Increased production of cadaverine and anabasine in hairy root cultures of Nicotiana tabacum expressing a bacterial lysine decarboxylase gene

Abstract

Several hairy root cultures of Nicotiana tabacum varieties, carrying two direct repeats of a bacterial lysine decarboxylase (ldc) gene controlled by the cauliflower mosaic virus (CaMV) 35S promoter expressed LDC activity up to 1 pkat/mg protein. Such activity was, for example, sufficient to increase cadaverine levels of the best line SR3/1-K1,2 from ca. 50 micrograms (control cultures) to about 700 micrograms/g dry mass. Some of the overproduced cadaverine of this line was used for the formation of anabasine, as shown by a 3-fold increase of this alkaloid. In transgenic lines with lower LDC activity the changes of cadaverine and anabasine levels were correspondingly lower and sometimes hardly distinguishable from controls. Feeding of lysine to root cultures, even to those with low LDC activity, greatly enhanced cadaverine and anabasine levels, while the amino acid had no or very little effect on controls and LDC-negative lines.