期刊
JOURNAL OF PLANT BIOLOGY
卷 51, 期 1, 页码 35-41出版社
BOTANICAL SOC KOREA
DOI: 10.1007/BF03030738
关键词
ascorbic acid; CaMV35S promoter; dehydroascorbate (DHA); dehydroascorbate reductase (DHAR); Patatin promoter; sesame hairy root; transgenic potato
In plants, ascorbic acid (AsA) is a strong antioxidant or reductant that can be converted to dehydroascorbate (DHA) by oxidation. DHA, a very short-lived chemical, can either be hydrolyzed irreversibly to 2,3-diketogulonic acid or recycled to AsA by dehydroascorbate reductase (DHAR). DHAR cDNA, isolated from sesame hairy roots, was inserted into two plant expression vector systems with the CaMV35S promoter (CaMV35S::DHAR) and a potato tuber-specific promoter, Patatin (Patatin::DHAR). Southern and northern blot hybridization analyses indicated that DHAR cDNA was successfully integrated into the potato genome and actively transcribed. High levels of sesame DHAR transcript and DHAR enzyme activity were determined, by the Patatin promoter, in regenerated potato tubers, but their levels in leaves were very low. In contrast, much higher amounts of transcript were accumulated in the leaves of CaMV35S::DHAR regenerants than in the tubers while the activity of DHAR enzyme was higher in the latter. AsA content in the tubers of Patatin::DHAR transgenic lines was also increased (1.1- to 1.3-fold) compared with that of non-transgenic plants. However, this was not true for the transgenic leaves. in contrast, the CaMV35S promoter was associated with AsA accumulations in both the tubers (up to 1.6-fold) and the leaves (up to 1.5-fold). However, more detailed analyses indicated that this increased enzyme activity was not always accompanied by an elevation in AsA content from transgenic plants. This suggests that other factors may limit the accumulation of vitamin C via ascorbate-recycling in transgenic potato plants.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据