Hydrophobized laminarans as new biocompatible anti-oomycete compounds for grapevine protection.

Laminaran, a β-(1→3)-glucan extracted from Laminaria digitata, is a known elicitor of plant defenses, but provides only low level of disease control in vineyard trials. In this context, laminaran was partly hydrophobized by grafting from 1.6 to 7.

Correction: The Sulfated Laminarin Triggers a Stress Transcriptome before Priming the SA- and ROS-Dependent Defenses during Grapevine's Induced Resistance against Plasmopara viticola.

[This corrects the article DOI: 10.1371/journal.pone.

Water extracts from winery by-products as tobacco defense inducers.

Water extracts from winery by-products exhibited significant plant defense inducer properties. Experiments were conducted on three marc extracts containing various amounts of polyphenols and anthocyanins. Infiltration of red, white and seed grape marc extracts into tobacco leaves induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining.

The sulfated laminarin triggers a stress transcriptome before priming the SA- and ROS-dependent defenses during grapevine's induced resistance against Plasmopara viticola.

Grapevine (Vitis vinifera) is susceptible to many pathogens which cause significant losses to viticulture worldwide. Chemical control is available, but agro-ecological concerns have raised interest in alternative methods, especially in triggering plant immunity by elicitor treatments. The β-glucan laminarin (Lam) and its sulfated derivative (PS3) have been previously demonstrated to induce resistance in grapevine against downy mildew (Plasmopara viticola).

Elicitor and resistance-inducing activities of beta-1,4 cellodextrins in grapevine, comparison with beta-1,3 glucans and alpha-1,4 oligogalacturonides.

Cellodextrins (CD), water-soluble derivatives of cellulose composed of beta-1,4 glucoside residues, have been shown to induce a variety of defence responses in grapevine (Vitis vinifera L.) cells. The larger oligomers of CD rapidly induced transient generation of H2O2 and elevation in free cytosolic calcium, followed by a differential expression of genes encoding key enzymes of the phenylpropanoid pathway and pathogenesis-related (PR) proteins as well as stimulation of chitinase and beta-1,3 glucanase activities.

Laminarin elicits defense responses in grapevine and induces protection against Botrytis cinerea and Plasmopara viticola.

Grapevine (Vitis vinifera L.) is susceptible to many pathogens, such as Botrytis cinerea, Plasmopara viticola, Uncinula necator, and Eutypa lata. Phytochemicals are used intensively in vineyards to limit pathogen infections, but the appearance of pesticide-resistant pathogen strains and a desire to protect the environment require that alternative strategies be found.