转大肠杆菌过氧化氢酶基因棉花的抗旱生理研究

以导入大肠杆菌过氧化氢酶基因KatE的T3代转基因棉花为供试材料,经卡那霉素检测和PCR鉴定,将筛选出的阳性转基因植株与对照棉花进行整个生育期的持续水分胁迫处理直至收获,比较材料间的生理生化指标的差异,鉴定转基因植株的耐旱能力。结果显示:(1)干旱胁迫持续至初蕾期时,转基因棉花与对照植株间各项抗旱生理指标差异均未达到显著水平。(2)水分胁迫持续至盛蕾和盛花期时,转基因棉花叶片相对含水量、光系统Ⅱ最大光化学效率(Fv/Fm)、CAT活性,以及叶片的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)均显著或极显著高于对照植株,叶绿素含量也都明显高于对照植株。干旱胁迫持续至吐絮期时,转基因棉花的株高、果枝数和铃数均显著或极显著高于对照植株,且转基因棉花和对照的籽棉产量分别比正常灌溉处理降低57.5%和60.1%,全生育期的水分胁迫严重影响了棉花籽棉产量,但转基因棉花的籽棉产量仍显著高于对照。研究表明,在新疆石河子当地自然降水(干旱胁迫)条件下,转KatE基因棉花表现出了较好的生理和生长优势,KatE基因有助于提高棉花的抗旱性。

Drought Resistance of Cotton with Escherichia coli Catalase Gene KatE

T₃ generation of KatE transgenic upland cotton was applied to investigate the drought resistance of transgenic cotton.Transgenic cotton were detected and identified by kanamycin and PCR.These positive plants were used to the drought resistance experiment with control plants,with the aim to compare the differences of physiological and biochemical,identify drought resistance between transgenic plants and control plants under drought stress until the cotton harvest.The results show that:(1)With drought stress to squaring stage,the drought resistance physiological indexes were not significantlt different between transgenic and contrast plants.(2)Water stress to budding peak stage and full-bloom stage,transgenic cotton leaf relative water content,F_v/F_m,CAT activity,leaf net photosynthetic rate(P_n),stomatal conductance(G_s) and transpiration rate(T_r) were significantly or extremely significantly higher than that of controlled plant.Drought stress to boll opening period,the transgenic cotton plant height,branch number and boll number were significantly or extremely significantly higher than that of controlled plant,transgenic and contrast of the cotton seed cotton yield than the normal irrigation treatment reduced by 57.5% and 60.1%,respectively.The whole growth period of cotton production has been affected by the water stress,but transgenic cotton seed and cotton yield is still significantly higher than that of control.The experimental results show that KatE cotton showed good physiological and growth advantage under the natural rainfull condition(water stress) in Xinjiang Shihezi,which help to increase drought resistance of the cotton.