Endomembrane Ca2+-ATPases play a significant rolein virus-induced adaptation to oxidative stress（文献编号：R2011-003）
Although the role of Ca2+ influx channels in oxidative stress signaling and cross-tolerance in plants is well established, little is known about the role of active Ca2+ efflux systems in this process. In our recent paper, we reported Potato Virus X (PVX)- induced acquired resistance to oxidative stress in Nicotiana benthamiana and showed the critical role of plasma membrane Ca2+/H+ exchangers in this process. The current study continues this research. Using biochemical and electrophysiological approaches, we reveal that both endomembrane P2A and P2B Ca2+-ATPases play significant roles in adaptive responses to oxidative stress by removing excessive Ca2+ from the cytosol, and that their functional expression is significantly altered in PVX-inoculated plants. These findings highlight the crucial role of Ca2+ efflux systems in acquired tolerance to oxidative stress and open up prospects for practical applications in agriculture, after in-depth comprehension of the fundamental mechanisms involved in common responses to environmental factors at the genomic, cellular and organismal levels.
Effect of known Ca2+-AT Pase blockers on light-induced Ca2+ flux kinetics after 20 min of UV-C treatment. Leaf mesophyll segments were pre-treated in either 5 μM TG (thapsigargin) or 50 μM CPA (cyclopiazonic acid) for 1–1.5 h prior to exposure to UV-C light. Net Ca2+ fluxes were measured 2 h after the end of UV treatment. These were compared with two controls: (1) no pretreatment/ no UV exposure (closed circles) and (2) no pre-treatment/20 min UV exposure (open squares). Mean ± SE (n = 4 to 7).