Abstract
Desirable morphological traits in rice plants, such as shorter stalks and erect leaves, are being pursued in breeding programs. Rice brassinosteroid (BR)-deficient mutants display the phenotype of reduced heights and erect lamina. Therefore, biotechnology can be used for controlled deactivation of bioactive BRs in specific tissues. Here, we isolated a gene encoding for a BR-deactivating enzyme. Based on its sequence identity with a known enzyme, Arabidopsis Cytochrome P450 734A1, we identified a rice homolog named OsCYP734A6 (LOC_Os01g29150). A search of the rice T-DNA mutant population for insertional mutants of this gene revealed two alleles. These T-DNA loss-of-function mutants displayed a strongly bending lamina phenotype similar to the morphology of rice plants treated with BRs. These two mutants were named bending lamina (bla)2-1 and bla2-2. In Arabidopsis, the transcript level of a putative BR biosynthetic gene, OsDWARF4, is feed-back down-regulated in response to exogenous application of BRs. Similarly, a steady-state level of OsDWARF4 transcripts was significantly down-regulated here in the bla2 mutant background. Based on their sequence similarity, the bending-lamina phenotype in the bla2 mutant, and down-regulation of the BR biosynthetic gene OsDWARF4, we therefore propose that OsCYP734A6 (BLA2) is likely to be involved in BR deactivation.
| Original language | English |
|---|---|
| Pages (from-to) | 469-476 |
| Number of pages | 8 |
| Journal | Journal of Plant Biology |
| Volume | 49 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2006 Dec 31 |
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All Science Journal Classification (ASJC) codes
- Plant Science
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Rice bending lamina 2 (bla2) mutants are defective in a Cytochrome P450 (CYP734A6) gene predicted to mediate brassinosteroid catabolism. / Park, Wanki; Ho, Bang Kim; Woo, Taek Kim; Phun, Bum Park; An, Gynheung; Choe, Sunghwa.
In: Journal of Plant Biology, Vol. 49, No. 6, 31.12.2006, p. 469-476.Research output: Contribution to journal › Article
TY - JOUR
T1 - Rice bending lamina 2 (bla2) mutants are defective in a Cytochrome P450 (CYP734A6) gene predicted to mediate brassinosteroid catabolism
AU - Park, Wanki
AU - Ho, Bang Kim
AU - Woo, Taek Kim
AU - Phun, Bum Park
AU - An, Gynheung
AU - Choe, Sunghwa
PY - 2006/12/31
Y1 - 2006/12/31
N2 - Desirable morphological traits in rice plants, such as shorter stalks and erect leaves, are being pursued in breeding programs. Rice brassinosteroid (BR)-deficient mutants display the phenotype of reduced heights and erect lamina. Therefore, biotechnology can be used for controlled deactivation of bioactive BRs in specific tissues. Here, we isolated a gene encoding for a BR-deactivating enzyme. Based on its sequence identity with a known enzyme, Arabidopsis Cytochrome P450 734A1, we identified a rice homolog named OsCYP734A6 (LOC_Os01g29150). A search of the rice T-DNA mutant population for insertional mutants of this gene revealed two alleles. These T-DNA loss-of-function mutants displayed a strongly bending lamina phenotype similar to the morphology of rice plants treated with BRs. These two mutants were named bending lamina (bla)2-1 and bla2-2. In Arabidopsis, the transcript level of a putative BR biosynthetic gene, OsDWARF4, is feed-back down-regulated in response to exogenous application of BRs. Similarly, a steady-state level of OsDWARF4 transcripts was significantly down-regulated here in the bla2 mutant background. Based on their sequence similarity, the bending-lamina phenotype in the bla2 mutant, and down-regulation of the BR biosynthetic gene OsDWARF4, we therefore propose that OsCYP734A6 (BLA2) is likely to be involved in BR deactivation.
AB - Desirable morphological traits in rice plants, such as shorter stalks and erect leaves, are being pursued in breeding programs. Rice brassinosteroid (BR)-deficient mutants display the phenotype of reduced heights and erect lamina. Therefore, biotechnology can be used for controlled deactivation of bioactive BRs in specific tissues. Here, we isolated a gene encoding for a BR-deactivating enzyme. Based on its sequence identity with a known enzyme, Arabidopsis Cytochrome P450 734A1, we identified a rice homolog named OsCYP734A6 (LOC_Os01g29150). A search of the rice T-DNA mutant population for insertional mutants of this gene revealed two alleles. These T-DNA loss-of-function mutants displayed a strongly bending lamina phenotype similar to the morphology of rice plants treated with BRs. These two mutants were named bending lamina (bla)2-1 and bla2-2. In Arabidopsis, the transcript level of a putative BR biosynthetic gene, OsDWARF4, is feed-back down-regulated in response to exogenous application of BRs. Similarly, a steady-state level of OsDWARF4 transcripts was significantly down-regulated here in the bla2 mutant background. Based on their sequence similarity, the bending-lamina phenotype in the bla2 mutant, and down-regulation of the BR biosynthetic gene OsDWARF4, we therefore propose that OsCYP734A6 (BLA2) is likely to be involved in BR deactivation.
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U2 - 10.1007/BF03031128
DO - 10.1007/BF03031128
M3 - Article
AN - SCOPUS:33846432336
VL - 49
SP - 469
EP - 476
JO - Journal of Plant Biology
JF - Journal of Plant Biology
SN - 1226-9239
IS - 6
ER -