摘要
Improving chilling tolerance in cold-sensitive crops,e.g.tomato,requires knowledge of the early molecular response to low temperature in these under-studied species.To elucidate early responding processes and regulators,we captured the transcriptional response at 30 minutes and 3 hours in the shoots and at 3 hours in the roots of tomato post-chilling from 24℃ to 4℃.We used a pre-treatment control and a concurrent ambient temperature control to reveal that majority of the differential expression between cold and ambient conditions is due to severely compressed oscillation of a large set of diurnally regulated genes in both the shoots and roots.This compression happens within 30 minutes of chilling,lasts for the duration of cold treatment,and is relieved within 3 hours of return to ambient temperatures.Our study also shows that the canonical ICE1/CAMTA-to-CBF cold response pathway is active in the shoots,but not in the roots.Chilling stress induces synthesis of known cryoprotectants(trehalose and polyamines),in a CBF-independent manner,and induction of multiple genes encoding proteins of photosystems I and II.This study provides nuanced insights into the organ-specific response in a chilling sensitive plant,as well as the genes influenced by an interaction of chilling response and the circadian clock.
