Oral – New biotechnological tools

The development and application of CRISPR (clustered regularly interspaced short palindromic repeats)/Cas (CRISPR-associated protein) technologies have revolutionized genome editing in plants due to its simplicity, high efficiency, and versatility. As an economically important fruit crop worldwide, grapevine genome editing using CRISPR/Cas technologies has also been reported these years. Here we introduce the development briefly of the most popular CRISPR/Cas9 system and also the state-of-the-art CRISPR technologies developed so far. Moreover, we summarize CRISPR/Cas9-mediated applications for gene functional study and trait improvement in grapevine.

Wine viticulture, being firmly linked to the vine-terroir relationship, has always encountered significant bottlenecks to genetic innovation. Nonetheless, the development of new breeding strategies leading to the selection of stress resilient genotypes is urgent, especially in viticulture, where it would allow reducing the use of chemical treatments adopted to control fungal diseases. Genome editing represents an extremely promising breeding technique. Unfortunately, the well-known recalcitrance of several wine grape cultivars to in vitro regeneration strongly limits the exploitation of this approach, which to our knowledge has so far been developed on table grape genotypes with high regeneration potential.

Grapevine (Vitis Vinifera L.), one of the most important cultivated fruit crops, is facing significant challenges due to climate change. Specifically, increasing temperatures negatively impact the physiological traits and disrupt plant phenology. Additionally, increased virulence in pathogen attacks and pests leads to significant yield loss, requiring widespread application of plant protection products. Traditional agronomic practices offer only partial mitigation, requiring the development of precise and effective intervention strategies. The economic worth of viticulture has prompted continuous efforts in grapevine genetic improvement programs, traditionally involving conventional breeding and clonal selection that, however, are complex and time-consuming approaches.

DNA-binding proteins play a pivotal role in critical cellular processes such as DNA replication, transcription, recombination, repair, and other essential activities. Consequently, investigating the interactions between DNA and proteins is of paramount importance to gain insights into these fundamental cellular mechanisms. Several methodologies have been devised to uncover DNA-protein interactions, which can be broadly categorized into two approaches. The “protein-centered” approach focuses on identifying the DNA sequences bound by a specific transcription factor or a set of TFs. Techniques falling within this category include chromatin immunoprecipitation, and protein-binding microarrays.

Successful powdery mildew (PM) infection in plants relies on Mildew Resistance Locus O (MLO) genes, which encode susceptibility factors essential for fungal penetration. In Arabidopsis, loss-of-function mutations in three clade-V MLOs, AtMLO2, 6, and 12 confer complete resistance to PM infection. Since then, efforts are on to discover MLO genes contributing to PM susceptibility in many species to introduce mlo-based PM-resistance. Earlier studies in tomato and grapevine, using the RNAi approach, attributed PM susceptibility to SlMLO1, 5, and 8 and VvMLO3, 13, and 17, respectively indicating likely functional redundancy among MLOs.

Efforts to improve the New Zealand wine industry’s climate resilience and sustainability through grapevine improvement are limited by germplasm availability and a reliance on Sauvignon Blanc exports. To address this, we are working to generate a population of 12,000 individuals with unique genetic traits, from which to select future clones for major export varieties.

Sauvignon Blanc plantlets are being regenerated from embryogenic callus, using an approach designed to mobilise endogenous transposable elements as mutagens.