Impact of Low Temperature on Fatty Acid Composition of Crop Species with Different Cold Resistance

The study was focused on fatty acid (FA) composition of lipids from seedlings and roots of crops having different cold resistance and grown at 27 degrees C and 4 degrees C. FA biosynthesis in the lipids of seedlings of cold-susceptible maize (Zea mays L.) under both growth temperatures was controlled by chloroplast omega-6 desaturase and in the lipids of roots, by microsomal omega-6 desaturase. The content of linoleic acid in coleoptiles of maize seedlings grown at 4 and 27 degrees C was 56.2% and 43.3%, respectively, and in the roots, it was 52.2% and 38.5%, respectively. The content of alpha-linolenoic acid in coleoptiles was 6.7-6.8% at both temperatures and in root lipids it was higher at low temperature (3.15% at 27 degrees C vs. 4.7% at 4 degrees C). Biosynthesis of FA in seedling coleoptiles of wheat (Triticum aestivum L.) and Siberian wildrye (Elymus sibiricus L.) grown at low temperature was controlled by chloroplast omega-3 desaturase. A small increase of the alpha-linolenoic acid content was observed at low temperature: from 29.7% to 30.2% in wheat and from 22.8% to 25.8% in wildrye. In root tissues of these species biosynthesis of alpha-linolenoic acid was controlled by microsomal omega-3 desaturase. The content of alpha-linolenoic acid increased at low temperature: from 6.1% to 17.1% in wheat and from 7.1% to 12.0% in Siberian wildrye at 27 and 4 degrees C, respectively.