engleski

NOVEL PROTEINS INVOLVED IN DROUGHT AND SALT STRESS RESPONSE IN SUGAR BEET REVEALED USING PROTEOMIC APPROACH

Drought and salt stress are major abiotic stresses that significantly impact every aspect of plant physiology, leading to severe loss in crop yield. However, response to these stresses is plant specific. The objective of this study was to unravel cellular mechanisms of stress response using sugar beet cells. The cells were cultivated for 72h in liquid PG medium, and salt stress was induced using 300 mM NaCl, while drought was induced using 600 mM mannitol. The expression patterns of cellular proteins were resolved by two-dimensional electrophoresis, and salt stress provoked statistically different regulation of 43 proteins, of which 22 were upregulated and 21 were downregulated. Drought stress significantly regulated 67 proteins of which 41 were upregulated and 26 were downregulated. These protein spots were subjected to identification by mass spectrometry. According to functional protein classification, 80 % of the identified proteins were involved in metabolism, energy or cell rescue, defense and virulence. These include superoxide dismutase, peroxidases, glutathione S-transferases, heat shock proteins, four different subunits of ATP-ases and proteins of the oxygen evolving complex of photosystem II. Proteins such as histidinol dehydrogenase, telomerase reverse transcriptase and condensin complex were for the first time implicated in the stress response. Analysis was extended to extracellular proteins. Expression pattern of these proteins, resolved by SDS-PAGE, showed involvement of β-D-xylosidase and SKU similar proteins in abiotic stress response. Finally, changes in glycan parts of electrophoretically resolved cellular proteins were detected using plant lectins. Both stresses provoked marked changes in glycoprotein pattern, which suggests that glycosylation is affected by abiotic stress.

proteomics; sugar beet; drought; salt stress; glycoproteins; extracellular proteins

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