Mechanical stress rapidly induces E-resveratrol and E-piceatannol biosynthesis in grape canes stored as a freshly-pruned byproduct

Abstract

Grape canes represent a promising source of bioactive phytochemicals. However the stabilization of the raw material after pruning remains challenging. We recently reported the induction of stilbenoid metabolism after winter pruning including a strong accumulation of E-resveratrol and E-piceatannol during the first six weeks of storage. In the present study, the effect of mechanical wounding on freshly-pruned canes was tested to increase the induction of stilbenoid metabolism. Cutting the grape canes in short segments immediately after pruning triggered a transient expression of phenylalanine ammonia-lyase (PAL) and stilbene synthase (STS) genes, followed by a rapid accumulation of E-resveratrol and E-piceatannol. The degree of stilbenoid induction was related to the intensity of mechanical wounding. Data suggest that a global defense response is triggered involving jasmonate signaling, PR proteins and stilbenoid metabolism. Mechanical wounding of freshly-pruned canes drastically shortens the time required to reach maximal stilbenoid accumulation from 6 to 2weeks.

Keywords: Ampelopsin A (PubChem CID: 182999); Byproduct; E-miyabenol C (PubChem CID: 6475924); E-piceatannol; E-piceatannol (PubChem CID: 667639); E-resveratrol; E-resveratrol (PubChem CID: 445154); E-ε-viniferin (PubChem CID: 5315232); Grape canes; Hopeaphenol (PubChem CID: 6712231); Isohopeaphenol (PubChem CID: 13844644); Mechanical wounding; Stilbenoid biosynthesis; Stress induction; Z/E-vitisin B (PubChem CID: 16138152).