Alteration in chemical composition and antioxidant defense potential of essential oil of Jatropha curcas L. grown in fly ash-amended soil

Fly ash (FA) is a problematic solid waste, possessing essential elements which modifies the properties of soil and improve the plant growth. FA also contains toxic heavy metals, thus there is an urgent need to study the influence of heavy metals present in FA on the growth of plant. The present study was designed to analyze improvement in chemical composition and antioxidant defense mechanism of seed oil extracts from Jatropha curcas grown in different doses of FA (0% FA, 25% FA, 50% FA, 75% FA and 100% FA) along with garden soil (GS). A comparison of methyl esters of fatty acids was analyzed in oil extracts using gas chromatography-mass spectrometry (GC-MS). Sixteen compounds were detected, constituting 99.94% of the total oil constituents. Methyl esters of oleic acid, linoleic acid and hexadecanoic acid were the major compounds present. Comparative GC-MS analysis of the three samples showed an increase of 2.15 and 87.84-fold in 25% FA and 50% FA. The antioxidant potential was determined using 2-2 '-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing potential (FRAP). Highest scavenging activity and lowest IC50 were observed in 50% FA sample followed by 25% FA and 100% GS. Activity of various antioxidant defense enzymes like SOD, CAT, POD and APX was analyzed. Treatment (50% FA with 50% GS) demonstrated enhanced chemical contents and antioxidant defense enzymes. These results suggest the utilization of FA as soil amendment for the growth of non-food crop J. curcas. altered chemical composition and antioxidative defense enzymes induced in response to FA amendment to soil reflects its suitability for phytoremediation.

Automated summary

The study indicates that using FA as a soil amendment can enhance the chemical composition and antioxidant defense mechanism of plants, promoting the growth of non-edible crops like Jatropha curcas.