开放式臭氧浓度升高条件下转Bt(Cry1Ab/Ac)基因水稻的光合特性

摘要

[目的]明确臭氧(O3)浓度升高对转Bt基因水稻(Oryza Sativa L.)光合特性的影响.[方法]利用中国农田开放式O3浓度升高(O3-FACE)研究平台,以Bt汕优63 (Bt-SY63)及汕优63 (SY63)为试验材料,采用盆栽种植,分别于处理26 d、47d和75d对其光合特性相关生理指标进行测定分析.[结果]随着O3处理时间的延长,Bt-SY63和SY63剑叶净光合速率(Pn)呈现下降趋势,与各自对照相比75d时分别下降21.1％和15.1％(P＜0.01),气孔导度(Gs)和蒸腾速率(Tr)的变化趋势与Pn基本保持一致;PS Ⅱ最大光化学效率、PSⅡ实际光化学效率、光化学猝灭也表现出不同程度的下降;而两品种非光化学猝灭、吸收光能用于PS Ⅱ天线色素耗散部分的变化则是处理高于对照;叶绿素以及类胡萝卜素含量也呈下降趋势,Bt-SY63可溶性蛋白含量在后期处理高于对照,核酮糖-1,5-二磷酸羧化/加氧酶( Rubisco)的含量未显著减少.[结论]03浓度升高使Bt-SY63的光合特性相关指标都发生了不同程度的改变且变幅大于SY63,说明Bt-SY63对O3的响应较SY63敏感,在O3胁迫下,Bt-SY63各性状指标的波动性较大.%[Objective] The purpose of this study was to identify the effects on photosynthetic characteristics of transgenic Bt rice (Oryza saliva L.) under elevated O3 concentration during the period of May-October of 2010. [Method] Pot experiments were conducted with Bt-Shanyou 63 (hereinafter called Bt-SY63, a transgenic rice with Cry1Ab/Ac) and Shanyou 63 (hereinafter called SY63, a hybrid indica cultivar) at 26 d, 47 d and 75 d of ozone treatment, respectively, the indicators relating to the photosynthetic characteristic were measured under Ozone Free Air Controlled Enrichment Conditions (O3-FACE). [Result] The results showed that the net photosynthetic rate of flag leaves in Bt-SY63 and SY63, compared with the control, took on a significantly decline up to 21.1% and 15.1% on 75 d (P<0.01), respectively, by prolonged elevated O3 exposure. The downtrend of stomatal conductance and transpiration was also consistent with Pn. As for the chlorophyll fluorescence kinetics parameters, the maximal photochemical efficiency of PS II, actual photochemical efficiency of PS II and photochemical quenching all descended by elevated O3 concentration while non-photochemical quenching and fraction of light absorbed in PS II which was dissipated in the PS II antenna in varied ranges companied with Pn enhanced. The content of chlorophyll and carotenoid of the two varieties also declined, the same with the total soluble protein content in SY63. However, the alteration of TSP content in Bt-SY63 was in perfectly opposite to the SY63's, there was no remarkable decrease in ribulose-l,5-bisphosphate carboxylas/oxygenase contents in Bt-SY63. [Conclusion] Photosynthetic parameters had presented to be changed in leaves of the genetic modified rice and the traditional plant under the O3-FACE conditions, with a larger amplitude for Bt-SY63 compared to SY63. In conclusion, the results suggested that Bt-SY63 was more sensitive to elevated O3 concentration than SY63 coupled with great volatility.