title: A comprehensive genetic study reveals a crucial role of CYP90D2/D2 in regulating plant architecture in rice (Oryza sativa).
abstract: Brassinosteroids (BRs) are essential regulators of plant architecture. Understanding how BRs control plant height and leaf angle would facilitate development of new plant type varieties by biotechnology. A number of mutants involved in BR biosynthesis have been isolated but many of them lack detailed genetic analysis. Here, we report the isolation and characterization of a severe dwarf mutant, chromosome segment deleted dwarf 1 (csdd1), which was deficient in BR biosynthesis in rice. We isolated the mutant by screening a tissue culture-derived population, cloned the gene by mapping, and confirmed its function by complementary and RNAi experiments, combined with physiological and chemical analysis. We showed that the severe dwarf phenotype was caused by a complete deletion of a cytochrome P450 gene, CYP90D2/D2, which was further confirmed in two independent T-DNA insertion lines in different genetic backgrounds and by RNA interference. Our chemical analysis suggested that CYP90D2/D2 might catalyze C-3 dehydrogenation step in BR biosynthesis. We have demonstrated that the CYP90D2/D2 gene plays a more important role than previously reported. Allelic mutations of CYP90D2/D2 confer varying degrees of dwarfism and leaf angle, thus providing useful information for molecular breeding in grain crop plants.
authors.affiliation: State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Youn
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Cheng
authors.forename: Tianyun
authors.initials: T
authors.lastname: Jin
authors.forename: Xiaoding
authors.initials: X
authors.lastname: Ma
authors.forename: Xiuping
authors.initials: X
authors.lastname: Guo
authors.forename: Jiulin
authors.initials: J
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Fuqing
authors.initials: F
authors.lastname: Wu
authors.forename: Chuanyin
authors.initials: C
authors.lastname: Wu
authors.forename: Seong-Ki
authors.initials: SK
authors.lastname: Kim
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wan
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D020029:Base Pairing; D001483:Base Sequence; D060406:Brassinosteroids / Q000494:pharmacology; D032461:Chromosomes, Plant / Q000235:genetics; D003001:Cloning, Molecular; D017343:Genes, Plant / Q000235:genetics; D005816:Genetic Complementation Test; D056426:Genetic Loci / Q000235:genetics; D008969:Molecular Sequence Data; D012275:Oryza / Q000033:anatomy & histology* / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D010641:Phenotype; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D034622:RNA Interference / Q000187:drug effects; D017384:Sequence Deletion
chemical_list: D060406:Brassinosteroids; D010940:Plant Proteins
keywords: C-23 hydroxylase; C-3 dehydrogenase; CYP90D2/D2; brassinosteroid biosynthesis; chromosome segment deleted dwarf 1 (csdd1); dwarf; plant architecture; rice (Oryza sativa)