Triacontanol-induced changes in growth, oxidative defense system in Coriander (Coriandrum sativum) under arsenic toxicity

Abstract

Triacontanol (TRIA) is a plant growth regulator that enhances crops growth and yield when applied exogenously. The present study was carried out to investigate the effects of TRIA pretreatment on the activities of antioxidant enzymes and some biochemical attributes in coriander (Coriandrum sativum L.) seedling leaves exposed to arsenic (As) stress. TRIA was applied to seedlings at the three-leaf stage @ 5, 10 and 20 μmol l−1. Arsenic treatment was given after completion of TRIA treatment @ 100 and 200 μmol l−1. The As toxicity in coriander leaves was revealed by reduction of growth parameters. Arsenic-induced oxidative stress also showed a pronounced increase in the contents of hydrogen peroxide (H2O2) and levels of lipid peroxidation, and proline content. TRIA ameliorated the adverse effects of As on these attributes. Arsenic induced the activities of key antioxidant enzymes, viz., superoxide dismutase, catalase and peroxidase, which further increased under TRIA pre-treatment. The results suggested that TRIA might alleviate As toxicity in coriander by activating antioxidant enzymes, thereby preventing membrane peroxidation.