RESUMO
In this study, we searched for anther-specific genes involved in male gametophyte development in apple (Malus x domestica Borkh. cv. Fuji) by differential display-PCR. Three full-length cDNAs were isolated, and the corresponding genomic sequences were determined by genome walking. The identified genes showed intronless 228- to 264-bp open reading frames and shared 82-90% nucleotide sequence. Sequence analysis identified that they encoded a putative arabinogalactan protein (AGP) and were designated MdAGP1, MdAGP2, and MdAGP3, respectively. RT (reverse transcriptase)-PCR revealed that the MdAGP genes were selectively expressed in the stamen. Promoter analysis confirmed that the MdAGP3 promoter was capable of directing anther- or pollen-specific expression of the GUS reporter in tobacco and apple. Furthermore, expression of ribosome-inactivating protein under the control of the MdAGP3 promoter induced complete sporophytic male sterility as we had expected.
Assuntos
Flores/genética , Malus/genética , Mucoproteínas/genética , Regiões Promotoras Genéticas , Sequência de Aminoácidos , DNA Complementar/genética , DNA de Plantas/genética , Flores/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Biblioteca Gênica , Genes de Plantas , Genoma de Planta , Malus/metabolismo , Dados de Sequência Molecular , Mucoproteínas/metabolismo , Infertilidade das Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNA , Nicotiana/genéticaRESUMO
Phytophthora capsici Leonian, an oomycete pathogen, is a serious problem in pepper worldwide. Its resistance in pepper is controlled by quantitative trait loci (QTL). To detect QTL associated with P. capsici resistance, a molecular linkage map was constructed using 100 F(2) individuals from a cross between Capsicum annuum 'CM334' and C. annuum 'Chilsungcho'. This linkage map consisted of 202 restriction fragment length polymorphisms (RFLPs), 6 WRKYs and 1 simple sequence repeat (SSR) covering 1482.3 cM, with an average interval marker distance of 7.09 cM. QTL mapping of Phytophthora root rot and damping-off resistance was performed in F(2:3) originated from a cross between resistant Mexican landrace C. annuum 'CM334' and susceptible Korean landrace C. annuum 'Chilsungcho' using composite interval mapping (CIM) analysis. Four QTL explained 66.3% of the total phenotypic variations for root rot resistance and three 44.9% for damping-off resistance. Of these QTL loci, two were located close to RFLP markers CDI25 on chromosome 5 (P5) and CT211A on P9. A bacterial artificial chromosome (BAC) library from C. annuum 'CM334' was screened with these two RFLP probes to obtain sequence information around the RFLP marker loci for development of PCR-based markers. CDI25 and CT211 probes identified seven and eight BAC clones, respectively. Nine positive BAC clones containing probe regions were sequenced and used for cytogenetic analysis. One single-nucleotide amplified polymorphism (SNAP) for the CDI25 locus, and two SSRs and cleaved amplified polymorphic sequence (CAPS) for CT211 were developed using sequences of the positive BAC clones. These markers will be valuable for rapid selection of genotypes and map-based cloning for resistance genes against P. capsici.
