Grape gene could boost disease resistance

A newly identified grapevine gene could give breeders another tool for developing vines with greater natural resistance to fungal disease, potentially benefiting both wine and table grapes.

Researchers have identified VvMYB3R5, a naturally occurring Vitis vinifera gene, that helps grapevines defend themselves against the fungus Colletotrichum viniferum. The gene acts as a transcription factor, switching on other genes involved in producing protective compounds called proanthocyanidins. Proanthocyanidins are the main type of tannins in wine.

The researchers found that increasing VvMYB3R5 activity raised proanthocyanidin levels and improved resistance to the fungus. Silencing the gene had the opposite effect, making vines more susceptible.

The discovery could eventually prove useful in grape breeding. If researchers can transfer or enhance this natural defence mechanism in new V. vinifera varieties, it could help produce vines that need fewer chemical disease treatments. It may also be relevant to future disease-resistant varieties, including PIWI grapes.

There is still considerable work before this becomes a commercial reality, but VvMYB3R5 gives breeders an intriguing new genetic target.