Sugar and Acid Metabolism-Transport Crosstalk: Regulatory Networks and Source–Sink Dynamics

Sugars and organic acids are central to plant carbon balance, cellular energy status and homeostasis. They not only serve as metabolic substrates and osmolytes but also as signaling molecules that coordinate growth, development, and stress responses. In recent years, it has become increasingly clear that sugar and acid metabolism are not isolated pathways; rather, they are tightly interconnected through shared precursors, common regulatory nodes, and dynamic transport systems. This metabolic-transport crosstalk is particularly critical in governing source–sink relationships, where photoassimilates are partitioned between sites of production and utilization. Understanding how sugars and organic acids interact at the metabolic, transcriptional, and post-translational levels is essential for deciphering plant resource allocation and for improving crop yield and quality.Despite significant progress in characterizing individual sugar and acid metabolic pathways, the integrative regulatory networks that link their metabolism with long-distance and cellular transport remain incompletely understood. Recent advances—including the identification of sugar and acid transporters (e.g., SWEETs, TDTs, ALMTs), the elucidation of tonoplast and plasma membrane trafficking mechanisms, and the application of multi-omics approaches—have opened new avenues to explore this crosstalk. However, critical questions persist: How do sugar signals modulate organic acid accumulation and remobilization? What transcriptional and hormonal circuits coordinate metabolic flux with transport capacity across source and sink tissues? How does this crosstalk adapt under abiotic stress or during fruit development? This Research Topic aims to bridge these gaps by bringing together studies that dissect the molecular, physiological, and systems-level mechanisms underlying sugar–acid metabolism–transport integration, ultimately advancing knowledge toward sustainable crop improvement.We invite contributions that explore the interface of sugar and organic acid metabolism with membrane transport and source–sink dynamics. Specific themes include, but are not limited to: (i) molecular characterization of transporters and channels mediating sugar and acid fluxes; (ii) transcriptional and hormonal regulatory networks linking metabolic status to transport activity; (iii) metabolic flux analysis and modeling of carbon allocation; (iv) source–sink communication during fruit development, seed filling, and tuber/root expansion; (v) stress-induced remodeling of sugar–acid homeostasis; and (vi) biotechnological or breeding strategies that leverage this crosstalk for yield and quality improvement. We welcome Original Research, Reviews, Mini Reviews, and Perspectives that provide mechanistic insights accompanied by clear plant phenotypic or physiological evidence, in alignment with the journal’s scope on plant metabolism, physiology, and crop relevance. Topic editors: Lingcheng Zhu, Tie Liu, Lihua Zhang, Jing Su Source: https://www.frontiersin.org/research-topics/82756/sugar-and-acid-metabolism-transport-crosstalk-regulatory-networks-and-source-sink-dynamics