抗坏血酸对暗诱导拟南芥叶片衰老的影响  

Effects of Ascorbate on Darkness Induced Aging in Arabidopsis

作　　者：李媚[1] 陈晓锋[1] 彭长连[1] 

机构地区：[1]华南师范大学生命科学学院,广州510631

出　　处：《华南师范大学学报（自然科学版）》2015年第5期71-77,共7页Journal of South China Normal University(Natural Science Edition)

基　　金：国家自然科学基金项目(31270287)

摘　　要：分析黑暗诱导衰老条件下3种内源抗坏血酸含量不同的拟南芥(GLDH基因超表达植株gldh236OE、哥伦比亚野生型Col和拟南芥抗坏血酸缺乏突变体vtc2-1)表型、抗坏血酸含量及叶绿素荧光参数等生理指标的变化,研究抗坏血酸对暗诱导拟南芥叶片衰老的影响.结果表明,黑暗胁迫后3种拟南芥抗坏血酸含量均呈下降趋势,与Col相比,vtc2-1的抗坏血酸含量显著降低(P<0.05),叶片黄化速度明显较快;gldh236OE叶片黄化速度较慢;黑暗均引起了PSII最大光能转化效率(Fv/Fm)和PSII实际光化学量子产量(Yield)降低,PSII的光合效率受到阻碍;也减少了vtc2-1非光化学猝灭(NPQ),外施抗坏血酸对植株热耗散能力显著增强(P<0.05).研究表明,内源抗坏血酸含量的缺失会导致植株对黑暗胁迫的适应性降低,外施1 mmol/L抗坏血酸能部分缓解植物的黑暗胁迫.Arabidopsis thaliana had been selected as the research material in this study, to test the darkness stress on the eco-physiological characteristics （including phenotype, total ascorbate content and the chlorophyll fluores- cence） of three genotype plants with different endogenous aseorbate contents （ GLDH gene over-expression named as gldh2360E, wide type Col and the AsA deficient mutants vtc2-1 ）. The results indicated that the contents of total aseorbic acid of the three genotype plants were trended down under the darkness. Compared with the wide type （Col）, total ascorbate content of vtc2-1 was significantly reduced （P 〈 0. 05 ）. The leaf etiolation speed of vtc2-1 was faster than Col, but gldh2360E was slower. The darkness induced the decrease of Fv/Fm and Yield, which hindered photosynthetic efficiency of PS[I. It also reduced the NPQ of vtc2-1, and exogenous applied ascorbic acid markedly enhanced its capability of the heat dissipation （ P 〈 0. 05 ）. The present results indicated that the deficient of endogenous ascorbate reduced plants＇ resistance to dark stress and exogenous aseorbate relieved the stress of the dark in part.

关 键 词：拟南芥 抗坏血酸 黑暗处理 叶绿素荧光参数 抗逆性 

分 类 号：Q945.3[生物学—植物学]