程序降温过程中吲哚乙酸对生菜种子抗低温胁迫的影响

摘要

Seed is an important survival strategy for hibernating,and seed cryopreservation is the main way for germ plasm resources conservation.In this paper,choosing lettuce seed as the object,and using programmed cooling apparatus to create different cooling rates (3 ℃/h and 60 ℃/h),study the mechanism of IAA responding to low temperature stress.The results showed that compared with fast cooling(60 ℃/h),slow cooling (3 ℃/h) is beneficial to the increasing of IAA;using IAA can reduce frozen hurt of the lettuce seed during the program cooling process,especially in 200μm IAA in slow cooling;regardless of cooling rate,SOD activity and proline content will increased significantly,and SOD activity was directly proportional to the IAA concentration,while proline content was having exactly the opposite effect;different cooling rates,and the concentrations of IAA can also influence to cold relative genes:ICE 1,HOS 1.%种子是植物越冬的重要生存策略,种子低温保存是种质资源保存的主要方式.选取含水生菜种子作为研究对象,利用程序降温仪制造不同的降温速率(3℃/h和60℃/h),研究吲哚乙酸(IAA)对种子抗寒性的影响.结果表明,相比于快速降温(60℃/h),慢速降温(3℃/h)有利于生菜种子内源IAA的积累.外源施加IAA可以降低程序降温(经慢速降温后更显著)过程中生菜种子的冷冻伤害,其中以200 μm的IAA对种子进行预处理效果最显著.无论降温速率如何,生菜种子遇到低温胁迫后SOD活性和脯氨酸含量会显著增加.外源施加IAA浓度越高,对SOD活性产生抑制作用,而IAA对脯氨酸含量有促进作用.降温速率以及外源IAA浓度也会对冷相关的ICE 1、HOS 1基因的相对表达量产生影响.