title: Functional roles of three cutin biosynthetic acyltransferases in cytokinin responses and skotomorphogenesis.
abstract: Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis.
authors: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors: Lei
authors: L
authors: Wu
authors: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors: Zhao-Yang
authors: ZY
authors: Zhou
authors: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China; Laboratory of Molecular and Cell Biology, Hebei Normal University, Shijiazhuang, China.
authors: Chun-Guang
authors: CG
authors: Zhang
authors: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors: Juan
authors: J
authors: Chai
authors: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors: Qin
authors: Q
authors: Zhou
authors: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors: Li
authors: L
authors: Wang
authors: Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, Czech Republic.
authors: Eva
authors: E
authors: Hirnerová
authors: Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, Czech Republic.
authors: Michaela
authors: M
authors: Mrvková
authors: Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Faculty of Science, Palacký University, Šlechtitelů 11, Olomouc, Czech Republic.
authors: Ondřej
authors: O
authors: Novák
authors: MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
authors: Guang-Qin
authors: GQ
authors: Guo
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003583:Cytokinins / Q000378:metabolism* / Q000494:pharmacology; D003624:Darkness; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D008563:Membrane Lipids / Q000096:biosynthesis*; D018519:Meristem / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D009024:Morphogenesis / Q000187:drug effects / Q000528:radiation effects; D009154:Mutation; D010641:Phenotype; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D008563:Membrane Lipids; C000521:cutin; D000217:Acyltransferases