Bashir Sabeeha, Bhat Showkat Ahmad, Rather Rayees Ahmad, Wani Umer Majeed, Raja Vaseem, John Riffat
Plant Molecular Biology Lab, Department of Botany, University of Kashmir, Srinagar, Kashmir, India.
Int J Phytoremediation. 2025 Jul 13:1-16. doi: 10.1080/15226514.2025.2527324.
With advancement in functional genomics, it is now possible to engineer plants for heavy metal tolerance by altering the expression of proteins and genes involved in heavy metal stress resistance. The present study was carried out to evaluate the tomato transgenic plants overexpressing the genes associated with ascorbate-glutathione (AsA-GSH) pathway, namely, (ascorbate peroxidase), (mono-dehydroascorbate reductase), (dehydroascorbate reductase), (glutathione reductase), and (superoxide dismutase) for the response to chromium stress (Cr). Transgenic tomato plants with altered antioxidant pathway had higher levels of carotenoids (41.64%) and anthocyanins (34.60%) besides improved photosynthetic rate, transpiration, and stomatal conductance compared to untransformed wild type (WT) when supplied with potassium dichromate (KCrO) at a concentration of 100 µM. Moreover, transgenic tomato showed increased osmolytes and phenolic concentrations with a simultaneous reduction in electrolyte leakage, malondialdehyde (MDA) and reactive oxygen species (ROS). Transcript analysis indicated higher expression of all the transgenes, whereas scanning electron microscopy (SEM) revealed lesser deformities in transgenic plants in response to Cr stress. Transgenic lines accumulated higher Cr in leaves (68%) and roots (56.89%) compared to the WT under Cr stress. We conclude that overexpressing the AsA-GSH pathway in tomato makes them suitable for use as phytoremediator.
随着功能基因组学的发展，现在可以通过改变参与重金属胁迫抗性的蛋白质和基因的表达来培育耐重金属的植物。本研究旨在评估过表达与抗坏血酸 - 谷胱甘肽（AsA - GSH）途径相关基因的番茄转基因植物对铬胁迫（Cr）的响应，这些基因包括抗坏血酸过氧化物酶（APX）、单脱氢抗坏血酸还原酶（MDHAR）、脱氢抗坏血酸还原酶（DHAR）、谷胱甘肽还原酶（GR）和超氧化物歧化酶（SOD）。当以100 µM的重铬酸钾（K₂Cr₂O₇）处理时，与未转化的野生型（WT）相比，具有改变的抗氧化途径的转基因番茄植物除了光合速率、蒸腾作用和气孔导度得到改善外，还具有更高水平的类胡萝卜素（41.64%）和花青素（34.60%）。此外，转基因番茄显示渗透调节物质和酚类物质浓度增加，同时电解质渗漏、丙二醛（MDA）和活性氧（ROS）减少。转录分析表明所有转基因均有更高的表达，而扫描电子显微镜（SEM）显示转基因植物在响应Cr胁迫时畸形较少。在Cr胁迫下，转基因株系在叶片（68%）和根（56.89%）中积累的Cr比WT更高。我们得出结论，在番茄中过表达AsA - GSH途径使其适合用作植物修复剂。
