The effect of glutathione metabolism on the release of Wound-Induced Spores from Pyropia yezoensis

Abstract

Oxidative stress from mechanical injury can trigger the development of Wound-Induced Spores (WIS) in Pyropia yezoensis, yet the regulatory mechanisms underlying this process require further elucidation. In this study, comparative transcriptomic analysis between injured and uninjured P. yezoensis thalli revealed significant differential gene expression within the glutathione (GSH) metabolism pathway during WIS development. There was a down-regulation in the expression of genes encoding for γ-glutamyl-cystein synthetase (GCL) and glutathione synthetase (GSS), which were pivotal for GSH biosynthesis, during the development of WIS. Moreover, a diminished expression level was also observed in genes associated with oxidative metabolism of GSH during this process, including those encoding glutathione S-transferase (GST), glutathione peroxidase (GPX), glutathione reductase (GR), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and dihydroascorbate reductase (DHAR). However, this transcriptional regulation does not correspond to a significant decrease in intracellular GSH levels, which may be associated with a reduction in the oxidative metabolism of GSH, leading to decreased cellular utilization of GSH. Treatment injured P. yezoensis with Buthionine sulfoximine (BSO) promoted the release probability of WIS, the release efficiency of WIS and germination rate of asexual spores, while supplementation of GSH produced opposite results, suggesting that modulating GSH levels can regulate the release of WIS. Correlation analysis suggested that there was a significant positive correlation between the release of WIS and the germination rate of asexual spores, suggesting that promoting the release of WIS could lead to the acquisition of a greater number of asexual spore seedlings. Our findings underscore the key role of GSH metabolism in WIS regulation and provide a theoretical foundation for the subsequent development of strategies to obtain asexual spore seedlings.