Comprehensive analysis of pepper (Capsicum annuum) RAV genes family and functional identification of CaRAV1 under chilling stress

Abstract

Background The RAV gene family in Capsicum annuum remains largely unexplored in response to chilling stress, despite its known significance in plant abiotic stress responses. Results In this study, we identified and characterized six members of the CaRAVs gene subfamily in pepper through genome-wide analysis. Subsequently, the CaRAVs subfamily was classified into four branches based on homology with Arabidopsis thaliana, each exhibiting relatively conserved domains within the branch. We discovered that light response elements accounted for the majority of CaRAVs, whereas low-temperature response elements were specific to the NGA gene subfamily. After pepper plants were subjected to chilling stress, qRT-PCR analysis revealed that CaRAV1, CaRAV2 and CaNGA1 were significantly induced in response to chilling stress, indicating that CaRAVs play a role in the response to chilling stress. Using virus-induced gene silencing (VIGS) vectors, we targeted key members of the CaRAVs gene family, resulting in plants with increased susceptibility to chilling damage and reduced antioxidant enzyme activity, particularly evident under repeated chilling stress. These findings suggest that CaRAV1 and CaNGA1 positively regulate the response to chilling stress. Conclusions Silencing targeting key members of the CaRAVs gene family, results in plants with increased susceptibility to chilling damage and reduced antioxidant enzyme activity in plants, particularly evident under repeated chilling stress. This present study provides valuable information for understanding the classification and putative functions of the RAV transcription factors in ppepper.