Genome‐Wide Analysis of Soybean LATERAL ORGAN BOUNDARIES Domain ‐Containing Genes: A Functional Investigation of GmLBD12

Abstract

Plant-specific LBD (LATERAL ORGAN BOUNDARIES Domain) genes play critical roles in various plant growth and development processes. However, the number and characteristics of LBD genes in soybean [Glycine max (L.) Merr.] remain unknown. Here, we identified 90 LBD homologous genes in the soybean genome that phylogenetically clustered into two classes (I and II). The majority of the GmLBD genes were evenly distributed across all 20 soybean chromosomes, and 77 (81.11%) of them were detected in segmental duplicated regions. Furthermore, the exon-intron organization and motif composition for each GmLBD were analyzed. A close phylogenetic relationship was identified between the soybean LBD genes and 41 previously reported genes of different plants in the same group, providing insights into their putative functions. Expression analysis indicated that more than half of the LBD genes were expressed, with the two gene classes showing differential tissue expression characteristics; in addition, they were differentially induced by biotic and abiotic stresses. To further explore the functions of LBD genes in soybean, GmLBD12 was selected for functional characterization. GmLBD12 was mainly localized to the nucleus and showed high expression in root and seed tissues. Overexpressing GmLBD12 in Arabidopsis thaliana (L.) Heynh resulted in increases in lateral root (LR) number and plant height. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrated that GmLBD12 was induced by drought, salt, cold, indole acetic acid (IAA), abscisic acid (ABA), and salicylic acid SA treatments. This study provides the first comprehensive analysis of the soybean LBD gene family and a valuable foundation for future functional studies of GmLBD genes. PU - WILEY PI - HOBOKEN PA - 111 RIVER ST, HOBOKEN 07030-5774, NJ USA