Separation of AG function in floral meristem determinacy from that in reproductive organ identity by expressing antisense AG RNA

Mizukami, Y., Ma, H. (1995) Separation of AG function in floral meristem determinacy from that in reproductive organ identity by expressing antisense AG RNA. Plant Mol Biol, 28 (5). pp. 767-84. ISSN 0167-4412 (Print)

URL: http://www.ncbi.nlm.nih.gov/pubmed/7640351

Abstract

The Arabidopsis floral homeotic gene AGAMOUS (AG) is a regulator of early flower development. The ag mutant phenotypes suggest that AG has two functions in flower development: (1) specifying the identity of stamens and carpels, and (2) controlling floral meristem determinacy. To dissect these two AG functions, we have generated transgenic Arabidopsis plants carrying an antisense AG construct. We found that all of the transgenic plants produced abnormal flowers, which can be classified into three types. Type I transgenic flowers are phenocopies of the ag-1 mutant flowers, with both floral meristem indeterminacy and floral organ conversion; type II flowers are indeterminate and have partial conversion of the reproductive organs; and type III flowers have normal stamens and carpels, but still have an indeterminate floral meristem inside the fourth whorl of fused carpels. The existence of type III flowers indicates that AG function can be perturbed to affect only floral meristem determinacy, but not floral organ identity. Furthermore, the fact that floral meristem determinacy is affected in all transformants, but floral organ identity only in a subset of them, suggests that the former may required a higher level of AG activity than the latter. This hypothesis is supported by the levels of AG mRNA detected in different transformants with different frequencies of distinct types of abnormal antisense AG transgenic flowers. Finally, since AG inhibits the expression of another floral regulatory gene AP1, we examined AP1 expression in antisense AG flowers, and found that AP1 is expressed at a relatively high level in the center of type II flowers, but very little or below detectable levels in the inner whorls of type III flowers. These results provide further insights into the interaction of AG and AP1 and how such an interaction may control both organ identity and floral meristem determinacy.

Item Type: Paper
Uncontrolled Keywords: AGAMOUS Protein, Arabidopsis Arabidopsis/ genetics/physiology DNA-Binding Proteins/ genetics Gene Expression Regulation, Plant Genes, Homeobox Genes, Plant Genes, Regulator Homeodomain Proteins Meristem/physiology Phenotype Plant Proteins/ genetics Plants, Genetically Modified RNA, Antisense/ genetics Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.
Subjects: organism description > plant > Arabidopsis
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > DNA binding protein
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > gene regulation
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > gene regulation

bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > genes: types > homeobox genes
organs, tissues, organelles, cell types and functions > tissues types and functions > meristem
organism description > plant
CSHL Authors:
Communities: CSHL labs
Depositing User: Jessica Koos
Date Deposited: 08 Aug 2014 19:39
Last Modified: 08 Aug 2014 19:39
Related URLs:
URI: http://repository.cshl.edu/id/eprint/30623

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