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作 者 ：谢寅峰,杨万红,杨阳,蔡贤雷,周坚

期 刊 ：生态学报 2007年 27卷 12期 页码：5193~5201

关键词：模拟酸雨；一氧化氮；髯毛箬竹；光合作用；叶绿素荧光；

Keywords:simulated acid rain, nitric oxide, Indocalamus barbatus McClures, photosynthesis, chlorophyll fluorescence,

摘 要 ：为了探讨外源一氧化氮对酸胁迫下植物生理响应的调节作用，以髯毛箬竹为试验材料，以硝普钠（SNP）为一氧化氮供体，研究了一氧化氮对模拟酸雨胁迫下叶片叶绿素相对含量、光合作用日变化以及叶绿素荧光特性等的影响。结果表明：（1）外源一氧化氮（50~450mg/L SNP）预处理可不同程度地缓解pH3.0酸雨胁迫下叶绿素含量的下降，其中以450mg/L SNP处理效果最明显；（2）酸雨胁迫下，箬竹叶片光合“午休”现象加重，日均净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）和气孔限制值（Ls）均明显降低，而细胞间隙CO2浓度（Ci）增大，经过外源SNP预处理后Pn、Gs、Tr和Ls不同程度增加，而Ci有所降低，以450mg/LSNP预处理的效果最好；（3）酸雨胁迫下，箬竹叶片的最大荧光（Fm）、PSⅡ最大光化学效率（Fv/Fm）、有效光化学效率（Fv′/Fm′）、最大荧光产额（Fm′）、稳态荧光产额（Fs′）、光化学淬灭系数(qP)、非光化学淬灭系数（NPQ）、PSII实际光化学效率（ΦPSⅡ）及表观光合电子传递速率（ETR）均降低，而暗适应下最小荧光（F0）、光适应下最小荧光产额（F′0）则升高；经450mg/L SNP预处理后，上述荧光参数在胁迫下的变化均受到不同程度的抑制。可见，一氧化氮预处理能够不同程度地缓解酸雨胁迫下非气孔因素引起的箬竹叶片光合速率的下降以及对光合系统的破坏作用，提高胁迫下光合能力。光化学效率的提高和过剩光能的非光合耗散的增强可能是一氧化氮缓解胁迫对光合机构破坏的机制之一。

Abstract:To understand the regulating effect of exogenous nitric oxide on the plant physiological response on the stress condition of simulated acid rain, we examined the effects of exogenous nitric oxide with the donor of sodium nitroprusside i.e. SNP on the relative chlorophyll content, diurnal variations of photosynthesis and chlorophyll fluorescence with the experimental materials of Indocalamus barbatus McClure in 2007
The results showed as follows:（1) By treatment with exogenous nitric oxide(50-450 mg/L SNP),the decreases of relative chlorophyll content were significantly alleviated at the stress condition of pH 3.0 simulated acid rain,especially the treatment with 450mg/L sodium nitroprusside was the best.（2) Under the stress of simulated acid rain, the midday depression of photosynthesis became more serious. The daily average of net photosynthetic rate(Pn),stomatal conductance(Gs), transpiration rate(Tr) and stomatal limitation value(Ls) all were decreased significantly, while intercellular CO2 concentration(Ci) was increased. By treated with exogenous nitric oxide, Pn, Gs、Tr and Ls was increased at different extent, while Ci was decreased, especially the treatment with 450mg/L sodium nitroprusside was the most obvious .（3) Under the stress condition of simulated acid rain, the maximum fluorescence of dark adaptation(Fm),PSII maximal photochemical efficiency(Fv/Fm),PSII effective photochemical efficiency(Fv′/Fm′),maximum fluorescence of light adaptation(Fm′),stable fluorescence(Fs) photochemical quench(qP),non-photochemical quench(NPQ),PSII actual photochemical efficiency(ΦPSⅡ) and acyclic electron transfer rate(ETR) were all decreased, but the minimum fluorescence of dark adaptation(F0), and minimum fluorescence of light adaptation(F′0) were increased. After treated with 450 mg/L sodium nitroprusside, the changes of all the above fluorescence parameters under the stress condition were inhibited in different degree. The results suggest that, nitric oxide treatment can alleviate the decrease of photosynthetic rate induced by non-stomata factors and the damage of photosynthesis system, and improve the foliar photosynthetic ability under a acid rain stress condition. Increasing of photochemical efficiency and the non- photochemical dissipation of excess light energy is probably one of mechanisms which nitric oxide alleviates the damage of photosynthetic apparatus by acid rain.

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