title: A wheat aminocyclopropane-1-carboxylate oxidase gene, TaACO1, negatively regulates salinity stress in Arabidopsis thaliana.
abstract: TaACO1 could catalyze ACC into ethylene in vitro. Constitutive expression of TaACO1 in Arabidopsis conferred salt sensitivity, and TaACO1 regulates salt stress mainly via the DREB1/CBF signal transduction pathway. Ethylene signaling plays essential roles in mediating plant responses to biotic and abiotic stresses, besides regulating plant growth and development. The roles of ethylene biosynthesis in abiotic stress, however, remain elusive. In this study, an aminocyclopropane-1-carboxylate oxidase gene, TaACO1, affecting the terminal step in ethylene biosynthesis, was isolated from a salt-tolerant bread wheat introgression line Shanrong No. 3 (SR3) and its effect on salt-stress response was examined. Purified recombinant protein of TaACO1 heterogenously expressed in Escherchia coli could catalyze ACC into ethylene in vitro. TaACO1 transcripts were down-regulated by salt, drought, oxidative stress and ABA. TaACO1-transgenic plants conferred salt sensitivity as judged from the seed germination, cotyledon greening and the relative root growth under salt stress. Constitutive expression of TaACO1 in Arabidopsis increased AtMYB15 expression and suppressed the expression of stress-responsive genes AtRAB18, AtCBF1 and AtCBF3. These findings are helpful in understanding the roles of ethylene biosynthesis in plant salt-stress response.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Donghua
authors.initials: D
authors.lastname: Chen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Ma
authors.forename: Chunlong
authors.initials: C
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Guangmin
authors.initials: G
authors.lastname: Xia
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000594:Amino Acid Oxidoreductases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D000598:Amino Acids, Cyclic / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000201:enzymology; D003593:Cytoplasm / Q000201:enzymology; D055864:Droughts; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000235:genetics; D018613:Microscopy, Confocal; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics*; D012639:Seeds / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014908:Triticum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism
chemical_list: D000598:Amino Acids, Cyclic; D029681:Arabidopsis Proteins; D005030:Ethylenes; C539643:Myb15 protein, Arabidopsis; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C023863:1-aminocyclopropane-1-carboxylic acid; D012965:Sodium Chloride; D000040:Abscisic Acid; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase