conference schedule and program with abstracts - Horticulture ...

P-46
Defense response to downy mildew in grapevine: Learning from transcriptomics and
metabolomics
A. Figueiredo 1 , K. Ali 2 , A.M. Fortes 1 , F. Maltese 2 , Y.H. Young 2 , F. Monteiro 1 , S. Lisete 3 , M.
Rex 4 , E. Zyprian 4 , R. Verpoorte 2 , M.S. Pais 1*
1
Unit of Molecular Biology and Plant Biotechnology, Centre for Biodiversity, Functional and
Integrative Genomics, Science Faculty of Lisbon, Lisbon, Portugal; 2 Division of
Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, Leiden, The
Netherlands; 3 Department of Statistics and Operational Investigation, Center of Applied
Statistics, Science Faculty of Lisbon, Lisbon, Portugal; 4 Julius Kühn Institute, Federal Research
Centre for Cultivated Plants, Institute for Grapevine Breeding, Geilweilerhof, Siebeldingen,
Germany
*Corresponding author: msalomepais@gmail.com
Grapevine (Vitis vinifera L.) is the most widely cultivated and economically important fruit crop
in the world. With the global warming, fungal infections are becoming higher risk factors for
wine producers. Plasmopara viticola [(Berk. and Curt) Berl. et De Toni], the causal agent of
grapevine downy mildew, is one of the most devastating pathogens in viticulture. Fungicide
application during the vegetative period has become obligatory since Vitis vinifera varieties are
generally susceptible to this disease. To better understand the mechanisms underlying disease
tolerance/resistance, cDNA microarrays and H 1 NMR-based metabolomics analyses were
performed. Transcriptional and metabolic changes during the defence response of V. vinifera
`Regent´ (a resistant grapevine cultivar) were accessed and compared to susceptible cultivar
‘Trincadeira’. Both cultivars were inoculated with P. viticola and analyzed at the following time
points: 0h, 6hpi, 12hpi, 18hpi, 24hpi and 48hpi. So far, 22 transcripts were found to be
differentially expressed at 0h. At 6hpi, 96 transcripts were found to be differentially expressed
(54 up-regulated and 42 down-regulated). The main changes regarding the defense response at
6hpi are observed in the resistant cultivar. The transcript regulation suggests that the resistant
cultivar perceives and reacts to the pathogen before the susceptible one. The multivariate data
analyses, like Principal Component Analysis (PCA) and Partial Least Square-Discriminant
Analysis (PLS-DA), of the 1 H NMR spectra showed evident innate differences between the
resistant and susceptible cultivars in terms of primary and secondary metabolites possibly
associated with the acquired resistance of grapevine against the pathogen. This study may
contribute to the defining molecular and chemical markers of resistance to downy mildew in
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