Key Laboratory of Molecular Biology and Gene Engineering of Jiangxi Province, College of Life Science, Nanchang University, Nanchang, China.
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture of People's Republic of China, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China.
Gene. 2019 Feb 5;684:124-130. doi: 10.1016/j.gene.2018.10.064. Epub 2018 Oct 25.
High temperature (HT) stress is a major environmental stress that limits agricultural production worldwide. Discovery and application of genes promoting high temperature tolerance is essential to enhance crop tolerance to heat stress. Proteins associated with chaperone and protein folding plays an important role in the high temperature stress response of plants. MTH1745 (MtPDI), a disulfide isomerase-like protein (PDI) with a chaperone function and disulfide isomerase activity from Methanothermobacter thermautotrophicus delta H, was selected for studying the heat stress tolerance using an ectopic expression method in rice. Through molecular identification via quantitative real-time PCR and western blot, we demonstrated that the MtPDI gene was expressed stably in transgenic rice. Heat stress tolerance and survival ratio were significantly improved in seedling transgenic rice. At the same time, proline content, superoxide dismutase (SOD) and peroxidase (POD) activities were increased in MtPDI transgenic rice with a reduced malondialdehyde (MDA) content. Moreover, increased content of thiols group was discovered in transgenic plants. These results indicate that heterologous expression of MtPDI from extremophiles could confer heat stress tolerance of transgenic rice through the accumulation of proline content, the synergistic increase of the antioxidant enzymes activity and elevated production of more thiols group, which finally ameliorated the oxidative damage.
高温（HT）胁迫是限制全球农业生产的主要环境胁迫之一。发现和应用促进高温耐受性的基因对于提高作物对热胁迫的耐受性至关重要。与伴侣蛋白和蛋白质折叠相关的蛋白质在植物的高温胁迫反应中起着重要作用。MTH1745（MtPDI）是一种来自产甲烷菌（Methanothermobacter thermautotrophicus delta H）的二硫键异构酶样蛋白（PDI），具有伴侣蛋白功能和二硫键异构酶活性，被选为通过异位表达方法在水稻中研究耐热性的候选基因。通过定量实时 PCR 和 Western blot 进行分子鉴定，我们证明 MtPDI 基因在转基因水稻中稳定表达。幼苗期转基因水稻的耐热性和存活率显著提高。同时，在 MtPDI 转基因水稻中，脯氨酸含量、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性增加，丙二醛（MDA）含量降低。此外，还发现转基因植物中巯基含量增加。这些结果表明，来自极端微生物的异源表达 MtPDI 可以通过脯氨酸含量的积累、抗氧化酶活性的协同增加和更多巯基的产生来赋予转基因水稻耐热性，从而最终减轻氧化损伤。
