Submitted to: BMC Research Notes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2020
Publication Date: 7/29/2020
Citation: Wallis, C.M. 2020. Determining roles of grapevine (Vitis spp.) stilbenoids on providing host resistance to root knot nematodes, Meloidogyne incognita. BMC Research Notes. 13:360. https://doi.org/10.1186/s13104-020-05201-3.
Interpretive Summary: Root knot nematodes can severely decrease grapevine yields and necessitate vineyard replanting. Although resistant grapevine rootstocks exist, the mechanisms of resistance remain unknown. This study examined potential roles of stilbenoids in providing resistance, as these compounds have exhibited a variety of antibiotic activity against other pathogens. A resistant rootstock, Freedom, was observed to have greater levels of stilbenoid trimer and tetramer levels than a susceptible rootstock, O39-16, which may suggest stilbenoid polymers provide resistance to nematodes. Thus, the ability of grapevine rootstocks to produce these compounds could be a desired trait to target in nematode resistance breeding programs.
Technical Abstract: Root knot nematodes (RKN), including Meloidogyne incognita, can severely impact vineyards and reduce grapevine yields over time. To counter this, grapevine rootstocks have been developed from wild Vitis species that provide natural resistance to nematode infections. However, the potential biochemical or mechanical mechanisms of resistance have not been thoroughly explored. Therefore, this study measured levels of stilbenoids, including resveratrol and its polymers, in roots of non-infected and RKN-infected grapevines with Cabernet Sauvignon scion grafted to susceptible (O39-16) and resistant (Freedom) rootstocks at six and twelve weeks post-inoculation. Whereas levels of resveratrol increased in O39-16 in response to RKN infection, no increases were observed in Freedom restocks, albeit infection levels were low. Non-infected and RKN-infected levels of stilbenoid trimers and tetramers were overall much greater in Freedom than O39-16 rootstocks, although some individual stilbenoids were greater in O39-16 than Freedom. O39-16 and Freedom had similar levels of stilbenoids monomers and dimers. Based on these results, it appeared that greater levels of stilbenoid trimers and tetramers were correlated with improved resistance to RKN observed in Freedom compared to O39-16. If validated, breeding programs could detect increased presence of these compounds when screening for potential resistance to nematodes in newly developed rootstock cultivars.