Regulation of Acyl-desaturase genes and tolerance to temperature stress in plants

Under fluctuating environmental temperatures, maintenance of a proper physical state and fluidity of celluiar membrane is essential for plant growth and, ultimately, plant survival. One of the most common adaptive mechanism to temperature stress is the change in the level of unsaturation of membrane lipids, which is regulated by desaturases. We have cloned two full-length clones encoding a delta-9 and delta-12 desaturases, respectivel. The level of expression of the two genes was regulated by changes in growth temperature. Increase in temperature caused down-regulation of delta-9 desaturase, while delta-12 desaturase was actively expressed by decreasing the temperature. The effects of over- or under-expressi?on of such genes in transgenic potato plants will be presented and discussed.