水杨酸对高温强光胁迫下小麦叶片光合机构的保护作用

以0.1、0.3、0.5 mmol/L的水杨酸(SA)预先处理灌浆期的小麦叶片,然后进行不同温度和照光处理,探讨水杨酸对高温强光胁迫下小麦叶片psbA基因表达和PSⅡ功能的影响。结果表明,叶面喷施水杨酸可有效调节抗氧化酶SOD、APX的活性,降低叶片MDA的含量,维持较高的光合速率(Pn),减轻逆境对光合机构的破坏。RT-PCR分析结果也显示,水杨酸可以促进小麦psbA基因的表达。其中,以0.3 mmol/L的水杨酸效果最好。

Protective Effect of SA on Photosynthetic Apparatus of Wheat Leaves under Heat and High Irradiance Stress

In order to elucidate the protective mechanism of salicylic acid(SA) on photosynthetic apparatus of wheat leaves under heat and high irradiance stress,the leaves of wheat were sprayed with solution of SA at grain-filling stage and exposed to different temperature and irradiance conditions.Afterwards,the effect of SA on psbA gene and photosystemⅡ(PSⅡ) performance of wheat leaves were studied.The results showed that pretreatment with SA enabled the wheat leaves to keep relatively high activities of superoxide dismutase(SOD) and ascorbate peroxidase(APX),lower malondialdehyde(MDA) content and higher Pn.Analysis of RT-PCR indicated that SA pretreatment can increase the expression of psbA gene.Comparatively,the concentration of 0.3mmol/L of SA was the most efficient.