Submitted to: Current Opinion in Plant Biology
Publication Type: Review Article
Publication Acceptance Date: 5/1/2006
Publication Date: 7/1/2006
Citation: Young, N.D., Shoemaker, R.C. 2006. Genome studies and molecular genetics: exploring the structure function and evolution of legume genomes. Current Opinion in Plant Biology. 9:1-16. Interpretive Summary:
Technical Abstract: Phylogenomics is revealing the complex taxonomic relationships that exist among legumes. Genomics is providing detailed insights into this extraordinary process and its role in genome dynamics. In the field of plant-microbe symbiosis, legumes provide the foundation for much of what we know today. Extending the tools of genomics, especially the capacity to isolate genes that underlie critical mutants, is helping to construct an integrated understanding of crucial signal transduction pathways. The biology of the seed has played a major role in the radiation of legumes. Similarly, flower morphology shows widely divergent developmental processes. A growing repetoire of expression profiling tools, and other 'omic' technologies is now available for model and crop legumes. The advent of powerful bioinformatic tools facilitates these studies. Genetic maps and other high-throughput genomic tools permit the comparative analysis of QTLs affecting seed composition and seed development in multiple legumes. This review addresses the complexity of genome structure in legumes, especially soybean. Almost without exception, paleopolploidy contributes to this complexity. It further addresses genome-sequencing projects and the importance of legume-specific genes and physiological processes. The fixation of atmospheric nitrogen into a form useable by plants has major agricultural and environmental impacts. Genomics is enhancing our understanding of these processes and of the genes that control the genes involved in the signaling between plant and symbiont appear to be legume-specific. It is thought that many of these genes were either recruited from other metabolic pathways or created de novo. Emerging evidence suggests that some nodule-specific peptides (CCPs) provide antimicrobial defense to the plant, protecting the nutritionally rich nodule. Among these reviews we see examples of the recent blossoming of legume genomics. Legumes, with their 16,000 species, possess an impressive breadth of phenotypic diversity. The family contains members that are key in food, feed and fiber, human health and nutrition, and also promising supplements for the world’s energy needs. Genomic initiatives on just a few of these species provide a wealth of sequence information. Rapid developments in technology will soon make whole genome sequencing in more legume species feasible. The information we gain from these initiatives will open the floodgates to evolutionary studies of legume genomes and permit the phylogenetic resolution of this complex family. Genomic information from key evolutionary nodes will be critical to ensuring the quality and quantity of food and feed for a growing world population.