ALLEVIATION OF ADVERSE IMPACT OF CADMIUM STRESS IN SUNFLOWER (HELIANTHUS ANNUUS L.) BY ARBUSCULAR MYCORRHIZAL FUNGI

Sunflower (Helianthus annuus L.) is an important ornamental plant and good source of vegetable oil, widely accepted as potential promising plant for phytoremediation. A pot experiment was conducted to evaluate the impact of cadmium on the growth and some biochemical attributes of sunflower and role of arbuscular mycorrhizal fungi (AMF) in assuaging the cadmium stress induced changes. Cadmium treatment reduced growth, chlorophyll contents and cell membrane stability. AMF inoculated plants showed increased growth, chlorophyll contents and cell membrane stability and also mitigated changes caused due to cadmium. Cadmium caused increase in lipid peroxidation, and hydrogen peroxide production. An increase in antioxidant enzyme activity was observed due to cadmium treatment which was further enhanced by inoculation of AMF. Increase in proline and total phenols due to cadmium stress was obvious. Cadmium stressed plants showed enhanced fatty acid content. AMF inoculated plants showed higher activities of acid and alkaline phosphatases which were reduced by cadmium stress. However palmitoleic acid (C-16:1), oleic (C-18:1), linoleic (C-18:2) and linolenic acid (C-18:3) reduced in cadmium treated plants and the negative impact of cadmium was mitigated by AMF.