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Tag: stress resilience (page 2 of 8)

Water is key to ending Africa’s chronic hunger cycle

By Esther Ngumbi

For Africa to end chronic hunger, governments must invest in sustainable water supplies.

The fields are bare under the scorching sun and temperatures rise with every passing week. Any crops the extreme temperatures haven’t destroyed, the insect pests have, and for many farmers, there is nothing they can do. Now, news about hunger across Africa makes mass media headlines daily.

Globally, hunger levels are at their highest. In fact, according to the Famine Early Warning Systems Network, over 70 million people across 45 countries will require food emergency assistance in 2017, with Africa being home to three of the four countries deemed to face a critical risk of famine: Nigeria, South Sudan, Sudan and Yemen. African governments, non-governmental organisations (NGOs) and humanitarian relief agencies, including the United Nations World Food Programme, continue to launch short-term solutions such as food relief supplies to avert the situation. Kenya, for example, is handing cash transfers and food relief to its affected citizens. The UN World Food Programme is also distributing food to drought-stricken Somalia. And in Zambia, the government is employing every tool including its military to combat insect pest infestation.

But why are we here? What happened? Why is there such a large drought?

Reasons for chronic hunger

Many African smallholder farmers depend on rain-fed agriculture, and because last year’s rains were inadequate, many farmers never harvested any crops.

Indeed, failed rains across parts of the Horn of Africa have led to the current drought that is affecting Somalia, south-eastern Ethiopia and northern and eastern Kenya.

Then, even in the countries where adequate rains fell, many of the farmers had to farm on depleted soils, and consequently, the yields were lower. Degraded soils and dependence on rain-fed agriculture coupled with planting the wrong crop varieties are some of the fundamental problems that lead to poor harvests and then to hunger. Worsening the situation is the unpredictable climate. Given these fundamental and basic issues that fuel the hunger cycle in Africa, it naturally makes sense to tackle them.

It is not rocket science. Farming goes hand-in-hand with water. There can be no farming without it. While this seems easy to reason, there are few organisations working to make sure that African farmers and citizens have access to permanent water sources. Access to water sources all year round would ensure that farmers can farm year in and year out.

What African governments must do

African governments must, therefore, invest in ensuring that their citizens have access to water. Measures that can be implemented include drilling and rehabilitating boreholes, creating reservoirs and irrigation systems, constructing hand-pumps and implementing water harvesting schemes. Such measures would go a long way and ensure that countries continue to face the same problem both in the short and long term periods.

“If Africa wants to end the recurring droughts, hard decisions must be made.”

Esther Ngumbi, Auburn University in Alabama. United States

Of course it is understandable that it can be hard to choose long-term solutions such as ensuring that citizens have access to permanent water sources year round over investing in short-term solutions when there are people who need help now.

Acknowledging this dilemma, Mitiku Kassa, the Ethiopia’s commissioner for disaster risk management, is reported to have described how hard it was to direct even a fifth of his budget towards well drilling. But such decisions must be made. The Ethiopian government still made that tough decision and sunk hundreds of bore wells throughout the country.

There is a great need to ramp up water harvesting and conservation efforts across the African continent. African governments and other stakeholders need to increase investment in multiple water-storing techniques. Such techniques include rain and flood water harvesting and the construction of water storage ponds and dams. But there should be no need to reinvent the wheel.

Time to learn from others

African countries can learn from other countries. Countries in the developed world have sustained their agriculture efforts by either drilling water wells to ensure they have access to the water they need for farming or by investing in rain and flood water harvesting. In California, for example, there have been a rise in the number of wells being drilled by farmers who use well water for farming. In 2016 alone, farmers in the San Joaquin Valley dug about 2,500 wells, a number that was five times the annual average reported in the last 30 years.

Countries such as Bangladesh, China, India, Myanmar, Sri Lanka and Thailand have made progress and are working on pilot projects that capture, harvest and store flood water. Stored water is then available for use by communities when they need it the most. Harvesting and storing water and making it available for agriculture, especially during the dry seasons, will allow citizens and smallholder farmers to farm throughout the year. These would further improve the resilience of farmers to the unpredictability of climate change.

If Africa wants to end the recurring droughts, hard decisions must be made. By addressing the fundamental and basic issues of long-term availability of water for agriculture, African countries can once and for all end this never-ending cycle of hunger.

Esther Ngumbi is a postdoctoral researcher at the Department of Entomology and Plant Pathology at Auburn University in Alabama, United States. She serves as a 2015 Clinton Global University (CGI U) Mentor for Agriculture and is a 2015 New Voices Fellow at the Aspen Institute. 

This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.

 

References

Humphrey Nkonde Dramatic threat to maize harvest (Development and Cooperation, 6 March 2017)
Mohammed Yusuf UN: 17 Million People Face Hunger East Africa (Voice of America, 8 March 2017)
Karen McVeigh Somalia famine fears prompt UN call for ‘immediate and massive’ reaction (the Guardian, 3 February 2017)
Emergency food assistance needs unprecedented as Famine threatens four countries (Famine Early Warning Systems Network, 25 January 2017)
Kazungu Samuel Kenya: Red Cross Comes to the Aid of Drought-Hit Kilifi Residents (allAfrica, 2017)
Army worms invades Zambia’s farms (Azania Post, 6 February 2017)
Lesson learned? An urgent call for action in response to the drought crisis in the horn of Africa (Inter Agency Working Group on Disaster Preparedness for East and Central Africa, 2017)
Amanda Little The Ethiopian Guide to Famine Prevention (Bloomberg Business Week, 22 December 2016)
Central Valley farmers drill more, deeper wells as drought limits loom (CBS SF Bay Area, 15 September 2016)
Underground taming floods for irrigation(International Water Management Institute, 2017)

 

This article was originally published on SciDev.Net. Read the original article.

Just add water: Could resurrection plants help feed the world?

This week we spoke to Professor Henk Hilhorst (Wageningen University and Research) about his research on desiccation tolerance in seeds and plants.

 

Could you begin by telling us a little about your research?

I am a plant physiologist specializing in seed biology. I have a long research record on various aspects of seeds, including the mechanisms and regulation of germination and dormancy, desiccation tolerance, as well as issues in seed technology. Being six years from retirement now, I decided to extend my desiccation tolerance studies from seeds to resurrection plants, which display vegetative desiccation tolerance. I strongly believe that unveiling of the mechanism of vegetative desiccation tolerance may help us create crops that are truly tolerant to severe drought, rather than (temporarily) resistant.

 

How did you become interested in this field of study, and how has your career progressed?

As with many things in life, it was coincidence. I majored in plant biochemistry and applied for a PhD position in seed biology. After obtaining the degree I was offered a tenure track position in seed physiology by the Laboratory of Plant Physiology at Wageningen University, where I still work as a faculty member. My career has progressed nicely and I am an authority in the field of seed science, editor-in-chief of the journal Seed Science Research, and will become the President of the International Society for Seed Science in September of this year.

I see my current work on vegetative desiccation tolerance as a highlight in my professional life. I have always been more interested in the desiccation tolerance of seeds until about five years ago, when my current collaborator Prof Jill Farrant of the University of Cape Town, South-Africa, made me enthusiastic about these wonderful resurrection plants. We started to work together and published our first study recently in Nature Plants.

Read the paper here ($): A footprint of desiccation tolerance in the genome of Xerophyta viscosa.


 

In your recent paper, you sequenced the genome of the resurrection plant, Xerophyta viscosa, which can survive with less than a 5% relative water content. How is it possible for a plant to lose so much of its water and still survive?

These plants have a lot of characteristics that we’ve seen in seeds. They display protective desiccation tolerance mechanisms in their leaves, including anti-oxidants, protective proteins, and even dismantle their photosynthetic machinery during periods of drought. Even the cell wall structure and composition of resurrection plants resemble those of seeds. We are currently working on a paper describing the striking similarities between seeds and resurrection plants.

 

What was the most interesting discovery you made upon sequencing the genome of the resurrection plant?

First, the similarities between resurrection plants and seeds listed above were also apparent at the molecular level. For example, previous work suggested that the “ABI3 regulon”, consisting of about 100 genes regulated by the transcription factor ABI3, is specific to seeds, but we found that it is almost completely present (and active) in the leaves of Xerophyta viscosa too!

Secondly, we found “islands” or clusters of genes specific for desiccation tolerance that aren’t found in other species. Many of these regulate secondary metabolite pathways.

 

How challenging was it to sequence the genome of this plant? How did you overcome any difficulties?

It was very challenging. First, the species is an octoploid, meaning it has eight copies of each chromosome. This meant that we had to sequence its genome at very high coverage and employing the most advanced sequencing facilities, e.g. PacBio. Getting funding for this complex analysis was another challenge. We then took almost a year to assemble the genome and annotate it at the desired quality.

 

Xerophyta viscosa

Xerophyta viscosa before and after the rains. Image credit: Prof. Henk Hilhorst.

 

You identified some of the most important genes involved in desiccation tolerance. Is it possible to translate this work into other species, such as crops that may be threatened by drought as the climate changes?

That will be our ultimate goal. It’s important to remember that desiccation-sensitive plants, including all our major crops, produce seeds that are desiccation tolerant. This implies that the information for desiccation tolerance is present in the genomes of these crops but that it is only turned on in the seeds. We are trying to determine how this is localized, in order to find a method to turn on the desiccation tolerance mechanism in vegetative parts of the (crop) plant too. In parallel we are expressing some of the key transcription factors from Xerophyta viscosa in some important crops to see how this affects them.

 

Are there any other interesting aspects of Xerophyta viscosa biology?

Contrary to plants that wilt and ultimately die because of (severe) drought, leaves of resurrection species do not show such stress-related senescence. This is related to the engagement of active anti-senescence genes during the drying of the leaves of resurrection species. We are currently investigating these senescence-related mechanisms too.

 

Rose of Jericho (Anastatica hierochuntica)

The rose of Jericho (Anastatica hierochuntica) is another resurrection plant. Image credit: FloraTrek. Used under license: CC BY-SA 3.0.

 

Do you expect to find that different types of desiccation-tolerant plants use the same subset of genes to survive drought, or could they have developed other pathways to resilience?

We expect that the core mechanism is very similar among the resurrection species but that each species may have adapted to its specific environment.

Funding permitting, we will sequence the genomes of at least another ten resurrection species to further clarify the various evolutionary pathways to desiccation tolerance and, importantly, to discriminate between species-specific and desiccation tolerance-specific genes.

 

What advice do you have for early career researchers?

Stick to what you believe in, even if you have to (temporarily) be involved in research that you appreciate less, e.g., because of better funding opportunities.

 


Read Henk’s recent paper in Nature Plants here ($): A footprint of desiccation tolerance in the genome of Xerophyta viscosa.

Roots of a second green revolution

This week we spoke to Professor Jonathan Lynch, Penn State University, whose research on root traits has deepened our understanding of how plants adapt to drought and low soil fertility.

 

 

Could you begin by giving us a brief introduction to your research?

We are trying to understand how plants adapt to drought and low soil fertility. This is important because all plants in terrestrial ecosystems experience suboptimal water and nutrient availability, so in rich nations we maintain crop yields with irrigation and fertilizer, which is not sustainable in the long term. Furthermore, climate change is further degrading soil fertility and increasing plant stress. This topic is therefore both a central question in plant evolution and a key challenge for our civilization. We need to develop better ways to sustain so many people on this planet, and a big part of that will be developing more resilient, efficient crop plants.

 

Drought is devastating for crops

Drought and low soil fertility are devastating for crops. Image credit: CIAT. Used under license: CC BY-SA 2.0.

 

What got you interested in this field, and how has your career developed over time?

When I was 9 years old I became aware of a famine in Africa related to crop failure and resolved to do something about it. I studied soils and plant nutrition as an undergraduate, and in graduate school worked on plant adaptation to low phosphorus and salinity stress, moving to a research position at the CIAT headquarters in Colombia. Later I moved to Penn State, where I have maintained this focus, working to understand the stress tolerance of staple crops, and collaborating with crop breeders in the USA, Europe, Africa, Asia, and Latin America.

 

Your recent publications feature a variety of different crop plants. Could you talk about how you select a species to study?

We work with species that are important for food security, that grow in our field environments, and that I think are cool. We have devoted most of our efforts to the common bean – globally the most important food legume – and maize, which is the most important global crop. These species are often grown together in Africa and Latin America, and part of our work has been geared to understanding how maize/bean and maize/bean/squash polycultures perform under stress. These are fascinating, beautiful plants with huge cultural importance in human history. They are also supported by talented, cooperative research communities. One nice feature of working with food security crops is that their research communities share common goals of achieving impact to improve human welfare.

 

Common bean (Phaseolus vulgaris)

The common bean (Phaseolus vulgaris) is an important staple in many parts of the world. Image credit: Ervins Strauhmanis. Used under license: CC BY 2.0.

 

Many researchers use Arabidopsis thaliana for plant research, but are crops better suited for root research than the delicate roots of Arabidopsis? Are crop plants more or less difficult to work with in your research than Arabidopsis?

The best research system is entirely a function of your goals and questions. We have worked with Arabidopsis for some questions. Since we work with processes at multiple scales, including crop stands, whole organisms, organs, tissues, and cells, it has been useful to work with large plants such as maize, which are large enough to easily measure and to work with in the field. The most interesting stress adaptations for crop breeding are those that differ among genotypes of the same species, and at that level of organization there is a lot of biology that is specific to that species, that cannot readily be generalized from model organisms with very different life strategies. There has been considerable attention to model genomes and much less attention to model phenomes.

 

You have developed methodologies for the high-throughput phenotyping of crop plants. What does this technique involve and what challenges did you have to overcome to succeed?

We have developed multiple phenotyping approaches – too many to summarize readily here. Our overall approach is simply to develop a tool that helps us achieve our goals. For example, we have developed tools to quantify the root architecture of thousands of plants in the field, to measure anatomical phenotypes of thousands of samples from field-grown roots, to help us determine which root phenotypes might affect soil resource capture, etc. Working with geneticists and breeders, we are constantly asked to measure something meaningful on thousands of plants in a field, in many fields, every season. ARPA-E (the US Advanced Research Projects Agency for Energy) has recently funded us to develop phenotyping tools for root depth in the field, but this is the first time we have been funded to develop phenotyping tools – generally we just come up with things to help us do our work, which fortunately have been useful for other researchers as well.

 

Could you talk about some of the computational models you have developed for investigating plant growth and development?

The biological interactions between plants and their environment are so complex, we need computational (in silico) tools to help us evaluate them. Increasingly, in silico tools can integrate information across multiple scales, from gene expression to crop stands. These tools also allow us to evaluate things that are difficult to measure, such as phenotypes that do not yet exist, or future climates. In silico biology will be an essential tool in 21st Century biology, which will have access to huge amounts of data at multiple scales that can be used to try to understand incredibly complex systems, such as the human brain or roots interacting with living soil. Our main in silico tool is SimRoot, developed over the past 25 years to understand how root phenotypes affect soil resource capture.

Check out a SimRoot model below:


 

You have been working on breeding plants that have improved yield in soils with low fertility. What have you achieved in this work?

In collaboration with crop breeders and colleagues in various nations we have developed improved common bean lines with better yield under drought and low soil fertility that are being deployed in Africa and Latin America, improved soybean lines with better yield in soils with low phosphorus being deployed in Africa and Asia, and are now working with maize breeders in Africa to develop lines with better yield under drought and low nitrogen stress. Many crop breeders are using our methods for root phenotyping to target root phenotypes in their selection regimes in multiple crops.

 

What piece of advice do you have for early career researchers?

You are at the forefront of an unprecedented challenge we face as a species – how to sustain 10 billion people in a degrading environment. Plant biologists are an essential part of the effort to reshape how we live on this planet. Do not doubt the importance of your efforts. Do not lose sight of the very real human impact of your scientific choices. Do not be deterred by the gamesmanship and ‘primate politics’ of science. You can make a difference. We need you.

Creole maize reveals adaptation secrets

By Lucina Melesio

[MEXICO CITY] An international team of scientists identified a hundred genes that influence adaptation to the latitude, altitude, growing season and flowering time of nearly 4,500 native maize varieties in Mexico and in almost all Latin American and Caribbean countries.

Creole — or native — varieties of maize are derived from improvements made over thousands of years by local farmers, and contain genes that help them adapt to different environments.

“We are now using this analysis to find other genes that are of vital importance to breeders, such as those resistant to extreme heat, frost or drought — environmental conditions associated with climate change and that could affect maize production.”

Sarah Hearne, CIMMYT

“Latin American breeders will be able to use these results to identify native varieties that could contribute to improved adaptation”, Edward Buckler, a Cornell University researcher and co-author of the study published in Nature Genetics (February 6), told SciDev.Net.

The information on the genetic markers described in the study will be available online, said Sarah Hearne, a researcher at the International Maize and Wheat Improvement Center (CIMMYT) and co-author of the study. “Meanwhile, any breeder can contact us to request information”, she said.

“We are now using this analysis to find other genes that are of vital importance to breeders, such as those resistant to extreme heat, frost or drought — environmental conditions associated with climate change and that could affect maize production”, Hearne said.

Maize ears from CIMMYT’s collection, showing a wide variety of colors and shapes. CIMMYT’s germplasm bank contains about 28,000 unique samples of cultivated maize and its wild relatives, teosinte and Tripsacum. These include about 26,000 samples of farmer landraces—traditional, locally-adapted varieties that are rich in diversity. The bank both conserves this diversity and makes it available as a resource for breeding.
Photo credit: Xochiquetzal Fonseca/CIMMYT.

Studying native maize varieties is extremely difficult because of their genetic variation. Although domesticated, they are wilder than commercial varieties.

For this study, the researchers cultivated hybrid creole varieties in various environments in Latin America and identified regions of the genome that control growth rates. They looked into where the varieties came from and what genetic features contributed to their growth in that environment.

 In comments to SciDev.Net, James Holland, a researcher at North Carolina State University, Jeffrey Ross-Ibarra, a researcher at the University of California Davis, and Rodomiro Ortiz, a researcher at the Swedish University of Agricultural Sciences — who did not participate in the study — commended the magnitude of the study and the original method developed by the researchers to access the rich set of genetic information about native maize varieties.

Hearne added that the research team has initiated a “pre-breeding” programme with a small group of breeders in Mexico. As part of that programme, CIMMYT delivers to breeders materials from its germplasm bank of Creole maize; it also provides molecular information the breeders can use to generate new varieties.

This piece was produced by SciDev.Net’s Latin America and Carribean edition.

This article was originally published on SciDev.Net. Read the original article.

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