亚精胺对PEG渗透胁迫下白三叶种子萌发及幼苗抗旱效应的影响  

Effects of spermidine on seed germination and seedling drought resistance of white clover under osmotic stress induced by PEG

作　　者：彭丹丹[1] 王晓娟[1] 李州[1] 李亚萍[1] 彭燕[1] 

机构地区：[1]草业科学重点实验室四川农业大学动物科技学院草业科学系,四川成都611130

出　　处：《草业科学》2016年第9期1739-1746,共8页Pratacultural Science

基　　金：国家自然科学基金(31372371);四川省科技支撑项目(2013NZ0013)

摘　　要：以‘拉丁诺’白三叶(Trifolium repens cv.Ladino)为试材,研究不同浓度PEG-6000(聚乙二醇-6000)渗透胁迫下亚精胺(spermidine,Spd)对白三叶种子萌发和幼苗抗旱的影响。结果表明,20μmol·L-1 Spd浸种能够显著(P<0.05)提高10%和15%PEG-6000渗透胁迫下白三叶种子的萌发率和萌发指数,显著促进15%PEG-6000渗透胁迫下胚根的伸长生长和幼苗的单株鲜重,但对单株干重影响很小;20%PEG-6000渗透胁迫下,外源添加20μmol·L-1 Spd能不同程度地提高白三叶幼苗叶片超氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)、过氧化氢酶(catalase,CAT)和抗坏血酸过氧化物酶(ascorbate peroxidase,APX)活性,降低电解质渗透率(EL)和丙二醛(MDA)含量,有效缓解叶片相对含水量(RWC)下降。表明渗透胁迫下Spd能有效促进白三叶种子的萌发,增强幼苗抗氧化能力,从而减轻渗透胁迫对白三叶幼苗的过氧化伤害,提高植株的耐旱性。The aim of this study was to investigate the effect of spermidine（Spd）on seed germination and seedling drought resistance of Trifolium repens cv.Ladino under osmotic stress induced by different concentration of polyethylene glycol 6000（PEG-26000）.The results showed that 20μmol·L^-1 Spd soaking significantly enhanced seed germination percentage and germination index under 10% and 15% PEG solution,and increased radicle length and seedling fresh weight under 15% PEG solution,whereas had no effect on dry weight.Meanwhile,when exposed to 20% PEG,seedlings treated with 20μmol·L^-1 Spd showed a higher antioxidant enzymes activities including SOD,POD,CAT and APX,and leaf RWC,and decreased the electrolyte leakage and MDA content compared to control.In conclusion,these results indicated that Spd can effectively promote the ability of seed germination and environmental adaptability of whiter clover seedlings under osmotic stress,protect the structure of cell membrane,and alleviate the oxidative damage induced by osmotic stress resulting in the improved drought tolerance of white clover.

关 键 词：白三叶 渗透胁迫 亚精胺 种子萌发 抗氧化酶 

分 类 号：S541.2[农业科学—作物学]