title: Genetic control of petiole length in Arabidopsis thaliana.
abstract: Shade-avoidance syndrome is characterized by the formation of elongated petioles and unexpanded leaf blades under low-intensity light, but the genetic basis for these responses is unknown. In this study, two-dimensional mutational analysis revealed that the gene for phytochrome B, PHYB, had opposing effects in the leaf petioles and leaf blades of Arabidopsis, while the ROT3, ACL2, and GAI genes influenced the length of leaf petioles more significantly than the length of leaf blades. Anatomical analysis revealed that the PHYB and ACL2 genes control the length of leaf petioles exclusively via control of the length of individual cells, while the GAI, GA1 and ROT3 genes appeared to control both the elongation and proliferation of petiole cells, in particular, under strong light. By contrast, both the size and the number of cells were affected by the mutations examined in leaf blades. The differential control of leaf petiole length and leaf blade expansion is discussed.
authors.affiliation: National Institute for Basic Biology, 38 Nishigonaka, Myodaiji-cho, Okazaki, 444-8585 Japan. tsukaya@nibb.ac.jp
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tsukaya
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kozuka
authors.forename: Gyung-Tae
authors.initials: GT
authors.lastname: Kim
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics; D048429:Cell Size / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D005875:Gibberellins / Q000494:pharmacology; D008027:Light; D009154:Mutation; D010641:Phenotype; D010786:Photoreceptor Cells; D010834:Phytochrome / Q000235:genetics*; D051939:Phytochrome B; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D012639:Seeds / Q000187:drug effects; D014157:Transcription Factors
chemical_list: D029681:Arabidopsis Proteins; C109555:GAI protein, Arabidopsis; D005875:Gibberellins; C497952:PHYB protein, Arabidopsis; D014157:Transcription Factors; D010834:Phytochrome; D051939:Phytochrome B; D003577:Cytochrome P-450 Enzyme System; C007842:gibberellic acid; C113876:ROT3 protein, Arabidopsis