TY - JOUR
T1 - A Semidwarf Phenotype of Barley uzu Results from a Nucleotide Substitution in the Gene Encoding a Putative Brassinosteroid Receptor
AU - Chono, Makiko
AU - Honda, Ichiro
AU - Zeniya, Haruko
AU - Yoneyama, Koichi
AU - Saisho, Daisuke
AU - Takeda, Kazuyoshi
AU - Takatsuto, Suguru
AU - Hoshino, Tsuguhiro
AU - Watanabe, Yoshiaki
PY - 2003/11
Y1 - 2003/11
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0344961281&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0344961281&partnerID=8YFLogxK
U2 - 10.1104/pp.103.026195
DO - 10.1104/pp.103.026195
M3 - Article
C2 - 14551335
AN - SCOPUS:0344961281
VL - 133
SP - 1209
EP - 1219
JO - Plant Physiology
JF - Plant Physiology
SN - 0032-0889
IS - 3
ER -