摘要
通过PEG-6000和NaCl模拟实验研究了干旱和盐分胁迫对沙枣幼苗叶片光系统Ⅱ(PSⅡ)活力的影响。结果显示:PEG胁迫使沙枣幼苗叶片PSⅡ在300μs时相对于FJ-Fo的可变荧光比值(Wk)升高,却降低了单位反应中心密度(RC/CSo)和最大量子产量(Fv/Fm),导致效能指数(PIABS)随水势降低而显著下降,阻碍了电子传递链中供体和受体侧的电子传递,也抑制了叶绿素的合成,从而全面抑制PSⅡ的活力;NaCl胁迫对沙枣叶片PSⅡ活力没有显著影响。比较两种处理等渗溶液下的结果发现,盐离子对沙枣叶片PSⅡ活力具有正效应,它抵消了渗透效应对沙枣叶片PSⅡ活力的抑制作用,这可能与盐离子进入叶片细胞,减轻了渗透胁迫有关。
Effects of polyethylene glycol（PEG-6000） and NaCl on PSⅡ activity of Elaeagnus angustifolia were investigated by an experiment carried out in greenhouse.PEG treatment increased ratio of variable fluorescence at 300 μs to the amplitude FJ-Fo（Wk） and decreased the density of the active photosynthetic reaction centers（RC/CSo）,inhibited electron transport,resulted in the decline of the maximum quantum yield for primary photochemistry（Fv/Fm） and the performance of PSⅡ activity（PIABS）,but increased the dissipated energy flux per reaction center,antenna size.The target sites of drought stress on PSⅡ of E.angustifolia leaves were both the donor and acceptor sides.However,NaCl treatment had no significant effect on PSⅡ activity of E.angustifolia.Compared the results in isosmotic solution of PEG and NaCl treatment,a positive effect could be observed in the treatment of NaCl,which removed the adverse effect of osmotic stress.It suggested that the entry of salt ion into leaf cell alleviated osmotic stress in the treatment of NaCl.
出处
《西北植物学报》
CAS
CSCD
北大核心
2011年第4期768-775,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家重点基础研究发展计划项目(2006CB705809)
国家自然科学基金项目(31070468)
