Investigation of synergistic action between coronatine and nitric oxide in alleviating arsenic-induced toxicity in sweet basil seedlings

The phytotoxin coronatine (COR) is a jasmonic acid mimic produced by several pathovars of plant pathogen. In this study, we evaluated the protective effect of COR and nitric oxide (NO) against the toxicity of sodium arsenate in sweet basil (Ocimum basilicum L.). According to the statistical analysis, arsenic had a significant adverse effect on length and biomass of plants. Seedlings that pretreated with COR and sodium nitroprusside (SNP), significantly reversed fresh and dry lose and relative water content decay induced by the metalloid. The protective effects of COR and SNP were indicated by extent of lipid peroxidation, increase glutathione (GSH), ascorbate and thiol (–SH) content, promote antioxidant enzymes and reduce H₂O₂ content in basil seedlings. The present observation suggested that reduction of excess arsenic As-induced toxicity in O. basilicum by COR and NO is through the activation of enzymes involved in ROS detoxification (CAT, SOD, POD, APX, GR) and maintenance contents of molecular antioxidant (GSH, ascorbate, non-protein thiol and protein-thiol). Moreover, the results revealed a mutually amplifying reaction between COR and NO in reducing As-induced damages.