过表达AtchyB基因提高洋桔梗光胁迫耐受性的研究

类胡萝卜素尤其是叶黄素循环类物质在植物抵抗由强光照引起的非生物胁迫中发挥着重要的作用,为了提高洋桔梗对强光照的抗性,从拟南芥中克隆了类胡萝卜素生物合成途径中参与叶黄素循环关键酶——β-胡萝卜素羟化酶基因(AtchyB),利用农杆菌介导法将其转入洋桔梗中,最终得到遗传转化植株2个株系,研究发现,转基因植株中总类胡萝卜素含量高于对照组,且叶黄素循环池被不同程度地放大。在不同光照强度下,转基因洋桔梗植株对光照耐受性明显强于对照组,且转基因植株生物量也明显提高。表明过表达AtchyB基因使洋桔梗光胁迫耐受性有所增强。

Research on Overexpression of AtchyB in Eustoma grandiflorum Shinn

Carotenoids are essential components of the photosynthetic apparatus taking part in plant photoprotection.Plants can remove the excess light through xanthophyll cycle which transforms the excess light energy to electronic energy.To enhance its tolerance to high-light stress,we have increased the capacity for their biosynthesis in Eustoma grandiflorum Shinn by overexpression of β-carotene hydroxylase gene(AtchyB) from Arabidopsis thaliana encoding β-carotene hydroxylase(BCH).This enzyme is involved in the conversion of β-carotene into zeaxanthin and plays an important role in the pathway of carotenoid biosynthesis.The transformation system of E.grandiflorum S was optimized.Not only the total carotenoid content of the transgenics was enhanced but also a greater amount of Xanthophyll cycle pigments in the transgenics was also detected.Under high-light stress,untransformed controls showed obvious growth retardation,while transformants were more tolerant.The net addition on biomass of the transformants was more than that of the non-transformants under high-light exposure.