Frontiers in Plant Science,
Год журнала:
2016,
Номер
7
Опубликована: Фев. 19, 2016
Melatonin
has
been
detected
in
numerous
plant
species.
A
particularly
surprising
finding
concerns
the
highly
divergent
levels
of
melatonin
that
vary
between
species,
organs
and
environmental
conditions,
from
a
few
pg/g
to
over
20
µg/g,
reportedly
up
200
µg/g.
Highest
values
have
determined
oily
seeds
exposed
high
UV
radiation.
The
divergency
concentrations
is
discussed
under
various
functional
aspects
focused
on
several
open
questions.
This
comprises
differences
precursor
availability,
catabolism,
relative
contribution
isoenzymes
biosynthetic
pathway,
rate
limitation
by
either
serotonin
N-acetyltransferase
or
N-acetylserotonin
O-methyltransferase.
Other
are
related
remarkable
pleiotropy
melatonin,
which
exhibits
properties
as
growth
regulator
morphogenetic
factor,
actually
debated
terms
auxin-like
effects,
signaling
molecule
modulates
pathways
ethylene,
abscisic,
jasmonic
salicylic
acids
involved
stress
tolerance,
pathogen
defense
delay
senescence.
In
context
light/UV
intensities,
elevated
exceed
those
required
for
via
stress-related
phytohormones
may
comprise
direct
antioxidant
photoprotectant
properties,
perhaps
with
its
oxidatively
formed
metabolites,
such
N1-acetyl-N2-formyl-5-methoxykynuramine
secondary
products.
High
also
serve
antioxidative
protection
shown
promote
seed
viability
germination
capacity.
Journal of Pineal Research,
Год журнала:
2011,
Номер
51(1), С. 1 - 16
Опубликована: Июнь 14, 2011
Abstract:
Oxidative
stress
has
been
proven
to
be
related
the
onset
of
a
large
number
health
disorders.
This
chemical
is
triggered
by
an
excess
free
radicals,
which
are
generated
in
cells
because
wide
variety
exogenous
and
endogenous
processes.
Therefore,
finding
strategies
for
efficiently
detoxifying
radicals
become
subject
great
interest,
from
both
academic
practical
points
view.
Melatonin
ubiquitous
versatile
molecule
that
exhibits
most
desirable
characteristics
good
antioxidant.
The
amount
data
gathered
so
far
regarding
protective
action
melatonin
against
oxidative
overwhelming.
However,
rather
little
known
concerning
mechanisms
involved
this
activity.
review
summarizes
current
progress
understanding
physicochemical
insights
radical–scavenging
activity
melatonin.
Thus
far,
there
general
agreement
electron
transfer
hydrogen
main
reactions
with
radicals.
relative
importance
other
also
analyzed.
nature
reacting
radical
influence
on
different
these
reactions.
point
discussed
detail
review.
Based
available
data,
it
concluded
protects
mechanisms.
Moreover,
proposed
even
though
referred
as
expression
darkness,
perhaps
could
light
health.
Journal of Pineal Research,
Год журнала:
2015,
Номер
59(2), С. 133 - 150
Опубликована: Июнь 19, 2015
The
number
of
studies
on
melatonin
in
plants
has
increased
significantly
recent
years.
This
molecule,
with
a
large
set
functions
animals,
also
shown
great
potential
plant
physiology.
review
outlines
the
main
physiology
higher
plants.
Its
role
as
antistress
agent
against
abiotic
stressors,
such
drought,
salinity,
low
and
high
ambient
temperatures,
UV
radiation
toxic
chemicals,
is
analyzed.
latest
data
their
plant-pathogen
interactions
are
discussed.
Both
biotic
stresses
produce
significant
increase
endogenous
levels,
indicating
its
possible
effector
these
situations.
existence
circadian
rhythms
levels
been
demonstrated
some
species,
data,
although
limited,
suggest
central
this
molecule
day/night
cycles
Finally,
another
aspect
that
led
to
volume
research
involvement
aspects
development
regulation.
Although
hormone
still
far
from
being
fully
established,
processes
growth,
rhizogenesis,
photosynthesis
seems
evident.
multiple
changes
gene
expression
caused
by
point
multiregulatory
capable
coordinating
many
development.
last
aspect,
together
an
alleviating-stressor
agent,
suggests
excellent
prospect
for
crop
improvement.
Journal of Experimental Botany,
Год журнала:
2014,
Номер
66(3), С. 647 - 656
Опубликована: Авг. 14, 2014
In
recent
years
melatonin
has
emerged
as
a
research
highlight
in
plant
studies.
Melatonin
different
functions
many
aspects
of
growth
and
development.
The
most
frequently
mentioned
are
related
to
abiotic
stresses
such
drought,
radiation,
extreme
temperature,
chemical
stresses.
This
review
mainly
focuses
on
the
regulatory
effects
when
plants
face
harsh
environmental
conditions.
Evidence
indicates
that
stress
can
increase
level
endogenous
plants.
Overexpression
biosynthetic
genes
elevates
levels
transgenic
show
enhanced
tolerance
Exogenously
applied
also
improve
ability
tolerate
mechanisms
by
which
alleviates
discussed.
Journal of Experimental Botany,
Год журнала:
2011,
Номер
63(2), С. 577 - 597
Опубликована: Окт. 20, 2011
The
presence
of
melatonin
in
plants
is
universal.
Evidence
has
confirmed
that
a
major
portion
the
synthesized
by
themselves
even
though
homologue
classic
arylalkylamine
N-acetyltransferase
(AANAT)
not
been
identified
as
yet
plants.
Thus,
serotonin
N-acetylating
enzyme
may
differ
greatly
from
animal
AANAT
with
regard
to
sequence
and
structure.
This
would
imply
multiple
evolutionary
origins
enzymes
these
catalytic
properties.
A
primary
function
serve
first
line
defence
against
internal
environmental
oxidative
stressors.
much
higher
levels
compared
those
found
animals
are
thought
be
compensatory
response
which
lack
means
mobility,
unlike
animals,
coping
harsh
environments.
Importantly,
remarkably
high
concentrations
have
measured
popular
beverages
(coffee,
tea,
wine,
beer)
crops
(corn,
rice,
wheat,
barley,
oats).
Billions
people
worldwide
consume
products
daily.
beneficial
effects
on
human
health
derived
consumption
must
considered.
also
indicates
an
ability
increase
production
crops.
mechanisms
involve
roles
preservation
chlorophyll,
promotion
photosynthesis,
stimulation
root
development.
Transgenic
enhanced
content
could
probably
lead
breakthroughs
crop
agriculture
improve
general
humans.
Journal of Pineal Research,
Год журнала:
2011,
Номер
52(2), С. 217 - 227
Опубликована: Авг. 3, 2011
We
studied
the
subcellular
levels
of
melatonin
in
cerebral
cortex
and
liver
rats
under
several
conditions.
The
results
show
that
cell
membrane,
cytosol,
nucleus,
mitochondrion
vary
over
a
24-hr
cycle,
although
these
variations
do
not
exhibit
circadian
rhythms.
membrane
has
highest
concentration
followed
by
mitochondria,
cytosol.
Pinealectomy
significantly
increased
content
all
compartments,
whereas
luzindole
treatment
had
little
effect
on
levels.
Administration
10
mg/kg
bw
to
sham-pinealectomized,
pinealectomized,
or
continuous
light-exposed
compartments.
Melatonin
doses
ranging
from
40
200
dose-dependent
manner
accumulation
accumulations
were
times
greater
former
than
latter.
nucleus
mitochondria
reached
saturation
with
dose
bw;
higher
injected
did
further
cause
additional
organelles.
suggest
some
control
extrapineal
production
support
existence
regulatory
mechanisms
cellular
organelles,
which
prevent
intracellular
equilibration
indolamine.
Seemingly,
different
concentrations
can
be
maintained
data
also
seem
requirement
high
obtain
therapeutic
effects.
Together,
add
information
assists
explaining
physiology
pharmacology
melatonin.
Journal of Pineal Research,
Год журнала:
2014,
Номер
56(3), С. 225 - 237
Опубликована: Фев. 26, 2014
Abstract
Free
radicals
generated
within
subcellular
compartments
damage
macromolecules
which
lead
to
severe
structural
changes
and
functional
alterations
of
cellular
organelles.
A
manifestation
free
radical
injury
biological
membranes
is
the
process
lipid
peroxidation,
an
autooxidative
chain
reaction
in
polyunsaturated
fatty
acids
membrane
are
substrate.
There
considerable
evidence
that
tends
reduce
fluidity.
However,
adequate
levels
fluidity
essential
for
proper
functioning
membranes.
Thus,
there
interest
antioxidant
molecules
able
stabilize
because
their
protective
effects
against
peroxidation.
Melatonin
indoleamine
modulates
a
wide
variety
endocrine,
neural
immune
functions.
Over
last
two
decades,
intensive
research
has
proven
this
molecule,
as
well
its
metabolites,
possess
substantial
activity.
In
addition
ability
scavenge
several
reactive
oxygen
nitrogen
species,
melatonin
increases
activity
glutathione
redox
enzymes,
is,
peroxidase
reductase,
other
enzymes.
These
beneficial
more
significant
small
molecular
size
amphipathic
behaviour,
facilitates
ease
penetration
into
every
compartment.
present
work,
we
review
current
information
related
maintaining
attack,
further,
discuss
implications
ageing
disease.
