Abstracts (poster) - Wissenschaft Online

Agnieszka Sokol, Aleksandra Kwiatowska, Andrzej Jerzmanowski, Marta
Prymakowska-Bosak
Up-regulation of stress-inducible genes in tobacco and
Arabidopsis cells in response to abiotic stresses and ABA
treatment correlates with dynamic changes in histone H3 and
H4 modifcations
Animal cells react to mitogenic or stress stimuli by rapid up-regulation of immediateearl(IE)
genes and a parallel increase in characteristic modifications of core histones:
chromatin changes, collectively termed the nucleosomal response. With regard to plants
little is known about the accompanying changes at the chromatin level. We have used
tobacco BY-2 and Arabidopsis T87 cell lines to study the nucleosomal response of plant
cells to high salinity, cold and exogenous abscisic acid (ABA). When in quiescent stage,
both tobacco and Arabidopsis cells show the typical nucleosomal response to high
salinity and cold stress, manifested by rapid transient up-regulation of histone H3 Ser-10
phosphorylation, immediately followed by transient up-regulation of H3
phosphoacetylation and histone H4 acetylation. For each of the studied stresses the
observed nucleosomal response was strictly correlated with the induction of stress-type
specifc genes. The dynamics of histone modifications in BY-2 cells in response to
exogenous ABA exhibited a more complex pattern than that evoked by the two abiotic
stresses, probably due to superposition of the primary and secondary effects of ABA. A
rapid increase in H3 Ser-10 phosphorylation was also observed in whole leaves
subjected to high salinity; however, the rate of change in this modification was much
slower than in cultured cells. Together, these results indicate that the quiescent BY-2
and T87 cell lines show a typical nucleosomal response to abiotic stresses and ABA
treatment and may represent suitable models for the study of chromatin-mediated
mechanisms of stress tolerance in plants.
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contact:
Ph. D. Marta Prymakowska-Bosak
Warsaw University
Laboratory of Plant Molecular Biology
marta@ibb.waw.pl
Pawinskiego 5A
02-106 Warsaw (Poland)