Fraissinet-Tachet L, Baltz R, Chong J, Kauffmann S, Fritig B, Saindrenan P
Institut de Biologie Moléculaire des Plantes du CNRS, Université Louis Pasteur, Strasbourg, France.
FEBS Lett. 1998 Oct 23;437(3):319-23. doi: 10.1016/s0014-5793(98)01257-5.
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.
两个与已知受水杨酸（SA）诱导的葡糖基转移酶基因具有同源性的烟草基因（TOGT），对真菌激发子或无毒病原体也有快速反应。SA虽然是一种有效的诱导剂，但在抗性反应中调节TOGT基因表达的信号转导途径中并非必不可少。在大肠杆菌中产生的重组TOGT蛋白对SA表现出较低但显著的葡糖基转移酶活性，而对羟基香豆素和羟基肉桂酸具有非常高的活性，葡萄糖酯是主要产物。这些结果表明，这些葡糖基转移酶在将芳香族代谢物结合起来以便在运输和交联到细胞壁之前可能在防御中发挥重要作用。
