脱落酸信号通过MeMKK6-MeMAPK7调控木薯采后生理变质的分子机制

Postharvest physiological deterioration (PPD) largely affects the commodity value of cassava, and reactive oxygen species (ROS)-accumulation is the fundamental cause of cassava PPD. Activation of ROS-scavenging system plays an important role in the delay of cassava PPD. However, the regulatory mechanism of ROS-scavenging system in the process of cassava PPD is currently unknown. In our previous study, we found that ABA could delay PPD by inducing ROS-scavenging system. Further transcriptomic and protein interaction analyses showed that MeMKK6-MeMAPK7 of ABA signaling pathway might be the crucial components in regulating PPD of cassava tuberous roots. Based on these evidences, this study will investigate the phosphorylation mechanism between MeMKK6 and MeMAPK7, the genetic function of MeMKK6 and MeMAPK7, the targets of MeMAPK7, and regulatory mechanism related to ROS-scavenging system by MeMKK6 and MeMAPK7. Finally, this study will reveal the molecular mechanism underlying ABA mediated PPD reduction of cassava tuberous roots, and supply theory evidences for the effective control of cassava PPD.

木薯采后生理变质严重影响木薯的商品价值，活性氧积累是木薯采后生理变质发生的根本原因之一。有效激活活性氧清除系统则成为控制木薯采后生理性变质的重要途径。然而，在木薯采后生理变质过程中，活性氧清除系统如何被调控尚不清楚。项目组前期的研究发现脱落酸能够通过诱导活性氧清除系统，进而延缓木薯采后生理变质；转录组和蛋白互作实验证实了脱落酸信号途径中MeMKK6-MeMAPK7组分可能是调控木薯采后生理变质的关键因子。在此基础上，本项目拟采用结构域拆分及突变、磷酸化反应、酵母双杂交、遗传转化等技术，对MeMKK6-MeMAPK7进行结构功能解析，找到MeMKK6磷酸化MeMAPK7的作用位点，解析MeMKK6和MeMAPK7的遗传功能，鉴定MeMAPK7直接作用的下游靶蛋白及其对抗氧化系统的调控方式，最终揭示脱落酸信号如何调控活性氧清除系统延缓木薯采后生理变质，为有效控制木薯采后生理变质提供科学依据。

木薯采后生理变质严重影响木薯的商品价值，活性氧积累是木薯采后生理变质发生的根本原因之一。有效激活活性氧清除系统则成为控制木薯采后生理性变质的重要途径。然而，在木薯采后生理变质过程中，活性氧清除系统如何被调控尚不清楚。项目组前期的研究发现脱落酸能够通过诱导活性氧清除系统，进而延缓木薯采后生理变质；转录组和蛋白互作实验证实了脱落酸信号途径中MeMKK6-MeMAPK7组分可能是调控木薯采后生理变质的关键因子。在此基础上，本项目采用结构域拆分、酵母杂交、遗传转化等技术，对MeMKK6-MeMAPK7进行结构功能解析，找到MeMKK6与MeMAPK7互作的区域，解析MeMKK6和MeMAPK7的遗传功能，鉴定MeMAPK7直接作用的下游靶蛋白及其对抗氧化系统的调控方式，最终揭示脱落酸信号如何调控活性氧清除系统延缓木薯采后生理变质，为有效控制木薯采后生理变质提供科学依据和优质基因资源。