中文摘要：

以‘天津白果’番茄品种的野生株系（WT）和转正义叶绿体ω-3脂肪酸去饱和酶基因（LeFAD7）株系T（＋）-12为试材,通过盆栽实验测定了它们在PEG-6000模拟干旱胁迫下的叶片类囊体膜脂脂肪酸组成,以及干旱胁迫后的光合参数、叶绿素荧光参数,以探讨类囊体膜脂LeFAD7基因在干旱胁迫下对番茄叶片光合作用的影响。结果表明：与WT株系相比,转正义基因番茄植株类囊体膜脂中亚麻酸（18∶3）含量升高12.67%,亚油酸（18∶2）含量下降26.98%,导致膜脂脂肪酸不饱和度升高;10%、20%和30%PEG干旱胁迫下,转正义基因番茄植株的实际光化学效率（ΦPSⅡ）、净光合速率（Pn）和叶绿素a（Chl a）含量分别比相应对照下降0.36%--5.11%、19.97%--28.13%、13.27%--23.66%,降幅均小于WT株系,且Pn和Chl a在转基因和野生株间大多存在显著差异。可见,LeFAD7基因能增加番茄叶片膜脂脂肪酸不饱和度,从而减轻干旱胁迫对细胞膜的伤害性,保持干旱逆境下光合系统结构和功能的相对稳定,维持较高的光合速率。

英文摘要：

With WT lines ‘Tianjinbaiguo＇ and sense-transgenic （LeFAD7） lines T （ ＋ ）-12 of tomato, we measured the fatty acid composition of thylakoid membrane, photosynthetic and chlorophyll fluorescence under PEG-6000 drought stress in the pot. In order to investigate effect of LeFAD7 gene of thylakoid membrane on drought resistance in tomato plants. The results showed that linolenic acid （18 ： 3） obviously increased 12.67% and the content of oleic acid （18 ： 2） concomitantly reduced 26.98% in the sense-transgenic lines, resulting in the increase of the unsaturation of thylakoid membrane lipids. Under drought stress,the actual photochemical efficiency of PS Ⅱ , photosynthetic rates （Pn） and the number of chlorophyll in T（＋）-12 lines descent 0.36%--5. 11%, 19.97%--28. 13%, 13.27%--23. 66% ,compared with CK. P. and Chl a also presence significantly deviation compared with WT. Those results indicated that LeFAD7 gene of thylakoid membrane lipids relief nocuity of tytolemma, retention stabilization of photosynthetic system,maintenance higher photosynthetic rates and the number of chlorophyll in tomato plants under drought stress for the increase of the unsaturation. In short, photosynthesis was protected by the higher content of unsaturated fatty acid in thylakoid under drought stress.