CAJ | 학술논문

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．
촉진협편쇠로시식물격소말리산（JA ）적일개중요생물학공능．재식물체내，JA최초경13-지양합매（Lipoxygenase ，LOX）적작용이형성．RT-PCR발현，재발생쇠로적협편중， LOX3、LOX4、LOX6기인전록발생명현상조，이 LOX2재협편쇠로후기명현하조．구건료의남개9-LOX활성결실돌변체 lox1/lox5，이용해재료이아마산위저물측정료의남개협편발육불동계단13-LOX적활성，발현：여유눈협편상비，쇠로협편중 LOX 활성명현증강．추측LOX3、LOX4、LOX6기인재협편자연쇠로중JA적합성중구유중요작용，이 LOX2기인재쇠로후기작용감약．
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 .