Mitochondrial ATP synthase activity assay
Mitochondrial ATP synthase activity was measured by a colorimetric assay using the ATPase activity assay kit (D799641-0050, Shenggong, China) following the manufacturer’s instructions. The seedlings were cultured on 1/2 MS medium for 2 weeks and leaves were collected for determination of ATP synthase activity. To approximately 0.1g of tissue, 1mL of reagent I was added, and the mixture was homogenized in an ice bath, centrifuged at 8000g for 10min at 4°C and the supernatant was used as the ATP synthase extract. Sample processing was according to the manufacturer’s protocol. Finally, ATP synthase activity was determined by measuring the OD at 660 nm. Each experiment was performed with three biological samples, each with three technical replicates.