Proteomic and transcriptomic analysis of the action mechanism of spermidine in mitigating the aging of Allium mongolicum seeds

Seed aging or deterioration can affect germination rate, vigor, and viability. Allium mongolicum seeds stored for different years were used to obtain germination indicators, physiological indicators, and proteomic and transcriptomic sequencing in seeds treated with spermidine (Spd). The germination ability of A. mongolicum seeds increased and then decreased with the extension of storage life. The germination rate was only about 40% after 6 years. Relative conductivity, malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) content first decreased and then increased, while catalase activity (CAT), peroxidase activity (POD), superoxide dismutase activity (SOD), Ascorbate peroxidase activity (APX), and respiratory rate first increased and then decreased. Spd increased the seed germination rate, CAT, POD, SOD, and APX activity. However, it significantly reduced MDA, H₂O₂ content, and relative conductivity. Differentially expressed proteins were concentrated in energy metabolism pathways. Ten proteins related to the aging of A. mongolicum seeds were identified. The gene expression trend was basically consistent with the proteomic assay results. Energy metabolism is a key pathway in the aging of A. mongolicum seeds. Regulating the expression of genes involved in energy metabolism pathway can effectively alleviate A. mongolicum seed aging. The results enriched the molecular mechanism of the seed storability of A. mongolicum, providing theoretical bases for molecular marker-assisted breeding of its storability traits.