Different cultivars differ in their susceptibility to Eutypa lata. The aim of this study was to determine the underlying molecular response that lead to cultivar tolerance or susceptibility to E. lata infection.
- The study was conducted over three years.
- Merlot, Cabernet Sauvignon (CS) and Ugni blanc were inoculated with E. lata.
- Physical symptoms were recorded and plant defence responses were monitored. This included monitoring the activation of pathogenesis-related (PR) genes, oxylipin and phenylpropanoid pathways and the accumulation of stilbenes.
- The latter analyses were carried out using the millicell system that enables the molecular dialogue between E. lata mycelium and grapevine leaves to take place without physical contact.
- Expression of genes involved in sugar transport and cleavage were also monitored.
- Merlot was the most tolerant to E. lata infection. In this variety infection triggered the expression of a number of defence related genes. Furthermore, cell wall invertase activity in the leaves were stimulated as certain genes were up-regulated.
- CS and Ugni blanc were much more susceptible than Merlot, and susceptibility of the two cultivars varied.
- Defence responses were not activated in Ugni blanc, even though the plant could recognise the fungus.
- This research also indicated that sugar transport and cleavage play an additional role in disease tolerance.
SIGNIFICANCE OF THE STUDY:
E.lata is one of the major grapevine trunk diseases with significant economic ramifications. Symptoms often only become visible years after infection and vines cannot be cured. This research revealed new insights and helped to identify a comprehensive set of genes responsible for disease tolerance/resistance of vines against E. lata. This knowledge is useful in future research and developing of resistant varieties through breeding programmes.
Link to article (open source): https://www.frontiersin.org/articles/10.3389/fpls.2019.00991/full
Image source: Prof Goussard