Wood-degrading diseases, in particular esca, Botryosphaeria dieback and Eutypa dieback, affect grape-
vines in vineyards around the world. The wood-inhabiting fungal pathogens degrade wood tissues in the
colonization areas and induce, at distance, characteristic foliar symptoms. These effects have been pre-
viously partly correlated with the secretion of polypeptides (PFpal) presenting toxic effects on plant cells
at various metabolic levels. These diseases are insidious and the symptoms can occur in mild or severe
forms, showing differences from one year to another. Observations allowed to assume that variations in
climatic conditions may intervene in this behavior. We showed here that a modification in the tem-
perature regime modified the fungal development of Phaeoacremonium aleophilum and induced modi-
fications of the intracellular structures, observed in particular in the nucleus, the vacuolar apparatus, the
Golgi, the endoplasmic reticulum and also in the hyphal coat. Furthermore, changes in the pattern of the
secreted polypeptides were observed as well quantitatively as qualitatively by electrophoretic analysis
and immunolabeling by anti-PFpal antibodies. Subsequently, the different polypeptide fractions obtained
from fungal cultures, either maintained at 20 C or respectively transferred to colder (5 C) and warmer
(30 C) temperatures, differentially affected the grapevine physiology as shown by the different effects
induced on leaf anthocyanin synthesis, modification of proton secretion and lethality of cells in culture.