MYB98 Is Required for Pollen Tube Guidance and Synergid Cell Differentiation in Arabidopsis

• Published in: The Plant cell 2005-11, Vol.17 (11), p.2981-2992
• Main Authors: Kasahara, Ryushiro D, Portereiko, Michael F, Sandaklie-Nikolova, Linda, Rabiger, David S, Drews, Gary N
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - isolation & purification; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Base Sequence; Cell differentiation; Cell Differentiation - physiology; Cell walls; Cellular differentiation; complementary DNA; DNA, Complementary - analysis; DNA, Complementary - genetics; endosperm; Female animals; Fertilization; fertilization (reproduction); Fertilization - physiology; Flowers - genetics; Flowers - growth & development; Flowers - metabolism; Flowers - ultrastructure; Gametophytes; gene expression; Gene Expression Regulation, Plant - physiology; Genes; Germ Cells - growth & development; Germ Cells - metabolism; Germ Cells - ultrastructure; messenger RNA; Microscopy, Electron, Transmission; Molecular Sequence Data; mutants; Mutation - physiology; nucleotide sequences; Ovules; phenotype; Plant cells; Plants; Pollen; Pollen tubes; Seeds - genetics; Seeds - metabolism; Seeds - ultrastructure; synergid cells; transcription factors; Transcription Factors - genetics; Transcription Factors - isolation & purification; Transcription Factors - metabolism; trichomes
• ISSN: 1040-4651; 1532-298X; 1532-298X
• DOI: 10.1105/tpc.105.034603

The synergid cells of the female gametophyte play a role in many steps of the angiosperm fertilization process, including guidance of pollen tube growth to the female gametophyte. However, the mechanisms by which the synergid cells become specified and develop their unique features during female gametophyte development are not understood. We identified MYB98 in a screen for Arabidopsis thaliana genes expressed in the female gametophyte. MYB98 is a member of the R2R3-MYB gene family, the members of which likely encode transcription factors. In the context of the ovule, MYB98 is expressed exclusively in the synergid cells, and mutations in this gene affect the female gametophyte specifically. myb98 female gametophytes are affected in two unique features of the synergid cell, pollen tube guidance and the filiform apparatus, but are otherwise normal. MYB98 also is expressed in trichomes and endosperm. Homozygous myb98 mutants exhibit no sporophytic defects, including trichome and endosperm defects. Together, these data suggest that MYB98 controls the development of specific features within the synergid cell during female gametophyte development.