In the past Aster tripolium has already proved to be a good candidate for saline agriculture in soils with low water availability. Thus, the aim of the present work was to disentangle the photobiological and biochemical mechanisms underlying the response of A. tripolium to PEG-induced drought stress, by exposing plants to PEG-induced moderate and severe drought conditions. Plant primary productivity was maintained under moderate drought conditions, due to the presence of alternative electron donors fueling the PSII. Additionally, the high anthocyanin production under drought conditions, act as photoprotective shields against photoinhibition. Moreover, the increased quinone turnover rate simultaneously with a net rate of RC closure and density increase, acted as a counteractive measure, allowing high energy fluxes into the photosystems under drought conditions. PSI showed an activity reduction, indicating that under drought conditions the ETC activity acts as an energetic escape route. Furthermore, membrane remodeling could also be observed under drought. The total fatty acid and omega-3 linolenic acid (18:3) contents were maintained, under osmotic stress. Membrane restructuring with lower amounts of polyunsaturated fatty acids (18:3) is considered an adaptation to osmotically stressful environments. Increased 18:1 and 16:1t fatty acids production improve the LHCs and chloroplast membrane stabilization, allowing the LHC to maintain its efficient functioning. The results here presented are very similar to the ones observed in the past regarding A. tripolium feedback to salinity stress, indicating that the mechanisms to overcome osmotic stress, either due to increased salinity or reduced water availability, are the same.

过去，Aster雷公藤已被证明是水分利用率低的土壤中盐分农业的良好候选者。因此，本研究的目的是弄清三叶草响应的光生物学和生化机制。使植物暴露于PEG诱导的中度和重度干旱条件下，可抵抗PEG诱导的干旱胁迫。由于存在替代电子供体，为PSII提供燃料，因此在中等干旱条件下保持了植物的初级生产力。另外，干旱条件下高的花色苷产量可作为防止光抑制的光防护罩。此外，增加的醌转化率与RC封闭的净速率和密度的增加同时作为一种反作用措施，在干旱条件下允许高能量通量进入光系统。PSI显示出活性降低，表明在干旱条件下，ETC活性充当了能量的逃逸路线。此外，在干旱下也可以观察到膜重塑。总脂肪酸和omega-3亚麻酸（18：3）在渗透压下保持内容物。用较少量的多不饱和脂肪酸（18：3）进行膜重组被认为是对渗透压环境的适应。增加18：1和16：1吨脂肪酸生产改善LHCs和叶绿体膜稳定，从而允许LHC保持其有效运作。此处给出的结果与过去关于曲霉对盐分胁迫的反馈所观察到的结果非常相似，表明克服由于盐分增加或水利用率降低而引起的渗透胁迫的机理是相同的。