Figure 6

Histochemical detection of lignin, phenolics, and flavonoids. Leaves from plants treated with water (B, E, G) or 30 mM thiamine (A, C, D, F, H, I) were collected at 1 dpt, and used for microscopic studies. (A, B, C) Leaves from plants were used for subcellular detection of lignin accumulation as a red coloration under light microscope following phloroglucinol-HCl staining. (D, E, F) Leaf segments were examined under auto-fluorescence (UV light Filter); white–blue coloration indicates the presence of phenolics. (G, H, I) Leaf sections (10 μm of thickness) were stained with Wilson’s reagent and observed under UV light; yellow coloration indicates presence of flavonoids. Six leaves from different plants were assessed for each treatment and the whole experiment was repeated three times with similar results. Bars = 40 μM for (A, B, D, E, G, H) and 20 μm for (C, F, I).