title: DELLA activity is required for successful pollen development in the Columbia ecotype of Arabidopsis.
abstract: Excessive gibberellin (GA) signalling, mediated through the DELLA proteins, has a negative impact on plant fertility. Loss of DELLA activity in the monocot rice (Oryza sativa) causes complete male sterility, but not in the dicot model Arabidopsis (Arabidopsis thaliana) ecotype Landsberg erecta (Ler), in which DELLA function has been studied most extensively, leading to the assumption that DELLA activity is not essential for Arabidopsis pollen development. A novel DELLA fertility phenotype was identified in the Columbia (Col-0) ecotype that necessitates re-evaluation of the general conclusions drawn from Ler. Fertility phenotypes were compared between the Col-0 and Ler ecotypes under conditions of chemical and genetic GA overdose, including mutants in both ecotypes lacking the DELLA paralogues REPRESSOR OF ga1-3 (RGA) and GA INSENSITIVE (GAI). Ler displays a less severe fertility phenotype than Col-0 under GA treatment. Col-0 rga gai mutants, in contrast with the equivalent Ler phenotype, were entirely male sterile, caused by post-meiotic defects in pollen development, which were rescued by the reintroduction of DELLA into either the tapetum or developing pollen. We conclude that DELLA activity is essential for Arabidopsis pollen development. Differences between the fertility responses of Col-0 and Ler might be caused by differences in downstream signalling pathways or altered DELLA expression.
authors.affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
authors.forename: Andrew R G
authors.initials: ARG
authors.lastname: Plackett
authors.affiliation: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
authors.forename: Alison C
authors.initials: AC
authors.lastname: Ferguson
authors.affiliation: Biomathematics and Bioinformatics Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Powers
authors.affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
authors.forename: Aakriti
authors.initials: A
authors.lastname: Wanchoo-Kohli
authors.affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Phillips
authors.affiliation: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
authors.forename: Zoe A
authors.initials: ZA
authors.lastname: Wilson
authors.affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Hedden
authors.affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Thomas
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060146:Ecotype; D005816:Genetic Complementation Test; D008540:Meiosis; D009154:Mutation / Q000235:genetics; D051479:Plant Infertility; D011058:Pollen / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C109555:GAI protein, Arabidopsis; C508468:RGA protein, Arabidopsis; D012097:Repressor Proteins
keywords: Arabidopsis thaliana; Col-0; DELLA; Ler; ecotypic differences; gibberellin; male sterility; pollen development