Effect of Acclimating at the Critical Growth Temperature on Chilling Resistance of Cotton Seedlings

Chilling tolerance of cotton seedlings has been studied after acclimating at different low temperature(12℃、14℃、16℃) for 7 days and chilling stress at 4℃ for 7 days,and the possible mechanism has been discussed.The results showed that the content of proline increased in all treatments acclimating at different temperature for 7 days,among which the acclimating temperature at 12℃ was beneficial preferably,and the seedlings can tolerate chilling stress at 4℃ longer(7 days).The results approved that the chilling-resistance of cotton seedlings may be improved after acclimation at the survival threshold low temperature(12℃).Moreover,the soluble proteins in cotton seedlings were separated by SDS-polyacrylamide gel electrophoresis(SDS-PAGE).The results of the analyzing by Tanon GIS showed that the content and types of protein had changed significantly,and the new low-temperature-induced proteins(namely anti-freeze protein) were discovered at 80 kd and 90 kd in cold-hardening cotton seedlings.