Ectopic expression of rice OsMADS1 reveals a role in specifying the lemma and palea, grass floral organs analogous to sepals

Prasad, Kalika and Sriram, P and Kumar, Santhosh C and Kushalappa, Kumuda and Vijayraghavan, Usha (2001) Ectopic expression of rice OsMADS1 reveals a role in specifying the lemma and palea, grass floral organs analogous to sepals. In: Development Genes and Evolution, 211 (6). pp. 281-290.

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Abstract

MADS-domain-containing transcription factors play diverse roles in plant development. The prototypic members of this gene family are the floral organ identity genes of the model dicotyledonous plant, Arabidopsis thaliana. Sequence relatedness and function ascribe them to AP1/AGL9, AG, AP3 and PI gene groups. The rice MADS-box gene, OsMADS1, is a member of the AP1/AGL9 sub-group. Tomato and Petunia members of this sub- group specify floral meristem identity and control organ development in three inner whorls. Reported here are phylogenetic analyses that show OsMADS1 to form a distinct clade within the AGL9 gene family. This sub-group currently has only three other monocot genes. We have studied the expression pattern of OsMADS1 and determined the consequences of its ectopic expression in transgenic rice plants. OsMADS1 is not expressed during panicle branching; earliest expression is in spikelet meristems where it is excluded from the outer rudimentary/sterile glumes. During organogenesis, OsMADS1 expression is confined to the lemma and palea, with weak expression in the carpel. Ectopic OsMADS1 expression results in stunted panicles with irregularly positioned branches and spikelets. Additionally, in spikelets, the outer rudimentary glumes are transformed to lemma/palea-like organs. Together, these data suggest a distinct role for OsMADS1 and its monocot relatives in assigning lemma/palea identity.

Item Type:	Journal Article
Publication:	Development Genes and Evolution
Publisher:	Springer Verlag
Additional Information:	Copyright of this article belongs to Springer Verlag.
Keywords:	OsMADS1;MADS-box genes;Flowerdevelopment;Lemma/palea;Phylogeny
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	15 Sep 2004
Last Modified:	19 Sep 2010 04:16
URI:	http://eprints.iisc.ac.in/id/eprint/1928

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