The Phytoalexin Resveratrol Regulates the Initiation of Hypersensitive Cell Death in Vitis Cell

Abstract

Resveratrol is a major phytoalexin produced by plants in response to various stresses and promotes disease resistance. The resistance of North American grapevine Vitis rupestris is correlated with a hypersensitive reaction (HR), while susceptible European Vitis vinifera cv. ‘Pinot Noir’ does not exhibit HR, but expresses basal defence. We have shown previously that in cell lines derived from the two Vitis species, the bacterial effector Harpin induced a rapid and sensitive accumulation of stilbene synthase (StSy) transcripts, followed by massive cell death in V. rupestris. In the present work, we analysed the function of the phytoalexin resveratrol, the product of StSy. We found that cv. ‘Pinot Noir’ accumulated low resveratrol and its glycoside trans-piceid, whereas V. rupestris produced massive trans-resveratrol and the toxic oxidative δ-viniferin, indicating that the preferred metabolitism of resveratrol plays role in Vitis resistance. Cellular responses to resveratrol included rapid alkalinisation, accumulation of pathogenesis-related protein 5 (PR5) transcripts, oxidative burst, actin bundling, and cell death. Microtubule disruption and induction of StSy were triggered by Harpin, but not by resveratrol. Whereas most responses proceeded with different amplitude for the two cell lines, the accumulation of resveratrol, and the competence for resveratrol-induced oxidative burst differed in quality. The data lead to a model, where resveratrol, in addition to its classical role as antimicrobial phytoalexin, represents an important regulator for initiation of HR-related cell death.

A survey of genes involved in Arachis stenosperma resistance to Meloidogyne arenaria race 1

“…(Sobolev 2008). Recently, it was shown in Vitis vinifera that resveratrol, in addition to its classical role as an antimicrobial phytoalexin, is an important regulator for initiation of HR-related cell death (Chang et al 2011). In the present study, a variant homolog of A. stenosperma RS gene AsRS1, previously analysed using macroarray by Guimarães et al (2010), named AsRS2, showed strong upregulation in the three time points analysed, coinciding with the occurrence of HR in A. stenosperma.…”

“…JA, a stressinduced hormone, is involved in defence against insects, pathogens and abiotic stresses, and can also induce the production of secondary metabolites, including alkaloids, anthocyanins, and terpenoid compounds (Niu et al 2011). The increase in ROS levels in the cells and the induction of the synthesis of secondary metabolites like phythoalexins cause cell death (Chang et al 2011). We suggest that the upregulation of AsbHLH during A. stenosperma response to M. arenaria infection induces the production of JA and therefore contributes to the HR response.…”

“…Another protein related to defence is resveratrol synthase (RS), the last of the four enzymes that participate in the resveratrol biosynthesis, which can be induced by different biotic and abiotic stresses (Chang et al 2011). Indeed, the accumulation of RS and its mRNA was observed in peanut in response to treatment with stress hormone, yeast extract, ultraviolet light, and after wounding (Chung et al 2003), fungal chitin treatment (Yang et al 2010), and infection with Aspergillus spp.…”

Regulation of stilbene biosynthesis in plants

“…These results indicate that some CDPKs are implicated in the regulation of stilbene biosynthesis as positive regulators. Chang et al (2011) demonstrated that the bacterial effector Harpin induced ROS production, STS transcript accumulation, and production of stilbenes in cell lines of cultivated and wild grapevines (V. vinifera cv. 'Pinot Noir' and V. rupestris cell lines).…”

Root Proteomic Analysis of Grapevine Rootstocks Inoculated with Rhizophagus irregularis and Fusarium oxysporum f. sp. herbemontis

“…Actin may also act as a defence mechanism in the plant hypersensitive cell-death reaction against pathogenic infection. Chang et al (2011) showed an increase in actin bundling and ensuing cell death in grapevines treated with phytoalexin. The spot ID 2143 corresponds to a superfamily of related proteins called Ras, constituted by small GTPase proteins.…”