Overview of the Cook Laboratory –Legume Species, Food Security and Plant-Microbe Interactions

The gap between basic and applied science is large, and the Cook lab has spent the better part of the past decade working to translate basic discoveries to crop improvement outcomes. Typically this has been achieved through international collaboration. Current projects involve a combination of genomics, gene discovery, and translation to breeding, with a focus on legume species

Legumes are important components of agricultural systems worldwide, but have special significance in the developing world due to their unique capacity for symbiotic nitrogen fixation. Legumes provide ~30% of humankind’s nutritional nitrogen. Nitrogen fixation also buffers legume productivity, especially in resource poor farming situations, because legumes produce their own fertilizer nitrogen. In non-legume cropping systems, input of fertilizer nitrogen accounts for ~15% of agricultural inputs and is the source of serious agricultural pollution.

Legumes have special significance in the developing world due to their unique capacity for symbiotic nitrogen fixation.
Chickpea is the world’s second most widely grown food legume.

A recently funded National Science Foundation project continues work under a prior NSF/Gates Foundation award, with a focus on the efficiency of nitrogen fixation and microbial communities associated with wild species and crop legumes. We hypothesize that the domestication of legumes from their wild progenitors will have made legumes less efficient at nitrogen fixation and altered the structure and function of their microbiomes.  Working in chickpea, the world’s second most widely grown food legume, we have identified domestication-related shifts in nitrogen-related traits in both plant and bacterial species, supporting our hypothesis. Research conducted in the current NSF award aims to identify the underlying genes, from which we can improve microbe related traits in crop legumes. For more information, please visit chickpealab.ucdavis.edu/index.php/research1/nsf-project/.

A second project, funded by USAID, aims to improve climate resilience in chickpea, especially tolerance to drought and heat. Climatic extremes not only reduce crop yield and quality, they also negatively impact legume nitrogen fixation. Our target countries are Ethiopia and India, where chickpea is a key crop and primary source of human nutrition. Improved tolerance to environmental extremes has the potential to significantly increase and stabilize chickpea yields. Our strategy is a radical departure from typical approaches to crop improvement, and is more akin to genomic studies of human disease where population level analyses are used to identify trait-gene associations. The premise is that the loss of genetic capacity during crop domestication constrains development of crop varieties that are tolerant to climatic extremes. chickpealab.ucdavis.edu/index.php/research1/usaid-project/.

Research will:

♦ identify the underlying genes from which to improve nitrogen related traits in the crop legume, and

♦ improve climate resilience in chickpea, especially tolerance to drought and heat.

Other funded activities in the Cook laboratory focus on the (1) fundamental biology of nitrogen fixation through genomics and molecular biology, (2) sequencing of the lentil genome funded by the Canadian government, and (3) a project from the Global Crop Diversity Trust to conserve wild species of Cicer (chickpea)  and to characterize their tolerance to drought in the Turkish environment. For more information, please visit chickpealab.ucdavis.edu/index.php/research1/global-crop-diversity-trust/.

All of these projects combine fundamental biological questions with genomics, genetics, computational biology and ecology in an attempt to discover and understand the role of genetic variation in shaping the evolution and function of crop species.