title: A new link between stress response and nucleolar function during pollen development in Arabidopsis mediated by AtREN1 protein.
abstract: Heat shock transcription factors (Hsfs) are involved in multiple aspects of stress response and plant growth. However, their role during male gametophyte development is largely unknown, although the generative phase is the most sensitive and critical period in the plant life cycle. Based on a wide screen of T-DNA mutant lines, we identified the atren1 mutation (restricted to nucleolus1) in early male gametophytic gene At1g77570, which has the closest homology to HSFA5 gene, the member of a heat shock transcription factor (HSF) gene family. The mutation causes multiple defects in male gametophyte development in both structure and function. Because the mutation disrupts an early acting (AtREN1) gene, these pollen phenotype abnormalities appear from bicellular pollen stage to pollen maturation. Moreover, the consequent progamic phase is compromised as well as documented by pollen germination defects and limited transmission via male gametophyte. In addition, atren1/- plants are defective in heat stress (HS) response and produce notably higher proportion of aberrant pollen grains. AtREN1 protein is targeted specifically to the nucleolus that, together with the increased size of the nucleolus in atren1 pollen, suggests that it is likely to be involved in ribosomal RNA biogenesis or other nucleolar functions.
authors: Laboratory of Pollen Biology, Institute of Experimental Botany v.v.i. ASCR, Rozvojová 263, Prague 6, 165 02, Czech Republic.
authors: David
authors: D
authors: Reňák
authors: Antónia
authors: A
authors: Gibalová
authors: Katarzyna
authors: K
authors: Solcová
authors: David
authors: D
authors: Honys
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002466:Cell Nucleolus / Q000378:metabolism*; D020090:Chromosome Segregation / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005091:Exons / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D018525:Germination; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000235:genetics; D009154:Mutation / Q000235:genetics; D019683:Penetrance; D010641:Phenotype; D011058:Pollen / Q000166:cytology* / Q000235:genetics / Q000254:growth & development*; D053205:Pollen Tube / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D021381:Protein Transport
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C000592618:REN1 protein, Arabidopsis; C036483:T-DNA; D049452:Green Fluorescent Proteins
keywords: heat shock response; heat shock transcription factor; male gametophyte development; nucleolus; pollen