n nnnLand plants are prone to strong thermal variations and musttherefore sense early moderate temperature increments to induceappropriate cellular defenses, such as molecular chaperones,in anticipation of upcoming noxious temperatures. To investigatehow plants perceive mild changes in ambient temperature, wemonitored in recombinant lines of the moss Physcomitrella patensthe activation of a heat-inducible promoter, the integrity ofa thermolabile enzyme, and the fluctuations of cytoplasmic calcium.Mild temperature increments, or isothermal treatments with membranefluidizers or Hsp90 inhibitors, induced a heat shock response(HSR) that critically depended on a preceding Ca2+ transientthrough the plasma membrane. Electrophysiological experimentsrevealed the presence of a Ca2+-permeable channel in the plasmamembrane that is transiently activated by mild temperature incrementsor chemical perturbations of membrane fluidity. The amplitudeof the Ca2+ influx during the first minutes of a temperaturestress modulated the intensity of the HSR, and Ca2+ channelblockers prevented HSR and the onset of thermotolerance. Ourdata suggest that early sensing of mild temperature incrementsoccurs at the plasma membrane of plant cells independently fromcytosolic protein unfolding. The heat signal is translated intoan effective HSR by way of a specific membrane-regulated Ca2+influx, leading to thermotolerance.展开▼
机译:ABSTRACTn FONT> TH> TR> TABLE> n
n TOP n <字体颜色= 464c53>抽象 FONT> n 介绍 n 结果 n 讨论 n 方法 n 参考文献 n FONT> TH> TR> TABLE> n nnn陆地植物容易发生强烈的热变化,因此必须 SUP>可以感觉到早期适度的温度升高,从而预期即将出现的有害温度,从而诱导 SUP>适当的细胞防御,例如分子伴侣, SUP>。为了调查 SUP>植物如何感知环境温度的轻微变化,我们 SUP>在苔藓
Department of Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH1015, Switzerland|Department of Biology, University of York, York YO10 5DD, United Kingdom;
Department of Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH1015, Switzerland;
Department of Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH1015, Switzerland;
Hadassah Hebrew University, School of Medicine, Hebrew University of Jerusalem, Jerusalem il-91120, Israel;
Hadassah Hebrew University, School of Medicine, Hebrew University of Jerusalem, Jerusalem il-91120, Israel|University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania 19104–2646;
Department of Biology, University of York, York YO10 5DD, United Kingdom;
Department of Plant Molecular Biology, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH1015, Switzerland;