Fig. 3.

Dosage and time-course experiments for the effect of exogenously applied salicylic acid on de-repression of caffeine biosynthesis in metabolically inactive endosperms (CC5 stage). Fruits from the CC5 stage which show complete repression of the NMTs were challenged with different concentrations of salicylic acid in aqueous solution viz. 5 μM (SA-5), 50 μM (SA-50), 250 μM (SA-250) and 500 μM (SA-500) to observe the augmentation of caffeine by interference of salicylic acid inducible signals with the maturation-triggered repression of caffeine biosynthesis. The treatment was carried out for 6 h, 12 h, and 24 h after which the treated seeds were placed in distilled water for 48 h (Control-retained). The fold changes of 7-MX (different shades of blue), Tb (different shades of magenta), Tp (different shades of green) and Cf (different shades of orange) compared to control untreated seeds are indicated. The error bars represent coefficient of variation of fold change obtained from the analysis of 4–8 seeds.