The cellulose biosynthesis inhibitor 2,6-diclorobenzonitrile (DCB) has been widely used to gain insights
into cell wall composition and architecture. Studies of changes occurring during incipient habituation to
DCB can provide information on early cell mechanisms leading to cope with DCB-induced stress. In this
context, maize cultured cells with a reduced amount of cellulose were obtained by stepwise habituation to
low DCB concentrations. The results reported here attempt to elucidate the putative role of an antioxidant
strategy during incipient habituation.
The short-term exposure to DCB of non-habituated maize cultured cells induced a substantial increase in
oxidative damage. Concomitantly, short-term treated cells presented an increase in class III peroxidase
and glutathione S-transferase activities and total glutathione content. Maize cells habituated to 0.3 – 1 μM
DCB (incipient habituation) were characterised by a reduction in the relative cell growth rate, an
enhancement of ascorbate peroxidase and class III peroxidase activities, and a net increment in total
glutathione content. Moreover, these cell lines showed increased levels of glutathione S-transferase
activity. Changes in antioxidant/detoxifying status enabled 0.3 and 0.5 μM DCB-habituated cells to
control lipid peroxidation levels, but this was not the case of maize cells habituated to 1 μM DCB, which
despite showing an increased antioxidant capacity were not capable of reducing the oxidative damage to
control levels. The results reported here confirm that exposure and incipient habituation of maize cells to
DCB are associated with an enhancement in antioxidant/detoxifying activities which could play a role in
incipient DCB habituation of maize cultured cells
