冷害影响采后香蕉果实成熟和品质形成过程中MYB转录因子的调控网络解析

冷害导致采后香蕉果实成熟及品质形成异常，是产业亟待解决的问题。作为植物最大的转录因子家族之一，MYB转录因子在冷害影响采后香蕉果实成熟和品质形成中的作用机制，尚不清楚。翻译后修饰和组蛋白修饰如何调控MYB转录因子，更是知之甚少。本项目首先筛选与冷害影响采后香蕉果实成熟和品质形成相关的MYB、E3泛素连接酶、蛋白激酶PK和组蛋白去乙酰化酶HDAC；鉴定与MYB互作的E3、PK和HDAC；分析蛋白质泛素化、磷酸化和组蛋白乙酰化单一或协同对MYB转录活性的影响，及其与品质形成的关系；最后挑选与果实品质形成密切相关的5-8个关键基因（包括MYB、E3、PK和HDAC）通过瞬时表达和稳定过表达进行功能鉴定。本项目旨在从转录水平、翻译后修饰及表观遗传修饰等多角度系统解析MYB参与冷害影响采后香蕉果实品质形成的调控网络，为探索采后香蕉果实品质调控提供新思路，并为培育耐贮、质优香蕉新品种提供基因资源。

The abnormal ripening and quality formation of postharvest banana fruit caused by chilling injury is a big problem in banana industry. MYB is one of the largest transcription factor families in the plant kingdom, but the molecular mechanism underlying chilling-affected ripening and quality formation of postharvest banana fruit mediated by MYB remains largely unknown. Moreover, the regulation of MYB by post-translational modification and epigenetic regulation is also poorly understood. In the current project, MYB, E3 ubiquitin ligases, protein kinases (PK) and histone deacetylases (HDAC) are identified firstly through ‘Omic’ technologies. The interactions between MYB and E3, PK or HDAC are characterized. Importantly, the regulation of MYB by ubiquitination, phosphorylation, histone acetylation individually or cooperatively, and their involvement in postharvest quality formation are also clarified. Finally, 5-8 key genes including MYB, E3, PK and HDAC that are closely related to quality formation are chosen for functional analyses via transient or stable over-expression strategies. Collectively, the aim of our project is to systematically elucidate the regulatory network of MYB transcription factor involved in chilling-affected ripening and quality formation of postharvest banana fruit at transcriptional, post-translational and epigenetic levels. Thus our project will provide new cues for exploring postharvest quality controlling technology of banana fruit as well as supply gene candidates for molecular breeding of long-term storage and good quality of new banana varieties.