CaCP15 Gene Negatively Regulates Salt and Osmotic Stress Responses in Capsicum annuum L

Salt and osmotic stress seriously restrict the growth, development, productivity of horticultural crops in greenhouse. The papain-like cysteine proteases (PLCPs) participate multi-stress responses plants. We previously demonstrated that salt affect protease 15 pepper (Capsicum annuum L.) (CaCP15); however, role CaCP15 is unknown. Here, function regulating resistance was explored. Pepper plants were subjected to abiotic (sodium chloride, mannitol, salicylic acid, ethrel, methyl jasmonate, etc.) biotic (Phytophthora capsici inoculation). silenced through virus-induced gene silencing (VIGS) transiently overexpressed full-length fragment 1568 bp, with an open reading frame 1032 encoding a 343 amino acid protein. senescence-associated 12 (SAG12) subfamily member containing two highly conserved domains, Inhibitor 129 Peptidase_C1. expression highest stems induced by infected Phytophthora inoculation. Furthermore, upregulated under stress, enhanced mannitol resistance. Conversely, transient overexpression increased sensitivity reducing antioxidant enzyme activities negatively stress-related genes. This study indicates regulates via ROS-scavenging.