title: AtMYB32 is required for normal pollen development in Arabidopsis thaliana.
abstract: AtMYB32 gene is a member of the R2R3 MYB gene family coding for transcription factors in Arabidopsis thaliana. Its expression pattern was analysed using Northern blotting, in situ hybridization and promoter-GUS fusions. AtMYB32 is expressed in many tissues, but most strongly in the anther tapetum, stigma papillae and lateral root primordia. AtMYB32-GUS was induced in leaves and stems following wounding, and in root primordia by auxin. T-DNA insertion populations were screened and two insertion mutants were identified, both of which were partially male sterile, more than 50% of the pollen grains being distorted in shape and lacking cytoplasm. AtMYB4 is closely related to AtMYB32 and represses the CINNAMATE 4-HYDROXYLASE gene. Distorted pollen grains were produced in both AtMYB4 insertion mutant and overexpression lines. In an AtMYB32 insertion mutant, the transcript levels of the DIHYDROFLAVONOL 4-REDUCTASE and ANTHOCYANIDIN SYNTHASE genes decreased while the level of the CAFFEIC ACID 0-METHYLTRANSFERASE transcript increased. Change in the levels of AtMYB32 and AtMYB4 expression may influence pollen development by changing the flux along the phenylpropanoid pathways, affecting the composition of the pollen wall.
authors.affiliation: Botany Department, School of Life Sciences, La Trobe University, Bundoora, Victoria 3083, Australia.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Preston
authors.forename: Janet
authors.initials: J
authors.lastname: Wheeler
authors.forename: Joshua
authors.initials: J
authors.lastname: Heazlewood
authors.forename: Song Feng
authors.initials: SF
authors.lastname: Li
authors.forename: Roger W
authors.initials: RW
authors.lastname: Parish
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011058:Pollen / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; C482738:BOTRYTIS SUSCEPTIBLE1 protein, Arabidopsis; D007210:Indoleacetic Acids; C499438:MYB32 protein, Arabidopsis; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors