Chen Xuejin, Zhou Ning, Yu Lisha, Han Zhaolan, Guo Yanjing, Ndombi Salome Njeri, Zhang Huan, Jiang Jie, Duan Yu, Zou Zhongwei, Ma Yuanchun, Zhu Xujun, Chen Shiguo, Fang Wanping
Tea Science Research Institute, Weed Research Laboratory, Binjiang Campus, Nanjing Agricultural University, No. 555, Binjiang Avenue, Pukou District, Nanjing, Jiangsu Province, China.
Department of Biology, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON N2L 3C5, Canada.
Hortic Res. 2025 Mar 5;12(6):uhaf073. doi: 10.1093/hr/uhaf073. eCollection 2025 Jun.
Plant resistance inducers represent an alternative strategy that mitigate stress-induced damage in plants. Previously, 2-amino-3-methylhexanoic acid (AMHA), a novel natural plant resistance inducer, was shown to significantly bolster cold tolerance, thermotolerance, and pathogen resistance in plants. However, the intricate mechanisms underlying AMHA's response to cold stress remain elusive. Thus, we investigated the physiological and transcriptomic analyses of AMHA pretreatment on tea plant to determine its substantial role of AMHA under cold stress. The results showed that pretreatment with 100 nM AMHA effectively mitigated the detrimental effects of cold stress on photosynthesis and growth. Furthermore, differentially expressed genes were identified through RNA-seq during pretreatment, cold stress, and 2 days of recovery. These genes were mainly enriched in pathways related to flavonoid/anthocyanin, carotenoid, and ascorbic acid-glutathione (AsA-GSH) cycle, including (encoding glutathione S-transferase). Potential regulatory relationships between the identified genes and transcription factors were also established. Antisense oligodeoxynucleotide-silencing and overexpression experiments revealed that enhances cold resistance by maintaining redox homeostasis. In conclusion, our study suggests that antioxidant-related signaling molecules play a critical role in the signaling cascades and transcriptional regulation mediating AMHA-induced cold-stress resistance in tea plant.
植物抗性诱导剂是一种减轻植物应激损伤的替代策略。此前，一种新型天然植物抗性诱导剂2-氨基-3-甲基己酸（AMHA）已被证明能显著增强植物的耐寒性、耐热性和抗病性。然而，AMHA对冷胁迫响应的复杂机制仍不清楚。因此，我们对茶树进行了AMHA预处理的生理和转录组分析，以确定AMHA在冷胁迫下的重要作用。结果表明，100 nM AMHA预处理有效减轻了冷胁迫对光合作用和生长的不利影响。此外，通过RNA测序在预处理、冷胁迫和恢复2天期间鉴定了差异表达基因。这些基因主要富集在与类黄酮/花青素、类胡萝卜素和抗坏血酸-谷胱甘肽（AsA-GSH）循环相关的途径中，包括（编码谷胱甘肽S-转移酶）。还建立了已鉴定基因与转录因子之间的潜在调控关系。反义寡脱氧核苷酸沉默和过表达实验表明，通过维持氧化还原稳态增强了抗寒性。总之，我们的研究表明，抗氧化相关信号分子在介导茶树AMHA诱导的抗冷胁迫信号级联和转录调控中起关键作用。
