Biochemical analysis of enhanced tolerance in transgenic potato plants overexpressing D-galacturonic acid reductase gene in response to various abiotic stresses
Biochemical analysis of enhanced tolerance in transgenic potato plants overexpressing D-galacturonic acid reductase gene in response to various abiotic stresses
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DOI：
10.1007/s11032-010-9465-6
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发表时间：
2011-06-01
影响因子：
3.1
通讯作者：
Park, Se Won
中科院分区：
文献类型：
--
作者：
Hemavathi;Upadhyaya, Chandrama Prakash;Park, Se Won
植物中抗氧化酶系统的上调为抵御各种非生物胁迫提供了保护。为了了解植物在体外条件下对各种非生物胁迫的耐受机制，使用了过表达草莓D -半乳糖醛酸还原酶（GalUR）基因且抗坏血酸（AsA）积累增加的转基因马铃薯植株来研究涉及抗坏血酸 - 谷胱甘肽循环的抗氧化系统。经甲基紫精、氯化钠和氯化锌诱导遭受各种非生物胁迫的转基因马铃薯块茎，与未转化的块茎相比，其超氧化物歧化酶（SOD，EC 1.15.1.1）、过氧化氢酶（CAT，EC 1.1.1.1.6）以及抗坏血酸 - 谷胱甘肽循环中的酶，如抗坏血酸过氧化物酶（APX，EC 1.11.1.11）、脱氢抗坏血酸还原酶（DHAR，EC 1.8.5.1）和谷胱甘肽还原酶（GR，EC 1.8.1.7）的活性增强，并且抗坏血酸、谷胱甘肽（GSH）和脯氨酸的水平升高。酶活性的增加与受胁迫的转基因块茎中的mRNA转录水平相关。在受胁迫的转基因马铃薯块茎中还观察到抗坏血酸和谷胱甘肽的氧化还原状态存在显著差异，与未转化的块茎相比，其对非生物胁迫的耐受性增强。这项研究表明，抗坏血酸积累的增加可以上调抗氧化系统，从而使转基因块茎相较于未转化的块茎对各种非生物胁迫具有更强的耐受性。
Upregulation of the antioxidant enzyme system in plants provides protection against various abiotic stresses. Transgenic potato plants overexpressing the strawberry D-galacturonic acid reductase (GalUR) gene with enhanced accumulation of ascorbate (AsA) were used to study the antioxidant system involving the ascorbate-glutathione cycle in order to understand the tolerance mechanism in plants in response to various abiotic stresses under in vitro conditions. Transgenic potato tubers subjected to various abiotic stresses induced by methyl viologen, sodium chloride and zinc chloride showed enhanced activities of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.1.1.1.6) and enzymes of the ascorbate-glutathione cycle such as ascorbate peroxidase (APX, EC 1.11.1.11), dehydroascorbate reductase (DHAR, EC 1.8.5.1) and glutathione reductase (GR, EC 1.8.1.7), as well as increased levels of ascorbate, glutathione (GSH) and proline when compared to untransformed tubers. The increased enzyme activities correlated with the mRNA transcript levels in the stressed transgenic tubers. Significant differences in redox status of AsA and GSH were also observed in stressed transgenic potato tubers that showed increased tolerance to abiotic stresses compared to untransformed tubers. This study suggests that the increased accumulation of AsA could upregulate the antioxidant system which imparts improved tolerance against various abiotic stresses in transgenic tubers compared to untransformed tubers.