J. Messiaen et P. Vancutsem, PECTIC SIGNAL-TRANSDUCTION IN CARROT CELLS - MEMBRANE, CYTOSOLIC AND NUCLEAR RESPONSES INDUCED BY OLIGOGALACTURONIDES, Plant and Cell Physiology, 35(4), 1994, pp. 677-689
Oligogalacturonides were applied at a concentration of 0.2 mg ml(-1) t
o Daucus carota cells and protoplasts. Fractions containing oligomers
of degree of polymerisation 9 to 16 in the presence of 150 mM NaCl and
0.5 mM CaCl2, and pure oligomers of degree of polymerisation 9 to 13
in the same ionic medium, triggered a cytosolic calcium mobilisation,
membrane depolarisation and cytosolic acidification. These membrane an
d cytosolic events coincided with the accumulation of transcripts enco
ding phenylalanine ammonia-lyase, catalytic activitation of the enzyme
and p-hydroxybenzoic acid accumulation in the cell wall of the elicit
ed cells. The effect of a calcium ionophore, calcium channel blockers,
calmodulin inhibitors, phosphatidyl inositol metabolism modulators an
d H+-ATPase modulators were investigated on oligogalacturonide-induced
phenylalanine ammonia-lyase enzyme and gene activation in suspension-
cultured carrot cells.