The effect of plant regulators on the concentration of carotenoids and phenolic compounds in foliage of coriander

• Methyl jasmonate and salicylic acid enhanced both carotenoids and phenolics.
• Methyl jasmonate treatment enhanced β-carotene (fourfold) and lutein (sixfold).
• Treatment with salicylic acid tripled chlorogenic acid content.
• Treatments also enhanced antioxidant activities of foliage extracts.

Foliage of coriander crop is a rich source of pro-vitamin-A carotenoids and phenolics of relevance to human health. Foliar-application of plant growth regulators – methyl jasmonate and salicylic acid, differentially elicited total carotenoids, β-carotene, lutein, chlorophylls, total phenolics and chlorogenic acid in coriander, GS4 Multicut and Mahak, the cultivars with high and low carotenoids respectively. Carotenoids and total phenolics increased 6.8 and 3 folds respectively when treated with methyl jasmonate (10 μmol/L), whereas salicylic acid (500 μmol/L) showed 5.4 and 3.5 folds of respective compounds. These treatments also enhanced levels of β-carotene, lutein, chlorophylls and chlorogenic acid, as observed by HPLC/MS analyses. Carotenoid and phenolic extracts of the best treatments showed significant increase in hydroxyl and superoxide radical scavenging antioxidant activities compared with controls. The observations made here indicate that the precise use of plant growth regulators is a simple method for naturally augmenting the nutritionally important compounds in coriander crop.