1,721,042 research outputs found
Resistence gene analogs are candidate markers for disease-resistance genes in grape (Vitis spp.)
No full textNucleotide binding site/leucine-rich repeats, Pto-like and receptor-like kinases related to disease resistance in grapevine
No full textNucleotide Binding Site/Leucine-Rich Repeat (NBS-LRR) and Serine/Threonine Kinase (STK) genes are two of the known classes of resistance (R-) genes in plants, and occur in large multigene families. Systematic identification of genes for NBS-LRRs and STKs provides a means of access to genomic regions that may be involved in disease resistance. Here we present a picture of these two families of R-gene analogs (RGAs) in grape with the aim of developing a set of resistance-related sequence-tagged-site (STS) markers. One hundred and three NBS-LRR sequences were isolated. They included members of the CC (coiled-coil) and TIR (Toll-interleukin receptor) sub-classes. A comparative analysis with other angiosperm NBSs is provided. Fifty-three genes for receptor-like kinases (RLKs) with serine/threonine specificity were identified. RLK sequences formed a putative monophyletic group within the kinase superfamily. They were similar to both cytoplasmic RLKs, such as Pto, and RLKs with LRR, S-locus, lectin-like and thaumatin-like extracellular binding-domains. The latter resembled the products of the R-related genes Xa21, FLS2, Rlk10, SFR2, and PRSK. Forty-five reference RGAs were converted into STSs by using appropriately designed specific primers. RGA-STSs were present in diverse grape genotypes, and > 85% of the primers were capable of amplifying the STSs across the taxa Vitis and Muscadinia. DNA sequence polymorphism among these RGAs was assessed by SSCP (single-strand conformation polymorphism) analysis in over 20 Vitis spp. Finally, 45 universal primers for grape RGAs are proposed that should permit tagging of R-related regions in any grape genome
Rinnovate prospettive per il miglioramento genetico della vite dopo il sequenziamento del genoma della vite
No full textApplication of genomics to grapevine improvement
No full textImagine a breeder browsing a grape chromosome nucleotide-by-nucleotide around a trait locus, scrolling
down the list of catalogued genes along a genetic interval, resequencing for a few thousand dollars a
potential parent or a selected breeding line. In the past couple of years, this vision has become a reality.
The availability of the reference genome sequence has provided significant assistance in the saturation of
loci with targeted genetic markers. Grape breeders are now offered unprecedented possibilities for
selecting plants using deoxyribonucleic acid (DNA) sequences within or near the gene that controls a
desirable trait rather than handling their phenotypes. Genomics-assisted selection offers unique advantages
in the correct choice of elite genotypes, in order to improve traits for which limitations of
phenotyping technologies or low hereditability adversely affect the efficiency of phenotypic selection.
DNA technologies enable the application of marker-assisted selection to thousands of grape seedlings
every year, which was previously feasible only for cereals and annuals, enhancing the possibilities of
finding an ideal recombinant in populations bred from highly heterozygous parents. The expected
outcome is a renewal of the varietal choices available to viticulturists, with novel genotypes that meet the
demand for disease-free vines and flavourful grapes. The depth of exploration and characterisation of the
existing germplasm is crucial for translating natural diversity into new varieties that could perform
beyond the fence of the experimental vineyards and gain substantial market share. We review here how
current achievements in genomics and genome sequencing are expected to increase the efficiency of
grapevine breeding programs
Impact of water deficit on the synthesis of phenolic compounds during berry ripening of Vitis vinifera cv. Merlot
No full textTranscriptional control of anthocyanin biosynthetic genes in extreme phenotypes for berry pigmentation of naturally occurring grapevines
Full text linkBackground. Fruit coloration of red-skinned grapevines is mainly due to anthocyanin pigments. We analysed a panel of nine cultivars that included extreme phenotypes for berry colour, ranging from green (absence of anthocyanins) to red, purple, violet and blue. Expression of six genes of the anthocyanin pathway coding for flavanone-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H), flavonoid 3',5'-hydroxylase (F3'5'H), UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT), glutathione-S-transferase (GST), O-methyltransferase (OMT) and four transcription factors (MybA, MybB, MybC, MybD) was analysed by quantitative RT-PCR at four developmental stages from before the onset of ripening until full maturity and compared to anthocyanin metabolites. Results. Total anthocyanin content at full maturity correlated well with the cumulative expression of F3H, UFGT and GST throughout ripening. Transcripts of the last two genes were absent in the green-skinned cultivar 'Sauvignonasse', also known as 'Tocai friulano', and were at least 10-fold less abundant in pale red cultivars, such as 'Pinot gris' and 'Gewürztraminer', compared to fully coloured cultivars. Predominance of tri-hydroxylated anthocyanins (delphinidin, petunidin and malvidin) in cultivars bearing dark berries with violet and blue hue was associated with higher ratios of F3'5'H/F3'H transcription, compared to red-skinned cultivars. Higher levels of OMT transcripts were observed in berries of cultivars that accumulated methoxylated forms of anthocyanins more abundantly than non-methoxylated forms. Conclusion. Colour variation of the grape berry conforms to a peculiar pattern of genotype-specific expression of the whole set of anthocyanin genes in a direct transcript-metabolite-phenotype relationship. Cumulative mRNA levels of the structural genes and their relative abundance throughout ripening explained per se the final phenotype for anthocyanin content, anthocyanin composition, colour intensity and colour hue of grapes at berry maturity. © 2007 Castellarin and Di Gaspero; licensee BioMed Central Ltd
- …
