title: Carlactone is converted to carlactonoic acid by MAX1 in Arabidopsis and its methyl ester can directly interact with AtD14 in vitro.
abstract: Strigolactones (SLs) stimulate seed germination of root parasitic plants and induce hyphal branching of arbuscular mycorrhizal fungi in the rhizosphere. In addition, they have been classified as a new group of plant hormones essential for shoot branching inhibition. It has been demonstrated thus far that SLs are derived from carotenoid via a biosynthetic precursor carlactone (CL), which is produced by sequential reactions of DWARF27 (D27) enzyme and two carotenoid cleavage dioxygenases CCD7 and CCD8. We previously found an extreme accumulation of CL in the more axillary growth1 (max1) mutant of Arabidopsis, which exhibits increased lateral inflorescences due to SL deficiency, indicating that CL is a probable substrate for MAX1 (CYP711A1), a cytochrome P450 monooxygenase. To elucidate the enzymatic function of MAX1 in SL biosynthesis, we incubated CL with a recombinant MAX1 protein expressed in yeast microsomes. MAX1 catalyzed consecutive oxidations at C-19 of CL to convert the C-19 methyl group into carboxylic acid, 9-desmethyl-9-carboxy-CL [designated as carlactonoic acid (CLA)]. We also identified endogenous CLA and its methyl ester [methyl carlactonoate (MeCLA)] in Arabidopsis plants using LC-MS/MS. Although an exogenous application of either CLA or MeCLA suppressed the growth of lateral inflorescences of the max1 mutant, MeCLA, but not CLA, interacted with Arabidopsis thaliana DWARF14 (AtD14) protein, a putative SL receptor, as shown by differential scanning fluorimetry and hydrolysis activity tests. These results indicate that not only known SLs but also MeCLA are biologically active in inhibiting shoot branching in Arabidopsis.
authors.affiliation: Department of Bioproductive Science, Graduate School of Agriculture, and.
authors.forename: Satoko
authors.initials: S
authors.lastname: Abe
authors.affiliation: Department of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan;
authors.forename: Aika
authors.initials: A
authors.lastname: Sado
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan;
authors.forename: Kai
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan;
authors.forename: Takaya
authors.initials: T
authors.lastname: Kisugi
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan;
authors.forename: Kei
authors.initials: K
authors.lastname: Asami
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan;
authors.forename: Saeko
authors.initials: S
authors.lastname: Ota
authors.affiliation: Department of Biological Production Science, The United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; and.
authors.forename: Hyun Il
authors.initials: HI
authors.lastname: Kim
authors.affiliation: Division for Biofunctional Molecular Analysis, Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya 321-8505, Japan;
authors.forename: Kaori
authors.initials: K
authors.lastname: Yoneyama
authors.affiliation: Department of Bioproductive Science, Graduate School of Agriculture, and Department of Biological Production Science, The United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; and Division for Biofunctional Molecular Analysis, Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya 321-8505, Japan;
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Applied Biochemistry, Graduate School of Agriculture, and Research Institute of Green Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ohnishi
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan;
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Seto
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan; shinjiro@m.tohoku.ac.jp akiyama@biochem.osakafu-u.ac.jp tnomura@cc.utsunomiya-u.ac.jp.
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Department of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan; shinjiro@m.tohoku.ac.jp akiyama@biochem.osakafu-u.ac.jp tnomura@cc.utsunomiya-u.ac.jp.
authors.forename: Kohki
authors.initials: K
authors.lastname: Akiyama
authors.affiliation: Department of Bioproductive Science, Graduate School of Agriculture, and Department of Biological Production Science, The United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; and Division for Biofunctional Molecular Analysis, Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya 321-8505, Japan;
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
authors.affiliation: Department of Bioproductive Science, Graduate School of Agriculture, and Department of Biological Production Science, The United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan; and Division for Biofunctional Molecular Analysis, Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya 321-8505, Japan; shinjiro@m.tohoku.ac.jp akiyama@biochem.osakafu-u.ac.jp tnomura@cc.utsunomiya-u.ac.jp.
authors.forename: Takahito
authors.initials: T
authors.lastname: Nomura
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000502:physiology*; D002264:Carboxylic Acids / Q000378:metabolism*; D002853:Chromatography, Liquid; D003001:Cloning, Molecular; D004926:Escherichia coli; D004952:Esters / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D007783:Lactones / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000096:biosynthesis*; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development; D053719:Tandem Mass Spectrometry; D015003:Yeasts
chemical_list: D029681:Arabidopsis Proteins; D002264:Carboxylic Acids; D004952:Esters; D007783:Lactones; C470445:MAX1 protein, Arabidopsis; D010937:Plant Growth Regulators; C571055:carlactone
keywords: Arabidopsis; biosynthesis; cytochrome P450; rice; strigolactone