【作者】 吴莎； 金晓玲； 张旻桓； 孙凌霄； 陈睿；

【Author】 WU Sha;JIN Xiao-ling;ZHANG Min-huan;SUN Ling-xiao;CHEN Rui;Central South University of Forestry and Technology;Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant,Central South University of Forestry and Technology;

【机构】 中南林业科技大学； 湖南省环境资源植物开发与利用工程技术研究中心；

【摘要】 为明确外源脱落酸(ABA)提高牡丹幼苗耐热性的作用机理,以牡丹品种’凤丹’(Paeonia astii’Fengdan’)幼苗为试材,首先研究了不同浓度ABA对高温胁迫后牡丹幼苗热窨指数和叶片电解质渗透串的影响,以确定提高牡丹幼苗耐热性的最适ABA浓度;然后,研究了最适浓度的ABA对高温胁迫下牡丹幼苗生长和叶片生理指标的影响。结果表明,40mg/L的ABA为提高牡丹幼苗耐热性的最适浓度。与单纯高温处理相比,40mg/L的ABA能显著增加牡丹幼苗根干质量,降低热害指数;显著降低电解质渗透率,丙二醛(MDA)含量;显著提高超氧化物歧化酶(SOD)活性;显著增加可溶性蛋白含量;在高温胁迫后期(≥4d)显著增加叶绿素、游离脯氨酸和可溶性糖含量。说明外源ABA可以通过提高牡丹幼苗抗氧化能力和渗透调节能力来诱导牡丹幼苗耐热性,缓解高温伤害。更多还原

【Abstract】 This study was designed to define mechanism of action of exogenous abscisic acid(ABA) in enhancing heat tolerance in tree peony seedlings.The plant material in this study was Paeonia ostii ’ Fengdan’ seedlings.Firstly,effects of ABA at different concentrations on heat injury index of the seedlings and leakage rate of electrolyte in the leaves were examined after the seedlings exposed to high temperature,thus,the most effective ABA concentration in enhancing heat tolerance in tree peony seedlings was determined.Then,on the basis of the above research results,we studied the effects of ABA on the seedlings’ growth and physiological index of leaves under high temperature stress.The results showed that,among ABA concentration,40 mg/L was most effective in enhancing heat tolerance in tree peony seedlings.Compared with high temperature treated alone,the application of 40 mg/L increased dry weight of root significantly and lowered its’ heat injury index.In addition,ABA treatment decreased leakage rate of electrolyte and malondialdehyde(MDA) content significantly,increased superoxide dismutase(SOD) activity significantly,increased soluble protein content significantly,and increased chlorophyll,soluble proline,and soluble sugar content significantly during the later period of stress(≥4 d).The results suggest that exogenous ABA could enhance heat tolerance and relieve high temperature damage of tree peony through improving its ability of antioxidant and osmotic adjustment.更多还原