Development and application of CRISPR/Cas in grapevine

Microbial pathogens of plant have evolved to sense, interpret, and use light to direct their development. One aspect of this evolved relationship is photolyase-mediated repair of UV-induced damage to pathogen DNA. Application of germicidal UV (UV-C) at night circumvents the blue light-driven repair of pathogen DNA and allows non-phytotoxic doses of UV-C to suppress a variety of pathogenic microbes and even certain arthropod pests without damage to vines or fruit. Lamps arrays have been designed specifically for the canopy architecture of grapevines and have been deployed on both tractor-drawn and robotic carriages for partial to near-complete suppression of powdery mildew (Erysiphe necator), sour rot (fungal, bacterial, and arthropod complex), and downy mildew (Plasmopara viticola).

The Valpolicella area (Veneto Region, Italy) is famous for its high quality wines: Amarone and Recioto, both obtained from partial post-harvest dehydrated red grapes.

The crossings of three wild Vitis species are commonly used as rootstocks in wine production worldwide. Factors such as disease resistance and vigor are most important for their selection.
With climate change extending drought conditions and water limitations, the selection of rootstocks conferring increased tolerance to drought takes on greater importance. Therefore, identifying Vitis species with improved drought tolerance and incorporating them into breeding programs could contribute to more resilient rootstocks under water limiting conditions. Furthermore, those species serve as a valuable resource to increase genetic variability of rootstocks. We hypothesize that species native to drier habitats will exhibit superior physiological performance under drought stress.

Rootstocks were the first sustainable and environmentally friendly strategy to cope with a major threat for Vitis vinifera cultivation. In addition to providing Phylloxera resistance, they play an important role in protecting against other soil-borne pests, such as nematodes, and in adapting V. vinifera to limiting abiotic conditions. Today viticulture has to adapt to ongoing climate change whilst simultaneously reducing its environmental impact. In this context, rootstocks are a central element in the development of agro-ecological practices that increase adaptive potential with low external inputs. Despite the apparent diversity of the Vitis genus, only few rootstock varieties are used worldwide and most of them have a very narrow genetic background. This means that there is considerable scope to breed new, improved rootstocks to adapt viticulture for the future.

The Grapevine Red Blotch Virus (GRBV) poses a critical challenge to the wine sector, lacking a uniquely identified vector. Current control methods involve costly and labor-intensive vine removal, emphasizing the urgency for targeted alternatives. The limited understanding of intricate host-virus interactions underscores the need for foundational knowledge to develop innovative disease control strategies. These include efforts to boost the plant’s RNA interference (RNAi) response, including RNA-based topical applications.