【作者】 王洋； 文婷婷； 胡伟民； 关亚静； 利站； 胡晋；

【Author】 WANG Yang;WEN Tingting;HU Weimin;Guan Yajing;LI Zhan;HU Jin;College of Agriculture and Biotechnology,Zhejiang University;School of Agricultural and Food Science,Zhejiang A&F University;Shandong Seed Administration Station;

【机构】 浙江大学农业与生物技术学院； 浙江农林大学农业与食品科学学院； 山东省种子管理总站；

【摘要】 外源水杨酸(SA)能够提高植物的非生物胁迫耐受性,而抗氧化系统尤其是过氧化氢酶(CAT)在非生物胁迫耐受性方面发挥了重要的作用。本文研究了低温胁迫下外源施用SA对两种不同耐寒型玉米自交系品种的生理特性以及过氧化氢酶基因表达的影响。试验结果表明0.5 mM的SA水培处理显著降低了低温胁迫下两个玉米品种幼苗根和叶部的MDA和H2O2含量的积累。此外,SA预处理显著提高了低温胁迫下玉米幼苗的CAT、抗坏血酸过氧化物酶(APX)和超氧化物歧化酶(SOD)的活性,降低了过氧化物酶(POD)的活性。低温胁迫下玉米幼苗根和叶部的三种Cat基因对外源SA的响应各不相同。SA处理促进了Mo17根和叶部的Cat1基因的表达,但却抑制了黄C幼苗中该基因的表达。另外,值得注意的是,SA处理显著促进了两种玉米自交系幼苗根和叶部的Cat2基因的表达。然而,SA处理对两个玉米品种幼苗根和叶部Cat3基因表达的影响则不一致。SA处理显著提高了低温胁迫下玉米幼苗的干鲜重。综上所述,本试验表明外源施用SA能够促进玉米植株对低温胁迫的耐受性,这主要是通过增加APX、SOD和CAT的活性以及Cat2基因的表达而实现的。更多还原

【Abstract】 Exogenous salicylic acid(SA) improved abiotic tolerance in plants,and antioxidant defense system especially catalase(CAT) played important roles in abiotic tolerance.This study investigated the effect of exogenously applied SA on physiological characteristics and catalase genes expression in two different chilling-tolerant maize(Zea mays L.) inbred lines under chilling stress.The results showed that hydroponic treatment with 0.5 mM SA significantly alleviated the accumulation of malondialdehyde and hydrogen peroxide in leaves and roots of both lines under chilling stress.Besides,the of activities of catalase,ascorbate peroxidases(APX) and superoxide dismutases(SOD) were significantly increased by SA pretreatment in maize seedlings under chilling stress,while SA application decreased peroxidases activity in those seedlings.Three Cat genes responded differentially to SA application in leaves and roots of seedlings after chilling stress.Cat1 gene expression was improved by SA treatment both in leaves and roots of Mo 17 and conversely,the gene expression was inhibited in those of Huang C.Notably,SA application significantly enhanced Cat2 gene expression in both leaves and roots of two maize lines.However,Cat3 gene expression was inconsistent between leaves and roots of two lines responding SA treatment.The fresh and dry weights of seedlings were significantly increased by SA treatment under chilling stress.Overall,our results indicated that exogenous SA application increased tolerance of maize plants to chilling stress,mainly by enhancing the activities of APX,SOD and CAT and related Cat2 gene expression.更多还原