Shikimic acid accelerates phase change and flowering in Chinese jujube

The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties.

Material design at nano and atomic scale for electrocatalytic CO2 reduction

Electrocatalytic CO2 reduction (ECR) into value-added chemicals offers potential solution for renewable energy as well as global carbon footprint concerns. In this review we introduce the general methods and metrics that are commonly applied in ECR, followed by a discussion of current reaction mechanisms and different pathways. We highlight how size and structure of electrocatalysts affect ECR performance and review recent advances in metalfree and single-atom catalysts. The challenges of ECR are also discussed and optimistic perspectives are made for future work.

Improving the True Cycling of Redox Mediators-assisted Li-O_(2) Batteries

The application of redox mediators has been considered as a promising strategy to boost the performance of aprotic Li-O_(2)batteries.However,the issues brought with redox mediators,especially on the Li anode side have been overlooked.Here,we propose a facile approach of preparing a gel polymer membrane that not only allow uniform Li plating/stripping withlarge current densities over extended cycling but also inhibit the diffusion of redox mediators and avoid redox shuttling,self-discharge,and internal shortcircuiting.More importantly,the gel polymer membrane prevents the penetration of O_(2)and superoxide intermediates from the Li anode.Therefore,it ensures the successful application of both lithium anode and redox mediators in Li-O_(2)batteries to achieve the desired high capacity and rate performance.Meanwhile,it helps understand the benefit and problems of added redox mediators and reactive oxygen species so that theperformance of such Li-O_(2)batteries can be truly evaluated.