Effect of tomato gmpase overexpression on tolerance of potato plants to temperature stress | 超表达番茄GDP-D-甘露糖焦磷酸化酶基因马铃薯对温度胁迫的响应

中国人. 目的研究番茄GDP-甘露糖焦磷酸化酶基因（GMPase）在马铃薯中的超表达对其抵御温度胁迫能力的影响。方法利用已经获得的超表达番茄GMPase的两个转基因马铃薯株系，用野生型马铃薯作对照，比较其在常温（25/20℃）、温度胁迫（10/5℃低温处理3 d，35/30℃高温处理3 d）及25/20℃恢复3 d后GMPase的相对表达量、抗坏血酸（AsA）含量及其相关生理指标的变化。结果在常温、温度胁迫与恢复阶段，与野生型植株相比，转基因马铃薯植株具有较高的GMPase相对表达量、GMPase活性、AsA和脱氢抗坏血酸（DHA）含量；高温和低温胁迫后，转基因马铃薯的脱氢抗坏血酸还原酶（DHAR）、单脱氢抗坏血酸还原酶（MDAHR）和抗坏血酸过氧化物酶（APX）活性均明显提高，丙二醛（MDA）和H2O2含量及细胞质膜透性均明显降低。结论番茄GMPase在马铃薯中的超表达可能有提高马铃薯植株抵御温度胁迫的能力。

英语. Objective The aim of the study was to clarify the function of the GDP-D-mannose pyrophosphorylase (GMPase) in the L-galactose pathway of ascorbic acid (AsA) synthesis in plants, and to make sure the relation of GMPase overexpression with ascorbic acid content and temperature-stress tolerance ability. Method Two transgenic potato strains of overexpressing tomato GMPase were obtained by agrobacterium-mediated transformation. The transgenic plants and wild-type plants were treated in temperature-stress conditions (10/5℃ as low-temperature stress, 35/30℃ as high-temperature stress) for 3 days then in the recover-condition (25/20℃) for 3 days. Real time RT-PCR was used to analyze the expression of GMPase gene. And ascorbic acid content and relative index to temperature stress were also determined. ResultCompared with wild-type plants, with the overexpression of GMPase gene in transgenic plants, the GMPase activity and contents of AsA and dehydroascorbate (DHA) in normal and temperature-stress conditions were increased as well as the activities of dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and ascorbate peroxidase (APX). Meanwhile, the malondialdehyde (MDA) and H2O2 contents and permeability were decreased in the transgenic plants. Conclusion The overexpression of GMPase may increase potato tolerance to temperature stress by increasing AsA level and lowering reactive oxygen species (ROS).