Saccharomyces cerevisiae, a potential pathogen towards grapevine, Vitis vinifera

Stresses applied to plants by pathogens such as fungi, bacteria, and viruses are well documented. However, to our knowledge, no study has focused on the effect of yeasts on plants. In this work the relationship between the growth of yeast, Saccharomyces cerevisiae, and its action on grapevine (Vitis vinifera L.) plantlets was studied. We observed that certain strains of S. cerevisiae could penetrate into the grapevine plants, bringing about a delay in the growth, or even causing the plantlets to die. We correlated this novel parasitic behavior of these strains of S. cerevisiae with their endopolygalacturonase activities and pseudohyphae formation. This study reports that the differences in behavior between the strains of S. cerevisiae are based on the filamentous forms, but that their pectolytic activities are required to invade grapevine tissues. The invasive process of the host plant has been confirmed histologically. Such yeast–plant interactions explain how S. cerevisiae may survive on grapevine throughout the years. The details of the parasitic relationship between S. cerevisiae and V. vinifera plantlets together with these parameters are discussed.