In this study, the mechanism by which the exogenous application of 150 nM signaling bioactive peptide phytosulfokine α (PSKα) delays senescence and improves antioxidant nutrient accumulation in strawberry fruit during storage at 4 °C for 18 d was investigated. Results showed that the higher endogenous accumulation of PSKα in strawberry fruit treated with 150 nM PSKα may result from the higher expression of PSK3 and PSK6 genes. Besides, the higher endogenous accumulation of Ca²⁺ in strawberry fruit treated with 150 nM PSKα may be ascribed to the higher cytosolic accumulation of cGMP, resulting from the triggering of endogenous PSKα signaling pathway, represented by higher expression of PSKR1 gene. Besides, the higher endogenous melatonin accumulation resulting from higher expression of TDC, T5H, SNAT, and ASMT genes in strawberry fruit treated with 150 nM PSKα may be ascribed to the higher endogenous accumulation of Ca²⁺. Moreover, the higher ABTS and DPPH scavenging capacity in strawberry fruit treated with 150 nM PSKα may be ascribed to the higher accumulation of phenols, flavonoids, and anthocyanins, resulting from higher gene expression and activities of PAL and CHS. Based on our findings, the exogenous application of PSKα could be employed as a beneficial procedure for delaying senescence and improving antioxidant nutrient accumulation in strawberry fruit during cold storage, by triggering endogenous PSKα signaling, promoting endogenous melatonin accumulation, and activating the phenylpropanoid pathway.

在这项研究中，研究了外源应用150 nM信号传递生物活性肽植物硫代植物因子α（PSKα）延迟衰老并改善草莓果实在4°C下储存18 d期间抗氧化剂营养物质积累的机制。结果表明，用150 nMPSKα处理的草莓果实中PSKα的内源性积累较高，可能是PSK3和PSK6基因的较高表达所致。此外，用150 nMPSKα处理的草莓果实中Ca ²⁺的较高内源性积累可能归因于内源性PSKα信号通路的触发导致cGMP较高的胞质积累，其表现为PSKR1的较高表达基因。此外，在150 nMPSKα处理的草莓果实中，TDC，T5H，SNAT和ASMT基因的高表达导致内源性褪黑素积累较高，这可能归因于Ca ^2+的内源性积累较高。此外，用150 nMPSKα处理的草莓果实中较高的ABTS和DPPH清除能力可能归因于较高的基因表达以及PAL和CHS的活性导致酚，类黄酮和花色苷的较高积累。。根据我们的发现，通过触发内源性PSKα信号传导，促进内源性褪黑激素积累和激活苯丙氨酸途径，PSKα的外源应用可作为延缓冷藏过程中草莓果实衰老和改善抗氧化剂营养物质积累的有益方法。