柿是我国特色浆果，目前栽培品种以涩柿为主，需经采后脱涩方可食用，但脱涩处理后的柿果实易软化，严重限制柿果实的货架寿命，影响产业增效，因此采后脱涩保脆始终是柿研究的重要主题之一。本项目在前期研究的基础上，围绕柿果实脱涩后易软化这一现实问题，以乙烯响应因子（DkERF）为核心，开展柿果实采后脱涩诱导软化的转录调控机制研究。研究不同采后处理对柿果实脱涩及软化的影响；利用RNA-seq结合QPCR技术，筛选与柿果实脱涩后软化相关的细胞壁相关结构基因，并利用脱涩保脆处理和脱涩后不易软化的特色品种进行相关验证；获得柿果实软化相关的DkERF转录因子，并利用双荧光素酶体系、酵母杂交技术等研究DkERF转录因子对柿果实软化相关细胞壁基因的调控效应及机制；利用双荧光素酶体系、BiFC等技术，分析不同DkERF间协同调控软化的效应；通过柿瞬时表达体系和番茄转基因体系，开展柿果实软化相关DkERF基因的同源功能

Most of persimmon (Diospyros kaki) cultivars belong to astringent type, which require artificial postharvest treatments to remove the astringency. Moreover, the undesirable rapid softening usually consequently happened after astringency removal. Thus, both deastringency and firmness maintain are critical for persimmon industry. We previously studied various de-astringency treatments and identified several DkERF genes that involved in deastringency. The present project will focus on the regulatory mechanism of DkERF genes on deastringency associated softening of persimmon fruit. In order to investigated the roles of DkERF genes on deastringency associated softening of persimmon fruit, different treatments will be applied to different persimmon cultivars; persimmon softening associated cell wall related genes will be isolated and characterized, using RNA-seq and QPCR; deastringent treatments responsive DkERF genes will obtained and their trans-activation effects on cell wall related genes will be investigated. Based on ERF-target gene analyses, the association between different DkERF genes will also be included. Moreover, using the established persimmon transient over-expression system and tomato transgenic system, functions of DkERF genes will be verified. The results of the present project will provide new insight for de-astringency associated persimmon fruit softening, and will also benefit for the improvements of persimmon fruit postharvest treatments.