摘要
通过PEG-6000和NaCl模拟试验,研究了水分和盐分胁迫对沙棘幼苗叶片光系统II(PSII)活力的影响。结果显示:2种胁迫抑制了PSII受体侧的电子传递,减少进入电子传递链的能量流,抑制叶绿素的合成,但对单位面积反应中心密度影响不大。不同的胁迫对沙棘叶片PSII活力的影响程度不同:在NaCl胁迫下,单位反应中心吸收的能量(ABS/RC)、捕获的能量(TRo/RC)和进入电子传递链的能量(ETo/RC)均高于PEG胁迫,但是由于分配进入电子传递链的能量比率(Ψo=ETo/TRo和φE0=ETo/ABS)下降的更剧烈,导致效能指数PIABS的显著降低,使得盐分胁迫比水分胁迫更强烈地抑制了PSII的活力,这显示了盐离子的毒害效应。
Effects of polyethylene Glycol（PEG-6000） and NaCl on PSII activity of Hippophae rhamnoides were investigated by an experiment carried out in greenhouse.Both NaCl and PEG exposure restricted the electron transfer in acceptor,resulted in a decrease of energy yield into electron transfer chain.The two stresses still caused the decrease of chlorophyll content,but had no effect to the density of active photosynthetic reaction centers（RC/CSo）.Compared with PEG treatment,NaCl exposure was higher in absorption flux,trapped energy flux and electron transport flux per excited reaction center（ABS/RC,TRo/RC,ETo/RC）,but it had lower value in performance index（PIABS） due to the decrease in electron transport（φEo）,probability that a trapped exciton moves an electron into the electron transport chain beyond Q-A（Ψo）.Our results suggested that NaCl inhibited more intensely the PSII activity than PEG,as had close relation with specific ion effect of NaCl.
出处
《干旱区研究》
CSCD
北大核心
2011年第4期649-654,共6页
Arid Zone Research
基金
国家重点基础研究发展计划项目(2006CB705809)资助
