Ra. Moreau et al., XYLANASE TREATMENT OF PLANT-CELLS INDUCES GLYCOSYLATION AND FATTY ACYLATION OF PHYTOSTEROLS, Physiologia Plantarum, 91(4), 1994, pp. 575-580
Treatment of tobacco suspension cells (Nicotiana tabacum cv. KY 14) wi
th a purified beta-1,4-endoxylanase from Trichoderma viride [1 mu g en
zyme (ml cells)(-1)] caused a 13-fold increase in the levels of acylat
ed sterol glycosides and elicited the synthesis of phytoalexins. A com
mercial preparation of xylanase from Trichoderma viride caused an iden
tical shift in sterols. In contrast, a commercial xylanase from Aureob
asidium pullulans had no effect on the levels of acylated sterol glyco
sides, but did elevate the levels of sterol esters. Treatment of the c
ells with Cu2+ or Ag+ also evoked a severalfold increase in the levels
of acylated sterol glycosides. Analysis of the various sterol lipid c
lasses revealed that the large xylanase-induced increase in acylated s
terol glycosides occurred at the expense of sterol esters, free sterol
s and sterol glycosides. Further analyses revealed that the most abund
ant phytosterol in each of the four classes of sterol lipids was beta-
sitosterol. Linoleic acid was the most abundant fatty acid in the ster
ol eaters, and palmitic and linoleic acids were the most abundant fatt
y acids in the acylated sterol glycosides. Glucose was the only sugar
moiety in the sterol glycoside and acylated sterol glycoside fractions
. The results of the present study demonstrate that xylanase from Tric
hoderma viride induces a dramatic shift in the level of acylated stero
l glycosides, indicating that endoxylanase was probably the active com
ponent in the cellulase enzyme preparations used in our previous study
.