外源水杨酸对低温下黄瓜幼苗CsFAD的表达调控  

Effects of Exogenous Salicylic Acid on the Expression of CsFAD Genes in Cucumber Seedlings Under Low Temperature

作　　者：曹宁[1] 董春娟[1] 尚庆茂[1] CAO Ning DONG Chun-juan SHANG Qing-mao(Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement ofHorticulturalCrops, Ministry ofAgriculture, Beijing 100081, China)

机构地区：[1]中国农业科学院蔬菜花卉研究所农业部园艺作物生物学与种质创制重点实验室,北京100081

出　　处：《园艺学报》2016年第10期1941-1952,共12页Acta Horticulturae Sinica

基　　金：国家现代农业产业技术体系建设专项资金项目(CARS-25);公益性行业(农业)科研专项(201303014);中国农业科学院科技创新工程项目(CAAS-ASTIP-IVFCAAS);农业部农业科研杰出人才及其创新团队项目

摘　　要：为探究外源水杨酸(SA)对低温下黄瓜幼苗脂肪酸组成的影响,采用根系施用SA的方法,测定了正常生长温度和低温(8℃)条件下SA处理对黄瓜幼苗叶片中脂肪酸含量、组分,以及脂肪酸去饱和酶基因(CsFAD)表达水平的影响。结果表明:根系施用SA能降低叶片中因低温引起的丙二醛积累和相对电解质渗漏,维持细胞膜稳定性;低温引起叶片中总脂肪酸含量减少,C_(18:3)等多不饱和脂肪酸相对含量降低,C_(18:0)、C_(18:1)等脂肪酸比例升高,脂肪酸双键指数降低;根系施用SA后,叶片中总脂肪酸含量、脂肪酸不饱和度及双键指数均得以恢复;低温诱导叶片中CsFAD的表达,低温下外源施用SA可进一步促进CsFAB2.1、CsFAB2.2、CsFAD2.1、Cs FAD6和CsFAD7等的表达。总之,SA可以诱导黄瓜幼苗中CsFAD的表达,维持细胞膜脂肪酸不饱和度,提高细胞膜稳定性,诱导耐低温性。To explore the effects of salicylic acid（SA）on fatty acid compositions in cucumber（Cucumis sativus L.）seedlings under low temperature,the changes in total contents of fatty acids and relative content of each composition,as well as the expression levels of fatty acid desaturase genes（CsFADs）were detected. The results showed that SA application could repress the low temperatureinduced increase in malondialdehyde content and relative electrolyte leakages,and maintain the stability of cell membranes. Under low temperature,total contents of fatty acids were decreased. Especially,the relative contents of polyunsaturated fatty acids（e.g. C18：3）were decreased,while the ratio of C18：0 and C18：1increased. Thereby,the double bond index of fatty acid was reduced. After SA application,both total contents and unsaturation degree of fatty acid could be restored. Low temperature could induce the expression of Cs FAD genes. After SA application,the induction folds of Cs FAB2.1,Cs FAB2.2,Cs FAD2.1 and Cs FAD7 were significantly increased. In summary,in the cucumber seedlings exposed to low temperature,exogenous application of SA could induce the expression of Cs FAD genes to increase the unsaturation degree of fatty acids,thereby enhance the stability of cell membranes,and finally increase the stress tolerance of seedlings.

关 键 词：黄瓜 脂肪酸 水杨酸 脂肪酸去饱和酶 低温 

分 类 号：S642.2[农业科学—蔬菜学]