title: Loose Plant Architecture1, an INDETERMINATE DOMAIN protein involved in shoot gravitropism, regulates plant architecture in rice.
abstract: Tiller angle and leaf angle are two important components of rice (Oryza sativa) plant architecture that play a crucial role in determining grain yield. Here, we report the cloning and characterization of the Loose Plant Architecture1 (LPA1) gene in rice, the functional ortholog of the AtIDD15/SHOOT GRAVITROPISM5 (SGR5) gene in Arabidopsis (Arabidopsis thaliana). LPA1 regulates tiller angle and leaf angle by controlling the adaxial growth of tiller node and lamina joint. LPA1 was also found to affect shoot gravitropism. Expression pattern analysis suggested that LPA1 influences plant architecture by affecting the gravitropism of leaf sheath pulvinus and lamina joint. However, LPA1 only influences gravity perception or signal transduction in coleoptile gravitropism by regulating the sedimentation rate of amyloplasts, distinct from the actions of LAZY1. LPA1 encodes a plant-specific INDETERMINATE DOMAIN protein and defines a novel subfamily of 28 INDETERMINATE DOMAIN proteins with several unique conserved features. LPA1 is localized in the nucleus and functions as an active transcriptional repressor, an activity mainly conferred by a conserved ethylene response factor-associated amphiphilic repression-like motif. Further analysis suggests that LPA1 participates in a complicated transcriptional and protein interaction network and has evolved novel functions distinct from SGR5. This study not only facilitates the understanding of gravitropism mechanisms but also generates a useful genetic material for rice breeding.
authors.affiliation: State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xinru
authors.initials: X
authors.lastname: Wu
authors.forename: Ding
authors.initials: D
authors.lastname: Tang
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Kejian
authors.initials: K
authors.lastname: Wang
authors.forename: Zhukuan
authors.initials: Z
authors.lastname: Cheng
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018522:Gravitropism; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018087:Plastids / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C112487:Id1 protein, plant; D010940:Plant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors