Pollen development and fertilization in Arabidopsis is dependent on the MALE GAMETOGENESIS IMPAIRED ANTHERS gene encoding a type V P-type ATPase.
In flowering plants, development of the haploid male gametophytes (pollen grains) takes place in a specialized structure called the anther. Successful pollen development, and thus reproduction, requires high secretory activity in both anther tissues and pollen. In this paper, we describe a novel member of the eukaryotic type V subfamily (P(5)) of P-type ATPase cation pumps, the MALE GAMETOGENESIS IMPAIRED ANTHERS (MIA) gene. MIA protein is highly abundant in the endoplasmic reticulum and small vesicles of developing pollen grains and tapetum cells. T-DNA insertional mutants of MIA suffer from imbalances in cation homeostasis and exhibit a severe reduction in fertility. Mutant microspores fail to separate from tetrads and pollen grains are fragile with an abnormal morphology and altered cell wall structure. Disruption of MIA affects expression of genes essential for secretion as well as a high number of genes encoding cell wall proteins and membrane transporters. MIA functionally complements a mutant in the P(5) ATPase homolog SPF1 from Saccharomyces cerevisiae, suggesting a common function for P(5) ATPases in single and multicellular organisms. Our results suggest that MIA is required in the secretory pathway for proper secretion of vesicle cargo to the plasma membrane.
Jakobsen
Mia Kyed
MK
Department of Plant Biology, The Royal Veterinary and Agricultural University, Frederiksberg C, Denmark.
Poulsen
Lisbeth R
LR
Schulz
Alexander
A
Fleurat-Lessard
Pierrette
P
Møller
Annette
A
Husted
Søren
S
Schiøtt
Morten
M
Amtmann
Anna
A
Palmgren
Michael G
MG
D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D002412:Cations / Q000378:metabolism; D005306:Fertilization / Q000235:genetics / Q000502:physiology*; D035264:Flowers / Q000235:genetics*; D005718:Gametogenesis / Q000235:genetics*; D017343:Genes, Plant / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D011058:Pollen / Q000235:genetics / Q000502:physiology*; D021381:Protein Transport / Q000235:genetics; D011506:Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000502:physiology*
D018528:ATP-Binding Cassette Transporters; D002412:Cations; D011506:Proteins; C406793:SPF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D025262:Vacuolar Proton-Translocating ATPases