Genome-Wide Identification of CLE Gene Family and Function Analysis of SbCLE39 Under Salt Stress in Sorghum

CLE proteins are a class of signalling factors involved in plant growth and abiotic stress response. They play crucial roles in processes such as cell differentiation, chlorophyll synthesis and abscisic acid (ABA) signal transduction. However, the function of the CLE genes in Sorghum bicolor remains unclear. In this study, 42 sorghum CLE genes were identified, and their evolutionary relationship, gene structure, amino acid sequence and homologous genes were analysed. We also examined the expression levels of CLE genes under various treatment conditions. Transcriptome data showed that there were significant differences in the expression patterns of 42 CLE genes in different tissues and organs. It is worth noting that SbCLE39 is mainly highly expressed in sorghum roots. At the same time, the expression of SbCLE39 decreased significantly under salt and ABA treatment. Compared with wild-type yeast cells (EV), yeast cells with high expression of SbCLE39 had lower tolerance to salt stress. In addition, the excessive accumulation of ABA caused by external application of SbCLE39p reduced the salt tolerance of sorghum. These findings suggest that SbCLE39 negatively regulates the salt tolerance of sorghum. These results lay a foundation for revealing the mechanism of CLE genes regulating the salt tolerance of sorghum and are of great significance for the cultivation of salt-tolerant crops.