| 杨甲辰,孔凡英.转反义SlMDAR番茄植株对干旱胁迫的响应[J].干旱地区农业研究,2026,(3):37~45 |
| 转反义SlMDAR番茄植株对干旱胁迫的响应 |
| Response of antisense SlMDAR transgenic tomato to drought stress |
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| DOI：10.7606/j.issn.1000-7601.2026.03.04 |
| 中文关键词: 番茄 SlMDAR基因 干旱胁迫 抗坏血酸再生 活性氧稳态 光合作用 |
| 英文关键词:tomato SlMDAR gene drought stress ascorbic acid regeneration reactive oxygen species homeostasis photosynthesis |
| 基金项目:国家自然科学基金项目（32372198）；山东省自然科学基金项目（ZR2022MC019） |
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| 中文摘要: |
| 单脱氢抗坏血酸还原酶（MDAR）是番茄叶绿体中抗坏血酸（AsA）再生的关键酶。以野生型（WT）和转反义SlMDAR番茄株系为材料，通过分子鉴定及干旱胁迫下表型与生理分析，系统探究SlMDAR在番茄抗旱性中的功能机制。结果表明：SlMDAR已成功整合至番茄基因组，其转录与翻译水平被有效抑制超过50%。25% PEG处理可诱导SlMDAR表达，表明该基因参与干旱胁迫响应。在干旱条件下，反义株系萎蔫与生长抑制更为严重，相对含水量仅为野生型的85%~94%，其MDAR活性较野生型下降35.0%~40.6%，AsA含量降低54.4%~67.4%，导致活性氧积累增加50.0%~62.0%，细胞膜受损程度上升50%以上。干旱处理后植株光合能力普遍下降，但转基因植株净光合速率和PSⅡ光抑制程度的变化率均为野生型的1.3倍。综上，SlMDAR通过调控AsA再生系统维持活性氧稳态并保护光合机构，从而正向调节番茄的干旱耐受性。 |
| 英文摘要: |
| Monodehydroascorbate reductase (MDAR) is a key enzyme for ascorbic acid (AsA) regeneration in tomato chloroplasts. In this study, wild\|type (WT) tomatoes and tomato lines transformed with antisense SlMDAR were used as materials. Through molecular identification and analysis of phenotypes and physiology under drought stress, the functional mechanism of SlMDAR in tomato drought resistance was systematically explored. The results showed that SlMDAR had been successfully integrated into the tomato genome, and its transcriptional and translational levels were effectively inhibited by more than 50%. Treatment with 25% polyethylene glycol (PEG) could induce the expression of SlMDAR, indicating that this gene is involved in the response to drought stress. Under drought conditions, the antisense lines exhibited more severe wilting and growth inhibition, with their relative water content being only 85%-94% of that of the wild type. Compared with the wild type, the MDAR enzyme activity of the antisense lines decreased by 35.0%-40.6%, and the AsA content decreased by 54.4%-67.4%. These changes led to a 50.0%-62.0% increase in reactive oxygen species (ROS) accumulation and a more than 50% increase in the degree of cell membrane damage in the antisense lines. After drought treatment, the photosynthetic capacity of all tested plants generally decreased. However, the rates of change in net photosynthetic rate and the degree of Photosystem Ⅱ (PSⅡ) photoinhibition of the transgenic plants were both 1.3 times those of the wild type. In conclusion, SlMDAR positively regulates tomato drought tolerance by regulating the AsA regeneration system, maintaining ROS homeostasis, and protecting photosynthetic machinery. |
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