In:
Plant Physiology, Oxford University Press (OUP), Vol. 140, No. 2 ( 2006-02-01), p. 580-590
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.
Type of Medium:
Online Resource
ISSN:
1532-2548
,
0032-0889
DOI:
10.1104/pp.105.072330
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2006
detail.hit.zdb_id:
2004346-6
detail.hit.zdb_id:
208914-2
SSG:
12
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