Effect of Feeding Salicylic Acid on 2,3-Dihydroxybenzoic Acid Formation in Cultured Cells of Catharanthus roseus

Abstract

Catharanthus roseus cell cultures produce a high amount of 2,3-dihydroxybenzoic acid (2,3-DHBA) and salicylic acid (SA) with a concomitant induction of isochorismate synthase (ICS, EC 5.4.99.6) after addition of a fungus Pythium aphanidermatum. To investigate whether 2,3-DHBA might be formed through an intermediacy of SA, the cells were fed with this compound. A significant increase of glycosidically bound 2,3-DHBA was obtained, although no effect on ICS was observed in the cells treated with SA. On the contrary, the addition of SA in combination with fungal elicitor led to a lower level of the total 2,3-DHBA found in the cells and the medium, but no influence on the induction of ICS activity. These results suggest SA is unlikely a direct precursor of 2,3-DHBA. However, it might have a regulatory role in the 2,3-DHBA biosynthetic pathway.