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San Michele, Italy

Domingos S.,University of Lisbon | Domingos S.,Institute Investigacao Cientifica Tropical | Fino J.,Institute Investigacao Cientifica Tropical | Fino J.,University of Lisbon | And 10 more authors.
BMC Plant Biology | Year: 2016

Background: Abscission is a highly coordinated developmental process by which plants control vegetative and reproductive organs load. Aiming at get new insights on flower abscission regulation, changes in the global transcriptome, metabolome and physiology were analyzed in 'Thompson Seedless' grapevine (Vitis vinifera L.) inflorescences, using gibberellic acid (GAc) spraying and shading as abscission stimuli, applied at bloom. Results: Natural flower drop rates increased from 63.1% in non-treated vines to 83% and 99% in response to GAc and shade treatments, respectively. Both treatments had a broad effect on inflorescences metabolism. Specific impacts from shade included photosynthesis inhibition, associated nutritional stress, carbon/nitrogen imbalance and cell division repression, whereas GAc spraying induced energetic metabolism simultaneously with induction of nucleotide biosynthesis and carbon metabolism, therefore, disclosing alternative mechanisms to regulate abscission. Regarding secondary metabolism, changes in flavonoid metabolism were the most represented metabolic pathways in the samples collected following GAc treatment while phenylpropanoid and stilbenoid related pathways were predominantly affected in the inflorescences by the shade treatment. However, both GAc and shade treated inflorescences revealed also shared pathways, that involved the regulation of putrescine catabolism, the repression of gibberellin biosynthesis, the induction of auxin biosynthesis and the activation of ethylene signaling pathways and antioxidant mechanisms, although often the quantitative changes occurred on specific transcripts and metabolites of the pathways. Conclusions: Globally, the results suggest that chemical and environmental cues induced contrasting effects on inflorescence metabolism, triggering flower abscission by different mechanisms and pinpointing the participation of novel abscission regulators. Grapevine showed to be considered a valid model to study molecular pathways of flower abscission competence acquisition, noticeably responding to independent stimuli. © 2016 Domingos et al.

Mescalchin E.,FEM IASMA | Agabiti B.,FEM IASMA | Bertoldi D.,FEM IASMA | Larcher R.,FEM IASMA | And 4 more authors.
Acta Horticulturae | Year: 2013

In this paper we propose a method enabling to assess in the field the correct setting of the sprayer considering specific varietal characteristics and changes occurring in the canopy throughout the vegetative season. The general aim of the present work was to set up a methodology to check the pesticide distribution at the canopy level and its loss onto the ground. The work was based on field trials and simple analytical methods. Performances of a sprayer with a product recycling device (tunnel sprayer) and a pneumatic nebulizer were compared. A certain number of vine leaves were sampled before and after the application of the agrochemical. A copper-based product was used because its quantification is easy and inexpensive in relation to other pesticides. For a more objective evaluation of pesticide distribution, the canopy was divided in high canopy and low canopy. Each of the two was sub-divided in inner canopy and outer canopy. Distribution homogeneity was determined using water-sensitive papers pinned to the upper page and lower page of vine leaves. The leaves sampled from different parts of the plants were washed with a solution of 1% nitric acid. The concentration of copper removed from the leaf surface was then quantified. In order to quantify the amount of product loss onto the ground, analytical measurements were performed along the treated rows and the adjacent ones. Results showed that the low and external part of the canopy was usually wetted easily, while a smaller amount of product was detected in the high, internal part, whereas the tunnel sprayer was able to lay on an amount of product which was 50% higher than the nebulizer. Moreover, the use of the tunnel sprayer allowed to reach a nearly homogeneous distribution on the two leaf pages, while some problems in wetting properly the lower page were denoted when the pneumatic nebulizer was used. The amount of pesticide lost onto the ground was observed to be also dependent upon the type of sprayer: the one provided with a product recycling device can limit the pesticide loss along the treated rows and especially in the adjacent ones.

De Rosso M.,Italian Agricultural Research Council | Tonidandel L.,FEM IASMA | Larcher R.,FEM IASMA | Nicolini G.,FEM IASMA | And 6 more authors.
Food Chemistry | Year: 2014

Grape flavonols are involved in the phenomenon of copigmentation in red wines. These compounds are characterised by nutraceutical properties, have antioxidant activity and are studied for chemotaxonomy of grapes. In general, hybrid grapes are characterised by presence of polyphenols often qualitatively and quantitatively different from Vitis vinifera varieties. In this work, flavonols of 34 hybrid grape varieties (22 red and 12 white) produced by crossing of V. vinifera, Vitis riparia, Vitis labrusca, Vitis lincecumii and Vitis rupestris species, were studied. Compounds were characterised by combining different liquid chromatography/mass spectrometry (LC/MS) methods: precursor-ion and neutral-loss multiple-reaction-monitoring (MRM), and high-resolution mass spectrometry. Twenty-four glycoside flavonols were identified, including 4 quercetin, 5 myricetin, 4 kaempferol, 3 isorhamnetin, 2 laricitrin, 3 syringetin and 3 dihydroflavonol derivatives; myricetin hexoside-glucuronide, myricetin O-di-hexoside, syringetin O-di-hexoside, isorhamnetin rutinoside and kaempferol rutinoside were found in grape for the first time. Statistical analysis (PCA and cluster analysis) divided the samples in four groups on the basis of their flavonol profiles. © 2014 Elsevier Ltd. All rights reserved.

De Rosso M.,Italian Agricultural Research Council | Tonidandel L.,FEM IASMA | Larcher R.,FEM IASMA | Nicolini G.,FEM IASMA | And 6 more authors.
Analytica Chimica Acta | Year: 2012

The anthocyanins of 21 hybrid red varieties produced by crossing . V. vinifera, . V. riparia, V. labrusca, . V. lincecumii and . V. rupestris species, the profiles for which have not yet been reported, were studied. Profiles were determined by LC/DAD, and identification of single anthocyanins was confirmed by LC/MS precursor-ion analysis. Anthocyanidin precursors (pelargonidin at . m/. z 271, dephinidin at . m/. z 303, cyanidin at . m/. z 287, petunidin at . m/. z 317, peonidin at . m/. z 301, and malvidin at . m/. z 331) and precursors of monoglucoside compounds allowed 24 different compounds to be identified. Analysis of precursor ions of monoglucoside anthocyanins at low capillary voltage revealed the signals of diglucosides only, providing a very selective method for analysis of diglucoside anthocyanins in grape. According to anthocyanin profile, the samples were subdivided into two groups: one characterized by the substantial presence of diglucoside compounds (particularly Seyve Villard 23-399 and Seyve Villard 23-369) and one by the scarce presence or practical absence of diglucosides (Seibel 10878, Burdin 4077, and Galibert 238-35). Particularly interesting for producing anthocyanin for the natural colorant industry were the varieties Siebel 8357, Bacò 30-12 and Terzi 100-31. © 2011 Elsevier B.V.

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