Dc GA20ox2 and DcGA2ox1 alter endogenous gibberellin contents and adjust lignin accumulation in carrot  

作　　者：Min Jia Yahui Wang Chen Chen Rongrong Zhang Guanglong Wang Aisheng Xiong 

机构地区：[1]State Key Laboratory of Crop Genetics&Germplasm Enhancement and Utilization,Ministry of Agriculture and Rural Affairs Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in East China,College of Horticulture,Nanjing Agricultural University,Nanjing,Jiangsu 210095,China [2]School of Life Science and Food Engineering,Huaiyin Institute of Technology,Huaian,Jiangsu 223003,China

出　　处：《Horticultural Plant Journal》2024年第6期1398-1413,共16页园艺学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.32102369;32372681);Natural Science Foundation of Jiangsu Province(BK20211366);the Priority Academic Program Development of Jiangsu Higher Education Institutions Project(PAPD)。

摘　　要：Gibberellins(GAs)are a class of plant hormones that can affect plant growth and development.GA-oxidases are rate-limiting enzymes,which play a direct role in GA accumulation in plants.However,the roles of GA-oxidase on carrot(Daucus carota L.)taproot development are still unclear.In this study,two GA-oxidase genes,DcGA20ox2 and DcGA2ox1,were identified in carrot.Transgenic carrot plants were obtained by using Agrobacterium-mediated genetic transformation method.The results showed that overexpression of DcGA20ox2 significantly promoted the accumulation of active GAs in carrot,increased plant height,generated more branches,and enhanced xylem development.Overexpression of DcGA2ox1 significantly reduced the total contents of active GAs compared with the control group,resulting in a dwarf phenotype and markedly increased lignin content of the transgenic carrot.The expression profiling showed that the genes of GA metabolic pathway responded to the negative feedback regulation mechanism.At the same time,the expression of most genes in lignin biosynthesis and polymerization process was up-regulated,corresponding to the massive accumulation of lignin.These findings indicated that DcGA20ox2 and DcGA2ox1affected carrot growth and development by regulating the levels of endogenous GAs.The results from current work might shed light on further studies aimed to regulate lignification in carrot and other crops.

关 键 词：Daucus carota GIBBERELLIN GA-oxidase Lignin GA accumulation 

分 类 号：S631.2[农业科学—蔬菜学]