Abstract
Protein expression from the berry skin of four red grape biotypes with varying hybrid character was compared at a proteome-wide level to identify the metabolic pathways underlying divergent patterns of secondary metabolites. A bottom-up shotgun proteomics approach with label-free quantification and MaxQuant-assisted computational analysis was applied. Red grapes were from (i) purebred Vitis vinifera (Aglianico cv.); (ii) V. vinifera (local Sciascinoso cv.) grafted onto an American rootstock; (iii) interspecific hybrid (V. vinifera × V. labrusca, Isabel), and (iv) uncharacterized grape genotype with hybrid lineage, producing relatively abundant anthocyanidin 3,5-O-diglucosides. Proteomics supported the differences between hybrids and purebred V. vinifera grapes, consistently with distinct phenotypic metabolite assets. Methanol O-anthraniloyltransferase, which catalyses the synthesis of methyl anthranilate, primarily responsible for the “foxy” odour, was exclusive of the Isabel hybrid grape. Most of the proteins with different expression profiles converged into coordinated biosynthetic networks of primary metabolism, while many possible enzymes of secondary metabolism pathways, including 5-glucosyltransferases expected for hybrid grapes, remained unassigned due to incomplete protein annotation for the Vitis genus. Minor differences of protein expression distinguished V. vinifera scion grafted onto American rootstocks from purebred V. vinifera skin grapes, supporting a slight influence of the rootstock on the grape metabolism.
Highlights
The grape phylloxera aphid (Daktulosphaira vitifoliae Fitch) was introduced unintentionally into Europe in the early 1860s through infected plant material from North America [1]
In a previous paper, using mass spectrometry we demonstrated that the metabolite expression profiles of berry skin from V. vinifera vines grafted onto American rootstocks included very low levels of anthocyanidin 3,5-O-diglucosides, which were missing in purebred V. vinifera cultivars [8]
Exocarp tissue shows higher abundance of transcripts for genes involved in flavonoid biosynthesis, pathogen resistance and cell wall modification compared with other berry and plant tissues [28]
Summary
The grape phylloxera aphid (Daktulosphaira vitifoliae Fitch) was introduced unintentionally into Europe in the early 1860s through infected plant material from North America [1]. The wild American grapevine species that have co-evolved with phylloxera tolerate this aphid pest with varying levels of resistance. Grapes of wild American species are unsuitable to produce any wine-like drink, and their resistant interspecific crosses with European Vitis vinifera (the so-called French hybrids) carry many of the defects of their American ancestors, such as low sugar content, a “foxy” odour and off-flavours, as well as poor tannin content and availability [3]. Grafting V. vinifera scions onto resistant rootstocks of American Vitis species (e.g., Vitis rupestris, Vitis labrusca, and Vitis riparia or their interspecific hybrids) allowed saving the European wine heritage, combining typical European oenological traits with the resistance against phylloxera and providing the most effective solution for overcoming the vineyard pandemic [4]. The technique of grapevine grafting is still a routine practice in Europe as well as worldwide, and it is applied to enhancing the tolerance to environmental and abiotic stresses, such as soil limestone, salinity, stagnation, drought, and frost
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
