Measurement of SA and JA content
SA and JA content was measured using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The leaves of A. thaliana before and after inoculation withS. sclerotiorum were obtained. 0.5-1 g of homogenized frozen leaves were suspended in 10 mL extraction solvent (2-propanol/H2O/HCl), and then add 8 μL internal standard (1 μg/mL). Samples were shaken for 30 min at 4°C with a speed of 100 rpm, and add 5 mL dichloromethane to the samples and shake for 30 min at 4°C. The organic phase was obtained in a centrifuge at 4°C for 5 min at 13,000×g . The organic phase was transferred to a new fresh tube and evaporated with the nitrogen flow. Pellets were resuspended in 0.4 mL of methanol. The extraction was analyzed using HPLC-MS/MS in Nanjing Convinced-test Technology Co., Ltd (Zang et al. 2021).