State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science , South China Agricultural University , Guangzhou 510642 , PR China.
J Agric Food Chem. 2018 Jun 20;66(24):6142-6150. doi: 10.1021/acs.jafc.8b01435. Epub 2018 Jun 7.
The transcriptional regulation of aroma formation genes remains poorly understood in the banana. In this work, we found that the expressions of a subset of aroma biosynthetic genes including MaOMT1, MaMT1, MaGT1, MaBCAT1, MaACY1, MaAGT1, and BanAAT, as well as two bZIP genes, MabZIP4 and MabZIP5, were down-regulated when prestored at 7 °C compared to those prestored at 22 °C during the ripening process of banana. Furthermore, MabZIP4 and MabZIP5 were shown to be able to activate the transcription of these aroma biosynthetic genes. Importantly, MabZIP4 directly binds to BanAAT promoter, while MabZIP5 binds to the promoters of MaMT1, MaACY1, MaAGT1, and BanAAT via the G-box motif, implicating the diverse functional significances of MabZIPs in controlling aroma biosynthesis in banana. Overall, this work sheds new insights on the understanding of transcriptional regulatory mechanisms associated with aroma formation during banana ripening.
在香蕉中，香气形成基因的转录调控仍知之甚少。在这项工作中，我们发现，包括 MaOMT1、MaMT1、MaGT1、MaBCAT1、MaACY1、MaAGT1 和 BanAAT 在内的一部分香气生物合成基因的表达，以及两个 bZIP 基因 MabZIP4 和 MabZIP5，在 7°C 预贮时比在 22°C 预贮时在香蕉成熟过程中下调。此外，MabZIP4 和 MabZIP5 被证明能够激活这些香气生物合成基因的转录。重要的是，MabZIP4 直接结合到 BanAAT 启动子上，而 MabZIP5 通过 G-盒基序结合到 MaMT1、MaACY1、MaAGT1 和 BanAAT 的启动子上，这表明 MabZIPs 在控制香蕉香气生物合成中的不同功能意义。总的来说，这项工作为理解香蕉成熟过程中与香气形成相关的转录调控机制提供了新的见解。
