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The transient nature of the oligogalaturonide‐induced ion fluxes of tobacco cells is not correlated with fragmentation of the oligogalacturonides
Author(s) -
Mathieu Yves,
Guern Jean,
Spiro Mark D.,
O’Neill Malcolm A.,
Kates Keith,
Darvill Alan G.,
Albersheim Peter
Publication year - 1998
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1998.00297.x
Subject(s) - galactitol , chemistry , kinetics , biochemistry , efflux , biophysics , fragmentation (computing) , chromatography , biology , galactose , physics , quantum mechanics , ecology
Summary The metabolism by suspension‐cultured tobacco cells of oligogalacturonides was investigated. Dodecagalacturonic acid‐[ 3 H]galactitol induces a rapid and transient alkalinization of the incubation medium resulting in part from enhanced K + efflux from tobacco cells. However, a threefold higher concentration of dodecagalacturonic acid‐[ 3 H]galactitol is required to induce a response with the same amplitude and kinetics as that induced by the unreduced tridecagalacturonic acid. Approximately 20% of the dodecagalacturonic acid‐[ 3 H]galactitol added to suspension‐cultured tobacco ionically binds to the cell walls within 1 min; maximum binding (approximately 30% of the oligogalacturonide) occurs in approximately 25 min. The unbound dodecagalacturonic acid‐[ 3 H]galactitol is rapidly (half‐life, 30 min) fragmented to smaller, biologically inactive fragments by a polygalacturonase present in the growth medium. In contrast, the wall‐bound dodecagalacturonic acid‐[ 3 H]galactitol is not degraded for at least 150 min. However, the kinetics, amplitude and duration of oligogalacturonide‐induced ion fluxes are not correlated with the rate at which oligogalacturonides are converted to biologically inactive fragments. We propose that the transient nature of the oligogalacturonide‐induced responses is likely to result from a temporary desensitization of the plant cells to the bioactive oligogalacturonides.