional breeding and genetic engineering. Alongside DivSeek and Stress Resilience, biofortification is one of the Global Plant Council’s three main initiatives and will be central to addressing many of the challenges facing world health. However, biofortification doesn’t always involve changing our crops in some way. Often the nutrients we are lacking are present in pre-existing crops. We can biofortify our diets simply by identifying what’s missing and altering our life style accordingly.

Tackling undernourishment

The share

The share (%) of undernourished people per country. From: Max Roser (2015) -‘Hunger and Undernourishment’. Published online at www.OurWorldInData.org

More often that not we intuitively link biofortification with tackling undernourishment in the developing world, and indeed improvements in the diets of deprived communities would be of enormous benefit to global health.

To do this, a key challenge is to increase the nutrient content of staple food crops such as rice in Asia and maize in sub-Saharan Africa. We need to do this in a sustainable and affordable way; ensuring foods are accessible to those who need it. Alongside the fortification of staple crops we need to identify economical crop species that will grow in harsh environments and provide nutrients currently absent from the diet.

Addressing obesity

It is easy to forget that malnutrition is also a problem in developed countries. Worldwide, at least 2.8 million people per year die from obesity-related illnesses, and in 2011 more than 40 million children under the age of five were overweight. Obesity and related health problems such as diabetes, heart disease and certain cancers, place enormous strain on health services, and are partly a function of poor diet lacking in fibre and key phytonutrients. Addressing this is as important as tackling undernourishment, and many of the same principles apply.

Simple lifestyle changes, such as encouraging the consumption of more fruits and vegetables, are clearly a priority. In addition to this dietary change, if we are going to biofortify foods, there should be an emphasis on crops that are already widely consumed.

Purple tomatoes

Professor Cathie Martin

Professor Cathie Martin works at the John Innes Centre researching the link  between diet and health, and how crops could be fortified to improve our diets and global health.

Tomatoes, are one crop plant already eaten widely in the West, commonly found in fast and convenience foods. For this reason they became the focus of the work of Professor Cathie Martin at the John Innes Centre in Norwich, UK. Cathie’s lab has developed a genetically modified tomato that is rich in anthocyanins, making them purple in colour. Anthocyanins are an important dietary component that can have numerous health benefits, including a potentially significant role in the prevention of diseases such as cancer and diabetes. They are the compounds that give some foods, such as blueberries or eggplant, their distinctive blue or purple colouring. Consuming higher quantities could be highly beneficial to health.

“We focused on anthocyanins because of their huge potential health benefits. Pre-clinical studies show that introducing our purple tomatoes into the diet could be an incredibly effective way to protect against diseases such as cancer. Our next steps will be to confirm these findings in human trials,” says Cathie.

However, naturally occurring tomato varieties containing anthocyanins already exist. Wouldn’t it be better to increase consumption of these rather than creating new ones?

“Indeed purple tomatoes do occur naturally. However, these have anthocyanins only in the skin, in quantities too small to make a significant impact on health. Our genetically modified tomatoes have anthocyanins in all tissues,” explains Cathie.

Since developing the purple tomatoes, Cathie, in collaboration with Professor Jonathan Jones, has set up Norfolk Plant Sciences, the UK’s first GM crop company. However, resistance and uncertainty in Europe surrounding GM technology means that progress has been slow.

“The company was founded in 2007 and we are currently working towards the approval of our purple tomato juice in the USA. Producing just the juice rather than the entire fruit means there are no seeds in the final product. This eliminates environmental challenges without compromising health benefits. If the juice proves successful in the USA we may then work towards approval in the UK and Europe.”

It’s not all about Genetic Modification

Of course if we want to make drastic changes to our foods, such as increase anthocyanins in our tomatoes or carotenoids in our rice, GM technology will be a necessity. However, we can go some way to biofortifying our diets without the use of GM.

Golden rice

Golden rice, shown on the left, is a biofortified crop that accumulates high quantities of provitamin A in the grain. This could help tackle Vitamin A Deficiency in developing countries, from which 500,000 children become blind every year, and nine million will die of malnutrition. Photo credit: IRRI photos used under Creative Commons 2.0

Primarily we really need to focus on changing diet and lifestyle. Promoting plants rich in the nutritional components we need is essential, in addition to encouraging traditional diets such as the Mediterranean diet rich in fish, fruits and vegetables. However, changing people’s behavior and relationship with food is a huge challenge. Cathie cites the UK 5-A-Day governmental campaign as an example.

This campaign was aimed at encouraging people to eat five portions of fruit or vegetables a day. At the end of this 25-year campaign only 3% more of the UK population was getting their five a day.”

In addition to dietary change, we could biofortify our crops through traditional breeding. For example, one answer to increasing anthocyanins in the diet could be red wheat. Red wheat is rich in anthocyanins, and furthermore less susceptible to pre-harvest sprouting, which causes large crop losses every year for farmers. However, we have so far resisted selecting for this trait in wheat breeding programs as it is not considered esthetically pleasing. To improve our diets we may need to change our expectations of what we want our plates to look like.

Next steps

Plant scientists alone cannot tackle biofortification of our diets! Cathie believes the key to a healthier future is interdisciplinary research:

“Everyone needs to come together: nutritionists, epidemiologists, plant breeders, and plant scientists. However, with such a diverse group of people it is hard to reach agreement on the next steps, and equally as difficult to secure funding for research projects. We really need to promote collaboration and interaction between all groups in order to move forwards.”