水杨酸预处理对甘蓝幼苗冷害的缓解效应

研究了外源水杨酸(SA)对甘蓝(Brassica oleraceaL.)幼苗低温(4±0.5)℃冷害的缓解效应.低温胁迫前不同浓度SA(0.1 mmol/L,0.5 mmol/L,1.0 mmol/L)对甘蓝幼苗的预处理,能不同程度地提高可溶性糖和可溶性蛋白质的含量和保护酶活性,降低MDA的含量,以0.5 mmol/L效果最明显.同一浓度SA(0.5 mmol/L)对幼苗预处理后,随低温时间的延长,可溶性糖和可溶性蛋白质含量和保护酶活性呈先升后降的变化趋势,并显著高于同一时期的对照,而MDA含量也呈显先升后降,但显著低于同期的对照.说明适当浓度的外源SA对甘蓝幼苗低温冷害有一定的缓解效应.

Mitigative Effect of Salicylic Acid on Chilling Stress-Induced Injuries in Brassica oleracea L. Seedlings

Mitigative effect of exogenous salicylic acid(SA) on chilling stress-indued injuries was studied in Brassica oleracea L.Seedings. The leaves of Brassica oleacea L.seedlings were sprayed by the different concentration of SA before chilling resistance.The result showed that the pretreatment with 0.1 mmol/L,0.5 mmol/L,1.0 mmol/LSA could enhance the content of soluble suger and protein and the activities of the protected enzyme,and reduce the content of MDA under chilling resistance.As a result,the SA concentration with best effect was 0.5 mmol/L.The effect of SA on chilling resistance at the different time was studied.The result manifested that the activities of the protected enzyme,soluble suger and protein contents were firstly increased and then decreased as the time extended,but markly higher than that in control at the same time.The MDA content was also firstly increased and then decreased,but markly lower than that in control at the same time.Therefore,the injuries caused by chilling stress are mitigatived by exogenous salicylic acid(SA) in Brassica oleracea L.seedings.