Regulation of endogenous phytohormones in response to Si and heavy metal stress treatments. The aerial parts of the rice plants were analyzed for signaling of abscisic acid (ABA), jasmonic acid (JA) and salicylic acid (SA) against 1, 5 and 10 days after treatments (DAT) of Si and metal. The hydroponic growth medium served as control. Bars represent means (of three replications) ± standard error. Means denoted by the same letter are not significantly different (P > 0.05) as evaluated by Duncan Multiple Range Test (DMRT).