Tytuł pozycji:
The effects of short-term selenium stress on Polish and Finnish wheat seedlings : EPR, enzymatic and fluorescence studies
Biochemical
analyses
of
antioxidant
content
were
compared
with
measurements
of
fluorescence
and
electron
paramagnetic
resonance
(EPR)
to
examine
the
alteration
of
radicals
in
wheat
seedlings
exposed
to
2
days
of
selenium
stress.
Two
genotypes
of
Polish
and
one
of
Finnish
wheat,
differing
in
their
tol-
erance
to
long-term
stress
treatment,
were
cultured
under
hydroponic
conditions
to
achieve
the
phase
of
3-leave
seedlings.
Afterwards,
selenium
(sodium
selenate,
100$\mu$M
concentration)
was
added
to
the
media.
After
Se-treatment,
all
varieties
showed
an
increase
in
carbohydrates
(soluble
and
starch),
ascor-
bate
and
glutathione
content
in
comparison
to
non-stressed
plants.
These
changes
were
more
visible
in
Finnish
wheat.
On
the
basis
of
lipid
peroxidation
measurements,
Finnish
wheat
was
recognized
as
the
genotype
more
sensitive
to
short-term
Se-stress
than
the
Polish
varieties.
The
antioxidant
enzyme
activities
(superoxide
dismutase,
ascorbate
peroxidase
and
glutathione
reductase)
increased
in
Polish
genotypes,
whereas
they
decreased
in
Finnish
wheat
plants
cultured
on
Se
media.
The
action
of
reactive
oxygen
species
in
short-term
action
of
Se
stress
was
confirmed
by
the
reduction
of
PSII
and
PSI
system
activities
(measured
by
fluorescence
parameters
and
EPR,
respectively).
EPR
studies
showed
changes
in
redox
status
(especially
connected
with
Mn(II)/Mn(III),
and
semiquinone/quinone
ratios)
in
wheat
cell
after
Se
treatment.
The
involvement
of
the
carbohydrate
molecules
as
electron
traps
in
production
of
long-lived
radicals
is
postulated.
