C. Deswarte et al., ULTRASTRUCTURAL-CHANGES PRODUCED IN PLANTLET LEAVES AND PROTOPLASTS OF VITIS-VINIFERA CV CABERNET-SAUVIGNON BY EUTYPINE, A TOXIN FROM EUTYPA-LATA, Vitis, 33(4), 1994, pp. 185-188
Eutypine is a toxin produced by Eutypa lata (Pers.: Pr.) Tul., the cau
sal agent of dying-arm disease of the grapevine. Ultrastructural alter
ations induced by eutypine in leaf cells and protoplasts isolated from
plantlets of Vitis vinifera cv. Cabernet Sauvignon, a very sensitive
variety cultured in vitro, were observed for the first time by transmi
ssion electron microscopy. Eutypine caused early cytoplasm lysis and v
esiculation followed by chloroplast swelling with thylakoid dilation.
The eutypine-induced alterations of the cellular ultrastructure are si
milar to those previously described in vivo in the leaves of diseased
grapevines. These results confirm that eutypine, synthesized by E. lat
a mycelium present in the trunk or arms, is involved in symptom expres
sion of eutypiosis in the herbaceous parts of grapevine.