conference schedule and program with abstracts - Horticulture ...
conference schedule and program with abstracts - Horticulture ...
conference schedule and program with abstracts - Horticulture ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
O-53<br />
An Integrated approach to studying the positional c<strong>and</strong>idate gene 1-deoxyxylulose-5-<br />
phosphate synthase (VvDXS) involved in Muscat flavor determination.<br />
F. Emanuelli* 1 , J. Battilana 1 , G. Gambino 2 , L. Costantini 1 , L. Le Cunff 3 , F. Gasperi 1 , P. Boss 4 , P.<br />
This 3 , I. Gribaudo 2 , M.S. Gr<strong>and</strong>o 1<br />
1<br />
IASMA Research Centre, Fondazione Edmund Mach, San Michele all’Adige, Trento, Italy; 2<br />
Istituto Virologia Vegetale, CNR Unità Grugliasco, Grugliasco (TO) , Italy; 3 INRA UMR 1097<br />
DIAPC Diversité et Adaptation des Plantes Cultivées, Montpellier, France; 4 CSIRO Plant<br />
Industry Horticultural, Glen Osmond, South Australia, Australia<br />
*Corresponding author: francesco.emanuelli@iasma.it<br />
Fragrance in table grapes <strong>and</strong> a persistent <strong>and</strong> complex aroma in wine are both sought after by<br />
the modern consumer. In particular, the floral flavor typical of Muscat varieties, due to high<br />
levels of monoterpenoids (geraniol, linalool <strong>and</strong> nerol), is highly distinct <strong>and</strong> has been greatly<br />
appreciated since ancient times. Muscat flavor determination in grapevine (Vitis vinifera L.) has<br />
up to now been studied by evaluating monoterpenoid quantity through QTL analysis. These<br />
studies have revealed co-localization of 1-deoxyxylulose-5-phosphate synthase (VvDXS) <strong>with</strong> the<br />
major QTL positioned on chromosome 5. The aim of the present study was to assess the<br />
connection between the positional c<strong>and</strong>idate gene VvDXS <strong>and</strong> muscat flavor by investigating the<br />
nucleotide diversity of VvDXS ORF <strong>and</strong> its expression profiles in the grape berry. Association<br />
between VvDXS polymorphisms <strong>and</strong> muscat flavor was evaluated through a structured<br />
association analysis. A putative causal SNP responsible for a predicted non-neutral substitution<br />
was found to be significantly associated <strong>with</strong> muscat-flavored varieties. Moreover, muscat-like<br />
aromatic mutants displayed unique heterozygous non-synonymous mutations near the mutated<br />
site of Muscat genotypes. The relationship between the transcription profile of VvDXS alleles <strong>and</strong><br />
monoterpenoid accumulation was investigated over an extended period of berry development. It<br />
is possible that a particular trend in expression rather than the level of expression ratio affects<br />
monoterpenoid accumulation in Moscato Bianco. In vivo experiments using transgenic tobacco<br />
<strong>and</strong> in vitro enzymatic assays suggest that the putative causal SNP raises monoterpenoid<br />
accumulation by changing the 3D protein structure <strong>and</strong> by increasing VvDXS activity in Muscat<br />
enzyme form.<br />
74