Li Rui, Li Jian, Sun Minghao, Qin Yang, Peng Yunling, Wang Yiru, Zheng Jun
State Key Laboratory of Arid Land Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China.
State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Plant Sci. 2025 Nov;360:112699. doi: 10.1016/j.plantsci.2025.112699. Epub 2025 Aug 6.
Drought stress is an important abiotic stress affecting maize (Zea mays L.) growth and productivity. Class III peroxidases (PODs) are plant-specific enzymes that play crucial roles in plant growth, development, and responses to abiotic stress. However, only a few studies have been conducted on the responses of PODs to drought stress in maize. In the present study, we identified a maize POD gene, ZmPOD5, whose expression was prominently upregulated by drought stress. ZmPOD5 overexpression lines showed enhanced drought tolerance, as evidenced by the improved survival rates and increased relative water content (RWC), alleviating water loss rate, malondialdehyde (MDA) content, relative electrical conductivity (REC), O• content, and reactive oxygen species (ROS) accumulation, whereas enhancing the activities of ROS-scavenging/antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD). In contrast, ZmPOD5-KO and ems3-06a97c mutants displayed opposite phenotypic and physiological responses under drought stress. Transcriptome sequencing analysis further revealed that drought stress substantially altered the expression patterns of genes involved in the stimulus response and oxidation-reduction processes in ZmPOD5-OE lines and ZmPOD5-KO mutants. These results demonstrated that ZmPOD5 functions as a positive regulator of maize response to drought stress. This study will provide new insights into the role of PODs in regulating drought tolerance in maize.
干旱胁迫是影响玉米（Zea mays L.）生长和生产力的重要非生物胁迫。Ⅲ类过氧化物酶（PODs）是植物特有的酶，在植物生长、发育及对非生物胁迫的响应中发挥关键作用。然而，关于玉米中PODs对干旱胁迫响应的研究较少。在本研究中，我们鉴定了一个玉米POD基因ZmPOD5，其表达在干旱胁迫下显著上调。ZmPOD5过表达株系表现出增强的耐旱性，存活率提高、相对含水量（RWC）增加、水分流失率减轻、丙二醛（MDA）含量、相对电导率（REC）、O•含量和活性氧（ROS）积累减少，同时超氧化物歧化酶（SOD）和过氧化物酶（POD）等ROS清除/抗氧化酶的活性增强，均证明了这一点。相反，ZmPOD5-KO和ems3-06a97c突变体在干旱胁迫下表现出相反的表型和生理反应。转录组测序分析进一步表明，干旱胁迫显著改变了ZmPOD5-OE株系和ZmPOD5-KO突变体中参与刺激响应和氧化还原过程的基因表达模式。这些结果表明ZmPOD5作为玉米干旱胁迫响应的正调控因子发挥作用。本研究将为PODs在调节玉米耐旱性中的作用提供新的见解。
