毛竹茎秆快速生长期PeATG1/PeATG4基因表达分析

  目的  探讨毛竹Phyllostachys edulis茎秆快速生长与PeATG1和PeATG4基因表达的关系。  方法  以毛竹笋竹茎秆为材料，采用透射电镜监测笋竹快速生长期不同时间（10:00、14:00、18:00、22:00、2:00和6:00）和不同部位（第4、7、10、13节）的自噬活性，并用实时荧光定量聚合酶链式反应（qRT-PCR）分析技术测定第7节PeATG1和PeATG4基因表达量。  结果  对毛竹茎秆24 h自噬活性监测，22:00和2:00在第7节和第10节观察到自噬体；第4节和第13节没有观察到自噬体。在夜间，PeATG1和PeATG4转录水平表达增强，PeATG1表达量在22:00最高，分别是18:00和6:00的3.0倍和1.3倍（P < 0.05）；PeATG4表达量在2:00最高，分别是18:00和6:00的1.7和1.6倍（P < 0.05）。  结论  毛竹茎秆不同时间段的生长发育存在显著差异，夜间有自噬体形成，PeATG1和PeATG4基因表达量较高，茎秆生长迅速。

Analysis of PeATG1/PeATG4 gene expression in Phyllostachys edulis during rapid growth

  Objective  The aim is to discuss the relationship between rapid growth of stems of Phyllostachys edulis and gene expression of PeATG1 and PeATG4.  Method  Stems of P. edulis shoots were used as materials, the autophagic activity at different periods (10:00, 14:00, 18:00, 22:00, 2:00, and 6:00) and in different parts (internodes 4, 7, 10 and 13) was monitored by transmission electron microscope (TEM), and the expression of PeATG1 and PeATG4 genes in the 7th internode was determined by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR).  Result  The autophagosomes were observed at 22:00 and 2:00 in internodes 7 and 10 during 24 h monitoring, while no autophagosome was observed in internodes 4 or 13. The expression of PeATG1 and PeATG4 enhanced at night. The expression of PeATG1 was highest at 22:00, which was 3.0-fold and 1.3-fold of 18:00 and 6:00 respectively (P < 0.05). The expression of PeATG4 was highest at 2:00, which was 1.7-fold and 1.6-fold of 18:00 and 6:00 respectively (P < 0.05).  Conclusion  The research showed significant differences in growth and development of P. edulis at different stages. Autophagosomes were formed at night, and the expressions of PeATG1 and PeATG4 were high, which resulted in rapid growth of stems.