RRC ID 641
Author Chono M, Honda I, Zeniya H, Yoneyama K, Saisho D, Takeda K, Takatsuto S, Hoshino T, Watanabe Y.
Title A semidwarf phenotype of barley uzu results from a nucleotide substitution in the gene encoding a putative brassinosteroid receptor.
Journal Plant Physiol.
Abstract Brassinosteroids (BRs) play important roles throughout plant growth and development. Despite the importance of clarifying the mechanism of BR-related growth regulation in cereal crops, BR-related cereal mutants have been identified only in rice (Oryza sativa). We previously found that semidwarf barley (Hordeum vulgare) accessions carrying the "uzu" gene, called "uzu" barley in Japan, are non-responding for brassinolide (BL). We then performed chemical and molecular analyses to clarify the mechanisms of uzu dwarfism using isogenic line pairs of uzu gene. The response of the uzu line to BL was significantly lower than that of its corresponding normal line. Measurement of BRs showed that the uzu line accumulates BRs, similar to known BR-insensitive mutants. The marker synteny of rice and barley chromosomes suggests that the uzu gene may be homologous to rice D61, a rice homolog of Arabidopsis BR-insensitive 1 (BRI1), encoding a BR-receptor protein. A barley homolog of BRI1, HvBRI1, was isolated by using degenerate primers. A comparison of HvBRI1 sequences in uzu and normal barley varieties showed that the uzu phenotype is correlated with a single nucleotide substitution. This substitution results in an amino acid change at a highly conserved residue in the kinase domain of the BR-receptor protein. These results may indicate that uzu dwarfism is caused by the missense mutation in HvBRI1. The uzu gene is being introduced into all hull-less barley cultivars in Japan as an effective dwarf gene for practical use, and this is the first report about an agronomically important mutation related to BRs.
Volume 133(3)
Pages 1209-19
Published 2003-11
DOI 10.1104/pp.103.026195
PII pp.103.026195
PMID 14551335
PMC PMC281616
MeSH Amino Acid Sequence Base Sequence Brassinosteroids Cholestanols / pharmacology* Chromosome Mapping Chromosomes, Plant / genetics Cloning, Molecular DNA, Complementary / chemistry DNA, Complementary / genetics Hordeum / drug effects Hordeum / genetics* Hordeum / growth & development Molecular Sequence Data Mutation Oryza / genetics Phenotype Plant Growth Regulators / pharmacology* Plant Leaves / drug effects Plant Leaves / genetics* Plant Leaves / growth & development Plant Proteins / genetics Plant Proteins / metabolism Protein Kinases / genetics* Protein Kinases / metabolism Sequence Analysis, DNA Sequence Homology, Amino Acid Sequence Homology, Nucleic Acid Signal Transduction / drug effects Signal Transduction / genetics Signal Transduction / physiology Steroids, Heterocyclic / pharmacology* Synteny
IF 5.949
Times Cited 103
Barley UZU lines