Photoprotective Strategies in Mediterranean High-Mountain Grasslands

Diversity

Adrián Escudero¹  MaríaPilar Gómez-Serranillos²  Rosina Magaña Ugarte²  RosarioG. Gavilán² 

[1] Department of Biology and Geology, Physics and Inorganic Chemistry, Universidad Rey Juan Carlos, 28933 Móstoles, Spain;Department of Pharmacy, Pharmacognosy, and Botany, Faculty of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain;

关键词: mountain area;    chlorophyll;    xanthophyll cycle;    chlorophyll fluorescence;    photoprotection;    conservation;   

DOI  :  10.3390/d13030137

来源: DOAJ

【 摘 要 】

Albeit the remarkably high Ultraviolet B loads, high temperatures, and drought stress substantiate the need for efficient photoprotective strategies in Mediterranean high-mountain plants, these remain understudied. Considering the sensitivity of photosystems to extreme conditions, we evaluated an environmental gradient’s weight on the photoprotection of five high-mountain specialists from Central Spain. Diurnal and seasonal variations in chlorophyll, chlorophyll fluorescence, carotenoids, and xanthophylls in consecutive and climatically contrasting years were taken to evaluate the effect of the impending climate coarsening at the photosystem level. Our results revealed significant differences among species in the xanthophyll cycle functioning, acting either as a continuous photoprotective strategy enhancing photochemistry-steadiness; or prompted only to counteract the cumulative effects of atypically adverse conditions. The lutein cycle’s involvement is inferred from the high lutein content found in all species and elevations, acting as a sustained photoprotective strategy. These findings added to high de-epoxidation state (DEPS) and minor seasonal changes in the chlorophyll a/b ratio, infer the xanthophyll and Lutein cycles are crucial for upkeeping the photosystems’ optimal functioning in these plants heightening their photoprotective capacity during periods of more unfavorable conditions. Nevertheless, an atypically dry growing season’s detrimental effect infers the feasible surpassing of stress-thresholds and the precariousness of the communities’ functional diversity under climate change.

【 授权许可】

Unknown