Τομέας Βοτανικής
Library of the School of Science

2013-07-30

2013

Βαλασάκη Χρυσάνθη

Α. Ρούσσης, Επίκ. Καθηγητής (επιβλέπων), Κ. Χαραλαμπίδης, Επίκ. Καθηγητής, Δ. Χατζηνικολάου, Επίκ. Καθηγητής

Διερευνηση του ρολου των γονιδίων SBP στο φυτό Arabidopsis thaliana κατά την οξειδωτική καταπόνηση

Greek

Investigation of the role of SBP genes in the plant Arabidopsis thaliana during oxidative stress

The SBP protein (Selenium Binding Protein) was initially isolated from mouse
liver
in radioactive labeling experiments to identify proteins that bind selenium.
Since
then, orthologous SBP proteins have been found in many prokaryotic and
eukaryotic
organisms. SBP is not a typical selenoprotein which incorporates selenium
through
the amino acid selenocysteine, encoded by the UGA codon, but a protein that
binds
selenium possibly by unknown conjugation mechanism of selenium with glutathione
(GSSe-). Studies in different plant species such as Arabidopsis, sorghum and
sunflower, have shown that SBP genes are transcriptionally regulated when
plants are
exposed to biotic and abiotic stress. Immunolocalization expreriments of sbp in
Lotus
japonicus showed that the protein was present in membrane accumulation areas. In
rice SBP expression is activated by endogenous signaling molecules which induce
resistance in pathogens and by substances producing reactive oxygen species
(ROS),
such as the herbicide paraquat and excised phytohormone acid. In Arabidopsis
there
are three homologues SBP genes. To investigate the role of the SBP genes
in Arabidopsis thaliana during normal development and oxidative stress
conditions,
experiments were performed studying the expression levels and the tissue
specific
expression in planta. In the first case effect of different metals and chemical
elements
in seedling A.thaliana was carried out and the expression levels of SBP genes
were
evaluated through semi-quantitative reverse transcriptase chain reaction
polymerase
(semi-quantitative RT-PCR). In the latter case, we constructed transcriptional
fusions
of the SBP3 promoter with the GUS reporter gene. Using these constructs, stably
transformed lines of A.thaliana were generated. The above analyses showed that
SBP
genes are subject to differential regulation both in development and conditions
of
oxidative stress, indicating the multiple roles of these genes in various
functions of the
plant. Moreover, in order to study the effect of oxidative stress during the
development of A.thaliana, several measurements of morphological characters were
made suggesting common mechanism of response to stresses through faster
transition
of the organism from the vegetative to reproductive phase as well as the
different
effect introduced by each stress factor.

Oxidative stress, Stress, SBP genes, Arabidopsis, Development

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Yes

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https://pergamos.lib.uoa.gr/uoa/dl/object/1316811