Functional Genomics: From Soybean to Legume

Abstract

The Fabaceae family, the third-largest among flowering plants, is nutritionally vital, providing rich sources of protein, dietary fiber, vitamins, and minerals. Leguminous plants, such as soybeans, peas, and chickpeas, typically contain two to three times more protein than cereals like wheat and rice, with low fat content (primarily unsaturated fats) and no cholesterol, making them essential for cardiovascular health and blood sugar management. Since the release of the soybean genome in 2010, genomic research in Fabaceae has advanced dramatically. High-quality reference genomes have been assembled for key species, including soybeans (<i>Glycine max</i>), common beans (<i>Phaseolus vulgaris</i>), chickpeas (<i>Cicer arietinum</i>), and model legumes like <i>Medicago truncatula</i> and <i>Lotus japonicus</i>, leveraging long-read sequencing, single-cell technologies, and improved assembly algorithms. These advancements have enabled telomere-to-telomere (T2T) assemblies, pan-genome constructions, and the identification of structural variants (SVs) and presence/absence variations (PAVs), enriching our understanding of genetic diversity and domestication history. Functional genomic tools, such as CRISPR-Cas9 gene editing, mutagenesis, and high-throughput omics (transcriptomics, metabolomics), have elucidated regulatory networks controlling critical traits like photoperiod sensitivity (e.g., <i>E1</i> and <i>Tof16</i> genes in soybeans), seed development (<i>GmSWEET39</i> for oil/protein transport), nitrogen fixation efficiency, and stress resilience (e.g., <i>Rpp3</i> for rust resistance). Genome-wide association studies (GWAS) and comparative genomics have further linked genetic variants to agronomic traits, such as pod size in peanuts (<i>PSW1</i>) and flowering time in common beans (<i>COL2</i>). This review synthesizes recent breakthroughs in legume genomics, highlighting the integration of multi-omic approaches to accelerate gene cloning and functional confirmation of the genes cloned.