RESUMEN
Adenine phosphoribosyltransferase (APRT) is the key enzyme that converts adenine to adenosine monophosphate (AMP) in the purine salvage pathway. It was found that several different forms of APRT gene exist in plants, but no APRT gene in maize has been reported up to now. In this study, a novel maize APRT gene was cloned and characterized through a combination of bioinformatic, RT-PCR and RACE strategies. The full length of APRT cDNA sequence is 1202 nucleotides, with an ORF encoding 214 amino acid residues. Alignment of the deduced protein with that of other plant APRT genes indicates that the new gene is the form 2 of maize APRT, thus it was named ZmAPT2. Through basic local alignment search tool, search in the genomic survey sequence database of MaizeGDB, the putative genomic sequence of ZmAPT2 was obtained. Comparison of the cDNA and genomic sequence of the ZmAPT2 gene revealed that it contained seven exons and six introns. The locations of the introns within the maize ZmAPT2 coding region were consistent with those in the previously isolated APRTs of arabidopsis and rice. RT-PCR analysis showed that ZmAPRT was constitutively expressing in different organs under high temperature and salt stresses. Southern blot analysis indicated that at least three APRT genes existed in maize genome. These results confirmed that the novel maize ZmAPT2 gene was truly identified, and its potential role in maize growth and development was discussed.
Asunto(s)
Adenina Fosforribosiltransferasa/genética , Zea mays/enzimología , Zea mays/genética , Adenina Fosforribosiltransferasa/química , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Dosificación de Gen , Regulación de la Expresión Génica de las Plantas , Orden Génico , Datos de Secuencia Molecular , Filogenia , Alineación de SecuenciaRESUMEN
Southern corn rust (SCR) is a fungal disease caused by Puccinia polysora Underw, which can infect maize and may result in substantial yield losses in maize production. The maize inbred line Qi319 carries the SCR resistance gene RppQ. In order to identify molecular markers linked to the RppQ gene, several techniques were utilized including random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR), and amplified fragment length polymorphism (AFLP). In addition, sequence characterized amplified region (SCAR) techniques combined with bulked segregant analysis (BSA) were used. Seven RAPD markers, eight SSR markers, and sixty-three AFLP primer combinations amplified polymorphisms between two parents and two bulk populations. A large F2 population was used for genetic analysis and for fine mapping of the RppQ gene region. One AFLP polymorphic band, M-CAA/E-AGC 324, was converted to a SCAR marker, MA7, which was mapped to a position 0.46 cM from RppQ. Finally, the RppQ gene was mapped between the SCAR marker MA7 and the AFLP marker M-CCG/E-AGA 157 with distances of 0.46 and 1.71 cM, respectively.
Asunto(s)
Genes de Plantas , Micosis/genética , Enfermedades de las Plantas/genética , Zea mays/genética , Mapeo Cromosómico , Cromosomas de las Plantas , Marcadores Genéticos , Inmunidad InnataRESUMEN
A rice gene, OsAPT2, which encodes a putative adenine phosphoribosyl transferase (APRT), was cloned and characterized. Analysis of the cDNA and genomic sequences revealed seven exons and six introns in the OsAPT2. The deduced amino acid sequence of OsAPT2 is highly homologous to those of previously isolated APRTs. RT-PCR analysis indicated that the OsAPT2 transcript in the young panicles of 'Annong S-1' is down-regulated at 29 degrees C, the critical temperature for induction of 'Annong S-1' fertility conversion. Since the panicle is likely the thermo-sensitive organ at the early stages of pollen fertility alternation, the observed heat-induced change in the OsAPT2 expression pattern in young panicles may mediate, at least in part, thermo-sensitive genic male sterility (TGMS) in 'Annong S-1'. An antisense strategy was used to suppress the expression of the OsAPT2 homolog in Arabidopsis, and the obtained homozygous transgenic plants contained lower AMP content, displayed lower pollen germination rates and exhibited some abnormalities in leaf phenotypes and flowering timing. These data suggest that OsAPT2 is likely to be involved in TGMS in the rice line 'Annong S-1'.
Asunto(s)
Adenina Fosforribosiltransferasa/genética , Oryza/genética , Adenina/química , Adenina Fosforribosiltransferasa/química , Adenosina/química , Adenosina Monofosfato/metabolismo , Alelos , Secuencia de Aminoácidos , Northern Blotting , Clonación Molecular , Biología Computacional/métodos , Cartilla de ADN/química , ADN Complementario/metabolismo , Regulación hacia Abajo , Exones , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Vectores Genéticos , Homocigoto , Calor , Intrones , Luz , Modelos Genéticos , Datos de Secuencia Molecular , Nucleótidos/química , Oligonucleótidos Antisentido/química , Oryza/enzimología , Fenotipo , Hojas de la Planta/metabolismo , Fenómenos Fisiológicos de las Plantas , Polen/metabolismo , Reacción en Cadena de la Polimerasa , Estructura Secundaria de Proteína , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido , Temperatura , TransgenesRESUMEN
beta-1,3-glucanase(BG2) is one of the pathogensis-related-proteins(PR). Study of these proteins and their related genes is one of the hot points in plant genetic engineering of disease resistance for a long time. In this research, specific primers were designed with the enzyme cleavage site of Spe I in its forward one and Not I site in the backward according to the BG2 gene sequence. Using this pair of primers, BG2 gene, which was contained in the plasmid of pRTL2, was amplified and confirmed by sequencing the amplified fragment inserted into T-easy vector. The positive clone containing BG2 gene was digested with the enzymes of Spe I/Not I and then BG2 gene was inserted into the Xba I/Not I sites of super expression binary vector pATC940. The reconstructed expression vector named as pATCBG2 was introduced into the wheat of Longfumai10 and Longfumai3 (Triticum aestivum L. em. Thell) through the particle gun transformation method. The Kanamysin resistant (Km') transformants were obtained. PCR, Dot-blotting and PCR-Southern hybridization analysis showed that the BG2 gene was integrated into the genome of wheat. Result of pathogen inoculation assay on the transgenic plants showed that the transgenic plants had a higher resistant disease score of 1-2 grade than the control.
Asunto(s)
Vectores Genéticos/genética , Glucano 1,3-beta-Glucosidasa/genética , Triticum/genética , Ascomicetos/crecimiento & desarrollo , Southern Blotting , Clonación Molecular/métodos , ADN de Plantas/genética , ADN de Plantas/metabolismo , Desoxirribonucleasa EcoRI/metabolismo , Desoxirribonucleasa HindIII/metabolismo , Inmunidad Innata/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Plantas Modificadas Genéticamente , Transformación Genética , Triticum/microbiologíaRESUMEN
Southern corn rust (SCR) is a destructive disease in maize. The inbred line Qi319 is highly resistant to southern corn rust. The inheritance of resistance to southern rust in Qi319 was investigated. Five F1 hybrids were derived from Qi319 crossed with five susceptible inbred lines respectively. The F2 generations were produced by F1 self-pollinated and BC1 F1 generations were abtained by backcrossing F1 with the susceptible parents. Inoculation of the P1, P2, F1 s and 10 individuals of F2, BC1 F1 were completed with the southern corn rust pathogen and showed that all of the 10 F1 s were resistant, the all 5 F2 populations segregated in a ratio of 3R:1S, and all of the 5 BC1 F1 populations segregated in a ratio of 1R:1S. Therefore, it is considered that Qi319 carries one dominant gene for resistance to southern corn rust.