Aerial microalga Trentepohlia jolithus is frequently exposed to drying and rewetting cycles. To characterize the adaptive mechanisms allowing survivability of this aerial microalga, the responses of photosynthetic characteristics and photoprotective mechanisms to moderate desiccation (80% and 60% relative air humidity) and severe desiccation (40% relative air humidity) were investigated in T. jolithus grown at 95% relative air humidity. Additionally, the recovery of photosynthetic performance in severe desiccated T. jolithus was monitored after rehydration. In T. jolithus, non-photochemical quenching (NPQ) decreased gradually as the relative air humidity decreased from 95% to 40%, but the actual photochemical efficiency of photosystem II (Φ_PSII) remained unchanged until the relative air humidity decreased to 40% under high light, indicating that the photoprotective mechanism NPQ was more sensitive to desiccation than photosynthetic linear electron flow. NPQ was maximally induced even under low light during moderate and severe desiccation. Under high light, excess excitation energy would not be well dissipated by NPQ in the desiccated state. However, a fraction of reaction centers were reversibly down-regulated during moderate and severe desiccation under high light. Inactive reaction centers well protected desiccated T. jolithus against photoinhibition by dissipating excess excitation energy as heat. The linear electron flow was inhibited significantly under severe desiccation. However, activated key Calvin cycle enzymes in severe desiccated T. jolithus promoted the surprisingly rapid recovery of linear electron flow after rehydration. The rapid reaction center recovery of severe desiccated T. jolithus might also favor the fast recovery of linear electron flow after rehydration. Therefore, the reversible down-regulation of reaction centers during desiccation, the maintenance of linear electron flow during moderate desiccation, and the rapid recovery of linear electron flow of severe desiccated algal cells after rehydration might be special adaptive mechanisms that allow T. jolithus to survive in an environment with rapidly changing water availability.

空中微藻Trentepohlia jolithus经常处于干燥和重新润湿的循环中。为了表征适应机制允许该天线微藻生存能力，光合特性和光保护机制的响应到中度干燥（80％和60％的相对空气湿度）和重度干燥（40％的相对空气湿度）中进行了研究Ť。jolithus在95％的相对空气湿度下生长。另外，在严重干燥的T中光合性能的恢复。补液后监测石。在T中。约利苏斯，随着相对空气湿度从95％降低到40％，非光化学猝灭（NPQ）逐渐降低，但是光系统II（_ΦPSII）的实际光化学效率保持不变，直到在强光下相对空气湿度降低到40％为止，表明光保护机制NPQ比光合作用线性电子流对干燥更敏感。在中度和严重干燥期间，即使在弱光下也能最大程度地诱导NPQ。在强光下，干燥状态下的NPQ无法很好地消散多余的激发能量。然而，在强光下中度和重度干燥期间，一部分反应中心可逆地下调。非活性反应中心很好的保护干燥的牛逼。约利苏斯通过消散多余的激发能作为热量来防止光抑制。在严重干燥下，线性电子流被显着抑制。但是，严重脱水的T中激活了关键的Calvin循环酶。补液后，jolithus促进了线性电子流的快速恢复。重度干燥T的反应中心快速恢复。约利苏斯也可能有利于补液后线性电子流的快速恢复。因此，脱水过程中反应中心的可逆下调，适度脱水过程中线性电子流的维持以及重度脱水后重度干燥藻类细胞线性电子流的快速恢复可能是允许T的特殊适应机制。jolithus能够在水供应迅速变化的环境中生存。