Expression characteristics and interference analysis of glucose-6-phosphate dehydrogenase reveal its importance in Pyropia yezoensis under salt stress

Glucose-6-phosphate dehydrogenase (G6PDH) is a key enzyme in the pentose phosphate pathway and plays a crucial role in photosynthetic organisms responding to stress. In this study, we analyzed the bioinformatics of enzymes involved in the oxidative pentose phosphate pathway in Pyropia yezoensis and examined the expression of corresponding genes under salt stress. The results showed that the presence of G6PDH and 6-phosphogluconate dehydrogenase in both the cytoplasm and chloroplasts of P. yezoensis, with upregulation of both enzyme genes in the cytoplasm and downregulation in the chloroplasts under high salt stress. Mutant strains with silenced cytoplasmic and plastidic G6PDH showed significantly reduced photosynthetic activity and restricted cyclic electron flow compared to the wild type under high salt stress, suggesting that interference with G6PDH weakened Pyropia's response to high salt stress. This study clarifies Pyropia's response to salt stress through the oxidative pentose phosphate pathway, and lays a theoretical foundation for deciphering the stress response mechanism of G6PDH. •Both cytoplasm and chloroplasts of P. yezoensis contain key enzymes of the oxidative PPP.•The expression of g6pdh and 6pgdh exhibited complementary patterns under salt stress.•Interference of G6PDH weakened the response of P. yezoensis to high salt stress.