Juglone promotes shooting and inhibits rooting in leaf explants of in vitro raised tomato (Solanum lycopersicum L. var. Pusa Ruby) seedlings

Juglone is an inhibitor of choline acetyltransferase, an enzyme that catalyzes the synthesis of acetylcholine. Previous works have shown the effect of acetylcholine on in vitro morphogenesis in tomato explants. This work on juglone is designed to indirectly test the presence of acetylcholine biosynthesis in tomato plants. Leaf explants harvested from 30-d-old tomato (Solanum lycopersicum L. variety Pusa Ruby) seedlings were cultured on juglone-fortified control media. Juglone concentrations ranging from 10(-9) to 10(-3) M were used to check the dose response. It was observed that juglone significantly inhibited rooting and caused transition from rhizogenesis to caulogenesis at 10(-7) to 10(-6) M. Supplementation of different levels of juglone to the shoot regeneration medium enhanced the shoot formation and callus amounts, exhibiting best response at 10(-5) M. This study suggests that juglone regulates morphogenesis in tomato via the acetylcholine system in plants.

Automated summary

The study found that juglone significantly inhibited root growth in tomatoes and promoted stem growth, exhibiting the best response at a concentration of 10(-5) M.