title: Sporophytic and gametophytic functions of the cell cycle-associated Mob1 gene in Arabidopsis thaliana L.
abstract: Mob1 genes are primarily involved in the cell cycle progression and mitosis exit in yeasts and animals. The function of a Mob1-like gene (At5g45550) from Arabidopsis thaliana was investigated using RNAi and immunological staining. AtMob1-like RNAi silenced lines showed a reduced radial expansion of the inflorescence stem and a reduced elongation zone of the primary root. Morphological features of plant organs were accompanied by a reduction in cell size. The fertility of AtMob1-like RNAi silenced lines was very low as seed production was strongly reduced. About 2% of the progeny of AtMob1-like RNAi silenced plants were tetraploid. The female and male sporogenesis was affected differentially. The ovules developed irregularly and one third of the megaspores and embryo sacs degenerated prematurely. Up to 20% of the ovules produced binucleated megaspores that failed to develop further, being their degeneration likely accompanied with a delayed programmed cell death. The anthers produced about 30% of aborted pollen grains, showing also a strong variation in their size. Together, the results show that Arabidopsis MOB1-like is required to regulate cell expansion and cell division, presumably by affecting the mitotic as well as the meiotic cell cycle.
authors.affiliation: Laboratory of Plant Genetics and Genomics, Department of Environmental Agronomy and Crop Science, University of Padova, Viale dell'Università 16, I-35020 Legnaro, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Galla
authors.forename: Sara
authors.initials: S
authors.lastname: Zenoni
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Marconi
authors.forename: Giada
authors.initials: G
authors.lastname: Marino
authors.forename: Alessandro
authors.initials: A
authors.lastname: Botton
authors.forename: Francesco
authors.initials: F
authors.lastname: Pinosa
authors.forename: Sandra
authors.initials: S
authors.lastname: Citterio
authors.forename: Benedetto
authors.initials: B
authors.lastname: Ruperti
authors.forename: Klaus
authors.initials: K
authors.lastname: Palme
authors.forename: Emidio
authors.initials: E
authors.lastname: Albertini
authors.forename: Mario
authors.initials: M
authors.lastname: Pezzotti
authors.forename: Martin
authors.initials: M
authors.lastname: Mau
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Sharbel
authors.forename: Nico
authors.initials: N
authors.lastname: De Storme
authors.forename: Danny
authors.initials: D
authors.lastname: Geelen
authors.forename: Gianni
authors.initials: G
authors.lastname: Barcaccia
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D005298:Fertility / Q000235:genetics; D020868:Gene Silencing; D017343:Genes, Plant; D018816:Genes, cdc; D056771:Ovule / Q000235:genetics*; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics; D018547:Plant Stems / Q000033:anatomy & histology / Q000235:genetics; D011058:Pollen / Q000235:genetics*; D013170:Spores / Q000235:genetics