Department of Molecular Biotechnology, Konkuk University, Seoul, Korea Republic.
Biotechnol Lett. 2011 Nov;33(11):2297-307. doi: 10.1007/s10529-011-0684-7. Epub 2011 Jul 13.
Salt-tolerance was studied in transgenic potato. It was conferred by overexpression of ascorbate pathway enzyme (D-galacturonic acid reductase, GalUR). As genetic engineering of the GalUR gene in potato enhances its ascorbic acid content (L-AsA), and subsequently plants suffered minimal oxidative stress-induced damage, we now report on the comprehensive aptness of this engineering approach for enhanced salt tolerance in transgenic potato (Solanum tuberosum L. cv. Taedong Valley). Potatoes overexpressing GalUR grew and tuberized in continuous presence of 200 mM of NaCl. The transgenic plants maintained a higher reduced to oxidized glutathione (GSH:GSSG) ratio together with enhanced activity of glutathione dependent antioxidative and glyoxalase enzymes under salinity stress. The transgenics resisted an increase in methylglyoxal that increased radically in untransformed control plants under salinity stress. This is the first report of genetic engineering of ascorbate pathway gene in maintaining higher level of GSH homeostasis along with higher glyoxalase activity inhibiting the accumulation in methylglyoxal (a potent cytotoxic compound) under salt stress. These results suggested the engineering of ascorbate pathway enzymes as a major step towards developing salinity tolerant crop plants.
对转基因马铃薯进行了耐盐性研究。这是通过过表达抗坏血酸途径酶（D-半乳糖酸还原酶，GalUR）实现的。由于在马铃薯中对 GalUR 基因进行遗传工程改造会提高其抗坏血酸含量（L-抗坏血酸），从而使植物受到最小的氧化应激诱导损伤，因此我们现在报告了这种工程方法在增强转基因马铃薯（Solanum tuberosum L. cv. Taedong Valley）耐盐性方面的综合适应性。过表达 GalUR 的马铃薯在持续存在 200mM NaCl 的情况下生长和结薯。在盐胁迫下，转基因植物保持较高的还原型与氧化型谷胱甘肽（GSH：GSSG）比值，以及增强的谷胱甘肽依赖性抗氧化和醛糖还原酶活性。与盐胁迫下未转化对照植物中甲基乙二醛（一种潜在的细胞毒性化合物）大量增加相比，转基因植物抵抗甲基乙二醛的增加。这是首次报道通过遗传工程改造抗坏血酸途径基因，在盐胁迫下维持较高的 GSH 动态平衡水平和较高的醛糖还原酶活性，从而抑制甲基乙二醛的积累。这些结果表明，工程改造抗坏血酸途径酶是开发耐盐作物的重要步骤。
