天山雪莲冷调节蛋白基因siCOR转化烟草植株的抗旱性分析

Drought-tolerance Analysis of Tobacco Plant Transformed with Sasussured involucrata siCOR Gene

冷调节蛋白(cold regulated proteins,CORPs)是植物在冷驯化下产生的特异性蛋白,与植物的抗寒性密切相关。然而,大量研究表明,绝大多数植物冷诱导基因同样会响应水分胁迫。采用半定量RT-PCR分析天山雪莲(Sasussured in-volucrata)冷调节蛋白基因siCOR的表达,结果表明siCOR是一个受干旱胁迫诱导表达的基因。为研究siCOR基因是否与抗旱性相关,以siCOR转基因烟草为研究材料,利用水分胁迫处理进行抗旱性分析。结果表明与野生型(wild-type,WT)相比,转siCOR植株叶片萎蔫较迟且程度较轻,复水后恢复快且较完全;其叶片相对含水量和PSII相对量子产率的降低幅度、相对电导率和丙二醛含量的升高幅度均低于野生型烟草植株。采用PEG6000模拟干旱胁迫,发现转siCOR植株T3代种子的萌发率较高,主根生长的受抑制程度较野生型轻。以上结果表明,siCOR基因在植物对干旱胁迫的响应中起重要作用。

Cold-regulated proteins（CORPs） are induced by cold and thus closely related with cold tolerance.Most cold-induced genes may respond to water stress.We used RT-PCR to confirm that cold-induced siCOR in Sasussured involucrata was also induced by water stress.To investigate the possible role of S.involucrata siCOR in drought toler-ance,we performed the drought-tolerance analysis using siCOR transgenic tobacco.Compared with untransformed wild-type（WT） plants,transgenic lines had greener leaves and more roots.Water stress experiments showed transgenic lines with delayed and slightly wilted leaves,but they recovered faster and more completely after rewatering as compared with WT plants.Transgenic lines also showed lower reduction of relative water content and relative quantum yield of PSII and smaller increase of relative conductivity and malondialdehyde content as compared with WT plants.Under drought stress simulated with PEG6000 treatment,transgenic T3 seeds showed higher germination rate and reduced inhibition of main root growth than WT.These results suggested that siCOR may play an important role in drought stress.