title: A pollen coat-inducible autoinhibited Ca2+-ATPase expressed in stigmatic papilla cells is required for compatible pollination in the Brassicaceae.
abstract: In the Brassicaceae, intraspecific non-self pollen (compatible pollen) can germinate and grow into stigmatic papilla cells, while self-pollen or interspecific pollen is rejected at this stage. However, the mechanisms underlying this selective acceptance of compatible pollen remain unclear. Here, using a cell-impermeant calcium indicator, we showed that the compatible pollen coat contains signaling molecules that stimulate Ca(2+) export from the papilla cells. Transcriptome analyses of stigmas suggested that autoinhibited Ca(2+)-ATPase13 (ACA13) was induced after both compatible pollination and compatible pollen coat treatment. A complementation test using a yeast Saccharomyces cerevisiae strain lacking major Ca(2+) transport systems suggested that ACA13 indeed functions as an autoinhibited Ca(2+) transporter. ACA13 transcription increased in papilla cells and in transmitting tracts after pollination. ACA13 protein localized to the plasma membrane and to vesicles near the Golgi body and accumulated at the pollen tube penetration site after pollination. The stigma of a T-DNA insertion line of ACA13 exhibited reduced Ca(2+) export, as well as defects in compatible pollen germination and seed production. These findings suggest that stigmatic ACA13 functions in the export of Ca(2+) to the compatible pollen tube, which promotes successful fertilization.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Iwano
authors.forename: Motoko
authors.initials: M
authors.lastname: Igarashi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tarutani
authors.forename: Pulla
authors.initials: P
authors.lastname: Kaothien-Nakayama
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakayama
authors.forename: Hideki
authors.initials: H
authors.lastname: Moriyama
authors.forename: Ryo
authors.initials: R
authors.lastname: Yakabe
authors.forename: Tetsuyuki
authors.initials: T
authors.lastname: Entani
authors.forename: Hiroko
authors.initials: H
authors.lastname: Shimosato-Asano
authors.forename: Masao
authors.initials: M
authors.lastname: Ueki
authors.forename: Gen
authors.initials: G
authors.lastname: Tamiya
authors.forename: Seiji
authors.initials: S
authors.lastname: Takayama
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D001681:Biological Assay; D029741:Brassica rapa / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003433:Crosses, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D017353:Gene Deletion; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D026901:Membrane Transport Proteins / Q000378:metabolism; D016254:Mutagenesis, Insertional / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D009930:Organic Chemicals / Q000378:metabolism; D010641:Phenotype; D011058:Pollen / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D054817:Pollination / Q000502:physiology*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D057945:Self-Fertilization; D013347:Subcellular Fractions / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004269:DNA, Bacterial; D026901:Membrane Transport Proteins; D009930:Organic Chemicals; C036483:T-DNA; C071336:calcium green; D000252:Calcium-Transporting ATPases; D002118:Calcium