不同需冷量桃休眠相关DAM基因表达特性及激素调控的响应分析

以"南山甜桃"(需冷量200 h)、"瑞光51号"(需冷量400 h)和"春美"(需冷量600 h)为试材,从大量落叶期开始至花芽萌动期间,约每15 d采样一次,RT-PCR分析DAM基因在不同冷量积累时期花芽中的表达量,PLC-MS-MS测定相同时期吲哚乙酸(IAA)、脱落酸(ABA)和玉米素(ZT)含量变化,以期了解不同需冷量桃休眠过程中DAM基因的表达特性及激素的调控机理。结果表明:DAM基因在不同需冷量桃休眠过程中的表达趋势一致,随着休眠的深入,"春美"中DAM基因的表达水平呈先升后降趋势;"南山甜桃"和"瑞光51号"在进入休眠期以后DAM基因表达水平急剧下降,与低温积累量呈负相关。"春美"中DAM基因表达量明显高于"瑞光51号"和"南山甜桃"。"春美"中DAM基因表达水平比"南山甜桃"和"瑞光51号"开始下调约晚30 d,但"瑞光51号"和"南山甜桃"中DAM基因下调的时间一致。IAA、ZT在不同需冷量桃休眠过程中的含量变化差异不显著,ABA含量变化差异显著,可能在休眠解除过程中起重要调控作用。

Analysis of Dormant-related DAM Gene Expression Characteristics and Hormonal Regulation Responses in Different Chilling Peaches

‘Nanshan Tiantao’(CR 200 hours),‘Ruiguang No.51’(CR 400 hours) and ‘Chunmei’(CR 600 hours) were taken as materials and sampled about every half a monthfrom the beginning of a large number of deciduous periods to the period of flower bud sprouting.The expression levels of DAM genes in flower buds during different cold accumulation periods were analyzed by RT-PCR.The contents of IAA,ABA and ZT in the same period were determined by PLC-MS-MS,in order to understand the expression characteristics of DAM genes and the regulation mechanism of hormones during the dormancy of different chilling peaches.The results showed that the expression trend of DAM genes was consistent in the dormancy of different chilling peaches.With the deepening of dormancy, the expression level of DAM genes in ‘Chunmei’ increased first and then decreased;the expression level of DAM genes in ‘Nanshan Tiantao’ and ‘Ruiguang No.51’ decreased sharply, which was negatively correlated with the accumulation of low temperature.The expression level of DAM genes in‘Chunmei’was significantly higher than that in‘Nanshan Tiantao’and‘Ruiguang No.51’,and the expression level began to be down-regulated about one month later than the ‘Ruiguang No.51’and‘Nanshan Tiantao’,but‘Ruiguang No.51’and ‘Nanshan Tiantao’had the same downregulation time.The content of IAA and ZT was no significant difference during the dormancy of different chilling peaches,but the content of ABA was significant difference,which may play an important role in the process of dormancy release.