Over-expression of strawberry D-galacturonic acid reductase in potato leads to accumulation of vitamin C with enhanced abiotic stress tolerance
Over-expression of strawberry D-galacturonic acid reductase in potato leads to accumulation of vitamin C with enhanced abiotic stress tolerance
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DOI：
10.1016/j.plantsci.2009.08.004
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发表时间：
2009-12-01
期刊：
影响因子：
5.2
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
维生素C（抗坏血酸）是胶原蛋白生物合成以及人类心血管系统正常运作的必需成分。与大多数动物不同，由于编码抗坏血酸生物合成最后一种酶的基因发生突变，人类自身缺乏合成抗坏血酸的能力。因此，维生素C必须从植物等膳食来源中获取。在这项研究中，我们培育出了在花椰菜 mosaic病毒35S启动子控制下过表达草莓GalUR基因的转基因马铃薯植株（Solanum tuberosum L. cv. Taedong Valley），其抗坏血酸水平有所提高。通过聚合酶链反应（PCR）和Southern杂交证实了GalUR基因在植物基因组中的整合。采用高效液相色谱法（HPLC）测定了转基因块茎中的抗坏血酸（AsA）水平。GalUR的过表达使转基因马铃薯中的AsA增加了1.6 - 2倍，并且AsA水平与GalUR活性的提高呈正相关。与未转化的对照植株相比，维生素C含量提高的转基因株系对甲基紫精（MV）、氯化钠或甘露醇诱导的非生物胁迫表现出更强的耐受性。叶片圆盘衰老试验表明，与未转化的对照植株相比，转基因株系通过保留更高的叶绿素而表现出更好的耐受性。本研究表明，GalUR基因的过表达提高了马铃薯块茎中AsA的水平，并且与未转化的对照相比，这些转基因植株在不同的非生物胁迫下表现更好。（C）2009 Elsevier Ireland Ltd保留所有权利
Vitamin C (ascorbic acid) is an essential component for collagen biosynthesis and also for the proper functioning of the cardiovascular system in humans. Unlike most of the animals, humans lack the ability to synthesize ascorbic acid on their own due to a mutation in the gene encoding the last enzyme of ascorbate biosynthesis. As a result, vitamin C must be obtained from dietary sources like plants. In this Study, we have developed transgenic potato plants (Solanum tuberosum L. cv. Taedong Valley) over-expressing strawberry GalUR gene under the control of CaMV 35S promoter with increased ascorbic acid levels. Integration of the GalUR gene in the plant genome was confirmed by PCR and Southern blotting. Ascorbic acid (AsA) levels in transgenic tubers were determined by high-performance liquid chromatography (HPLC). The over-expression of GalUR resulted in 1.6-2-fold increase ill AsA in transgenic potato and the levels of AsA were positively correlated with increased GalUR activity. The transgenic lines with enhanced vitamin C content showed enhanced tolerance to abiotic stresses induced by methyl viologen (MV), NaCl or mannitol as compared to untransformed control plants. The leaf disc senescence assay showed better tolerance in transgenic lines by retaining higher chlorophyll as compared to the untransformed control plants. Present study demonstrated that the over-expression of GalUR gene enhanced the level of AsA in potato tubers and these transgenics performed better under different abiotic stresses as compared to untransformed control. (C) 2009 Elsevier Ireland Ltd All rights reserved