Activity of an S Locus Gene Promoter in Pistils and Anthers of Transgenic Brassica.

AUTOR(ES)

Sato, T

RESUMO

The pollen-stigma interaction of self-incompatibility in crucifers is correlated with glycoproteins localized in the cell wall of the stigmatic papillae that are encoded by the S locus glycoprotein (SLG) gene. When fused to the [beta]-glucuronidase (GUS) reporter gene, the 5[prime] upstream regulatory region of SLG directed high level expression in the papillae of transgenic Brassica plants. Histochemical and fluorometric assays revealed that, in addition to its primary site of expression in the stigmatic papillae, the SLG-GUS fusion was also expressed in the transmitting tissue of stigma, style, and ovary, and in anthers. This conclusion was verified by the detection of transgene-encoded GUS transcripts and endogenous SLG-homologous transcripts by RNA gel blot analysis. Significantly, in anthers, the SLG promoter was active not only sporophytically in the nurse cells of the tapetum, but also in the haploid microspores. Because self-incompatibility systems exhibiting sporophytic control of pollen phenotype are thought to have evolved from systems with gametophytic control, we suggest that sporophytic control was acquired without loss of gametophytic function.

Documentos Relacionados

• Brassica S-Proteins Accumulate in the Intercellular Matrix along the Path of Pollen Tubes in Transgenic Tobacco Pistils.
• Distinct cis-acting elements direct pistil-specific and pollen-specific activity of the Brassica S locus glycoprotein gene promoter.
• An anther-specific gene encoded by an S locus haplotype of Brassica produces complementary and differentially regulated transcripts.
• RNA editing of transcripts of a chimeric mitochondrial gene associated with cytoplasmic male-sterility in Brassica.
• Evolution of the Brassica self-incompatibility locus: A look into S-locus gene polymorphisms