Influence De La Lumiere Et De La Temperature Sur La Teneur en Acide Linolenique Et La Resistance Au Gel Du Ble D’hiver

Abstract

The correlation between accumulation of linolenic acid in the crowns and roots of winter wheat and its frost hardening at low temperature is indirect. It results from their common requirement for light and low temperature. Light mainly produces energy and carbon reserves. The partial hardening obtained in darkness could be eliminated by preetiolation. The high levels of linolenic acid and frost resistance reached after hardening were maintained for a long time in darkness. The levels of linolenic acid and frost hardiness decreased faster at low temperature in hardened plants after treatment with BASF 13-338, a substituted pyridazinone, than in plants deprived of light. The mode of action of BASF 13-338 is apparently not limited to the inhibition of photosynthesis.

Desaturation of Fatty Acids Associated with Monogalactosyl Diacylglycerol: The Effects of San 6706 and San 9785

“…San 9785 has been observed to increase the proportion of 18:2 at the expense of 18:3 in wheat shoots (21), wheat roots and crowns (26,27) and cotton roots (22). However, this hypothesis is supported only by the observations of changes in fatty acid composition of developing plant tissue treated with herbicide and kinetic experiments on mature tissue have not been performed to confirm that these herbicides have a direct effect on fatty acid metabolism.…”