Zhang Hao, Wang Qiyue, Zhou Teng, Qiu Xiaoqian, Ma Chenhui, Zhang Jihong, Sahito Javed Hussain, Liu Yang, Zhao Jiawen, Li Juan, Guo Xiao, Guo Geming, Wan Keying, Zhang Xuehai, Tang Jihua, Ding Dong
State Key Laboratory of High-Efficiency Production of Wheat-Maize Double Cropping, College of Agronomy, Henan Agricultural University, Zhengzhou, China.
Maize Research Department, Hebi Academy of Agricultural Sciences, Hebi, Henan, China.
Physiol Plant. 2025 Sep-Oct;177(5):e70478. doi: 10.1111/ppl.70478.
Temperature fluctuations critically affect plant growth, but the molecular mechanisms that underlie heat-stress tolerance in maize (Zea mays L.) remain to be fully characterized. Here, we examined the role of the MYB transcription factor ZmMYB104 in thermotolerance regulation and identified its downstream target genes. Through molecular cloning and expression analysis, we demonstrated that ZmMYB104 transcription is induced by heat in maize seedlings. Subcellular localization assays confirmed its presence in the nucleus, and transactivation assays demonstrated its ability to activate transcription. Overexpression lines exhibited greater heat-stress resistance than wild-type. Integration of RNA sequencing and DNA affinity purification sequencing (DAP-seq) revealed that the catalase gene ZmCAT2 was a direct target of ZmMYB104. Electrophoretic mobility shift assays confirmed that ZmMYB104 bound to the ZmCAT2 promoter, and dual-luciferase reporter assays quantified its ability to activate ZmCAT2 transcription. Overexpression ZmMYB104-mediated upregulation of ZmCAT2 significantly increased hydrogen peroxide (HO) scavenging capacity under heat stress, effectively reducing reactive oxygen species accumulation and oxidative damage. These findings demonstrate that ZmMYB104 confers thermotolerance through direct transcriptional activation of the catalase gene ZmCAT2, which encodes a key enzyme in ROS detoxification. Our data provide the first evidence for a ZmMYB104-ZmCAT2 regulatory module that functions in plant heat-stress responses, advancing our understanding of the transcriptional networks that govern thermotolerance in cereal crops. The ZmMYB104-ZmCAT2 axis represents a promising genetic target for the development of climate-resilient maize varieties through molecular breeding strategies.
温度波动对植物生长有至关重要的影响，但玉米（Zea mays L.）耐热性的分子机制仍有待充分阐明。在此，我们研究了MYB转录因子ZmMYB104在耐热性调控中的作用，并鉴定了其下游靶基因。通过分子克隆和表达分析，我们证明了ZmMYB104转录在玉米幼苗中受热诱导。亚细胞定位分析证实其存在于细胞核中，反式激活分析证明了其激活转录的能力。过表达株系表现出比野生型更强的耐热性。RNA测序和DNA亲和纯化测序（DAP-seq）的整合表明，过氧化氢酶基因ZmCAT2是ZmMYB104的直接靶标。电泳迁移率变动分析证实ZmMYB104与ZmCAT2启动子结合，双荧光素酶报告基因分析定量了其激活ZmCAT2转录的能力。过表达ZmMYB104介导的ZmCAT2上调在热胁迫下显著提高了过氧化氢（H₂O₂）清除能力，有效减少了活性氧积累和氧化损伤。这些发现表明，ZmMYB104通过直接转录激活过氧化氢酶基因ZmCAT2赋予耐热性，ZmCAT2编码ROS解毒中的关键酶。我们的数据为ZmMYB104-ZmCAT2调控模块在植物热胁迫反应中的作用提供了首个证据，推进了我们对控制谷类作物耐热性转录网络的理解。ZmMYB104-ZmCAT2轴代表了通过分子育种策略培育气候适应型玉米品种的一个有前景的遗传靶点。
