Poster: Regulation of gene expression

Abs # 745: Expression patterns of similar anther MYB transcription factors in Arabidopsis thaliana.

Presenter:	Wheeler, Janet I., jwhe1@hotmail.com
Authors	Wheeler, Janet I. (A)   Preston, Jeremy D. (A)   Heazlewood, Joshua L. (A)   Li, Song F. (A)   Parish, Roger W. (A)
Affiliations:	(A): La Trobe University

MYB genes encode for transcription factors which have been found in a wide range of eukaryotes including animals, yeast and plants. These MYB proteins bind to DNA in a sequence specific manner, in order to regulate the transcription of target genes. In Arabidopsis MYBs form part of a large gene family with over 130 members. Some of these genes have been characterized and shown to regulate a range of metabolic and developmental processes. GUS reporter gene analysis of AtMYB 32 show it is expressed during early anther development and atmyb 32 knockout mutants show a partially aborted pollen phenotype. Recent promoter GUS analysis has shown AtMYB7 is also expressed in the developing anthers of Arabidopsis at a similar stage of development although the atmyb 7 mutant has no pollen phenotype. Both AtMYB 7 and AtMYB 32 show high putative protein sequence homology with each other and to AtMYB 4. AtMYB 4 negatively regulates the expression of the gene encoding cinnamate 4-hydroxylase in the phenylpropanoid pathway. Atmyb 4 mutant pollen is donut shaped. AtMYB 4,7 and 32 may be functionally redundant and analysis of double mutants is currently underway.