水杨酸处理对干旱胁迫下黄瓜幼苗氮素同化及其关键酶活性的影响  

B3 Effect of Exogenous Salicylic Acid on Nitrogen Assimilation of Cucumber Seedling Under Drought Stress

作　　者：郝敬虹[1] 易旸[1] 尚庆茂[1] 董春娟[1] 张志刚[1] 

机构地区：[1]中国农业科学院蔬菜花卉研究所,北京100081

出　　处：《园艺学报》2012年第1期81-90,共10页Acta Horticulturae Sinica

基　　金：科技部国际科技合作项目(2010DFB30550)

摘　　要：采用黄瓜盆栽试验,定量浇水模拟不同程度干旱胁迫并结合根际施用水杨酸(SA),分析了外源SA对干旱胁迫下幼苗含氮化合物含量及相关酶活性的影响。结果表明,干旱胁迫下黄瓜幼苗总氮和可溶性蛋白质含量,以及硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性下降,无机氮和游离氨基酸含量增加,并且随干旱胁迫强度增加以及时间延长表现更明显。外源施用0.1mmol·LP-1PSA显著提高了胁迫植株NR和GS活性,总氮、可溶性蛋白含量以及胁迫前期游离氨基酸含量,降低了无机氮的积累,其中NR和GS活性分别比不施SA的轻度和重度胁迫植株最多提高了19.63%、12.62%和21.92%、12.72%。表明外源SA提高了干旱胁迫条件下黄瓜幼苗的氮还原和同化能力,这可能是其提高植株抗旱能力的一个重要原因。A pot experiment was conducted under adequate water and different drought stress combined with or without rhizosphere application of salicylic acid （SA） to investigate the effect of exogenous SA on nitrogenous compounds and the related enzymes in cucumber （Cucumis sativus L.） seedlings under different drought stress treatments. Results showed that total nitrogen and soluble protein content, nitrate reductase （NR） and glutamine synthetase （GS） activities declined under drought stress, while the content of inorganic nitrogen and free amino acid increased, and the changes were more pronounced as the stress strengthening and time prolonging. Exogenous application of 0.1 mmol . L^-1 SA in the condition of drought stress significantly increased the activities of NR and GS, the content of total nitrogen and soluble protein, while decreased the accumulation of inorganic nitrogen. Also, the content of free amino acid in the early period of drought stress was enhanced after SA application. Compared with no SA treatments, NR and GS activities in SA treatments increased significantly under slight （ 19.63% and 12.62%） and heavy （21.92% and 12.72%） drought stress. The above results suggested that SA enhancedthe ability of nitrogen reduction and assimilation under drought stress, which might be a key reason for improving the drought tolerance of plants.

关 键 词：黄瓜 水杨酸 干旱胁迫 含氮化合物 

分 类 号：S642.2[农业科学—蔬菜学]