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 o...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.展开更多
The Gibberellic Acid-stimulated Arabidopsis(GASA)gene family is involved in the regulation of gene expression and plant growth,development,and stress responses.To investigate the function of loquat GASA genes in the g...The Gibberellic Acid-stimulated Arabidopsis(GASA)gene family is involved in the regulation of gene expression and plant growth,development,and stress responses.To investigate the function of loquat GASA genes in the growth and developmental regulation of plants,a loquat EjGASA6 gene homologous to Arabidopsis AtGASA6 was cloned.EjGASA6 expression was induced by gibberellin,and ectopic transgenic plants containing this gene exhibited earlier bloom and longer primary roots since these phenotypic characteristics are related to higher gibberellin content.Transcriptome analysis and qRT-PCR results showed that the expression levels of GA3ox1 and GA20ox1,which encode key enzymes in gibberellin biosynthesis,were significantly increased.Furthermore,we confirmed that EjGASA6 could promote the expression of GA20ox1 via the luciferase reporter system.Overall,our results suggest that EjGASA6 promotes blooming and main-root elongation by positively regulating gibberellin biosynthesis.These findings broaden our understanding of the role of GASAs in plant development and growth,and lay the groundwork for future research into the functions of EjGASA6 in regulating loquat growth and development.展开更多
Gibberellin(GA)functions in plant growth and development.However,genes involved in the biosynthesis and regulation of GA in crop plants are poorly understood.We isolated the mutant gad5-1(GAAssociated Dwarf 5),charact...Gibberellin(GA)functions in plant growth and development.However,genes involved in the biosynthesis and regulation of GA in crop plants are poorly understood.We isolated the mutant gad5-1(GAAssociated Dwarf 5),characterized by dwarfing,short internodes,and dark green and short leaves.Map-based gene cloning and allelic verification confirmed that ZmGAD5 encodes ent-kaurenoic acid oxidase(KAO),which catalyzes KA(ent-kaurenoic acid)to GA12 conversion during GA biosynthesis in maize.ZmGAD5 is localized to the endoplasmic reticulum and is present in multiple maize organs.In gad5-1,the expression of ZmGAD5 is severely reduced,and the levels of the direct substrate of KAO,KA,is increased,leading to a reduction in GA content.The abnormal phenotype of gad5-1 was restored by exogenous application of GA3.The biomass,plant height,and levels of GA12 and GA3 in transgenic Arabidopsis overexpressing ZmGAD5 were increased in comparison with the corresponding controls Col-0.These findings deepen our understanding of genes involved in GA biosynthesis,and could lead to the development of maize lines with improved architecture and higher planting-density tolerance.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.3210236932372681)+1 种基金Natural Science Foundation of Jiangsu Province(BK20211366)the Priority Academic Program Development of Jiangsu Higher Education Institutions Project(PAPD)。
文摘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.
基金financially supported by the National Key R&D Program of China (2023YFD1600800)the National Nature Science Foundation of China (32102321)+4 种基金the Chongqing Science and Technology Commission, China (cstc2024ycjh-bgzxm0202, cstc2021jscx-gksbX0010 and cstc2021jcyj-msxmX1156)the Chongqing Forestry Administration, China (YuLinKeYan2022-14)the Innovation Research Group Funds for Chongqing Universities, China (CXQT19005)the Characteristic Fruit Industry and Technology System Innovation Team of Chongqing Agriculture and Rural Affairs Commission, China [(2022)164 and 2020(3)01]the Chongqing Postgraduate Research and Innovation Programme, China (CYB23128)
文摘The Gibberellic Acid-stimulated Arabidopsis(GASA)gene family is involved in the regulation of gene expression and plant growth,development,and stress responses.To investigate the function of loquat GASA genes in the growth and developmental regulation of plants,a loquat EjGASA6 gene homologous to Arabidopsis AtGASA6 was cloned.EjGASA6 expression was induced by gibberellin,and ectopic transgenic plants containing this gene exhibited earlier bloom and longer primary roots since these phenotypic characteristics are related to higher gibberellin content.Transcriptome analysis and qRT-PCR results showed that the expression levels of GA3ox1 and GA20ox1,which encode key enzymes in gibberellin biosynthesis,were significantly increased.Furthermore,we confirmed that EjGASA6 could promote the expression of GA20ox1 via the luciferase reporter system.Overall,our results suggest that EjGASA6 promotes blooming and main-root elongation by positively regulating gibberellin biosynthesis.These findings broaden our understanding of the role of GASAs in plant development and growth,and lay the groundwork for future research into the functions of EjGASA6 in regulating loquat growth and development.
基金the National Natural Science Foundation of China(U21A20206,Chun-Peng Song)the Project of Sanya Yazhou Bay Science and Technology City(SCKJJYRC-2022-78,Baozhu Li)+1 种基金the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(21IRTSTHN019,Siyi Guo)the 111 Project of China(D16014).
文摘Gibberellin(GA)functions in plant growth and development.However,genes involved in the biosynthesis and regulation of GA in crop plants are poorly understood.We isolated the mutant gad5-1(GAAssociated Dwarf 5),characterized by dwarfing,short internodes,and dark green and short leaves.Map-based gene cloning and allelic verification confirmed that ZmGAD5 encodes ent-kaurenoic acid oxidase(KAO),which catalyzes KA(ent-kaurenoic acid)to GA12 conversion during GA biosynthesis in maize.ZmGAD5 is localized to the endoplasmic reticulum and is present in multiple maize organs.In gad5-1,the expression of ZmGAD5 is severely reduced,and the levels of the direct substrate of KAO,KA,is increased,leading to a reduction in GA content.The abnormal phenotype of gad5-1 was restored by exogenous application of GA3.The biomass,plant height,and levels of GA12 and GA3 in transgenic Arabidopsis overexpressing ZmGAD5 were increased in comparison with the corresponding controls Col-0.These findings deepen our understanding of genes involved in GA biosynthesis,and could lead to the development of maize lines with improved architecture and higher planting-density tolerance.
