Cold temperatures negatively impact crop yield and quality, posing significant limitations to the advancement of the vegetable industry. MYB transcription factors are pivotal in enhancing plant resilience against various abiotic stresses, including low-temperature stress. Pepper (Capsicum annuum L.) is a nutrient-rich vegetable crop sensitive to low temperatures. This study aimed to determine the function of CaMYB80 in the cold stress response of pepper through virus-induced silencing. The study also conducted heterologous expression of CaMYB80 in Arabidopsis and tomato plants. The results showed that CaMYB80 could respond to low-temperature stress in pepper. CaMYB80 was localized in the nucleus and cytoplasm and exhibited transcriptional activation ability. Moreover, CaMYB80 silencing decreased cold tolerance in pepper, while its heterologous overexpression increased cold tolerance in Arabidopsis and tomato. Further analysis showed that CaMYB80 interacted with CaPOA1 (peroxidase N1-like). Similarly, the expression of CaPOA1 also responded to low-temperature stress. Overexpression of CaPOA1 enhanced freezing tolerance in Arabidopsis, while its silencing reduced cold stress tolerance in pepper. Furthermore, overexpression of CaMYB80 in Arabidopsis and tomato could increase the activity of peroxidases and the expression levels of genes in the ICE-CBF-COR (inducer of CBF expression, C-repeat binding factor, cold-responsive) regulatory network. In conclusion, our research results indicate that CaMYB80 enhances pepper cold tolerance by interacting with CaPOA1 to increase peroxidase activity and influence the expression of ICE-CBF-COR related genes.

中文翻译：

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CaMYB80 通过直接靶向 CaPOA1 增强辣椒的耐寒性


寒冷的温度会对作物产量和质量产生负面影响，对蔬菜工业的发展构成重大限制。MYB 转录因子在增强植物对各种非生物胁迫（包括低温胁迫）的恢复力方面发挥着关键作用。辣椒 （Capsicum annuum L.） 是一种营养丰富的蔬菜作物，对低温敏感。本研究旨在通过病毒诱导的沉默确定 CaMYB80 在辣椒寒冷应激反应中的功能。该研究还在拟南芥和番茄植株中进行了 CaMYB80 的异源表达。结果表明，CaMYB80 能响应辣椒的低温胁迫。CaMYB80 定位于细胞核和细胞质中，并表现出转录激活能力。此外，CaMYB80 沉默降低了辣椒的耐寒性，而其异源过表达提高了拟南芥和番茄的耐寒性。进一步分析表明，CaMYB80 与 CaPOA1 （过氧化物酶 N1 样）相互作用。同样，CaPOA1 的表达也对低温胁迫有反应。CaPOA1 的过表达增强了拟南芥的耐冻性，而其沉默降低了辣椒的耐寒性。此外，在拟南芥和番茄中过表达 CaMYB80 可以增加过氧化物酶的活性和 ICE-CBF-COR （CBF 表达诱导剂，C 重复结合因子，冷响应性） 调控网络中基因的表达水平。总之，我们的研究结果表明，CaMYB80 通过与 CaPOA1 相互作用来提高过氧化物酶活性并影响 ICE-CBF-COR 相关基因的表达，从而增强辣椒的耐寒性。