巨桉EgrGBF1基因的克隆和表达模式分析

Gene Cloning and Expression Pattern Analysis of EgrGBF1 in Eucalyptus grandis

摘要:

G-box结合蛋白(GBF)是一类能够识别并结合G-box的转录因子，广泛参与植物基因响应外界刺激的表达调控。通过巨桉(Eucalyptus grandis)初生生长到次生生长的转录组测序筛选出差异表达基因EgrGBF1，为探讨其在桉树生长发育中的功能，从巨桉中克隆了该基因，并进行了结构和进化分析。结果表明，EgrGBF1编码区长度为984 bp，编码327个氨基酸, 存在2个转录本，分别命名为EgrGBF1α和EgrGBF1β。实时荧光定量PCR结果表明，EgrGBF1α和EgrGBF1β在不同组织中，不同激素、胁迫处理下的表达模式不同，EgrGBF1α主要在茎尖表达，沿节间向下表达量逐渐降低，而EgrGBF1β在韧皮部高表达，在节间的表达量无显著差异。在水杨酸和缺硼处理下，EgrGBF1α和EgrGBF1β的表达趋势相反。EgrGBF1α在缺磷处理168 h的表达量最高，而EgrGBF1β在处理6 h的表达量最高。因此，EgrGBF1在桉树生长发育以及响应胁迫中发挥着重要作用，且转录本EgrGBF1α和EgrGBF1β可能具有不同的功能。

Abstract:

G-box-binding protein (GBF), the transcription factors which can recognize and bind to G-box, is widely involved in the regulating gene expression in response to external stimuli. The differentially expressed gene EgrGBF was screened by RNA-seq from primary to secondary growth of Eucalyptus grandis. In order to investigate its function, EgrGBF was cloned from E. grandis, and its structure and evolution were analyzed. The results showed that the length of EgrGBF1 coding region was 984 bp, encoding 327 amino acids. There were two transcripts, named EgrGBF1α and EgrGBF1β. The real-time quantitative PCR showed that expression pattern of EgrGBF1α and EgrGBF1β were different in various tissues and hormones and stress treatments. The expression EgrGBF1α was main in shoot apex, and gradually decreased down the internode, while that of EgrGBF1β was high in phloem, and there was no significant difference among internodes. Meanwhile, the expression trend of EgrGBF1α and EgrGBF1β was opposite treated by salicylic acid and boron deficiency. Under phosphorus deficiency, the expression of EgrGBF1α and EgrGBF1β was the highest at 168 h and 6 h, respectively. Therefore, EgrGBF1 plays an important role in the growth and development of Eucalyptus and the response to stress, and the transcriptional EgrGBF1α and EgrGBF1β may have different functions.