The role of polyamines in the regulation of the plasma membrane and the tonoplast proton pumps under salt stress

• Published in: Journal of plant physiology 2010-03, Vol.167 (4), p.261-269
• Main Authors: Janicka-Russak, MaLgorzata, KabaLa, Katarzyna, MLodzinska, Ewa, KLobus, Grazyna
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphatases - genetics; Adenosine Triphosphatases - metabolism; Adenosine Triphosphate - metabolism; Biological and medical sciences; Biomass; Blotting, Western; Cell Membrane - drug effects; Cell Membrane - enzymology; Cell Membrane - metabolism; cucumbers; Cucumis sativus; Cucumis sativus - drug effects; Cucumis sativus - enzymology; Cucumis sativus - genetics; Cucumis sativus - metabolism; enzyme activity; Fundamental and applied biological sciences. Psychology; gene expression regulation; Gene Expression Regulation, Plant - drug effects; H-transporting ATP synthase; H-transporting ATPase; Hydrogen-Ion Concentration - drug effects; Hydrolysis - drug effects; Intracellular Membranes - drug effects; Intracellular Membranes - enzymology; Membranes; Plant physiology and development; plant response; Plant Roots - drug effects; Plant Roots - metabolism; Plants (organisms); Plasma membrane; Polyamines; Polyamines - metabolism; Polyethylene Glycols - pharmacology; Potassium - metabolism; Protein Subunits - genetics; Protein Subunits - metabolism; proton pump; Proton pumps; Proton Pumps - metabolism; Pumps; putrescine; RNA, Messenger - genetics; RNA, Messenger - metabolism; Roots; Salt stress; seedlings; Seedlings - drug effects; Seedlings - metabolism; Sodium - metabolism; Sodium Chloride - pharmacology; Solutions; spermidine; spermine; Stress concentration; Stress, Physiological - drug effects; Stresses; Tonoplast; transcription (genetics); Vacuoles - drug effects; Vacuoles - metabolism; Vanadium
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2009.09.010

Polyamine content (PAs) often changes in response to abiotic stresses. It was shown that the accumulation of PAs decreased in roots treated for 24 h with 200 mM NaCl. The role of polyamines (putrescine – PUT, spermidine – SPD and spermine – SPM) in the modification of the plasma membrane(PM) H +-ATPase (EC 3.6.3.6) and the vacuolar(V) H +-ATPase (EC 3.6.3.14) activities in cucumber roots treated with NaCl was investigated. 24 h treatment of seedlings with 50 μM PUT, SPD or SPM lowered the activities of proton pumps in both membranes. The decreased H +-ATPase activity in plasma membranes isolated from the PA-treated roots was positively correlated with a lower level of PM-H +-ATPase CsHA3 transcript. However, transcript levels of PM-H +-ATPase CsHA2 and V-ATPase subunit A and c in roots treated with 50 μM PAs were similar to those in the control. Additionally, treatment of plants with salt markedly increased the activity of the PM- and V-H +-ATPases. However, exposure of plants to 20% PEG had no effect on these activities. These data suggest that, under salt stress conditions, the increase in H +-ATPase activities is caused mainly by the ionic component of salt stress. It seems that the main role of the PAs in the 24 h salt-treated cucumber plants could be a result of their cationic character. The PA levels decreased when concentration of Na + increased, so action of PAs contributes to ionic equilibrium. Moreover, the decrease in the concentration of polyamines, which inhibit the PM-H +-ATPase and the V-H +-ATPase, at least under the studied conditions, seems to be beneficial. Thus, plants can increase salinity tolerance by modifying the biosynthesis of polyamines.