Genome-Wide Analysis of the Lateral Organ Boundaries Domain (LBD) Gene Family in Sweet Potato

Abstract

Abstract Background Sweet potato (Ipomoea batatas (L.) Lam.) serves as an important food source for human beings. The lateral organ boundary (LOB) structural domain (LBD) genes are a family of genes encoding plant-specific transcription factors that play important roles in regulating plant growth and development, nutrient metabolism, and environmental stresses. However, the function of IbLBD genes in sweet potato remains unclear. Results In this study, We identified a total of 53 IbLBD genes in sweet potato. Genetic structure showed that most of the IbLBD genes contained only two exons. Based on the phylogenetic analysis, the IbLBD gene family was classified into class I (45, with the largest number of Ia genes (20)) and class II (8), both classes of proteins contained relatively conservative Motif1 and Motif2 domains. The sweet potato LBD gene was also analyzed regarding its chromosomal distributions, gene duplications, promoters and PPI network. In addition, gene expression profiling and real-time quantitative PCR analysis showed that the expression of 12 IbLBD genes differed in six different tissues and different abiotic stresses. The IbLBD genes of Class I were mainly expressed in the primary root, pencil root, and leaves, while Class II genes were mainly expressed in the different roots of sweet potatoes. Besides the expression pattern analysis of salt and drought treatment plants showed that abiotic stress treatment could significantly induce the expression of IbLBD genes. Specific expression patterns of IbLBD genes under salt and drought stresses suggest their important role in resisting adverse external environments. Conclusions Taken together, the molecular basis of LBD genes in sweet potato was analyzed from multiple perspectives, which provides a theoretical basis to further investigate the functions of sweet potato LBD genes.