几十年来,南极地衣一直被用作气候变化的指标,但只有少数物种被研究过。我们使用PAM荧光系统在自然和实验室条件下评估了fruticose地衣的光合性能。与适应太阳的俄罗斯石油公司相比。,北极星的光合性能表现出适应阴影的地衣特征,它的叶绿素荧光不会在没有雨的干燥天发生。为了了解其干燥-再水化反应,我们测量了在黎明和日光的平均光照强度以及自然小气候的干燥条件下,北极星的PSII光化学变化。有趣的是,日光和快速干燥条件下的样品显示Fv/Fm和rETRmax延迟降低,以及Y(II)和Y(NPQ)水平的增加。这些结果表明,北极星的光保护机制取决于阳光,并且随着干燥耐受性的提高而变得更加有效。Amplicon测序显示,北极星的主要光生物是非甾体,这在南极洲以前没有报道过。总的来说,这些来自野外和实验室的结果可以更好地了解南极地区适应阴影的地衣的特定生态生理反应。
Antarctic lichens have been used as indicators of climate change for decades, but only a few species have been studied. We assessed the photosynthetic performance of the fruticose lichen Cladonia borealis under natural and laboratory conditions using the PAM fluorescence system. Compared to that of sun-adapted Usnea sp., the photosynthetic performance of C. borealis exhibits shade-adapted lichen features, and its chlorophyll fluorescence does not occur during dry days without rain. To understand its desiccation-rehydration responses, we measured changes in the PSII photochemistry in C. borealis under the average light intensity of dawn light and daylight and the desiccating conditions of its natural microclimate. Interestingly, samples under daylight and rapid-desiccation conditions showed a delayed reduction in Fv\'/Fm\' and rETRmax, and an increase in Y(II) and Y(NPQ) levels. These results suggest that the photoprotective mechanism of C. borealis depends on sunlight and becomes more efficient with improved desiccation tolerance. Amplicon sequencing revealed that the major photobiont of C. borealis was Asterochloris irregularis, which has not been reported in Antarctica before. Collectively, these results from both field and laboratory could provide a better understanding of specific ecophysiological responses of shade-adapted lichens in the
Antarctic region.