Book of Abstracts - Geyseco

P - Posters
P07-043: ROLE OF PROTECTIVE REACTIONS IN DI-
FFERENT KINDS PLANTS AT STRESSFUL CONDI-
TIONS
Gambarova, N.* - Gambarova, N.G.
Baku State University
*Corresponding author e-mail: nailya-gambarova@rambler.ru
The purpose of the dissertation is investigate of mechanisms of
protective reactions in different kinds C3 and C4 plants at action
of the various nature of stresses. Obtained results are generalized
on the basis of investigations of action of the high temperature
on transport electron chloroplast of different sort of wheat, distinguished
with thermal resistance, various concentration NaCl
in the sort of barley, distinguished with salt-endurance, various
speciation plants of the amarant, distinguished with contenting
of pigment betacyanin nature of amarantin.
Despite of the different nature, effective stressful factor, changing
functional activity of electronic transport in investigated
kinds C3 and C4plants have a general orientation of the processes
adducting to the change of mechanism of regulation of electronic
transport in extreme conditions. In particular, generally is
- at activity of above described factors – switching of the basic
linear stream of electrons (acyclic transport of electrons) on alternative
ways: cyclic around ФСI and also pseudo-cyclic with
participationspace separated photoreaction supervised redoxstatus
of components – carriers of electrons in ETC (pools of
plastokhinones, O2, oxidized НАДФ).
The basic purpose of the above-stated alternative ways at action
of the different nature of stressful influences is, first of all, prevention
of inflowing of surpluses of energy in ФСII, bound with
forming of singlet O2, elimination reduction ETC by carrying
of electrons on O2 with forming H2O2which probably serves as
the basic signal molecule in transcription chloroplast and nucleur
genes, and also synthesis of adenosinethrephosphate (ATP), necessary
for realization of the important processes in the cells.
P07-044: DISTINCT PROTECTIVE PATHWAYS OF 24
EPIBRASSINOLIDE AND 6-BENZYLAMINOPURINE IN
WHEAT SEEDLINGS
Yuldashev, R. - Avalbaev, A. - Lastochkina, O. - Shakirova, F.
Institute of Biochemistry and Genetics
Earlier we found that 0.4 μM 24-epibrassinolide (EB) and 4.4
μM 6-benzylaminopurine (BAP) comparably decreased the damaging
action of water deficit on growth of wheat seedlings. Further
we have found that EB and BAP stimulated gene expression
of TADHN dehydrin and accumulation of proline (Pro), osmoprotectants
which content are regulated by ABA. Interestingly
that ABA accumulation preceded the BAP-induced TADHN dehydrin
gene expression and increase in Pro content while EB had
no effect on these processes.
We have suggested that BAP induced defense reactions is ABAmediated.
Experiments with fluridon (Flu), an inhibitor of ABA
biosynthesis, confirmed the key role of ABA in BAP-induced Pro
accumulation.
There was no effect of BAP on Pro content in Flu-pretreated
plants. Meanwhile there was the same EB effect both in Flupretreated
and non-pretreated plants. Alongside with brassinosteroids
and cytokinins protective effect in response to abiotic
stresses there were data about their defense action in response to
viral, bacterial and fungal infection. So it was interesting to investigate
EB and BAP action on gene expression of pr-1 protein
which is related to pathogenesis-related proteins that accumulate
in plants following attack by different types of pathogens and
analyzed the role of ABA in this process. It was revealed that
both EB and BAP increased the pr-1 gene expression in plants.
Using Flu it was found that like in case of proline BAP realized
its effect in ABA-dependent manner. However action of EB was
ABA-independent because Flu did not affect the EB-induced
pr-1 gene expression. Thus these data indicate on distinction between
protective pathways of EB and BAP in wheat plants.This
work is supported by Grant RFFI 08-04-01563.
P07-045: MODIFICATIONS IN PLANT TRANSFER RNA
AT NORMAL AND STRESS CONDITIONS
Atanasova, L.
Institute of Plant Physiology, Bulgarian Academy of Sciences
Transfer RNA (tRNA) is the most extensively modified nucleic
acid in the cell. The four normal nucleosides adenosine, guanosine,
uridine and cytidine can be modified into derivatives with
different chemical structures and location along the tRNA chain.
The modifications belong to different tRNA species, and affect
their activity and stability. The appearance and the extent of a
tRNA modification depend on various factors, especially developmental
and environmental conditions can change the modifying
of tRNA. The levels of most abundant modified nucleosides were
examined in total tRNA from two plant species grown at normal
and stress conditions. Total RNA was isolated from organs of
maize (Z. mays L.) and pea (P.sativum L.) plants grown at normal
and prolonged stress conditions provoked by salinity (NaCl), metal
toxicity (Cd) and herbicide (atrazine). Total tRNA was fractioned
and digested to nucleosides which were analyzed by HPLC
(Umeå University, Sweden).
Numerous modified nucleosides were demonstrated in tRNA
preparations. Variations in the levels of several modifications
between plant organs and under stresses were found. Prominent
changes were noticed in the levels of queuosine, N4-acetyl-cytidine
and derivatives of N6-isopentenyl adenosine. The observed
trends in the distribution of tRNA modifications along the plant
as well as in the effects of stressors on their levels allow proposing
that these modifications exert specific functions in plant
growth and development as well as in surviving at the stresses.
Projects by the NSF (B1208/02, PISA/2005-08i)n Bulgaria;
grant by the SI Sweden (2005).
P07-046: ABSCISIC ACID IS AN INTERMEDIATE IN
PROTECTIVE ACTION OF SALICYLIC ACID ON
WHEAT PLANTS UNDER SALINITY
Lastochkina, O. - Maslennikova, D. - Shakirova, F.
Institute of Biochemistry and Genetics, Ufa Scientific Centre,
Russian Academy of Sciences
*Corresponding author e-mail: shakirova@anrb.ru
Earlier we found that salicylic acid (SA) exerts protective effect
to dehydration in wheat. It was revealed that treatment of wheat
seedlings with 50 μM SA causes reversible abscisic acid (ABA)
accumulation. Also it causes essential increase in osmoprotectant
levels - TADHN dehydrin gene expression and proline - both of
which are ABA-regulated. SA actively influence on pro- and antioxidant
(AO) systems connected with parallel and reversible
reactive oxygen species accumulation and increase in activities
of peroxidase and phenylalanine-ammonia-lyase (PAL) which
gene expression are ABA-controlled. To reveal the crucial role of
endogenous ABA in development of SA-induced defense reactions
in wheat plants, there was compared the effects of SA and
SA in mix with fluridon (Flu) (inhibitor of ABA biosynthesis)
on proline concentration, peroxidase and PAL activities, malonaldehyde
(MDA) content and dynamics of lignin deposit in
the cell wall of root basal part under salinity. Flu prevented SAinduced
proline accumulation, increase in PAL and peroxidase
activities that was reflected in delay of SA-induced lignification.
Meanwhile Flu completely prevented the SA-induced protective
effect which was visualized as decrease of salinity-induced
MDA accumulation which probably evoked through SA-induced
ABA-mediated activation of AO enzymes. Also we carried out
comparative analysis of SA and ABA influence on PR-1 gene
expression which is known marker of SA-induced systemic
acquired resistance. We have revealed the high sensitivity of
PR-1 gene not only to SA but also to ABA. Thus, the obtained
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