Combined physiological and transcriptomic analyses to identify candidate genes involved in aging during storage of Allium mongolicum Regel. seeds

Seed aging is a complex and irreversible process that occurs during seed development and storage. The quality of Allium mongolicum Regel seeds directly impacts its cultivation and production. However, the mechanism of aging seeds in A. mongolicum Regel is not well understood. Germination and physiological indicators were assessed, and RNA-Seq technique was performed on samples stored for 1, 4, and 8 years. In total, 5723, 7347 and 5293 differentially expressed genes (DEGs) were identified in 1 year old (S1) versus 4 year old (S2), S1 versus 8 year old (S4), and S2 versus S4, respectively. The number of DEGs increased as the storage time increased. The analysis revealed that the majority of the these DEGs were involved in a wide range of processes, such as protein synthesis, degradation and targeting; RNA processing and regulation; transport; DNA; signaling; stress; metabolism; amino acid metabolism; secondary metabolism; and hormone metabolism. The germination rate of A. mongolicum seeds remained consistently high, exceeding 80%, even after four years of storage. This observation indicates a potential correlation with the increased expression levels of aspartic proteases. However, as the storage time surpassed the seed's lifespan, there was a notable decline in the expression levels of genes that encode aspartic proteases, cysteine proteases, and serine proteases. Conducting further research on these candidate genes could enhance our comprehension of the regulatory mechanisms involved in seed aging during storage for varying durations.