13-脂氧合酶在拟南芥叶片衰老中的作用分析  

Analysis of the role of 13-Lipoxygenases in Arabidopsis leaf senescence

作　　者：孙炎锋 吕东[2] 王丽[2] 苗琛[2] 林宏辉[1] 

机构地区：[1]四川大学生命科学学院生物资源与生态环境教育部重点实验室,成都610064 [2]河南大学生命科学学院棉花生物学国家重点实验室,开封475004

出　　处：《四川大学学报（自然科学版）》2013年第6期1391-1396,共6页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(91017004;31170252;31070238)

摘　　要：促进叶片衰老是植物激素茉莉酸(JA)的一个重要生物学功能.在植物体内,JA最初经13-脂氧合酶(Lipoxygenase,LOX)的作用而形成.RT-PCR发现,在发生衰老的叶片中,LOX3、LOX4、LOX6基因转录发生明显上调,而LOX2在叶片衰老后期明显下调.构建了拟南芥9-LOX活性缺失突变体lox1/lox5,利用该材料以亚麻酸为底物测定了拟南芥叶片发育不同阶段13-LOX的活性,发现:与幼嫩叶片相比,衰老叶片中LOX活性明显增强.推测LOX3、LOX4、LOX6基因在叶片自然衰老中JA的合成中具有重要作用,而LOX2基因在衰老后期作用减弱.Promotion of leaf senescence is one of the most important function of the phytohormone Jas-monic acid （JA ） .In plants ,JA is initially synthesized by the reaction catalyzed by 13-lipoxygenase （LOX） .Four genes are predicted to encode 13-LOX in A rabidopsis genome ,however ,little is known a-bout their role in JA regulated leaf senescence .Expression pattern analysis by RT-PCR showed that LOX3 ,LOX4 and LOX6 genes expression were significantly enhanced in senescing leaves ,while the ex-pression of LOX2 genes decreased in late stage of leaf senescence dramatically .The 9-LOX activity defi-cient mutant lox1/lox5 was acquired and the 13-LOX activities in leaves at different developmental sta-ges were further measured using linolenic acid as substrate .The activity in senescing leaves was signifi-cantly higher than that in developing young leaves .The results indicated that LOX3 , LOX4 , LOX6 might play important roles in JA synthesis during leaf senescence and the importance of LOX2 might be impaired at the late stage of this process .

关 键 词：衰老 脂氧合酶 茉莉酸 拟南芥 

分 类 号：Q945[生物学—植物学]