CsJAZ11 positively regulates tea plant resistance to Colletotrichum camelliae via transient silencing and overexpression.

Abstract

Key message: CsJAZ11 interacts with CsMYC2.2 in the nucleus and positively regulates disease resistance to Colletotrichum camelliae in tea plants. In the jasmonic acid signaling pathway, JASMONATE ZIM DOMAIN (JAZ) proteins act as repressors by inhibiting the activity of MYELOCYTOMATOSIS (MYC) transcription factors. However, the role of JAZ proteins in modulating tea plant resistance to Colletotrichum camelliae, a major causal pathogen of tea anthracnose, remains largely unexplored. In our previous study, yeast two-hybrid analysis revealed an interaction between CsJAZ11 and CsMYC2.2, a transcription factor that negatively regulates tea plant resistance to C. camelliae. In this study, bimolecular fluorescence complementation assays further confirmed that CsJAZ11 interacts with CsMYC2.2 in the nucleus. Co-immunoprecipitation assays also validated this interaction. To investigate the role of CsJAZ11 in regulating tea plant resistance to C. camelliae, transient silencing and overexpression of CsJAZ11 were performed in tea plant leaves. Notably, transient silencing of CsJAZ11 attenuates disease resistance to C. camelliae, while overexpression of CsJAZ11 enhanced disease resistance, suggesting that CsJAZ11 positively regulates tea plant resistance to C. camelliae. Surprisingly, qRT-PCR analysis showed that CsJAZ11 did not inhibit the expression of CsMYC2.2. In contrast, CsJAZ11 positively influenced the expression of CsRPM1, a MeJA-responsive CNL gene essential for disease resistance to C. camelliae in tea plants. Our findings indicate that CsJAZ11 positively regulates tea plant resistance to C. camelliae, potentially through the modulation of CsRPM1, an NBS-LRR-encoding gene. This study provides new insights into the role of JAZ proteins in regulating disease resistance in tea plants.