Changes in fatty acid composition of winter wheat during frost hardening

Protoplast plasmalemma fluidity of hardened wheats correlates with frost resistance

“…Table 1 indicates a non-specific increase in the level of linolenic acid during the hardening process, which is in agreement with observations [12,14]. Whether the hardiness-dependent augmentation of membranes [9 ,15,16] and accumulation of phosphatidyl choline [9,15] alone, or favourable changes in the ratio of phospholipids to steroids together with some unknown factors, is involved in adapting membrane fluidity to (16 h) and 12'C night (8 h) temperature.…”

Simultaneous Inhibition of Linolenic Acid Synthesis in Winter Wheat Roots and Frost Hardening by BASF 13-338, a Derivative of Pyridazinone

“…The lipids were extracted from 2 g of root and crown tissue and 0.5 g of shoot tissue as described earlier (11,12), and their fatty acids determined by GLC according to Grenier et al (4). Chl was measured on separate 0.5-g shoot samples as described by Arnon (1).…”

“…Before and during hardening the frost resistance of the plants was tested by controlled freezing. The plants were cut above the crown and the pots were transferred to a programmed freezer (12). The temperature was lowered at a rate of 2 C/hr, equilibrated for 12 hr at -4 C, and kept for 2 hr at each test temperature.…”

“…Although linolenic acid content greatly increases in the roots of winter wheat during frost hardening, it accumulates to the same extent in cultivars showing a large difference in frost resistance (3,7,12). Increased unsaturation of membranes does not seem directly involved in the cold-hardening process in winter wheat.…”

“…Increased asaturation of fatty acids is therefore probably an important part of the mechanism of cold adaptation in winter wheat.BASF 13-338 also prevents the increase in per cent dry weight in roots and shoots during hardening and causes a decrease in root lipid phosphorus and total fatty adds.The concurrent incea in linoleic acid and decream in linolenic acid in the treated plats, while the level of the otber fatty adds is but ittle affected, suggest that BASF 13-338 specifically inhibits linoleic acid desuae.Although linolenic acid content greatly increases in the roots of winter wheat during frost hardening, it accumulates to the same extent in cultivars showing a large difference in frost resistance (3,7,12). Increased unsaturation of membranes does not seem directly involved in the cold-hardening process in winter wheat.…”