| 28 matches found in 12 documents. Search time: 0.001 seconds. |
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Score: 5.00 |
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| Title: Loss of function of a rice brassinosteroid insensitive1 homolog prevents internode elongation and bending of the lamina joint .
| | Author: Yamamuro C Ihara Y Wu X Noguchi T Fujioka S Takatsuto S Ashikari M Kitano H Matsuoka M | | Journal: Plant Cell Citation: V : 12 ( 9 ) P : 1591-606 Year: 2000 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub11006334 Accession (PMID): 11006334 | | Abstract: Brassinosteroids ( BRs ) are plant growth-promoting natural products required for plant growth and development .
Physiological studies have demonstrated that exogenous BR , alone or in combination with auxin , enhance bending of the lamina joint of rice .
However , little is known about the function of endogenous BR in rice or other grass species .
We report here the phenotypical and molecular characterization of a rice dwarf mutant , d61 , that is less sensitive to BR compared to the wild type .
We cloned a rice gene , OsBRI1 , with extensive sequence similarity to that of the Arabidopsis BRI gene , which encodes a putative BR receptor kinase .
Linkage analysis showed that the OsBRI1 gene is closely linked to the d61 locus .
Single nucleotide substitutions found at different sites of the d61 alleles would give rise to amino acid changes in the corresponding polypeptides .
Furthermore , introduction of the entire OsBRI1 coding region , including the 5 and 3 flanking sequences , into d61 plants complemented the mutation to display the wild-type phenotype .
Transgenic plants carrying the antisense strand of the OsBRI1 transcript showed similar or even more severe phenotypes than those of the d61 mutants .
Our results show that OsBRI1 functions in various growth and developmental processes in rice , including ( 1 ) internode elongation , by inducing the formation of the intercalary meristem and the longitudinal elongation of internode cells ; ( 2 ) bending of the lamina joint ; and ( 3 ) skotomorphogenesis . | | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: A semidwarf phenotype of barley uzu results from a nucleotide substitution in the gene encoding a putative brassinosteroid receptor .
| | Author: Chono M Honda I Zeniya H Yoneyama K Saisho D Takeda K Takatsuto S Hoshino T Watanabe Y | | Journal: Plant Physiol .
Citation: V : 133 ( 3 ) P : 1209-19 Year: 2003 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub14551335 Accession (PMID): 14551335 | | 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 . | | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: A rice brassinosteroid-deficient mutant , ebisu dwarf ( d2 ) , is caused by a loss of function of a new member of cytochrome P450 .
| | Author: Hong Z Ueguchi-Tanaka M Umemura K Uozu S Fujioka S Takatsuto S Yoshida S Ashikari M Kitano H Matsuoka M | | Journal: Plant Cell Citation: V : 15 ( 12 ) P : 2900-10 Year: 2003 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub14615594 Accession (PMID): 14615594 | | Abstract: We characterized a rice dwarf mutant , ebisu dwarf ( d2 ) .
It showed the pleiotropic abnormal phenotype similar to that of the rice brassinosteroid ( BR ) -insensitive mutant , d61 .
The dwarf phenotype of d2 was rescued by exogenous brassinolide treatment .
The accumulation profile of BR intermediates in the d2 mutants confirmed that these plants are deficient in late BR biosynthesis .
We cloned the D2 gene by map-based cloning .
The D2 gene encoded a novel cytochrome P450 classified in CYP90D that is highly similar to the reported BR synthesis enzymes .
Introduction of the wild D2 gene into d2-1 rescued the abnormal phenotype of the mutants .
In feeding experiments , 3-dehydro-6-deoxoteasterone , 3-dehydroteasterone , and brassinolide effectively caused the lamina joints of the d2 plants to bend , whereas more upstream compounds did not cause bending .
Based on these results , we conclude that D2/CYP90D2 catalyzes the steps from 6-deoxoteasterone to 3-dehydro-6-deoxoteasterone and from teasterone to 3-dehydroteasterone in the late BR biosynthesis pathway . | | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 4.00 |
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| Title: The role of OsBRI1 and its homologous genes , OsBRL1 and OsBRL3 , in rice .
| | Author: Nakamura A Fujioka S Sunohara H Kamiya N Hong Z Inukai Y Miura K Takatsuto S Yoshida S Ueguchi-Tanaka M Hasegawa Y Kitano H Matsuoka M | | Journal: Plant Physiol .
Citation: V : 140 ( 2 ) P : 580-90 Year: 2006 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub16407447 Accession (PMID): 16407447 | | Abstract: Since first identifying two alleles of a rice ( Oryza sativa ) brassinosteroid ( BR ) -insensitive mutant , d61 , that were also defective in an orthologous gene in Arabidopsis ( Arabidopsis thaliana ) BRASSINOSTEROID INSENSITIVE1 ( BRI1 ) , we have isolated eight additional alleles , including null mutations , of the rice BRI1 gene OsBRI1 .
The most severe mutant , d61-4 , exhibited severe dwarfism and twisted leaves , although pattern formation and differentiation were normal This severe shoot phenotype was caused mainly by a defect in cell elongation and the disturbance of cell division after the determination of cell fate .
In contrast to its severe shoot phenotype , the d61-4 mutant had a mild root phenotype .
Concomitantly , the accumulation of castasterone , the active BR in rice , was up to 30-fold greater in the shoots , while only 1 . 5-fold greater in the roots .
The homologous genes for OsBRI1 , OsBRL1 and OsBRL3 , were highly expressed in roots but weakly expressed in shoots , and their expression was higher in d61-4 than in the wild type .
Based on these observations , we conclude that OsBRI1 is not essential for pattern formation or organ initiation , but is involved in organ development through controlling cell division and elongation .
In addition , OsBRL1 and OsBRL3 are at least partly involved in BR perception in the roots . | | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 10.00 |
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| Title: Morphological alteration caused by brassinosteroid insensitivity increases the biomass and grain production of rice .
| | Author: Morinaka Y Sakamoto T Inukai Y Agetsuma M Kitano H Ashikari M Matsuoka M | | Journal: Plant Physiol .
Citation: V : 141 ( 3 ) P : 924-31 Year: 2006 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub16714407 Accession (PMID): 16714407 | | Abstract: The rice ( Oryza sativa ) dwarf mutant d61 phenotype is caused by loss of function of a rice BRASSINOSTEROID INSENSITIVE1 ortholog , OsBRI1 .
We have identified nine d61 alleles , the weakest of which , d61-7 , confers agronomically important traits such as semidwarf stature and erect leaves .
Because erect-leaf habit is considered to increase light capture for photosynthesis , we compared the biomass and grain production of wild-type and d61-7 rice .
The biomass of wild type was 38% higher than that of d61-7 at harvest under conventional planting density because of the dwarfism of d61-7 .
However , the biomass of d61-7 was 35% higher than that of wild type at high planting density .
The grain yield of wild type reached a maximum at middensity , but the yield of d61-7 continued to increase with planting density .
These results indicate that d61-7 produces biomass more effectively than wild type , and consequently more effectively assimilates the biomass in reproductive organ development at high planting density .
However , the small grain size of d61-7 counters any increase in grain yield , leading to the same grain yield as that of wild type even at high density .
We therefore produced transgenic rice with partial suppression of endogenous OsBRI1 expression to obtain the erect-leaf phenotype without grain changes .
The estimated grain yield of these transformants was about 30% higher than that of wild type at high density .
These results demonstrate the feasibility of generating erect-leaf plants by modifying the expression of the brassinosteroid receptor gene in transgenic rice plants . | | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
