外源NO对缺铁豌豆幼苗生长以及光合作用的影响

以水培豌豆(Pisum sativum)品种‘陇碗一号’幼苗为材料,以硝普钠(SNP)为一氧化氮(NO)供体,研究外源NO对缺铁豌豆幼苗的生长及光合作用的影响。结果显示:0.6 mmol.L-1的外源SNP所产生的NO能够促进缺铁豌豆幼苗的生长,并促进叶绿素的合成,增强净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr),而使胞间CO2浓度(Ci)下降;同时,叶绿素荧光最大光化学量子产量(Fv/Fm)、实际光化学量子效率(Yield)和光化学淬灭系数(qP)均升高,在一定程度上缓解缺铁对豌豆幼苗叶片PSII反应中心的影响。外源NO对正常铁(100μmol.L-1Fe)处理下豌豆幼苗的生长和光合作用具有一定的抑制作用。研究表明,缺铁和正常铁处理的豌豆幼苗对NO的敏感性不同,适宜浓度的NO对缺铁下豌豆幼苗的生长和光合都具有一定的改善作用。

Effects of Exogenous Nitric Oxide on Growth and Photosynthetic Characteristics of Pea Seedling under Iron-deficiency Stress

The effects of nitric oxide(NO) on the growth and photosynthetic characteristics of pea seedlings under iron-deficiency stress were investigated.The results showed that NO which derived from 0.6 mmol·L-1 exogenous sodium nitroprusside(SNP) could not only increase their chlorophyll content,photosynthetic rate,stomatal conductance and transpiration rate,but raise their chlorophyll Fv/Fm,Yield,qP,while reduce their intercellular carbon dioxide concentration in pea seedling under iron-deficiency stress.As a result,appropriate NO can prevent the injury of iron-deficiency stress on PSⅡ and protect the photosynthetic activities of pea seedlings.However,the different effects had been found in 100 μmol·L-1 Fe seedlings treated with the same concentration SNP.These results indicate the different demands on the dose of nitric oxide for plants under 0 μmol·L-1 Fe and 100 μmol·L-1 Fe treatments and appropriate concentration of nitric oxide can ameliorate pea growth and photosynthesis stress caused by iron-deficiency.