Research progress on molecular mechanism, structure-function relationship and application of salt ions regulating plant protein fibrils.

Plant proteins are increasingly recognized as sustainable and cost-effective alternatives to animal proteins in food applications. However, its poor natural solubility and insufficient functional properties seriously limit its high-value application. Amyloid fibrillation is a frontier strategy for the functional modification of plant proteins, and salt ions are the critical environmental factors regulating their self-assembly behavior and functional properties. In this review, the mechanism of salt ion-mediated assembly of plant protein amyloid fibrils (PPAFs) is summarized as three hierarchically coupled regulatory links: conformational modulation, electrostatic shielding, and ion bridging. The regulation rules and ion-specific effects of monovalent and multivalent ions are clarified. The multi-dimensional structure-function relationship of PPAFs under the regulation of salt ions is analyzed, and the potential application prospects of plant protein fibrils in the food industry are summarized. Finally, this review highlights current research bottlenecks and future directions, providing a theoretical framework for the structure-guided design and food applications of PPAFs.