The regulation of postharvest strawberry quality mediated by abscisic acid under elevated CO₂ stress

Elevated CO₂ was a potential strategy for strawberry preservation. However, the regulatory mechanism remained unclear. In current study, transcriptome analysis showed that elevated CO₂ played important roles in regulating strawberry fruit quality at the transcriptional level, and plant hormones metabolism at least partially involved in the regulatory process. Further, ABA was demonstrated to play important roles in the response to elevated CO₂. Elevated CO₂ inhibited the accumulation of ABA, which was 61% lower than that in control. Elevated CO₂ repressed ABA synthesis by inhibiting NCED activity and the expression of FaNCED1/2, leading to the reduction of ABA accumulation as a result. Meanwhile, elevated CO₂ also decreased ABA sensitivity by down-regulating FaSnRK2.4/2.6 and FaABI5 expression. The dual down-regulation of ABA signaling accounted for the regulation of fruit quality under elevated CO₂ treatment. These results provide new insights into the mechanism of strawberry fruit response to elevated CO₂.