Determination of glutathione and ascorbate contents
For measuring the reduced glutathione (GSH) and oxidized glutathione
(GSSG) content in soybean leaves, we used a GSH and GSSG assay kit
(Comin Biotechnology, Suzhou, China) following the manufacturer’s
instructions. GSH and GSSG content were measured at
OD412. The ascorbic acid (ASA) and dehydroascorbate
(DHA) content determination of the soybean leaves were measured the
manufacturer’s protocols for the ASA and DHA kits (Comin Biotechnology,
Suzhou, China). ASA and DHA content were measured at
OD402 and OD265. The activities of
monodehydro reductase (MDHAR), dehydroascorbate reductase (DHAR), and
glutathione reductase (GR) were measured using enzymatic activity assay
kits (Comin Biotechnology, Suzhou, China) according to the
manufacturer’s instructions. MDHAR, DHAR, and GR activities were
determined at OD340, OD265 and
OD340, respectively.