Book of Abstracts - Geyseco

P07
Molecular
Mechanism Of
Abiotic Stress
P07-001: EXPRESSION OF SMALL MICRORNA MIR398
UNDER ABIOTIC STRESSES IN THELLUNGIELLA HA-
LOPHILA PLANTS
Pashkovskiy, P. 1 * - Ryazansky, S. 2 - Kuznetsov, V.L. 1
1
Institute of Plant Physiology
2
Institute of Molecular Genetic
*Corresponding author, e-mail: biomaquinademuerte@gmail.com
miRNA is a big class of small, 21-23 nt, RNAs capable to posttranscriptionaly
regulate expression of plant genes by inducing
the degradation of complementary mRNAs (target mRNAs).
miRNA-dependent regulation of gene expression is important
for many biological processes including growth, development
and metabolism. In Arabidopsis thaliana MIR398 and its target
Cu/Zn superoxiddismutese encoded by CSD1 have a key role in
formation of plant response to an abiotic oxidative stress. The
oxidative stress induces the decrease of the miR398 abundance
leading to accumulation of mRNA CSD1.We have found that
salt-resisted Thellungiella halophila probably have a similar
mechanism of response formation to oxidative stress. First, high
concentration of NaCl or UV-B irradiation results in changing of
MIR398 and mRNA CSD1 abundances dose-dependent manner.
Second, these alterations of expressions have oppositely directed
character and occur both in leaves and roots. Third, irradiation of
plant by high intensity light also lead to alterations of MIR398
expression. Thus, we suggest that MIR398-dependent regulation
of mRNA CSD1 can take place not only in glycophyte A. thaliana
but also in halophytes Th. halohila and have stress- and
organ-nonspecific character.
P07-002: LIPOXYGENASE ACTIVITY AND ROS FOR-
MATION IN PLANT CELL COMPARTMENTS UNDER
HYPOXIA AND CO2-MEDIA
Ershova A* - Berdnikova, O.
Voronezh State Pedagogical University
*Corresponding author, e-mail: aershova@vspu.ac.ru
P - Posters
Under hypoxia in plants lipid peroxidation processes are activated.
Activity of lipoxigenase (LOX ) and reactive oxygen species
(ROS) in cytoplasm, mitochondria and chloroplasts of pea seedlings
exposed to 3-9h hypoxia and CO 2
-media (100%) in dark
were studied. It was discovered that superoxide anion content
was increasing in mitochondria for 50% after 6h, in chloroplasts
for 2.7 fold after 3h and then decreasing to aerated plants. In
cytoplasm superoxide content was increasing only to experiment
end to 250%. Hydrogen peroxide level, the most long-lived ROS
form, was 40% higher after 3h of hypoxia in mitochondria and
was 376% in chloroplasts, but it was decreasing for 20-30% in
cytoplasm of aerated plants. It was determined that LOX activity
in cytoplasm was 67%, in chloroplasts – 18% and 9% in
mitochondria of total activity. LOX activity was rising in mitochondria
till 170.1 after 3h of hypoxia, was 156.2 after 6h and
than decreasing to 87.9 U/mg protein that was lower than aerated
plants. LOX activity was consistent to control plants in chloroplasts
and cytoplasm of seedlings. When studying dynamics of
ROS accumulation in cytoplasm, mitochondria and chloroplast
of pea it was shown that only in mitochondria LOX can reinforce
ROS formation due to lipoperoxides accumulation in first hours
of hypoxia. It was noted that high CO 2
cocentrations increased
hypoxia effects on these processes.
P07-003: IDENTIFICATION OF GENES INVOLVED IN
NON-TARGET-SITE-BASED RESISTANCE TO HERBI-
CIDES IN THE ARABLE GRASS WEED ALOPECURUS
MYOSUROIDES (BLACK-GRASS)
Délye, C.* - Petit, C.
INRA
*Corresponding author, e-mail: delye@dijon.inra.fr
Arable weeds are essentially annual plants infesting crops. They
are mostly non-model plant species dwelling in highly anthropised,
highly disturbed environments (i.e., agricultural fields). To
secure crop yield, weeds are destroyed using herbicide applications.
The repeated use of herbicides selected for adapted (‘resistant’)
weed individuals surviving herbicide applications. In A.
myosuroides, non-target-site-based resistance (NTSR) plays the
major role in resistance. NTSR is generally considered a quantitative
trait endowed by many genes belonging to the general
pathways of plant response to stresses. Such genes are differentially
regulated in resistant and sensitive individuals. Despite the
considerable economical consequences of herbicide resistance
in weeds, hardly any data is available regarding the nature of
the genes involved in NTSR. No genomic data being available
for A. myosuroides, we used heterologous hybridisation on wheat
DNA microarrays to identify genes with a moderate level of differential
expression between resistant and sensitive plants, and
suppression subtractive hybridisation to identify genes strongly
up-regulated in resistant plants. Nine candidate genes were identified.
Eight encoded proteins homologous to enzymes that may
degrade herbicides or compensate for herbicide action. One potentially
encoded an homologue of a protein involved in signal
transduction during plant response to stress. Our data will aid
gaining an insight into the processes driving the selection for
adaptive life traits in weeds.
P07-004: ON MOLECULAR MECHANISMS OF TUNGS-
TATE TOXIC EFFECT ON PEA ROOT GROWTH
Gazizova, N.* - Karimova, F.
Kazan Institute of Biochemistry and Biophysics
*Corresponding author, e-mail: natgazizova@mail.ru
The anthropogenic contamination of environment by heavy
metal salts can exert stress actions on plant cells leading to cell
metabolism disturbance, alteration of cell proliferation activity
and growth inhibition. Tungsten is widely used in the industrial,
civilian andmilitary activities. Its concentration in environment
can be also increased by the application of phosphate fertilizers.
Tungsten belongs to toxic heavy metals and is biologically significant
for very limited range of organisms. Protein phosphorylation/dephosphorylation
is known to be the main events in cell
signaling and plant responses to abiotic stresses. Protein tyrosine
phosphorylation is critical for cell division and growth. The aim
of this work was to study the effect of sodium tungstate on cell
proliferation activity, root growth, and root protein tyrosine phosphorylation.
It was shown that tungstate caused the alteration of
cell mitotic activity, which was accompanied by the increase of
mitotic phase duration and the delay of root growth. Tungstate induced
an increase of phosphotyrosine proteins amount and level
of protein tyrosine phosphorylation. Regulatory, metabolic and
defense proteins were among the identified ones. The increase
of tyrosine phosphorylation of 14-3-3 proteins is of special interest.
It is known that activity of some enzymes depends on their
binding with 14-3-3 proteins and on their phosphorylation. The
data obtained reveal the molecular mechanisms of tungstate toxic
effect on pea root growth.
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