Mechanical stress rapidly induces E-resveratrol and E-piceatannol biosynthesis in grape canes stored as a freshly-pruned byproduct.
Food Chem 2017;
240:1022-1027. [PMID:
28946218 DOI:
10.1016/j.foodchem.2017.07.105]
[Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/29/2017] [Accepted: 07/24/2017] [Indexed: 12/27/2022]
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.
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