水分胁迫下外源NO对核桃叶绿素荧光的影响

探讨了外源NO对水分胁迫下核桃叶片荧光参数的影响。结果表明,水分胁迫下,核桃叶片的荧光参数最大光化学量子效率(Fv/Fm)、PSⅡ反应中心的实际光化学效率(φPSⅡ)、光化学猝灭系数(qP)、非光化学猝灭系数(NPQ)均降低,经NO供体硝普钠(SNP)诱导处理后,荧光参数下降程度减小,且随着SNP处理浓度增大,缓解作用愈明显。表明外源NO处理一方面提高了光能转换效率和PSⅡ的潜在活性,另一方面增强了过剩光能的非化学耗散,有利于保护光合机构免受环境胁迫的伤害。

Effects of exogenous nitric oxide on the chlorophyll fluorescence parameters of walnut under water stress

The effects of NO donor sodium nitroprusside (SNP) on the chlorophyll fluorescence parameters of walnut leaves under water stress were studied. The result showed that the maximum photochemical efficiency (Fv/Fm), the actual photochemical efficiency of PSⅡ reaction center (φPSⅡ), photochemical quenching coefficient (qP) and the non-photochemical quenching coefficient (NPQ) had the deceasing trend under drought stress. The SNP treatment was able to alleviate the decrease of fluorescence parameters; with increasing SNP lever, the fluorescence parameters were increased. All the above showed that the light energy conversion efficiency, potential activity of photosynthetic reaction center and the non-photochemical dissipation of excess light energy, which resisted the damage on photosynthetic apparatus of environmental stress, were improved.