中文摘要：

对NaCl胁迫下番茄幼苗叶片分别喷施还原型谷胱甘肽（GSH）、氧化型谷胱甘肽（GSSG）和谷胱甘肽合成抑制剂（BSO）构建不同氧化还原水平的番茄植株,研究外源GSH介导的氧化还原状态对NaCl胁迫下番茄幼苗光合作用的影响.结果表明： 外源喷施GSH诱导NaCl胁迫下番茄幼苗叶片的还原力水平提高,叶片净光合速率（Pn）、气孔导度（gs）、蒸腾速率（Tr）及最大光化学效率（Fv/Fm）、实际光化学效率（ФPSⅡ）、光化学猝灭系数（qP）、非光化学猝灭系数（NPQ）值均提高,核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）活性及大亚基（RbcL）、小亚基（RbcS）和Rubisco活化酶（RCA）的基因表达水平上调,从而有效保护了光合系统,促进了（光系统Ⅱ）PSⅡ光化学反应活性、降低了NaCl胁迫对光合暗反应的抑制,缓解了NaCl胁迫对番茄植株的危害.喷施GSSG显著降低了NaCl胁迫下番茄幼苗叶片还原力水平,造成叶片光损伤和光抑制加剧,但RbcS和RbcL的基因表达水平上调可能是导致NaCl＋GSSG处理下叶片Pn未下降的原因.喷施BSO对NaCl胁迫下番茄幼苗叶片氧化还原状态、CO2传导能力和PSⅡ反应中心无显著影响,但BSO上调碳同化关键酶Rubisco初始活性、总活性及RCA和RbcS表达水平是导致Pn提高的原因.

英文摘要：

By spraying tomato leaves with reduced glutathione （GSH）, oxidized glutathione （GSSG） and glutathione synthesis inhibitor （BSO）, respectively, the effects of glutathionmediated redox state on leaf photosynthesis in tomato under NaCl stress were investigated. The results showed that the application of exogenous GSH significantly induced an increase in reducing power level, increased the net photosynthetic rate （Pn）, stomatal conductance （gs）, transpiration rate （Tr）, as well as the maximum quantum yield of PSⅡ （Fv/Fm）, actual photochemical efficiency of PSⅡ （ФPSⅡ）, photochemical quenching coefficient （qP） and nonphotochemical quenching coefficient （NPQ）, and enhanced the Rubisco activity and expression levels of RbcL, RbcS and RCA genes in leaves of tomato seedlings under NaCl stress. These results suggested that GSH alleviated saltinduced oxidative stress by protecting PSⅡ from damage caused by excess energy, and improving the photochemical efficiency of PSⅡ and dark reaction activity of photosynthesis. Although spraying GSSG decreased the level of reducing power and further aggravated the damage and photoinhibition of the leaf photosynthetic apparatus, Pn was not affected in combined stressed （NaCl and GSSG） plants, which might be due to the upregulation of expression levels of RbcL and RbcS genes. The application of BSO had no significant effects on redox state, CO2 conductivity capacity and PSⅡ photochemical efficiency in tomato leaves under NaCl stress. However, compared to salt singly stressed plants, BSO application increased Pn, likely due to the upregulation of Rubisco initial activity and RCA and RbcS expression levels.