亚精胺浸种对渗透胁迫下玉米幼苗叶片抗氧化非酶物质含量的影响

Effects of Seed Soaking with Spermidine on Antioxidation Non-enzyme Substance Contents in Leaves of Maize Seedlings under Osmotic Stress

[目的]探讨多胺增强植物抗旱性的机理。[方法]用亚精胺(Spd)浸种,研究了渗透胁迫下玉米品种农大108(抗旱性较强)和掖单13(抗旱性较弱)幼苗叶片中抗氧化非酶物质含量的变化。[结果]渗透胁迫2 d,抗旱性弱的掖单13幼苗叶片的过氧化氢(H2O2)和丙二醛(MDA)含量的上升幅度明显大于抗旱性强的农大108,而农大108幼苗叶片中抗坏血酸(ASA)和谷胱甘肽(GSH)含量的上升幅度明显大于掖单13;Spd浸种处理,明显促进渗透胁迫条件下掖单13幼苗叶片内ASA和GSH含量的升高,并且明显抑制其H2O2和MDA含量的上升。[结论]渗透胁迫下,Spd浸种促进了玉米(特别是抗旱性较弱的品种)幼苗叶片中抗氧化非酶物质ASA和GSH含量的上升,降低叶片内的活性氧水平,从而减轻活性氧对幼苗的伤害,增强玉米幼苗的抗渗透胁迫能力。

[Objective] The research aimed to probe into the mechanism of polyamine enhancing the tolerance of plants against drought stress.[Method] The changes in contents of antioxidation non-enzyme substances were investigated in seedling leaves of two maize（Zea mays L.） cultivars,Nongda 108（drought tolerance） and Yedan 13（drought sensitive） under osmotic stress with the spermidine seed-soaking.[Result] At the 2nd day,after polyethylene glycol（PEG）-6,000 treatment,MDA and H2O2 contents increased more significantly in leaves of Yedan 13 than in Nongda 108,while Nongda 108 showed more significant increase in contents of ASA and GSH.Under osmotic stress,treatment of seed-soaking with Spd resulted in the increase in ASA and GSH,in concert with the decrease in MDA and H2O2 contents in seedling leaves of Yedan 13.[Conclusion] Spd seed-soaking could alleviate the active oxygen injury to maize seedlings as well as increase the resistance ability to osmotic stress,especially the drought-sensitive cultivar,via increasing the contents of antioxidation non-enzyme substances ASA and GSH and reducing MDA and H2O2 contents in the leaves.