Natural ultraviolet radiation exposure alters photosynthetic biology and improves recovery from desiccation in a desert moss.

Autor:	Ekwealor JTB; Department of Integrative Biology, and University and Jepson Herbaria, University of California, Berkeley, CA, USA., Clark TA; School of Life Sciences, University of Nevada, Las Vegas, NV, USA., Dautermann O; Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA., Russell A; School of Life Sciences, University of Nevada, Las Vegas, NV, USA., Ebrahimi S; School of Life Sciences, University of Nevada, Las Vegas, NV, USA., Stark LR; School of Life Sciences, University of Nevada, Las Vegas, NV, USA., Niyogi KK; Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.; Howard Hughes Medical Institute, University of California, Berkeley, CA, USA.; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA., Mishler BD; Department of Integrative Biology, and University and Jepson Herbaria, University of California, Berkeley, CA, USA.
Jazyk:	angličtina
Zdroj:	Journal of experimental botany [J Exp Bot] 2021 May 18; Vol. 72 (11), pp. 4161-4179.
DOI:	10.1093/jxb/erab051
Abstrakt:	Plants in dryland ecosystems experience extreme daily and seasonal fluctuations in light, temperature, and water availability. We used an in situ field experiment to uncover the effects of natural and reduced levels of ultraviolet radiation (UV) on maximum PSII quantum efficiency (Fv/Fm), relative abundance of photosynthetic pigments and antioxidants, and the transcriptome in the desiccation-tolerant desert moss Syntrichia caninervis. We tested the hypotheses that: (i) S. caninervis plants undergo sustained thermal quenching of light [non-photochemical quenching (NPQ)] while desiccated and after rehydration; (ii) a reduction of UV will result in improved recovery of Fv/Fm; but (iii) 1 year of UV removal will de-harden plants and increase vulnerability to UV damage, indicated by a reduction in Fv/Fm. All field-collected plants had extremely low Fv/Fm after initial rehydration but recovered over 8 d in lab-simulated winter conditions. UV-filtered plants had lower Fv/Fm during recovery, higher concentrations of photoprotective pigments and antioxidants such as zeaxanthin and tocopherols, and lower concentrations of neoxanthin and Chl b than plants exposed to near natural UV levels. Field-grown S. caninervis underwent sustained NPQ that took days to relax and for efficient photosynthesis to resume. Reduction of solar UV radiation adversely affected recovery of Fv/Fm following rehydration. (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
Databáze:	MEDLINE
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