Genome-wide identification and expression analysis of the PP2C gene family in Apocynum venetum and Apocynum hendersonii

Abstract Background Protein phosphatase class 2C (PP2C) is the largest protein phosphatase family in plants, which plays an important role in plant growth and development and response to adversity stress. Apocynum is a perennial persistent herb, divided into Apocynum venetum and Apocynum hendersonii. It mainly grows in saline soil, desert and other harsh environments, and is widely used in saline soil improvement, ecological restoration, textile and medicine. It was found that Apocynum hendersonii is more tolerant of adverse conditions. The main purposeof this study was to investigate the PP2C gene family and its expression pattern under salt stress and to identify important candidate genes related to salt tolerance. Results In this study, 68 AvPP2C genes and 68 AhPP2C genes were identified from the genomes of Apocynum venetum and Apocynum hendersonii, respectively. They were classified into 13 subgroups based on their phylogenetic relationships and further analyzed for their subcellular locations, gene structures, conserved structural domains and cis-acting elements. The results of qRT-PCR analyses of seven AvPP2C genes and seven AhPP2C genes proved that they differed significantly in gene expression under salt stress. It has been observed that the PP2C genes in Apocynum venetum and Apocynum hendersonii exhibit different expression patterns. Specifically, AvPP2C2, 6, 24, 27, 41 and AhPP2C2, 6, 24, 27, 42 have shown significant differences in expression under salt stress. This indicates that these genes may play a crucial role in the salt tolerance mechanism of Apocynum venetumand Apocynum hendersonii. Conclusions In this study, we conducted a genome-wide analysis of the AvPP2C and AhPP2C gene families in Apocynum, which provided a reference for further understanding the functional characteristics of these genes.