title: Identification and functional analysis of pistil self-incompatibility factor HT-B of Petunia.
abstract: Gametophytic self-incompatibility (GSI) in Solanaceae, Rosaceae, and Plantaginaceae is controlled by a multiallelic S-locus. The specificities of pistil and pollen are controlled by separate S-locus genes, S-RNase and SLF/SFB, respectively. Although the S-specificity is determined by the S-locus genes, factors located outside the S-locus are also required for expression of GSI. HT-B is one of the pistil non-S-factors identified in Nicotiana and Solanum, and encodes a small asparagine/aspartate-rich extracellular protein with unknown biochemical function. Here, HT-B was cloned from Petunia and characterized. The structural features and expression pattern of Petunia HT-B were very similar to those of Nicotiana and Solanum. Unlike other solanaceous species, expression of HT-B was also observed in self-compatible Petunia species. RNA interference (RNAi)-mediated suppression of Petunia HT-B resulted in partial breakdown of GSI. Quantitative analysis of the HT-B mRNA accumulation in the transgenics showed that a 100-fold reduction is not sufficient and a >1000-fold reduction is required to achieve partial breakdown of GSI.
authors.affiliation: Graduate School of Science and Technology, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan.
authors.forename: Alejandro Raul
authors.initials: AR
authors.lastname: Puerta
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ushijima
authors.forename: Takato
authors.initials: T
authors.lastname: Koba
authors.forename: Hidenori
authors.initials: H
authors.lastname: Sassa
mesh_terms: D000595:Amino Acid Sequence; D035264:Flowers / Q000235:genetics / Q000378:metabolism*; D005638:Fruit / Q000254:growth & development; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009928:Organ Specificity; D032306:Petunia / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D053205:Pollen Tube / Q000166:cytology / Q000254:growth & development; D054817:Pollination; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D016415:Sequence Alignment; D013489:Suppression, Genetic
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant