Botanical Institute, Christian-Albrechts University of Kiel, Olshausenstraße 40, DE, 24098, Kiel, Germany.
Planta. 2018 Sep;248(3):601-612. doi: 10.1007/s00425-018-2925-7. Epub 2018 May 30.
Desiccation-induced chlorophyll fluorescence quenching seems to be an indispensable part of desiccation resistance in the surveyed 28 green microalgal species. Lichens are desiccation tolerant meta-organisms. In the desiccated state photosynthesis is inhibited rendering the photobionts potentially sensitive to photoinhibition. As a photoprotective mechanism, strong non-radiative dissipation of absorbed light leading to quenching of chlorophyll fluorescence has been proposed. Desiccation-induced quenching affects not only variable fluorescence, but also the so-called basal fluorescence, F. This phenomenon is well-known for intact lichens and some free living aero-terrestrial algae, but it was often absent in isolated lichen algae. Therefore, a thorough screening for the appearance of desiccation-induced quenching was undertaken with 13 different aero-terrestrial microalgal species and lichen photobionts. They were compared with 15 aquatic green microalgal species, among them also three marine species. We asked the following questions: Do isolated lichen algae show desiccation-induced quenching? Are aero-terrestrial algae different in this respect to aquatic algae and is the potential for desiccation-induced quenching coupled to desiccation tolerance? How variable is desiccation-induced quenching among species? Most of the aero-terrestrial algae, including all lichen photobionts, showed desiccation-induced quenching, although highly variable in extent, whereas most of the aquatic algae did not. All algae displaying quenching were also desiccation tolerant, whereas all algae unable to perform desiccation-induced quenching were desiccation intolerant. Desiccation-induced fluorescence quenching seems to be an indispensable part of desiccation resistance in the investigated species.
脱水诱导的叶绿素荧光猝灭似乎是在调查的 28 种绿色微藻中抗脱水能力的一个不可或缺的部分。地衣是耐干燥的超有机体。在干燥状态下，光合作用受到抑制，使共生藻潜在地容易受到光抑制。作为一种光保护机制，强烈的非辐射吸收光的耗散导致叶绿素荧光猝灭已经被提出。脱水诱导的猝灭不仅影响可变荧光，而且影响所谓的基础荧光，F。这种现象在地衣和一些自由生活的气生陆地藻类中是众所周知的，但在分离的地衣藻类中经常不存在。因此，对 13 种不同的气生陆地微藻和地衣共生藻进行了彻底的筛选，以观察脱水诱导的猝灭现象。它们与 15 种水生绿色微藻进行了比较，其中包括三种海洋物种。我们提出了以下问题：分离的地衣藻类是否表现出脱水诱导的猝灭？气生藻类在这方面与水生藻类有何不同，脱水诱导的猝灭的潜力是否与抗干燥能力有关？在物种间，脱水诱导的猝灭的变异性如何？大多数气生藻类，包括所有的地衣共生藻，都表现出脱水诱导的猝灭，尽管在程度上有很大的差异，而大多数水生藻类则没有。所有显示猝灭的藻类都是抗干燥的，而所有不能进行脱水诱导猝灭的藻类都是不耐干燥的。脱水诱导的荧光猝灭似乎是在所研究的物种中抗干燥能力的一个不可或缺的部分。
