Ferric reduction oxidase ( LpFRO7 ) enhances salt (NaHCO 3 ) tolerance through ROS signaling pathways in Lilium pumilum

· Ferric reduction oxidase plays important roles in the attraction of iron to plants, which is also involved in how plants react to biotic and abiotic stressors. However, the molecular mechanism of ferric reduction oxidase ( LpFRO7) from Lilium pumilum responding to NaHCO is unknown. ·RT-qPCR and bacterial solution resistance analysis were used to demonstrate that LpFRO7 is tolerant to NaHCO . Overexpressing LpFRO7 L. pumilum enhances plant tolerance to NaHCO . The wilting degree and H O content of LpFRO7 overexpressed lines was relatively lower than that of wild type under NaHCO treatment. In addition, the stomatal changes of the overexpressed lines were smaller, and the ferrite reductase activity, chlorophyll content, iron content, and respiration rate were greater than those of the wild type. ·The bHLH family is participating in the ROS signaling pathway. We demonstrate that the LpbHLH115 transcription factor binds to the promoter of LpFRO7 using EMSA, Yeast one-hybrid assay, and luciferase complementation assay. ·By using yeast two-hybrid, 8 distinct interacting proteins were discovered. Yeast two-hybrid assay and BiFC assay were perform to verify whether there is a reciprocal relationship between LpFRO7 and LpTrx. ·Our results showed that LpFRO7 increases the tolerance of L. pumilum to NaHCO through the ROS signaling pathway.