拟南芥扩张蛋白AtEXP1参与气孔运动的调控

Arabidopsis Expansin AtEXP1 Involved in the Regulation of Stomatal Movement

本文以过量表达扩张蛋白AtEXP1的转基因烟草为材料,通过分析不同刺激因子作用下,AtEXP1的过量表达对烟草气孔运动的影响,研究了扩张蛋白AtEXP1是否参与气孔运动的调控作用。表皮条的生物学分析表明,AtEXP1的过量表达促进了光和K+诱导的气孔开放,以及Ca2+、ABA和黑暗诱导的气孔关闭过程,但对气孔密度影响不大;充足光照、水分供应条件下,成熟转基因烟草植株的光合与蒸腾速率均明显高于野生型。以上结果表明AtEXP1的过量表达提高了气孔对环境刺激应答的灵敏性,这可能是由于AtEXP1的过量表达改变了保卫细胞细胞壁的特性,进而参与了烟草气孔运动的调控。说明AtEXP1在气孔运动中发挥积极的调控作用。

Our objective was to study the possible function of expansin AtEXP1 in the stomatal movement of transgenic tobaccos with over-expressed AtEXP1, the differences of stomatal movement under the condition of different stimuli between the transgenic and wild plants were analyzed. Bioassays on epidermal peels showed that the stomatal opening induced by light, K^＋ and the stomatal closure induced by Ca^2＋ , ABA and darkness were promoted by over-expressed AtEXP1, but the density of stomata had little difference between the transgenic and wild plants. Moreover, the transgenic plant had significantly higher photosynthesis and transpiration rates than the wild plant under favorable conditions. All the results suggested that via altering the characteristic of the guard cell wall, over-expressed AtEXP1 increased the sensitivity of stomata to different stimuli, then involved in the regulation of tobacco stomatal movement, showing that expansin AtEXP1 did play an active role in the regulation of stomatal movement.