Functional Association between Storage Protein Mobilization and Redox Signaling in Narrow-Leafed Lupin (Lupinus angustifolius L.) Seed Germination and Seedling Development. DOI: 10.3390/genes14101889

(1) Seed storage mobilization, together with oxidative metabolism, with the ascorbate–glutathione (AsA-GSH) cycle as a crucial signaling and metabolic functional crossroad, is one of the main regulators of the control of cell morphogenesis and division, a fundamental physiological process driving seed germination and seedling growth. This study aims to characterize the cellular changes, composition, and patterns of the protein mobilization and ROS-dependent gene expression of redox metabolism in Lupinus angustifolius L. (narrow-leafed lupin, NLL) cotyledons during seed germination. (2) Our results showed that a large amount of seed storage protein (SSP) accumulates in protein bodies (PBs) and mobilizes during germination. Families of conglutins (β and γ) may play important roles as functional and signaling molecules, beyond the storage function, at intermediate steps of the seed germination process. In this regard, metabolic activities are closely associated with the regulation of oxidative homeostasis through AsA-GSH activities (γ-L-Glutamyl-L-cysteine synthetase, NOS, Catalase, Cu/Zn-SOD, GPx, GR, GS, GsT) after the imbibition of NLL mature seeds, metabolism activation, and dormancy breakage, which are key molecular and regulatory signaling pathways with particular importance in morphogenesis and developmental processes. (3) The knowledge generated in this study provides evidence for the functional changes and cellular tightly regulated events occurring in the NLL seed cotyledon, orchestrated by the oxidative-related metabolic machinery involved in seed germination advancement.