13 research outputs found
Effects of salinity and drought on growth, ionic relations, compatible solutes and activation of antioxidant systems in oleander (Nerium oleander L.)
[EN] Nerium
oleander
is an
ornamental
species
of high
aesthetic
value,
grown
in arid
and
semi-
arid
regions
because
of its
drought
tolerance,
which
is also
considered
as
relatively
resistant
to salt;
yet
the
biochemical
and
molecular
mechanisms
underlying
oleanderÂżs
stress
toler-
ance
remain
largely
unknown.
To
investigate
these
mechanisms,
one-year-old
oleander
seedlings
were
exposed
to 15
and
30
days
of treatment
with
increasing
salt
concentratio
ns,
up
to 800
mM
NaCl,
and
to complete
withholding
of irrigation;
growth
parameters
and
bio-
chemical
markers
characteristic
of conserved
stress-response
pathways
were
then
deter-
mined
in stressed
and
control
plants.
Strong
water
deficit
and
salt
stress
both
caused
inhibition
of growth,
degradation
of photosynthetic
pigments,
a slight
(but
statistically
signifi-
cant)
increase
in the
leaf
levels
of specific
osmolytes,
and
induction
of oxidative
stressÂżas
indicated
by
the
accumulation
of malondialdehyde
(MDA),
a reliable
oxidative
stress
marker
Âżaccompanied
by
increases
in the
levels
of total
phenolic
compounds
and
antioxidant
fla-
vonoids
and
in the
specific
activities
of ascorbate
peroxidase
(APX)
and
glutathione
reduc-
tase
(GR).
High
salinity,
in addition,
induced
accumulation
of Na
+
and
Cl
-
in roots
and
leaves
and
the
activation
of superoxide
dismutase
(SOD)
and
catalase
(CAT)
activities.
Apart
from
anatomical
adaptations
that
protect
oleander
from
leaf
dehydration
at moderate
levels
of
stress,
our
results
indicate
that
tolerance
of this
species
to salinity
and
water
deficit
is based
on
the
constitutive
accumulation
in leaves
of high
concentratio
ns
of soluble
carbohydrates
and,
to a lesser
extent,
of glycine
betaine,
and
in the
activation
of the
aforementioned
antiox-
idant
systems.
Moreover,
regarding
specifically
salt
stress,
mechanisms
efficiently
blocking
transport
of toxic
ions
from
the
roots
to the
aerial
parts
of the
plant
appear
to contribute
to a
large
extent
to tolerance
in
Nerium
oleanderThis work was financed by internal funds of the Polytechnic University of Valencia to Monica Boscaiu and Oscar Vicente. Dinesh Kumar’s stay in Valencia was financed by a NAMASTE fellowship from the European Union, and Mohamad Al Hassan was a recipient of an Erasmus Mundus pre-doctoral scholarship financed by the European Commission (Welcome Consortium).Kumar, D.; Al Hassan, M.; Naranjo Olivero, MA.; Agrawal, V.; Boscaiu, M.; Vicente, O. (2017). Effects of salinity and drought on growth, ionic relations, compatible solutes and activation of antioxidant systems in oleander (Nerium oleander L.). PLoS ONE. 12(9). doi:10.1371/journal.pone.0185017Se018501712
Hydrogen peroxide priming modulates abiotic oxidative stress tolerance: insights from ROS detoxification and scavenging
Plants are constantly challenged by various abiotic stresses that negatively affect growth and productivity worldwide. During the course of their evolution, plants have developed sophisticated mechanisms to recognize external signals allowing them to respond appropriately to environmental conditions, although the degree of adjustability or tolerance to specific stresses differs from species to species. Overproduction of reactive oxygen species (ROS) (hydrogen peroxide, H2O2; superoxide, O2ˉ˙; hydroxyl radical, OH. and singlet oxygen, 1O2) is enhanced under abiotic and/or biotic stresses, which can cause oxidative damage to plant macromolecules and cell structures, leading to inhibition of plant growth and development, or to death. Among the various ROS, freely diffusible and relatively long-lived H2O2 acts as a central player in stress signal transduction pathways. These pathways can then activate multiple acclamatory responses that reinforce resistance to various abiotic and biotic stressors. To utilize H2O2 as a signaling molecule, non-toxic levels must be maintained in a delicate balancing act between H2O2 production and scavenging. Several recent studies have demonstrated that the H2O2-priming can enhance abiotic stress tolerance by modulating ROS detoxification and by regulating multiple stress-responsive pathways and gene expression. Despite the importance of the H2O2-priming, little is known about how this process improves the tolerance of plants to stress. Understanding the mechanisms of H2O2-priming-induced abiotic stress tolerance will be valuable for identifying biotechnological strategies to improve abiotic stress tolerance in crop plants. This review is an overview of our current knowledge of the possible mechanisms associated with H2O2-induced abiotic oxidative stress tolerance in plants, with special reference to antioxidant metabolism
Investigative approaches associated with plausible chemical and biochemical markers for screening wheat genotypes under salinity stress
Genetic diversity, heritability and inter-relationships of fruit quality and taste attributes among Iranian pomegranate (Punica granatum L.) cultivars using multivariate statistical analysis
A Multivariate Approach to Determine the Economic Profitability of Sugarcane Production Under Diverse Climatic Conditions in Brazil
Exogenous Sucrose Protects Potato Seedlings Against Heat Stress by Enhancing the Antioxidant Defense System
The sunflower TLDc-containing protein HaOXR2 confers tolerance to oxidative stress and waterlogging when expressed in maize plants
The sunflower (Helianthus annuus L.) genome encodes six proteins containing a TLDc domain, typical of the eukaryotic OXidation Resistance (OXR) protein family. Expression of sunflower HaOXR2 in Arabidopsis generated plants with increased rosette diameter, higher number of leaves and increased seed production. Maize inbred lines expressing HaOXR2 also showed increased total leaf area per plant. In addition, heterologous expression of HaOXR2 induced an increase in the oxidative stress tolerance in Arabidopsis and maize. Maize transgenic plants expressing HaOXR2 experienced less oxidative damage and exhibited increased photosynthetic performance and efficiency than non-transgenic segregant plants after treatment of leaves with the reactive oxygen species generating compound Paraquat. Expression of HaOXR2 in maize also improved tolerance to waterlogging. The number of expanded leaves, aerial biomass, and stem height and cross-section area were less affected by waterlogging in HaOXR2 expressing plants, which also displayed less aerial tissue damage under these conditions. Transgenic plants also showed an increased production of roots, a typical adaptive stress response. The results show the existence of functional conservation of OXR proteins in dicot and monocot plants and indicate that HaOXR2 could be useful to improve plant performance under conditions that increase oxidative stress.Fil: Torti, Pablo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de AgrobiotecnologĂa del Litoral. Universidad Nacional del Litoral. Instituto de AgrobiotecnologĂa del Litoral; ArgentinaFil: Raineri, Jesica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de AgrobiotecnologĂa del Litoral. Universidad Nacional del Litoral. Instituto de AgrobiotecnologĂa del Litoral; ArgentinaFil: Mencia, Regina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de AgrobiotecnologĂa del Litoral. Universidad Nacional del Litoral. Instituto de AgrobiotecnologĂa del Litoral; ArgentinaFil: Campi, Mabel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de AgrobiotecnologĂa del Litoral. Universidad Nacional del Litoral. Instituto de AgrobiotecnologĂa del Litoral; ArgentinaFil: Gonzalez, Daniel Hector. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de AgrobiotecnologĂa del Litoral. Universidad Nacional del Litoral. Instituto de AgrobiotecnologĂa del Litoral; ArgentinaFil: Welchen, Elina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de AgrobiotecnologĂa del Litoral. Universidad Nacional del Litoral. Instituto de AgrobiotecnologĂa del Litoral; Argentin