A systematic analysis of the phloem protein 2 (PP2) proteins in Gossypium hirsutum reveals that GhPP2-33 regulates salt tolerance

BackgroundPhloem protein 2 (PP2) proteins play a vital role in the Phloem-based defense (PBD) and participate in many abiotic and biotic stress. However, research on PP2 proteins in cotton is still lacking.ResultsA total of 25, 23, 43, and 47 PP2 genes were comprehensively identified and characterized in G.arboretum, G.raimondii, G.barbadense, and G.hirsutum. The whole genome duplication (WGD) and allopolyploidization events play essential roles in the expansion of PP2 genes. The promoter regions of GhPP2 genes contain many cis-acting elements related to abiotic stress and the weighted gene co-expression network analysis (WGCNA) analysis displayed that GhPP2s could be related to salt stress. The qRT-PCR assays further confirmed that GhPP2-33 could be dramatically upregulated during the salt treatment. And the virus-induced gene silencing (VIGS) experiment proved that the silencing of GhPP2-33 could decrease salt tolerance.ConclusionsThe results in this study not only offer new perspectives for understanding the evolution of PP2 genes in cotton but also further explore their function under salt stress.

Automated summary

In this study, PP2 genes in cotton were comprehensively identified and characterized. It was found that GhPP2-33 was significantly upregulated under salt stress and silencing it decreased salt tolerance in cotton. These results provide new insights into the evolution of PP2 genes in cotton and their function under salt stress.