共 30 条
Involvement of C-22-Hydroxylated Brassinosteroids in Auxin-Induced Lamina Joint Bending in Rice
被引:48
作者:
Nakamura, Ayako
[1
]
Fujioka, Shozo
[1
]
Takatsuto, Suguru
[2
]
Tsujimoto, Masafumi
[1
]
Kitano, Hidemi
[3
]
Yoshida, Shigeo
[4
]
Asami, Tadao
[1
,5
]
Nakano, Takeshi
[1
,6
]
机构:
[1] RIKEN, Adavanced Sci Inst, Wako, Saitama 3510198, Japan
[2] Joetsu Univ Educ, Dept Chem, Niigata 9438512, Japan
[3] Nagoya Univ, Biosci & Biotechnol Ctr, Chikusa Ku, Nagoya, Aichi 4648601, Japan
[4] RIKEN, Plant Sci Ctr, Kanagawa 2300045, Japan
[5] Univ Tokyo, Grad Sch Agr & Life Sci, Bunkyo Ku, Tokyo 1138657, Japan
[6] JST PRESTO, Kawaguchi, Saitama 3320012, Japan
基金:
日本科学技术振兴机构;
日本学术振兴会;
关键词:
Auxin;
Brassinosteroid;
Lamina joint;
Rice;
INCLINATION BIOASSAY;
BIOSYNTHETIC-PATHWAY;
BRASSINOLIDE;
ARABIDOPSIS;
LEAVES;
CYTOCHROME-P450;
MUTANT;
HYDROXYLATION;
DEFICIENCY;
ELONGATION;
D O I:
10.1093/pcp/pcp106
中图分类号:
Q94 [植物学];
学科分类号:
071001 ;
摘要:
The rice lamina joint is ideal material for investigating the activity of brassinosteroids (BRs) and auxin because of its high sensitivity to these compounds. Using a series of rice BR biosynthetic and receptor mutants, we conducted lamina joint tests to elucidate the mechanism of cross-talk between BR and auxin signaling in lamina joint bending. In BR biosynthetic mutants d2 and brd1, which are defective in C-23 hydroxylase and C-6 oxidase, respectively, the lamina joint response to auxin was significantly higher than that of wild-type plants. The other BR-biosynthetic mutants, brd2, osdwarf4 and d11, which are defective in C-22-hydroxylated BRs, showed less or no response to auxin. These results suggest that C-22-hydroxylated BRs are involved in auxin-induced lamina joint bending. The results were supported by the observation that inhibition of the hyper-response to auxin in d2 was reduced by treatment with brassinazole, which inhibits the function of DWARF4, the C-22 hydroxylase. In d61, which is defective in OsBRI1, a possible BR receptor in rice, the bending angle of the lamina joint in response to auxin and C-22-hydroxylated 6-deoxoBRs was nearly the same as that in wild-type plants. This implies that C-22-hydroxylated BRs function in auxin signaling independently of OsBRI1. From these observations, we propose that C-22-hydroxylated BRs participate in auxin signaling via a novel OsBRI1-independent signaling pathway.
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页码:1627 / 1635
页数:9
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