| ||||||||||||||||||||
Role for reductase in ROS resistance?
Water deficit is already the major abiotic factor that
affects crop productivity worldwide and as the effects of global climate change
become more intense, things can only get worse (misquoting a well-known song).
Work on drought-response mechanisms, such as that carried out by Contour-Ansel et al. (Universite` Paris 12, pp.
1279–1287), is therefore very
important. The authors have focused on glutathione reductase (GR), an enzyme
involved both in maintaining the pool of reduced glutathione (GSH) and in
protection against reactive oxygen species (ROS). Drought-tolerant and
non-tolerant cultivars of cowpea (Vigna
unguiculata) were exposed to
drought by withholding water; leaves were desiccated by air drying. Changes in
leaves of the levels of mRNAs encoding the cytosolic and the organellar GRs
were assayed by RT–PCR. In the drought-tolerant cultivar, progressive drought
of whole plants led to a decrease in the expression of the organellar GR and an
increase in the expression of cytosolic GR. In the non-tolerant cultivar,
expression of both genes increased. In air-dried leaves, the tolerant cultivar
exhibited no overall change in expression of the organellar GR whereas the
expression of cytosolic GR increased, as already seen in whole plants. In the
non-tolerant cultivar, it was expression of the organellar form that increased.
Application of
Professor J. A. Bryant
University of Exeter, UK
j.a.bryant{at}exeter.ac.uk
| ||||||||||||||||||||