Abstract: [Objective] Jasmonic methylester transferase(JMT)can effectively facilitate the production of jasmonic methylester,so that it enhances plant drought resistance.[Method]A 450 bp silence fragment of GhJMT was cloned from cotton XLZ17(Gossypium hirsutum)using PCR amplification,and then constructed into vector pTRV.The recombinant plasmid pTRV-GhJMT was transformed into competent Agrobacterium tumefaciens(GV3101).Cotton seedlings in hydroponic conditions were infected with the transformed A.tumefaciens GV3101.After one month,the growing cotton seedlings were treated with PEG6000 for 24 h.The water content,the molality of osmotic adjustment substances,photosynthetic pigments,antioxidants and malondialdehyde(MDA)as well as enzymes activities in cotton leaves under drought stress were measured.[Result]The results showed that content of soluble sugar,ASA,betaine,proline and SOD were reduced by 42.1;,36.6;,69.4;and 71.6;compared with the pTRV-00,and MDA,O2-and H2O2 were increased 0.43,1.45 and 0.59 times compared with pTRV-GhJMT,respectively.[Conclusion]Our results demonstrate that GhJMT gene silencing can directly affect the physiological and biochemical characteristics of cotton seedlings treated with drought stress and reduce drought resistant ability of cotton.

摘要： [目的]通过病毒诱导的基因沉默技术(VIGS)沉默棉花茉莉酸甲酯转移酶(GhJMT)基因,分析GhJMT基因在干旱胁迫下的功能.[方法]利用PCR技术扩增获得450 bp的GhJMT沉默基因片段,与pTRV-RNA2质粒连接构建成重组载体pTRV-GhJMT,转化农杆菌(GV3101),侵染的棉花幼苗1个月后再进行PEG6000干旱胁迫处理24 h,检测干旱胁迫下棉花幼苗的含水量、光合色素含量及渗调物质、抗氧化物、丙二醛(MDA)浓度和酶活性的变化.[结果]显示沉默GhJMT后棉花幼苗叶片中可溶性糖、抗坏血酸(ASA)、甜菜碱、脯氨酸含量和超氧化物气化酶(SOD)活力分别降低了42.1;、36.6;、69.4;、71.6;和16.67;,而MDA、O2-和H2O2含量则分别增加了0.43、1.45和0.59倍.[结论]棉花GhJMT基因的沉默能够直接影响干旱胁迫后棉花幼苗的抗旱生理生化特性,降低棉花的抗旱能力.