Publications

• Effect of 2,4-dichlorophenoxyacetic Acid on glucosylation of scopoletin to scopolin in tobacco tissue culture.

  Hino F., Okazaki M., Miura Y.

  2,4-Dichlorophenoxyacetic acid (2,4-D) stimulated the formation of scopoletin and scopolin in tobacco (Nicotiana tabacum L. ;Bright Yellow') cell culture. It especially stimulated the uptake of scopoletin from culture medium into the cells and the glucosylation of scopoletin to its monoglucoside, ... >> More

  2,4-Dichlorophenoxyacetic acid (2,4-D) stimulated the formation of scopoletin and scopolin in tobacco (Nicotiana tabacum L. ;Bright Yellow') cell culture. It especially stimulated the uptake of scopoletin from culture medium into the cells and the glucosylation of scopoletin to its monoglucoside, scopolin. This phenomenon is peculiar to 2,4-D, in contrast to other plant hormones. 2,4-D (1 mug/ml) stimulated the glucosylation of scopoletin to scopolin by enhancing UDP-glucose:scopoletin glucosyltransferase (SGTase) activity. The enhancement of SGTase activity caused by treatment with 2,4-D was observed when the syntheses of RNA and protein were inhibited by either actinomycin-D and/or cycloheximide. However, the stimulatory effect of 2,4-D was inhibited by treatment with dinitrophenol. Furthermore, SGTase with or without treatment by 2,4-D in vivo for 24 hours, was isolated from cultured tobacco cells. The enzymes were purified about 200-fold by precipitation with (NH(4))(2)SO(4) and chromatography with Sephadex G-100, DEAE-cellulose, and hydroxyapatite. The specific activity of 2,4-D-treated SGTase was 10 times higher than that of untreated SGTase even in the purified fraction, which showed one protein band under electrophoresis. These results suggest that the enhancement of SGTase activity by 2,4-D is due to the energy-dependent activation of the enzyme already present, but not due to the de novo synthesis of the enzyme. << Less

  Plant Physiol 69:810-813(1982) [PubMed] [EuropePMC]

• Two tobacco genes induced by infection, elicitor and salicylic acid encode glucosyltransferases acting on phenylpropanoids and benzoic acid derivatives, including salicylic acid.

  Fraissinet-Tachet L., Baltz R., Chong J., Kauffmann S., Fritig B., Saindrenan P.

  Two tobacco genes (TOGT) with homology to glucosyltransferase genes known to be induced by salicylic acid (SA) also responded rapidly to a fungal elicitor or to an avirulent pathogen. SA, although an efficient inducer, was shown not to be essential in the signal transduction pathway regulating TOG ... >> More

  Two tobacco genes (TOGT) with homology to glucosyltransferase genes known to be induced by salicylic acid (SA) also responded rapidly to a fungal elicitor or to an avirulent pathogen. SA, although an efficient inducer, was shown not to be essential in the signal transduction pathway regulating TOGT gene expression during the resistance response. Recombinant TOGT proteins produced in Escherichia coli exhibited low, but significant, glucosyltransferase activity towards SA, but very high activity towards hydroxycoumarins and hydroxycinnamic acids, with glucose esters being the predominant products. These results point to a possible important function in defense of these glucosyltransferases in conjugating aromatic metabolites prior to their transport and cross-linking to the cell wall. << Less

  FEBS Lett. 437:319-323(1998) [PubMed] [EuropePMC]