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

Abstract

The LBD family is a plant-specific transcription factor family that plays an important role in a variety of biological processes. However, the function of IbLBD genes in sweet potato remains unclear. 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. Following the phylogenetic investigation, the IbLBD gene family was separated into Class I (45 members) and Class II (8) members. Both classes of proteins contained relatively conservative Motif1 and Motif2 domains. The chromosomal locations, gene duplications, promoters, PPI network, and GO annotation of the sweet potato LBD genes were also investigated. Furthermore, gene expression profiling and real-time quantitative PCR analysis showed that the expression of 12 IbLBD genes altered in six separate tissues and under various abiotic stresses. The IbLBD genes belonging to Class I were mostly expressed in the primary root, the pencil root, and the leaves of sweet potatoes, while the genes belonging to Class II were primarily expressed in the various sweet potato roots. The IbLBD genes belonging to Class I were mostly expressed in the primary root, the pencil root, and the leaves of sweet potatoes, while the genes belonging to Class II were primarily expressed in the fibrous root, pencil root, and tuber root.