1,720,985 research outputs found
CDNA-NBS PROFILING OF HORTENSIA RGA-LIKE GENES RESPONSIVE TO LEAF SPOT FUNGAL INFECTION.
No full textCDNA-NBS PROFILING OF HORTENSIA RGA-LIKE GENES RESPONSIVE TO LEAF SPOT FUNGAL INFECTION.
WOODROW P., KAFANTARIS I., IANNUZZI F., MIRTO A., FUGGI A. AND CARILLO P.
Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, via Vivaldi 43, 81100 Caserta, Italy.
Keywords: biotic stress, resistance genes, nbs profiling, leaf spot, hortensia.
Hydrangeas are susceptible to leaf spot fungus Cercospora hydrangeae. Fungal spores germinate quickly and spread over the plant leaves under warm and rainy weather forming small purple or brown spots. Although Hydrangea plants are not killed by leaf spot, it reduces the flowering and plant vigor decreasing the market value of the plants. The aim of our study was to isolate and characterize Hortensia resistance (R) gene transcripts under C. hydrangeae fungus infection and investigate their expression profile and evolutionary relationships. The majority of disease R-genes in plants encode nucleotide-binding site leucine-rich repeat (NBS-LRR) proteins. A cDNA-NBS strategy was carried out using as template cDNAs isolated from control and infected plant leaves. The cDNA-NBS profiling gave an excellent bands reproducibility. Twenty new transcripts corresponding to NBS-LRR proteins were identified only in infected plants. Their phylogenetic analysis revealed that most of them evolved through concerted evolution probably due to a selective pressure from a certain pathogen and/or genetic evolutionary events such as gene conversion, crossing-over, duplication and diversifying selection
A PCR based SNPs marker for specific characterization of English walnut (Juglans regia L.) cultivars
No full textEnglish walnut (Juglans regia L.) is the most economically important species from all the 21 species belonging to the genus Juglans and is an important and healthy food as well as base material for timber industry. The aim of this study was to develop a simple technique for specific characterization of English walnut using DNA method. The first and second internal transcribed spacers (ITS1 and ITS2) as well as the intervening 5.8S coding region of the rRNA gene for 18 cultivars of J. regia L. isolated from different geographic origins were characterized. The size of the spacers sequences ranged from 257 to 263 bases for ITS1 and from 217 to 219 bases for ITS2. Variation of GC contents has also been observed and scored as 55-56.7 and 57.1-58.9% for ITS1 and ITS2, respectively. This data exhibited the presence of polymorphism among cultivars. Alignment of the ITS1-5.8S-ITS2 sequences from 18 walnut cultivars showed that there were 244 single nucleotide polymorphisms (SNPs) and 1 short insertion-deletion (indel) at 5′ end ITS1. Amplification refractory mutation system strategy was successfully applied to the SNP markers of the ITS1 and ITS2 sequences for the fingerprinting analysis of 17 on 18 walnut cultivars. The prediction of ITS1 and ITS2 RNA secondary structure from each cultivar was improved by detecting key functional elements shared by all sequences in the alignments. Phylogenetic analysis of the ITS1-5.8S-ITS2 region clearly separated the isolated sequences into two clusters. The results showed that ITS1 and ITS2 region could be used to discriminate these walnut cultivars. © 2010 Springer Science+Business Media B.V
CDNA cloning and differential expression patterns of ascorbate peroxidase during post-harvest in Brassica rapa L.
No full textAscorbate is an antioxidant and a cofactor of many dioxygenases in plant and animal cell metabolism. A well-recognized enzyme consuming ascorbate is ascorbate peroxidase (APX), which catalyses the reduction of hydrogen peroxide to water with the simultaneous oxidation of ascorbate with a high specificity. The isolation and characterisation of new Apx cDNAs, could provide new insights about the physiological roles and regulation of these enzymes. In this work chloroplastic (Br-chlApx) and cytosolic (Br-cApx) isoform transcripts were isolated by RT-PCR in Brassica rapa and expression changes were analysed by semi-quantitative RT-PCR performed in different tissues (layer, stalk and florets) at different days (0, 4 and 14 day). The result showed that BrApx isoforms were differentially expressed and the Br-chlApx, in particular in the layer, had the highest expression level and remained unchanged also after 14 day after harvest. In addition, expression changes were compared with total BrAPX activity and the results showed that the activity decreased in all tissues at 14 day after harvest, independently of transcripts. Finally, additional solutes as the substrate of APX ascorbate and its oxidized form, dehydroascorbate, as well as α-tocopherol, the major vitamin E compound that prevents the propagation of lipid peroxidation in thylakoid membranes, were followed. The changes in the BrApx expression, BrAPX activity and metabolites can provide further evidence of the close relationships that exist between antioxidants which compensate for each other and suggest that there are multiple sites of reciprocal control. © 2012 Springer Science+Business Media B.V
MOBILITY OF TTD1A RETROTRANSPOSON BY STRESS MODULATE RESISTANCE EXPRESSION GENE IN DURUM
No full textUse of Nuclear and Mitochondrial Single Nucleotide Polymorphisms to Characterize English Walnut (Juglans regia L.) Genotypes
No full textEnglish walnut (Juglans regia L.) is the most economically important species, for both food and timber, of the 21 species belonging to the genus Juglans. This study was undertaken to analyze and compare DNA sequences of the mitochondrial cytochrome oxidase subunit II (COX2) and ribosomal DNA (rDNA) genes in the molecular characterization of 30 English walnut genotypes. rDNA sequences revealed the presence of 402 variations, including 101 in 3′ ends of 18S, 21 in internal transcribed spacer 1(ITS1), 170 in ITS2, 30 in 5.8S, and 80 in 5′ ends of 28S regions. Cox2 intron I sequences showed 769 variable positions and GG insertion/deletion at 3′ end regions. Based on single nucleotide polymorphism markers of rDNA and cox2 intron I sequences, an amplification refractory mutation system was used to fingerprint 18 out of 30 walnut genotypes. The findings revealed that the cox2 intron I region, either alone or in conjunction with rDNA, could be used effectively in identifying these walnut genotypes. © 2013 Springer Science+Business Media New York
Polymorphism of a new Ty1-copia retrotransposon in durum wheat under salt and light stresses
No full textLong terminal repeat retrotransposons are the
most abundant mobile elements in the plant genome and
play an important role in the genome reorganization
induced by environmental challenges. Their success
depends on the ability of their promoters to respond to
diVerent signaling pathways that regulate plant adaptation
to biotic and abiotic stresses. We have isolated a new Ty1-
copia-like retrotransposon, named Ttd1a from the Triticum
durum L. genome. To get insight into stress activation pathways
in Ttd1a, we investigated the eVect of salt and light
stresses by RT-PCR and S-SAP proWling. We screened for
Ttd1a insertion polymorphisms in plants grown to stress
and showed that one new insertion was located near the
resistance gene. Our analysis showed that the activation and
mobilization of Ttd1a was controlled by salt and light
stresses, which strengthened the hypothesis that stress
mobilization of this element might play a role in the
defense response to environmental stresses.Long terminal repeat retrotransposons are the most abundant mobile elements in the plant genome and play an important role in the genome reorganization induced by environmental challenges. Their success depends on the ability of their promoters to respond to different signaling pathways that regulate plant adaptation to biotic and abiotic stresses. We have isolated a new Ty1-copia-like retrotransposon, named Ttd1a from the Triticum durum L. genome. To get insight into stress activation pathways in Ttd1a, we investigated the effect of salt and light stresses by RT-PCR and S-SAP profiling. We screened for Ttd1a insertion polymorphisms in plants grown to stress and showed that one new insertion was located near the resistance gene. Our analysis showed that the activation and mobilization of Ttd1a was controlled by salt and light stresses, which strengthened the hypothesis that stress mobilization of this element might play a role in the defense response to environmental stresses
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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