Siberian Institute of Plant Physiology and
Biochemistry, Siberian Branch of RAS, Irkutsk, Russia
*E-Mail: elga74@yandex.ru
Received July 23, 2013
The gdh2 gene encoding beta-subunit of
glutamate dehydrogenase in Arabidopsis
belongs to diurnal-regulated genes. Its expression is highly increased
in the dark and reduced to minimal rates at the day light. Some
sugar-responsive regulatory pathways are known to be involved in the gdh2 light repression, but the
specific mechanisms of this regulation are unknown. In our experiments
expression of gdh2
gene increased 6-11 fold in Arabidopsis
seedlings grown in presence of the tetrapyrrole synthesis inhibitor
norflurazon. The increasing rate depended on the light
intensity and did not correlate
with the induction of ROS marker
genes. This observation can be explained by both a low glucose
level in the cells treated with norflurazon and absence
of repression by the
chloroplast-to-nucleus retrograde pathways
because of chloroplast dysfunction. We
assume that the diurnal regulation
of gdh2
gene expression involves not only sugar-dependent, but also
chloroplast-to-nucleus regulatory signals.
Key
words: glutamate dehydrogenase, retrograde regulation of gene
expression, chloroplast-to-nucle us signals, Arabidopsis thaliana.
