转Bt(Cry1Ab)基因对水稻光合特性及光合产物积累的影响

 【目的】明确外源Bt基因插入对水稻倒1叶光合速率及光合作用相关生理特性的影响。【方法】以转Bt基因水稻及亲本水稻为试材,研究盆栽及田间条件下转Bt基因及亲本水稻苗期、拔节期、抽穗期和成熟期倒1叶光合特性及其相关光合酶活性、光合产物积累的动态变化。【结果】转Bt基因及亲本水稻生理活动峰值均出现在拔节期。与亲本水稻相比,转Bt基因水稻苗期叶片净光合速率显著低于亲本;而拔节期和抽穗期,转Bt基因水稻倒1叶净光合速率、叶绿素含量和乙醇酸氧化酶活性显著高于亲本水稻（P＜0.05）,且拔节期转Bt水稻倒1叶气孔导度和胞间CO2浓度也显著高于亲本水稻（P＜0.05）;成熟期,转Bt基因与亲本水稻倒1叶光合特性无显著性差异（P＞0.05）。【结论】与亲本水稻相比,外源Bt基因的插入对水稻叶片光合特性产生短暂影响,但这种影响不具有持续性。

Effect of Cry1Ab Gene on Photosynthetic Characteristics and Photosynthate Accumulation of Rice

【Objective】The objective of this study was to identify the effect of exogenous Cry1Ab gene on photosynthetic characteristics in Bt transgenic rice.【Method】 Pot and field experiments were conducted with Bt transgenic and non-Bt transgenic rice at seedling, booting, heading and maturing stages, photosynthesis and enzyme activities of reciprocal first leaf were analyzed. 【Result】 The results showed that all of the maximum net photosynthetic rate (Pn) appeared at booting stage. At seedling stage, the Pn of transgenic Bt rice was significantly lower than that of non-Bt transgenic rice. However, Pn, total chlorophyll content and activity of glycolate oxidase in Bt transgenic rice were significantly higher than those in non-Bt transgenic rice at booting and heading stages. Moreover, intercellular CO2 concentration of Bt transgenic rice at booting stage was significantly higher than that of non-Bt transgenic rice. The significant changes of stomatal conductance, transpiration rate, intercellular CO2 concentration, the total chlorophyll content and the enzyme activities in the leaves of Bt transgenic and non-Bt transgenic rice were not detected at maturing stage. 【Conclusion】 Compared with non-Bt transgenic rice, the photosynthesis and chlorophyll of Bt transgenic rice were changed at some development stages, which suggested that the effect of Cry1Ab gene on photosynthetic characteristics of rice was transitory and no continuous.