The MALE STERILITY1 gene of Arabidopsis, encoding a nuclear protein with a PHD-finger motif, is expressed in tapetal cells and is required for pollen maturation.
We identified the Arabidopsis MALE STERILITY1 (MS1) gene by transposon-mediated mutagenesis. In the transposon-inserted allele ms1-8, normal immature microspores separated from tetrads, but their subsequent maturation was abnormal: the outer layer of the microspore was absent, and both the microspore and the tapetal layer gradually became vacuolated. Empty locules resulted. The MS1 gene was expressed only in the tapetal layer during a very short period when the microspores were packed as tetrads. By the time the microspores had separated, the gene was no longer expressed. MS1 was not expressed in microspores. MS1 encodes a protein with a PHD-finger motif characteristic of some transcriptional regulators. A fusion protein consisting of the N-terminus of MS1 and green fluorescent protein was localized in the nucleus. These results suggest that MS1 protein is a nuclear signal molecule indispensable for pollen maturation.
Ito
Takuya
T
Laboratory of Plant Molecular Biology, RIKEN, 3-1-1 Koyadai, Tsukuba, 305-0074 Japan.
Shinozaki
Kazuo
K
D000483:Alleles; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004251:DNA Transposable Elements / Q000235:genetics; D005298:Fertility / Q000235:genetics; D035264:Flowers / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D011058:Pollen / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D029681:Arabidopsis Proteins; D004251:DNA Transposable Elements; D018398:Homeodomain Proteins; D008164:Luminescent Proteins; C461559:MS1 protein, Arabidopsis; D009687:Nuclear Proteins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins