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试验采用硝普钠(SNP)为NO供体,夏枯草幼苗为材料,研究外源0.01~0.50 mmol/L SNP对70 mmol/L NaCl胁迫下夏枯草幼苗抗氧化系统、光合参数与叶绿素荧光参数的影响。结果表明,0.05~0.10mmol/L SNP可以缓解NaCl胁迫对夏枯草幼苗造成的伤害,其中0.10mmol/L SNP缓解效果最显著,该处理显著提高了NaCl胁迫下夏枯草幼苗叶片的过氧化物酶(POD)、过氧化氢酶(CAT)活性,降低了电导率与丙二醛(MDA)的含量。显著提高了夏枯草叶片叶绿素a含量、叶绿素b含量、总叶绿素含量、净光合速率(Pn)、气孔导度(Gs)与蒸腾速率(Tr),降低了胞间CO2浓度(Ci)。叶绿素荧光动力学参数显示,0.10mmol/L SNP处理显著降低了NaCl胁迫下夏枯草幼苗的初始荧光(Fo)与非光化学荧光猝灭系数(NPQ),提高了最大荧光(Fm)、PSⅡ潜在光化学效率(Fv/Fo)、PSⅡ最大光化学效率(Fv/Fm)和PSⅡ有效光化学量子产量(Fv′/Fm′)。外源NO通过提高抗氧化酶活性,来减少脂质过氧化作用,减少光抑制对PSⅡ的破坏,提高光化学能力,增强夏枯草叶片的光合能力,从而最终提高夏枯草的抗盐能力。本试验条件下,以0.10mmol/L SNP处理效果最为显著。
In this experiment, SNP as NO donor and Prunella vulgaris as material, the effect of exogenous 0.01 ~ 0.50 mmol / L SNP on the antioxidant system, photosynthetic parameters and chlorophyll fluorescence parameters of Prunella vulgaris seedlings under 70 mmol / L NaCl stress was studied. Impact. The results showed that 0.05-0.10 mmol / L SNP could alleviate the damage of Prunella vulgaris seedlings caused by NaCl stress, of which 0.10 mmol / L SNP had the most significant alleviation effect. The treatment significantly increased the peroxidase (POD) and catalase (CAT) activity, and decreased the conductivity and malondialdehyde (MDA) content. Chlorophyll a content, chlorophyll b content, total chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of Prunella vulgaris leaves were significantly increased and intercellular CO2 concentration (Ci) was decreased. Chlorophyll fluorescence kinetics parameters showed that 0.10mmol / L SNP significantly reduced the initial fluorescence (Fo) and non-photochemical quenching coefficient (NPQ) of Prunella vulgaris seedlings under NaCl stress, and increased the maximum fluorescence (Fm), potential photochemistry of PSⅡ Efficiency (Fv / Fo), maximum PSⅡ photochemical efficiency (Fv / Fm) and PS Ⅱ effective photochemical quantum yield (Fv ’/ Fm’). Exogenous NO can reduce the lipid peroxidation, decrease the damage of PSⅡ by photochemical inhibition, enhance the photochemical ability and enhance the photosynthetic capacity of Prunella vulgaris leaves by increasing the activity of antioxidant enzymes, so as to ultimately improve the salt-tolerance ability of Prunella vulgaris. Under the experimental conditions, the treatment with 0.10mmol / L SNP is the most obvious.