Yuri Shavrukov AbstractAustralian Centre for Plant Functional Genomics, University of Adelaide,
Waite Campus, SA 5064, Australia
Depending on the method of NaCl application, whether gradual or in a
single step, plants may experience either salt stress
or salt shock, respectively. The first phase of
salt stress is osmotic stress. However, in the event of salt shock,
plants
suffer osmotic shock, leading to cell plasmolysis
and leakage of osmolytes, phenomena that do not occur with osmotic
stress.
Patterns of gene expression are different in
response to salt stress and salt shock. Salt stress initiates relatively
smooth
changes in gene expression in response to osmotic
stress and a more pronounced change in expression of significant numbers
of genes related to the ionic phase of salt stress.
There is a considerable time delay between changes in expression of
genes
related to the osmotic and ionic phases of salt
stress. In contrast, osmotic shock results in strong, rapid changes in
the
expression of genes with osmotic function, and
fewer changes in ionic-responsive genes that occur earlier. There are
very
few studies in which the effects of salt stress and
salt shock are described in parallel experiments. However, the patterns
of changes in gene expression observed in these
studies are consistently as described above, despite the use of diverse
plant
species. It is concluded that gene expression
profiles are very different depending the method of salt application.
Imposition
of salt stress by gradual exposure to NaCl rather
than salt shock with a single application of a high concentration of
NaCl
is recommended for genetic and molecular studies,
because this more closely reflects natural incidences of salinity.
full text:http://jxb.oxfordjournals.org/content/early/2012/11/26/jxb.ers316.abstract
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