Background

Plant hormones are the trace organic substances synthesized in plants that are transported from the synthetic site to the active site to significantly regulate plant growth and development (Luo et al., 2016; Chen et al., 2020a and 2020b). Generally, plant hormones are classified according to their molecular structure and physiological function: auxins, cytokinins (CKs), abscisic acid (ABA), jasmonates (JA), salicy acid (SA), gibberellines (GAs), brassinasteroids (BRs), ethylene (ET), etc. The regulation of plant hormones to plant physiological activities involves the change of their own concentration. Uncovering the composition and content changes in plant hormones enables the discovery of possible mechanisms of action and more interactions between them. There are many methods to detect plant hormones, based on as enzyme-linked immunosorbent assays (ELISA), gas chromatography (GC), and high-performance liquid chromatography (HPLC) (Owen and Abrams, 2009; Prado et al., 2014). Nowadays, LC-MS and GC-MS have overcame the limitations of HPLC and GC in the qualitative and quantitative determination of plant hormones and become widely accepted and recognized methods.