Fatty acid composition and fad3 gene expression in roots of watermelon and gourd under low temperature.

摘要

Watermelon is a chilling sensitive plant and low temperature causes reduction in the growth and number of lateral roots of the crop. The chilling response of watermelon cv. Festival and bottle gourd (Lagenaria siceraria) seedlings was investigated. Watermelon seedlings were more sensitive than gourd plants at 15 degrees C. The relative content of linolenic acid of bottle gourd was about 10.7% higher than watermelon. No difference was observed between bottle gourd and watermelon roots in terms of palmitic acid (16:0) and 2 other minor fatty acid (18:0 and 18:1) contents. Linolenic acid content played an important role in plant chilling tolerance. Transcript levels for the fad3 gene that codes for desaturase markedly increased in response to decreased temperature in bottle gourd. Increase in double bond index (DBI) and linolenic: linoleic acid ratio of the root fatty acids have been assumed to occur in response to cold resistance..