AcTPR2基因诱导猕猴桃采后对灰霉病的抗性与木质素含量的关系  

Relationship Between AcTPR2 Induced Resistance of Harvested Kiwifruit(Actinidia chinensis)to Botrytis cinerea and Lignin Content

作　　者：李哲馨 任云 李强[2] 决登伟 唐建民[2] 宋洪元 LI Zhe-Xin;REN Yun;LI Qiang;JUE Deng-Wei;TANG Jian-Min;SONG Hong-Yuan(Key Laboratory of Horticulture Science for Southern Mountains Regions,Ministry of Education/College of Horticulture and Landscape Architecture,Southwest University,Chongqing 400715,China;Chongqing Key Laboratory of Economic Plant Biotechnology/Chongqing Special Plant Industry Collaborative Innovation Center/College of Landscape Architecture and Life Science/Institute of Special Plants,Chongqing University of Arts and Sciences,Chongqing 402160,China)

机构地区：[1]西南大学园艺园林学院/南方山地园艺学教育部重点实验室,重庆400715 [2]重庆文理学院园林与生命科学学院/特色植物研究院/重庆市特色植物产业协同创新中心/重庆市经济植物生物技术重点实验室,重庆402160

出　　处：《农业生物技术学报》2023年第10期2048-2057,共10页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(32001351);重庆市教育委员会科学技术研究项目(KJQN202201304)。

摘　　要：猕猴桃(Actinidia chinensis)是我国山区农民脱贫致富的支柱产业之一。由灰霉菌(Botrytis cinerea)引起的灰霉病极易造成猕猴桃采后腐败,严重制约着猕猴桃产业的发展。研究表明细胞壁的木质化是植物产生抗性的主要机制之一。本课题组前期采用病毒诱导的基因沉默(virus induced gene silencing,VIGS)技术获得了沉默表达TOPLESS/TOPLESS-RELATED(TPL/TPR)家族AcTPR2基因的猕猴桃果实。基于此,本研究以灭菌水处理的猕猴桃(WT)、转化未连接AcTPR2基因的空载体组(Tobacco rattle virus,TRV)以及成功实现AcTPR2基因下调表达的转基因组(AcTPR2-TRV)猕猴桃为实验材料,通过检测灰霉菌侵染前后猕猴桃的木质素含量及其合成途径关键酶基因的表达量,探究AcTPR2基因诱导猕猴桃果实对灰霉病的抗性与木质素含量的关系。结果显示,与对照组相比,灰霉菌侵染猕猴桃果实后24~48 h即检测到木质素含量显著增加(P<0.05),说明木质素的积累在猕猴桃抵御灰霉菌侵染的前期就参与了抗病反应,猕猴桃木质素合成途径关键酶苯丙氨酸解氨酶(phenylalanine ammonia lyase,PAL)基因、肉桂酸-4-羟化酶(cinnamate 4-hydroxylase,C4H)基因、香豆酸-3-羟化酶(coumaric acid 3-hydroxylase,C3H)基因及肉桂酰辅酶A还原酶(cinnamoyl-CoA reductase,CCR)基因的表达与木质素含量增加趋势相一致;AcTPR2-TRV2组猕猴桃木质素含量及相关基因的表达量在转化成功后24 h即较对照组显著增加(P<0.05),表明在AcTPR2基因沉默后,猕猴桃果实更加迅速地激活了木质素合成信号通路,以加速合成木质素参与猕猴桃对灰霉病的抗性响应。因此,AcTPR2调控的猕猴桃果实细胞壁的木质化与猕猴桃灰霉病的抗性响应有关,是猕猴桃抗病反应的机制之一。研究结果从理论上丰富了猕猴桃的抗病调控机制,也为实践中猕猴桃的抗病分子育种提供重要的基因资源信息。Kiwifruit(Actinidia chinensis)is one of the pillar industries for farmers in mountainous areas to fight poverty.Gray mold caused by Botrytis cinerea is easy to cause postharvest corruption of kiwifruit,which seriously restricts the development of kiwifruit industry.In our research group previous study,kiwifruit samples with AcTPR2 gene down-regulated were obtained by virus induced gene silencing(VIGS)method.On this basis,kiwifruit treated with sterile water(WT),transformed with empty vector Tobacco rattle virus(TRV)without AcTPR2 gene,and transgenic kiwifruit(AcTPR2-TRV)that successfully achieved the down-regulation of AcTPR2 gene expression were used as materials,By detecting the lignin content of kiwifruit infected by B.cinerea and the expression of key enzyme genes in lignin biosynthesis pathway,the relationship between AcTPR2 induced resistance of kiwifruit to B.cinerea and the lignin content was explored.The results showed that compared with the control group,a significant increase in lignin content was detected 24~48 h after B.cinerea infection,indicating that the lignin accumulation was involved in the early stage of kiwifruit resistance to B.cinerea infection,and the expression of key enzyme genes in lignin synthesis pathway like phenylalanine ammonia lyase(PAL),cinnamate 4-hydroxylase(C4H),coumaric acid 3-hydroxylase(C3H)and cinnamoyl-CoA reductase(CCR)was consistent with the increasing trend of lignin content.The lignin content and the expression of related genes in AcTPR2-TRV fruits increased significantly compared with the control group at 24 h after successful transformation,indicating that kiwifruit with AcTPR2 down-regulated activated the lignin synthesis signal pathway to accelerate lignin biosynthesis and participate in the resistance response of kiwifruit to gray mold(P<0.05).Therefore,the lignification of kiwifruit cell wall regulated by AcTPR2 is related to the resistance response of kiwifruit to B.cinerea,which is one of the mechanisms of disease resistance response in kiwifruit.The results o

关 键 词：猕猴桃 灰霉菌 AcTPR2(TOPLESS/TOPLESS-RELATED 2) 木质素 抗性 

分 类 号：S663.4[农业科学—果树学]