Exogenous phytosulfokine α (PSKα) applying delays senescence and relief decay in strawberry fruits during cold storage by sufficient intracellular ATP and NADPH availability

Herein, we employed exogenous phytosulfokine alpha (PSK alpha) for delaying senescence and lessening decay in strawberry fruits during storage at 4 degrees C for 18 days. Our results showed that the strawberry fruits treated with 150 nM PSK alpha exhibited lower expression of poly-ADP-ribose polymerase 1 (PARP1) gene, leading to a higher intracellular NAD availability, beneficial for a sufficient provision of intracellular NADP(+) with the activity of NAD kinase (NADK). Moreover, higher activities of glucose 6-phosphate dehydrogenase (G6PDH), 6-phos-phogluconate dehydrogenase (6PGDH), and methylenetetrahydrofolate dehydrogenase (MTHFD) may be the reason for the sufficient intracellular availability of NADPH in strawberry fruits treated with 150 nM PSK alpha. In addition, strawberry fruits treated with 150 nM PSK alpha exhibited a sufficient availability of ATP resulted from higher activities of succinate dehydrogenase (SDH) and cytochrome c oxidase (CCO). Therefore, our results indicate that exogenous PSK alpha could be beneficial for delaying senescence and reducing decay in strawberry fruits during cold storage.

Automated summary

The study showed that exogenous PSK alpha can delay senescence and reduce decay in strawberry fruits during cold storage by regulating gene expression and enzyme activities related to intracellular NAD and ATP availability.