Acclimation to salt modifies the activation of several osmotic stress-activated lipid signalling pathways in Chlamydomonas

作者：Meijer Harold J G; van Himbergen John A J; Musgrave Alan; Munnik Teun^*

来源：Phytochemistry, 2017, 135: 64-72.

DOI：10.1016/j.phytochem.2016.12.014

• Chlamydomonas moewusii
• Chlamydomonadaceae
• Green alga
• Acclimation
• Osmotic stress
• Phospholipids
• Signal transduction

Osmotic stress rapidly activates several phospholipid signalling pathways in the unicellular alga Chla-mydomonas. In this report, we have studied the effects of salt-acclimation on growth and phospholipid signalling. Growing cells on media containing 100 mM NaCI increased their salt-tolerance but did not affect the overall phospholipid content, except that levels of phosphatidylinositol phosphate (PIP) and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P-2] were reduced by one-third. When these NaCI-acclimated cells were treated with increasing concentrations of salt, the same lipid signalling path-ways as in non-acclimated cells were activated. This was witnessed as increases in phosphatidic acid (PA), lyso-phosphatidic acid (L-PA), diacylglycerol pyrophosphate (DGPP), Pl(4,5)P-2 and its isomer PI(3,5) P2. However, all dose-dependent responses were shifted to higher osmotic-stress levels, and the re-sponses were lower than in non-acclimated cells. When NaCI-acclimated cells were treated with other osmotica, such as KCI and sucrose, the same effects were found, illustrating that they were due to hyperosmotic rather than hyperionic acclimation. The results indicate that acclimation to moderate salt stress modifies stress perception and the activation of several downstream pathways.

• 出版日期2017-3