1. MALE STERILITY1 is required for tapetal development and pollen wall biosynthesis.
- Author
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Yang C, Vizcay-Barrena G, Conner K, and Wilson ZA
- Subjects
- Arabidopsis cytology, Arabidopsis genetics, Arabidopsis Proteins genetics, Arabidopsis Proteins ultrastructure, Cell Nucleus metabolism, Cysteine Endopeptidases genetics, Cysteine Endopeptidases metabolism, DNA, Complementary metabolism, Down-Regulation genetics, Gene Expression Regulation, Plant, Genes, Plant, Genetic Complementation Test, Green Fluorescent Proteins metabolism, Models, Biological, Mutation genetics, Organ Specificity, Pollen cytology, Pollen genetics, Pollen ultrastructure, Protein Biosynthesis, Recombinant Fusion Proteins metabolism, Transcription Factors genetics, Transcription Factors ultrastructure, Arabidopsis embryology, Arabidopsis Proteins metabolism, Cell Wall metabolism, Pollen embryology, Transcription Factors metabolism
- Abstract
The Arabidopsis thaliana MALE STERILITY1 (MS1) gene is critical for viable pollen formation and has homology to the PHD-finger class of transcription factors; however, its role in pollen development has not been fully defined. We show that MS1 transcription appears to be autoregulated by the wild-type MS1 transcript or protein. Using a functional green fluorescent protein (GFP) fusion to analyze the temporal and spatial expression of MS1, we demonstrate that the MS1:GFP protein is nuclear localized within the tapetum and is expressed in a developmentally regulated manner between late tetraspore and microspore release, then rapidly breaks down, probably by ubiquitin-dependent proteolysis. Absence of MS1 expression results in changes in tapetal secretion and exine structure. Microarray analysis has shown that 260 (228 downregulated and 32 upreglated) genes have altered expression in young ms1 buds. These genes are primarily associated with pollen wall and coat formation; however, a number of transcription factors and Cys proteases have also been identified as the putative primary regulatory targets of MS1. Ectopic expression of MS1 alters transcriptional regulation of vegetative gene expression, resulting in stunted plants with increased levels of branching, partially fertile flowers and an apparent increase in wall material on mature pollen. MS1 therefore plays a critical role in the induction of pollen wall and pollen coat materials in the tapetum and, ultimately, the production of viable pollen.
- Published
- 2007
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