Abstract:

【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.

Key words: Bt gene (Cry1Ab), photosynthetic characteristics, RuBPcase, photosynthate accumulation