Poster: Transcription Regulation

Abs # 1059: A Novel Selection Scheme for Identifying Genes in Regulatory Pathways

Presenter:	Westberg, Chad R., west0556@umn.edu
Authors	Westberg, Chad R. (A)   Smith, Alan G. (A)
Affiliations:	(A): University of Minnesota

An efficient strategy for the identification of regulatory mutants has been developed with the goal of understanding pollen development. The conditional lethal gene phosphonate monoester hydrolase (pehA), from Burkholderia caryophilli PG2982 (Dotson et al., 1996, Plant Journal 10(2): 383-392) was used to identify genes that regulate pollen development. Arabidopsis thaliana plants that express the pehA gene show no deleterious effects until treated with glyceryl glyphosate, which is cleaved by pehA into glycerol and glyphosate, inhibiting aromatic amino acid synthesis. An anther- and tapetal-specific promoter from Lycopersicon esculentum 127a gene (encoding a glycine-rich protein) driving the pehA gene causes cell ablation specifically in the anther after treatment with glyceryl glyphosate resulting in male sterility. A. thaliana plants transformed with the 127a promoter driving the pehA gene expression were mutagenized with ethyl-methane sulfonate, and screened for mutants that were fertile after treatment with glyceryl glyphosate. The mutant shows heritibility and an associated pollen phenotype. Utilizing this conditional lethal selection scheme we demonstrate its efficacy in identifying genes that regulate pollen development. We currently are mapping the mutant loci. We expect that using the pehA gene driven by different promoters will be useful in the identification of genes in other regulatory pathways.