Composition and content of fatty acids in Vitis vinifera L. var. Cabernet Sauvignon leaves infected with the eutypiosis fungus, Eutypa lata
Abstract
On Cabernet sauvignon, eutypiosis sensible variety, we have compared fatty acids content in healthy Jeaves (S: leaves beared by healthy vine stock), in leaves seeming healthy (Ap.S: leaves beared by arm without symptoms, the other arm is diseased) and in diseased leaves (M: leaves beared by diseased arm). The results show that disease does not alter the fatty acids order. Linolenic acid (CI 8:3) content is always the most important, followed by palmitic (CI6:0) and Iinoleic acids, then by stearic (CI8:0) and oleic acids and at last by arachidic acid (C20:0). During the three stages studied (flowers buds: H, flowering: I and closed cluster: L), only the development of CI 8:3 content was modified by disease. It increases in healthy leaves at stage I, while in Ap.S and M leaves there is a decrease from H to L stages. Otherwise, development of fatty acids proportions does not seem to be changed by eutypiosis.
Proportions and content comparison in S, Ap.S and M leaves show a decrease of C 18:3 synthesis benefit of C 18:2.
This increases is important as well as the symptoms are evident. These results seem to be in relationship with decrease of leaves size caused by eutypiosis. At the end, the disease induces a desaturation decrease of C18:0 and C18:2 as well as an aliphatic chain lengthening of C16:0. These inhibitions are showed by more increase of CI 6:0 and CI 8:2 in diseased leaves than in healthy leaves. No action is observed in CI 8: 1 desaturation.