苹果花芽和种子休眠过程中MdCIbHLH1基因的表达分析

Expression Analysis of a MdCIbHLH1 Gene from Apple Flower Buds and Seeds in the Process of Dormancy

对前期在苹果(Malus×domestica Borkh.)中发现的受低温诱导的b HLH转录因子进行了生物信息学分析,并以层积苹果种子和苹果芽为试材,用半定量和实时定量PCR技术分析其花芽休眠不同阶段的表达变化。蛋白质二级结构预测结果表明,MdCIbHLH1蛋白中以α螺旋和无规则卷曲为主,β折叠和延伸链较少,其中α螺旋145个(27.31%)、β折叠19个(3.58%)、无规则卷曲310个(58.38%)、延伸链57个(10.73%)。半定量和定量结果显示,在层积的苹果种子和休眠的花芽中MdCIbHLH1有相同的表达模式,在休眠解除之前表达较高,随着休眠的解除其表达量下调。因此推测MdCIbHLH1的表达对层积的苹果种子或者花芽休眠及解除具有调控作用。

A bHLH transcription factor was found from apple（Malus × domestica Borkh.）induced by low temperature. To understand sequence characteristics of the gene,bioinformatics analysis was carried out. Furthermore,the gene expression patterns of the laminated apple seeds and lateral flower buds were analyzed during the period of dormancy and release by semi RT-PCR and real-time PCR. On the basis of secondary structure prediction,the results showed that MdCIbHLH1 protein was mainly α-helix and random coil,the contents of β-sheet and extended strand were less,including random coil 310（58.38%）,α-helix 145（27.31%）and β-sheet 19（3.58%）,respectively,extending chain 57（10.73%）. q RT-PCR analysis showed that the expression patterns of MdCIbHLH1 was similar in the laminated apple seeds and lateral flower buds during the period of dormancy-release. The MdCIbHLH1 expression levels highly accumulated in dormant buds or apple seeds and were gradually down-regulated during the period of the release of dormancy. These results indicated that MdCIbHLH1 might play an important role in the regulation of dormancy-release in apple seeds and buds.