Genome-Wide Identification, Characterization, and Expression Analysis of Family Genes in Legume Species.

The () gene family encodes microtubule-associated proteins that are essential for the anisotropic growth of plant cells and abiotic stress resistance. Currently, little is known about the characteristics and roles of the gene family outside of . This study intended to investigate the gene family in legumes. In contrast to that of , the gene family has undergone shrinking in the model legume species and While the orthologues of were lost, very few () genes were identified given the genome size of the two species. Specifically, the and genomes only harbor two and eight genes, respectively. Multiple sequence alignment showed that all these members contain conserved N- and C-terminal regions. Phylogenetic analysis clustered the legume SP1L proteins into three clades. The genes showed similar exon-intron organizations and similar architectures in their conserved motifs. Many essential cis-elements are present in the promoter regions of the and genes associated with growth and development, plant hormones, light, and stress. The expression analysis revealed that clade 1 and clade 2 genes have relatively high expression in all tested tissues in and soybean, suggesting their function in plant growth and development. , as well as clade 1 and clade 2 genes, display a light-dependent expression pattern. The genes in clade 2 (, , and ) were significantly induced by sodium chloride treatment, suggesting a potential role in the salt-stress response. Our research provides essential information for the functional studies of genes in legume species in the future.