Phytic acid quantification
Phytic acid content was measured in accordance with Perera et al. (2019). Fully expanded leaves were homogenized in 0.66 M HCl with quartz sand, and phytic acid was extracted by shaking the homogenized solution at 25 oC for 17 h. The extracts were centrifuged (19,000×g , 10 min at 4 oC) and the supernatant was neutralized with 0.75 M NaOH. The phytic acid content was measured by using the Phytic Acid (Total Phosphorus) Assay Kit (Megazyme International Ireland Ltd., Ireland).