Proteomic-based analysis on membrane responses of Catharanthus roseus under UVB radiation

The plant plasma membrane (PM) not only plays a crucial role in translating external signals such as ultraviolet-B (UVB) radiation into adaptive responses, but also is essential for mediating transport of secondary metabolites in medicinal plants. To investigate membrane responsive mechanisms of Catharanthus roseus under UVB radiation for enriching knowledge towards PM regulation in plants, proteomic analysis via timsTOF platform was performed. Under UVB radiation, electrolyte leakage in C. roseus leaves increased. Altered proteins were mainly associated with solute transport, protein modification, protein biosynthesis/degradation, and vesicle trafficking. One MATE efflux family protein and one pleiotropic drug resistance protein were specifically identified. Several key PM proteins, including transmembrane kinase (TMK) and autoinhibited H⁺ ATPase, showed significant decreases, among which TMK was only quantifiable in the control group; in the meanwhile, proteins related to Ca²⁺ signaling increased, and one calcium-dependent protein kinase was only quantifiable in the UVB-radiated group. These results revealed changes associated with membrane systems in C. roseus leaves under UVB radiation, offering new insights into regulatory mechanisms for UVB adaptation in plants that could be involved in alkaloid transport.