Abstract Detail



Ecophysiology

Ekwealor, Jenna [1], Clark, Theresa [2], Dautermann, Oliver [3], Russel, Alexander [2], Ebrahimi, Sotodeh [2], Stark, Llo [2], Niyogi, Krishna [4], Mishler, Brent [5].

The photosynthetic effects of Mojave Desert sun on Syntrichia caninervis.

Desert mosses withstand intense sunlight while desiccated and metabolically inactive. We used in situ field experiments to uncover the effects of natural and reduced levels of UV radiation on maximum Photosystem II (PSII) quantum efficiency (Fv/Fm) and on the relative abundance of photosynthetic pigments and antioxidants in Syntrichia caninervis. We tested the hypothesis that if UV is a stressor, reduction of natural UV levels will result in increased photosynthetic efficiency, but that such reduction will de-harden plants and increase vulnerability to PSII damage with UV exposure. We also measured photosynthetic efficiency over a simulated winter recovery period to assess sustained non-photochemical quenching (NPQ) and its subsequent relaxation. Finally, we measured the effect of UV reduction on photosynthetic pigment and antioxidant abundance. All field-collected plants had low (Fv/Fm) at collection but recovered over eight days in winter conditions. Plants in the low-UV treatment had lower (Fv/Fm) during recovery than those exposed to natural UV levels and had higher zeaxanthin, lutein, tocopherols, and a higher ratio of chlorophyll a to chlorophyll b. Natural S. caninervisundergoes sustained NPQ that takes days to relax and for efficient photosynthesis to resume. Reduction of UV radiation from sunlight has adverse effects on recovery of (Fv/Fm).


1 - University of California, Berkeley, University and Jepson Herbaria andDepartment of Integrative Biology, 1001 Valley Life Sciences Bldg., #2465, Berkeley, CA, 94720, USA
2 - University of Nevada, Las Vegas, School of Life Sciences, Las Vegas, NV, USA
3 - University of California, Berkeley, Plant and Microbial Biology, Berkeley, CA, 94720, USA
4 - University of California, Berkeleyversity of Nevada, Las Vegas, Plant and Microbial Biology, Berkeley, CA, USA
5 - University of California, Berkeley, University and Jepson Herbaria andDepartment of Integrative Biology, 1001 Valley Life Sciences Bldg, #2465, Berkeley, CA, 94720, USA

Keywords:
none specified

Presentation Type: Oral Paper
Session: ECOPH2, Ecophysiology II
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 1:30 PM
Number: ECOPH2003
Abstract ID:333
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize,Physiological Section Best Paper Presentation


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