Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China.
Plant Cell Physiol. 2011 May;52(5):909-21. doi: 10.1093/pcp/pcr043. Epub 2011 Apr 6.
Inhibition of lycopene cyclization decreased the salt tolerance of the euhalophyte Salicornia europaea L. We isolated a β-lycopene cyclase gene SeLCY from S. europaea and transformed it into Arabidopsis with stable expression. Transgenic Arabidopsis on post-germination exhibited enhanced tolerance to oxidative and salt stress. After 8 and 21 d recovery from 200 mM NaCl treatment, transgenic lines had a higher survival ratio than wild-type (WT) plants. Three-week-old transgenic plants treated with 200 mM NaCl showed better growth than the WT with higher photosystem activity and less H(2)O(2) accumulation. Determination of endogenous pigments of Arabidopsis treated with 200 mM NaCl for 0, 2 or 4 d demonstrated that the transgenic plants retained higher contents of carotenoids than the WT. Furthermore, to compare the difference between SeLCY and AtLCY from Arabidopsis, we used viral vector mediating ectopic expression of SeLCY and AtLCY in Nicotiana benthamiana. Although LCY genes transformation increased the salt tolerance in tobacco, there is no significant difference between SeLCY- and AtLCY-transformed plants. These findings indicate that SeLCY transgenic Arabidopsis improved salt tolerance by increasing synthesis of carotenoids, which impairs reactive oxygen species and protects the photosynthesis system under salt stress, and as a single gene, SeLCY functionally showed no advantage for salt tolerance improvement compared with AtLCY.
抑制番茄红素环化降低了盐生植物盐角草的耐盐性。我们从盐角草中分离出β-番茄红素环化酶基因 SeLCY，并将其转化为具有稳定表达的拟南芥。萌发后的转基因拟南芥表现出对氧化和盐胁迫的增强耐受性。经过 200mM NaCl 处理 8 和 21 天后，转基因系的存活率高于野生型（WT）植物。用 200mM NaCl 处理 3 周大的转基因植物比 WT 植物生长更好，具有更高的光系统活性和更少的 H2O2 积累。用 200mM NaCl 处理 0、2 或 4d 的拟南芥内源色素测定表明，转基因植物比 WT 植物保留了更高含量的类胡萝卜素。此外，为了比较盐角草 SeLCY 和拟南芥 AtLCY 之间的差异，我们使用病毒载体介导的盐角草 SeLCY 和拟南芥 AtLCY 在本氏烟中的异位表达。尽管 LCY 基因转化增加了烟草的耐盐性，但 SeLCY 和 AtLCY 转化植物之间没有显著差异。这些发现表明，转基因拟南芥通过增加类胡萝卜素的合成来提高耐盐性，从而在盐胁迫下破坏活性氧物质并保护光合作用系统，并且作为单个基因，SeLCY 在提高耐盐性方面与 AtLCY 相比没有功能优势。
