title: LAZY1 controls rice shoot gravitropism through regulating polar auxin transport.
abstract: Tiller angle of rice (Oryza sativa L.) is an important agronomic trait that contributes to grain production, and has long attracted attentions of breeders for achieving ideal plant architecture to improve grain yield. Although enormous efforts have been made over the past decades to study mutants with extremely spreading or compact tillers, the molecular mechanism underlying the control of tiller angle of cereal crops remains unknown. Here we report the cloning of the LAZY1 (LA1) gene that regulates shoot gravitropism by which the rice tiller angle is controlled. We show that LA1, a novel grass-specific gene, is temporally and spatially expressed, and plays a negative role in polar auxin transport (PAT). Loss-of-function of LA1 enhances PAT greatly and thus alters the endogenous IAA distribution in shoots, leading to the reduced gravitropism, and therefore the tiller-spreading phenotype of rice plants.
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Peijin
authors.initials: P
authors.lastname: Li
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Fu
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.forename: Dali
authors.initials: D
authors.lastname: Zeng
authors.forename: Baohua
authors.initials: B
authors.lastname: Li
authors.forename: Xiujie
authors.initials: X
authors.lastname: Wang
authors.forename: Jiayang
authors.initials: J
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D001693:Biological Transport, Active; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018522:Gravitropism / Q000235:genetics*; D007210:Indoleacetic Acids / Q000378:metabolism*; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins