过表达和抑制表达2-Cys Prx基因烟草的生长、生理特性和叶片光合功能对模拟酸雨的响应

为揭示2-Cys Peroxiredoxins(2-Cys Prx)基因在烟草龙江911抗逆中的功能,以过表达2-Cys Prx基因烟草、抑制表达2-Cys Prx基因烟草和非转基因烟草幼苗为试材,研究了不同pH值的模拟酸雨对其生长指标、叶片生理生化特性和叶片光合生理的影响。结果表明:与对照相比,pH值4.0的模拟酸雨对3种基因型烟草的株高、叶面积、比叶重无明显影响,pH值2.5的模拟酸雨处理下,与对照相比,过表达2-Cys Prx基因烟草幼苗的株高无明显变化,抑制表达2-Cys Prx基因烟草和非转基因烟草幼苗的株高显著降低;随着模拟酸雨pH值降低,3种基因型烟草叶片的硝酸还原酶(NR)活性、可溶性蛋白含量、SOD和APX活性、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、实际光化学效率(ФPSⅡ)、光化学猝灭系数(qP)、光系统Ⅱ潜在光化学效率(Fv/Fo)和细胞膜稳定指数逐渐下降,非光化学猝灭系数(qN)和H_2O_2含量逐渐增加,但在相同pH值的模拟酸雨处理下,过表达2-Cys Prx基因烟草各项生理指标均优于抑制表达2-Cys Prx基因烟草和非转基因烟草幼苗。由此可知,增强2-Cys Prx基因在烟草中的表达可能提高烟草在模拟酸雨处理下的硝态氮利用能力,并在模拟酸雨处理造成APX活性下降时,清除叶绿体中的H_2O_2,使光合电子传递链保持稳定,增强烟草叶片的光合能力。

Responses of Growth and Physiological Features,Photosynthetic Function in Overexpression and Inhibition of Expression of Transgenic Tobacco Plants with 2-Cys Prx to the Simulated Acid Rain

The overexpression and inhibition of expression of transgenic tobacco plant with 2-Cys Prx (Longjiang 91 1 ),non transgenic tobacco were chosen to investigate the effects of simulated acid rain on their growth,physiological features and photosynthesis.The results showed that simulated acid rain at pH 4.0 had no sig-nificant effects on the plant height,leaf area and specific leaf weight,but at pH 2.5,the plant height of overexpres-sion and inhibition of expression of transgenic tobacco plant with 2-Cys Prx reduced significantly,With the pH value of the simulated acid rain decreased,chlorophyll content,nitrate reductase activity,soluble protein content,superox-ide dismutase and ascorbate peroxidase activity,net photosynthetic rate(Pn),stomatal conductance(Gs),transpira-tion rate(Tr),the actual photochemical efficiency of PSⅡ(ΦPSⅡ ),photochemical quenching coefficient(qP),po-tential photochemical efficiency of PSⅡ(Fv /Fo)and cell membrane stability index decreased,the non-photochemi-cal quenching(qN)and hydrogen peroxide content increased,but at the same pH value,these above-mentioned in-dexes of overexpression of transgenic tobacco plant with 2-Cys Prx were better than inhibition of expression of trans-genic tobacco plant with 2-Cys Prx and non transgenic tobacco plant.The results suggest that enhanced expression of 2-Cys Prx in tobacco plant can promote the capability of tobacco against acid rain,the capability of utilizing nitrate nitro-gen,and remove of excess H2 O2 while APX activity decreases,and enhance the photosynthetic capability of tobacco.