|Samac, Deborah - Debby|
Submitted to: International Conference on Legume Genomics and Genetics
Publication Type: Abstract Only
Publication Acceptance Date: 6/7/2004
Publication Date: 6/7/2004
Citation: Vance, C.P., Uhde-Stone, C., Ramirez, M., Fedorova, M., Allan, D., Graham, M., Liu, J., Samac, D.A., Lara, M., Hernandez, G. 2004. Legume improvement through functional genomic studies of N and P acquisition. In: Legumes for the Benefit of Agriculture, Nutrition and the Environment. Second International Conference on Legume Genomics and Genetics, June 7-11, 2004, Dijon, France. p. 304.
Technical Abstract: Grain and forage legumes are grown on some 180 million HA or about 15% of Earth's arable surface. They account for 27% of the world's primary crop production and provide more than 33% of the dietary protein nitrogen (N) needs of humans. N and phosphorus (P) are the two most costly fertilizer inputs into agriculture. Moreover, their production is not sustainable. Use of legumes can help to remedy these nutrient deficiencies because: 1) they fix N2 in symbiosis with rhizobia; and 2) they can be incorporated as green manures to improve P availability. Defining plant biochemical and molecular processes involved in symbiotic N2 fixation and root adaptation to P stress are crucial to legume improvement. Genes identified as important in these processes offer potential targets for modification to enhance legume productivity. Sequencing of Medicago and Phaseolus root nodule ESTs has revealed a plethora of new genes and gene networks, some specific to legumes, that extend our understanding of nodule development and N2 fixation. Likewise, sequencing of ESTs from P-deficiency stressed roots of Lupinus and Phaseolus has shown that legumes share common gene expression responses to -P stress, affecting root biochemistry, architecture, and exudates. As the arsenal of plant genes involved in N and P acquisition expands through whole-genome studies, we will undoubtedly see them translated into agriculture through mapping, marker-assisted selection, and biotechnology. Because of the critical need for germplasm with improved nutrient acquisition and use, it is imperative that we establish and foster multidisciplinary research teams that combine genomics, biochemistry, physiology, and plant breeding/genetics.