蒙古冰草咖啡酸氧甲基转移酶基因AmCOMT1的鉴定及功能分析  

Identification and Functional Analysis of an Agropyron mongolicum Caffeic Acid 3-O-methyltransferase Gene AmCOMT1

作　　者：杜锦瑜 孙震 苏彦龙 王贺萍 刘亚玲 吴振映[2,3,4] 何峰 赵彦 付春祥 Jinyu Du;Zhen Sun;Yanlong Su;Heping Wang;Yaling Liu;Zhenying Wu;Feng He;Yan Zhao;Chunxiang Fu(Key Laboratory of Grassland Resources and Education Ministry/Key Laboratory of Forage Cultivation,Processing and Efficient Utilization of Ministry of Agriculture and Rural Affairs/College of Grassland and Resources Environment of Inner Mongolia Agricultural University,Hohhot 010018,China;Qingdao Institute of Bioenergy and Process,Chinese Academy of Sciences,Qingdao 266101,China;Shandong energy Research Institute,Qingdao 266101,China;Qingdao New Energy Shandong Laboratory,Qingdao 266101,China;Inner Mongolia Grass Technology Innovation Center,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学草原与资源环境学院/农业农村部饲草栽培、加工与高效利用重点实验室/草地资源教育部重点实验室,呼和浩特010018 [2]中国科学院青岛生物能源与过程研究所,青岛266101 [3]山东能源研究院,青岛266101 [4]青岛新能源山东省实验室,青岛266101 [5]内蒙古草业技术创新中心有限公司,呼和浩特010018

出　　处：《植物学报》2024年第3期383-396,共14页Chinese Bulletin of Botany

基　　金：内蒙古自治区种业科技创新重大示范工程“揭榜挂帅”项目(No.2022JBGS0014);中央引导地方科技发展资金(No.2022ZY006);青岛新能源山东实验室“抓攻关”项目(No.QNESLKPP202302);国家林业和草原局重大应急科技“揭榜挂帅”项目(No.202201);呼和浩特市重大科技专项(No.2021-重-社-2)。

摘　　要：蒙古冰草(即沙芦草(Agropyron mongolicum))是我国北方代表性的多年生牧草之一,具有较强的耐寒和耐旱能力。在植物中,咖啡酸氧甲基转移酶基因(COMT)是参与木质素和褪黑素生物合成的关键基因,在调节植物生长、品质和抗逆性中发挥重要作用。通过分析蒙古冰草全长转录组数据,从蒙古冰草中克隆了COMT候选基因AmCOMT1。该基因在茎秆和根等木质素含量高的组织中高表达,且其表达受多种非生物胁迫诱导。在拟南芥(Arabidopsis thaliana)野生型(Col-0)和突变体(omt1-2)中过表达AmCOMT1,显著促进了转基因拟南芥的木质素合成,使突变体的木质素单体和组分恢复至野生型水平,同时Col-0/35S:AmCOMT1中木质素总量提高11%。此外, AmCOMT1过表达显著提高了Col-0/35S:AmCOMT1转基因拟南芥的褪黑素含量。在盐胁迫条件下,该株系平均根长相比野生型拟南芥提高20.3%,表现出更强的抗逆性。综上,蒙古冰草AmCOMT1基因在木质素和褪黑素合成中发挥关键作用,可提高转基因拟南芥的抗逆性,在蒙古冰草等单子叶牧草遗传改良方面具有重要应用潜力。Agropyron mongolicum is one of northern China’s most representative perennial forage grasses,showing strong tolerance to cold and drought.In plants,caffeic acid O-methyltransferase(COMT)is a key gene involved in the biosynthesis of lignin and melatonin,and plays an important role in regulating plant growth,biomass quality,and stress tolerance.In this study,through the analysis of the full-length transcriptome data of A.mongolicum,the COMT candidate gene AmCOMT1 was cloned.AmCOMT1 is highly expressed in tissues with high lignin content,such as stem and root,and its expression is induced by a variety of abiotic stresses,including drought and salt.Overexpression of AmCOMT1 in Arabidopsis wild type(Col-0)and mutant(omt1-2)significantly promoted the synthesis of lignin in transgenic Arabidopsis,restoring the lignin content and composition of the mutant to wild type level and the lignin content in Col-0/35S:AmCOMT1 was increased by 11%.In addition,overexpression of AmCOMT1 increased the melatonin content in Col-0/35S:AmCOMT1 transgenic Arabidopsis.Under salt stress conditions,the average root length of this transgenic line increased by 20.3%compared to the wild type,showing higher stress tolerance.In this study,we identified AmCOMT1 from A.mongolicum as a key gene regulating both lignin biosynthesis and melatonin biosynthesis,improving the stress tolerance of transgenic Arabidopsis.Our results highlighted the application potential of AmCOMT1 in genetic improvement of forage grasses through molecular breeding.

关 键 词：蒙古冰草 咖啡酸氧甲基转移酶 木质素 褪黑素 盐胁迫 

分 类 号：Q943.2[生物学—植物学] S543.9[农业科学—作物学]