Localization of stilbene synthase in Vitis vinifera L. during berry development

Abstract

The localization of stilbene synthase (STS) (EC 2.3.1.95) in grape berry (Vitis vinifera L.) was investigated during fruit development. The berries were collected at 2, 4, 7, 11, and 15 weeks postflowering from the cultivar Nebbiolo during the 2005 and 2006 growing seasons. High-performance liquid chromatography analysis showed that berries accumulated cis- and trans-isomers of resveratrol mainly in the exocarp throughout fruit development. Immunodetection of STS protein was performed on berry extracts and sections with an antibody specifically developed against recombinant grape STS1. In agreement with resveratrol presence, STS was found in berry exocarp tissues during all stages of fruit development. The labeled epidermal cells were few and were randomly distributed, whereas nearly all the outer hypodermis cells were STS-positive. The STS signal decreased gradually from exocarp to mesocarp, where the protein was detected only occasionally. At the subcellular level, STS was found predominantly within vesicles (of varying size), along the plasma membrane and in the cell wall, suggesting protein secretion in the apoplast compartment. Despite the differences in fruit size and structure, the STS localization was the same before and after veraison, the relatively short developmental period during which the firm green berries begin to soften and change color. Nevertheless, the amount of protein detected in both exocarp and mesocarp decreased significantly in ripe berries, in agreement with the lower resveratrol content measured in the same tissues. The location of STS in exocarp cell wall is consistent with its role in synthesizing defense compounds and supports the hypothesis that a differential localization of phenylpropanoid biosynthetic machinery regulates the deposition of specific secondary products at different action sites within cells.

Effects of Ultraviolet C Irradiation on Stilbene Biosynthesis in Vitis vinifera L. cv. Cabernet Sauvignon Berry Skins and Calli

“…1D) increased to a maximum of 71.06 ± 1.87 μg/g FW at 100 DAF and declined at 110 DAF. The stilbene content in grape berries depends on the grape cultivar (Douillet-Breuil et al, 1999;Li et al, 2006;Guerrero et al, 2010), and stilbene biosynthesis is related to the stage of development (Versari et al 2001;Fornara et al, 2008). Our results show that the stilbene content in berry skins increased from véraison to the ripening stage, in agreement with the findings of Gatto et al (2008) and Dai et al (2012).…”

Skin Browning and Expression of PPO, STS, and CHS Genes in the Grape Berries of ‘Shine Muscat’

“…Polyphenol oxidase (PPO) is one of major enzymes of browning factors, catalyzing the oxidation In grapevine, the stilbenoid synthetic pathway was found to be activated by abiotic stress factors where STS was localized in the cell walls of berry skin (Fornara et al, 2008). This STS activity has been detected in the primary and secondary cell walls after UV treatment, results that are consistent with a defense function (Pan et al, 2009).…”

Rootstock and soil induce transcriptome modulation of phenylpropanoid pathway in grape leaves

“…They may also occur after pathogen infection, as the socalled phytoalexins (Treutter 2005). In grape, the most studied stilbene compound is resveratrol which is well known for its potential medicinal properties, particularly against cardiovascular diseases and cancer (Fornara et al 2008). Many resveratrol derivatives, such as the viniferins, pterostilbene, and piceide, are also present in grape tissue and have been shown to be involved in plant defense mechanisms against biotic and abiotic stresses (Jeandet et al 2002).…”