Combined abiotic-biotic plant stresses on the roots of grapevine

In a context of sustainable agriculture, “agroecological immunity” is an emerging concept to reduce the use of chemical pesticides to protect crops against pathogens. This alternative strategy aims to combine different levers including the use of “bio”solutions. These include biocontrol products, some of which being plant defense elicitors, as well as products authorized in organic farming such as copper or sulfur. In vineyards, depending on climate conditions, powdery and downy mildews can be devastating diseases.

Red grape pomace can be an important source of polysaccharides, but currently they are little studied and even less with viable and environmental extraction processes (green extraction). These green techniques must be able to break the cell wall so that the compounds contained in the cells, including polysaccharides, are released and can have a great influence on extraction yields, the chemical structure of polysaccharides and applications in wines. Amongst the emerging green techniques most applied to the extraction of bioactive compounds, such as polysaccharides, high-power ultrasound (US) and enzyme-assisted extraction stand out.

Atmospheric CO2 levels have been rising continuously since the industrial revolution, affecting crop physiology, yield and quality of harvest products, and grapevine is no exception [1]. Most of previously reported studies used potted plants in controlled environments, and explored grapevine response to relatively high CO2 levels, 700 ppm or more. The vineyardFACE, established in Geisenheim in 2012, uses a free air carbon dioxide enrichment (FACE) system to simulate a moderate (ambient +20%) increase in atmospheric CO2 in a vineyard planted with cvs. Cabernet-Sauvignon and Riesling grafted on rootstock 161-49 Couderc and SO4, respectively.

Understanding grapevine molecular processes and the underlying defence responses is vital for developing sustainable disease control strategies. Lipid signalling pathways, involving the synthesis and degradation of lipid molecules, have emerged as a key regulator in plant defence against pathogens. This study aims to elucidate the role of fatty acids and lipid signalling in grapevine’s defence response to P. viticola infection. The expression of lipid metabolism-related as well as lipid signalling genes was analysed, by qPCR, in three grapevine genotypes: Chardonnay (susceptible), Regent (tolerant) with Rpv3-1 resistance loci, and Sauvignac (resistant) harbouring a pyramid of Rpv12 and Rpv3-1 resistance loci.

One of the most important effects of climate change in wine-growing areas is the advance of phenological stages, especially concerning early berry ripening. In the hottest seasons, this results in a lack of synchrony between sugar and phenolic ripeness. In order to cope with this fact, a general effort is being made by researchers and growers aiming at delaying ripening through different strategies. One of the proposed approaches is the application of elicitors. This study aims to assess the effect at the transcriptomic level of application of three elicitors (Vitalfit, Fruitel, and Protone) in Tempranillo.