Bürling Kathrin, Ducruet Jean-Marc, Cornic Gabriel, Hunsche Mauricio, Cerovic Zoran G
Chamber of Agriculture of the State of North Rhine-Westphalia, Siebengebirgsstraße 200, D-53229 Bonn, Germany; University of Bonn, Institute of Crop Science and Resource Conservation - Horticultural Science, Auf dem Huegel 6, D-53121 Bonn, Germany.
CNRS, Laboratoire Écologie, Systématique et Évolution, UMR 8079, Bât. 362, Orsay, Université Paris-Sud, 91405 Orsay, AgroParisTech, Paris 75231, France.
Plant Sci. 2014 Jun;223:116-23. doi: 10.1016/j.plantsci.2014.03.013. Epub 2014 Mar 21.
Thermoluminescence emission from wheat leaves was recorded under various controlled drought stress conditions: (i) fast dehydration (few hours) of excised leaves in the dark (ii) slow dehydration (several days) obtained by withholding watering of plants under a day/night cycle (iii) overnight rehydration of the slowly dehydrated plants at a stage of severe dessication. In fast dehydrated leaves, the AG band intensity was unchanged but its position was shifted to lower temperatures, indicating an activation of cyclic and chlororespiratory pathways in darkness, without any increase of their overall electron transfer capacity. By contrast, after a slow dehydration the AG intensity was strongly increased whereas its position was almost unchanged, indicating respectively that the capacity of cyclic pathways was enhanced but that they remained inactivated in darkness. Under more severe dehydration, the AG band almost disappeared. Rewatering caused its rapid bounce significantly above the control level. No significant differences in AG emission could be found between the two drought-sensitive and drought-tolerant wheat cultivars. The afterglow thermoluminescence emission in leaves provides an additional tool to follow the increased capacity and activation of cyclic electron flow around PSI in leaves during mild, severe dehydration and after rehydration.
(i) 在黑暗中对离体叶片进行快速脱水（数小时）；(ii) 通过在昼夜循环下停止给植物浇水实现缓慢脱水（数天）；(iii) 在严重干燥阶段对缓慢脱水的植物进行过夜复水。在快速脱水的叶片中，AG带强度不变但其位置向较低温度偏移，表明在黑暗中循环途径和叶绿体呼吸途径被激活，但其整体电子传递能力没有增加。相比之下，缓慢脱水后AG强度强烈增加而其位置几乎不变，分别表明循环途径的能力增强但它们在黑暗中仍处于失活状态。在更严重的脱水条件下，AG带几乎消失。复水导致其迅速反弹至显著高于对照水平。在两个对干旱敏感和耐旱的小麦品种之间未发现AG发射有显著差异。叶片中的余辉热发光发射提供了一种额外的工具，用于跟踪在轻度、重度脱水及复水期间叶片中围绕PSI的循环电子流能力的增加和激活情况。
