Increase in Linolenic Acid Is Not a Prerequisite for Development of Freezing Tolerance in Wheat

Seedlings of winter wheat (Triticum aestivum L. cv. Kharkov) were acclimated at 2 C in the dark in the presence of two inhibitors of linolenic acid synthesis, 4-chloro-5(dimethylamino)-2-phenyl-3(2H)pyridazinone-(BASF 13-338) and 4-chloro-5(dimethylamino)-2-(alpha,alpha,alpha-trifluoro-m-tolyl)- 3(2H)pyridazinone (Sandoz 6706). Although the increase in the proportion of linolenic acid generally observed at low temperature was completely inhibited, the development of freezing tolerance was unaffected. These results demonstrated that an enrichment in linolenic acid is not a prerequisite for low temperature acclimation.