caa a22 4500 606207732 CHVBK 20210128101018.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00425-015-2383-4 doi (NATIONALLICENCE)springer-10.1007/s00425-015-2383-4 Photoprotection related to xanthophyll cycle pigments in epiphytic orchids acclimated at different light microenvironments in two tropical dry forests of the Yucatan Peninsula, Mexico [Elektronische Daten] [Edilia de la Rosa-Manzano, José Andrade, Ernesto García-Mendoza, Gerhard Zotz, Casandra Reyes-García] Main conclusion : Epiphytic orchids from dry forests of Yucatán show considerable photoprotective plasticity during the dry season, which depends on leaf morphology and host tree deciduousness. Nocturnal retention of antheraxanthin and zeaxanthin was detected for the first time in epiphytic orchids. In tropical dry forests, epiphytes experience dramatic changes in light intensity: photosynthetic photon flux density may be up to an order of magnitude higher in the dry season compared to the wet season. To address the seasonal changes of xanthophyll cycle (XC) pigments and photosynthesis that occur throughout the year, leaves of five epiphytic orchid species were studied during the early dry, dry and wet seasons in a deciduous and a semi-deciduous tropical forests at two vertical strata on the host trees (3.5 and 1.5m height). Differences in XC pigment concentrations and photosynthesis (maximum quantum efficiency of photosystem II; F v/F m) were larger among seasons than between vertical strata in both forests. Antheraxanthin and zeaxanthin retention reflected the stressful conditions of the epiphytic microhabitat, and it is described here in epiphytes for the first time. During the dry season, both XC pigment concentrations and photosystem II heat dissipation of absorbed energy increased in orchids in the deciduous forest, while F v/F m and nocturnal acidification (ΔH+) decreased, clearly as a response to excessive light and drought. Concentrations of XC pigments were higher than those in orchids with similar leaf shape in semi-deciduous forest. There, only Encyclia nematocaulon and Lophiaris oerstedii showed somewhat reduced F v/F m. No changes in ΔH+ and F v/F m were detected in Cohniella ascendens throughout the year. This species, which commonly grows in forests with less open canopies, showed leaf tilting that diminished light interception. Light conditions in the uppermost parts of the canopy probably limit the distribution of epiphytic orchids and the retention of zeaxanthin can help to cope with light and drought stress in these forests during the dry season. Springer-Verlag Berlin Heidelberg, 2015 Carotenoids nationallicence Leaf morphology nationallicence Photoinhibition nationallicence Photosynthesis nationallicence Photosystem II heat dissipation nationallicence Xanthophyll cycle nationallicence de la Rosa-Manzano Edilia Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, A. C., Calle 43 Núm. 130, Colonia Chuburná de Hidalgo, 97200, Mérida, Yucatán, Mexico aut Andrade José Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, A. C., Calle 43 Núm. 130, Colonia Chuburná de Hidalgo, 97200, Mérida, Yucatán, Mexico aut García-Mendoza Ernesto Departamento de Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada, Km. 107 Carretera Tijuana-Ensenada, 22860, Ensenada, Baja California, Mexico aut Zotz Gerhard Functional Ecology Group, Institute of Biology and Environmental Sciences, University of Oldenburg, Box 2503, 26111, Oldenburg, Germany aut Reyes-García Casandra Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, A. C., Calle 43 Núm. 130, Colonia Chuburná de Hidalgo, 97200, Mérida, Yucatán, Mexico aut Planta Springer Berlin Heidelberg 242/6(2015-12-01), 1425-1438 0032-0935 242:6<1425 2015 242 425 https://doi.org/10.1007/s00425-015-2383-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00425-015-2383-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- de la Rosa-Manzano Edilia Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, A. C., Calle 43 Núm. 130, Colonia Chuburná de Hidalgo, 97200, Mérida, Yucatán, Mexico aut NATIONALLICENCE 700 1- Andrade José Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, A. C., Calle 43 Núm. 130, Colonia Chuburná de Hidalgo, 97200, Mérida, Yucatán, Mexico aut NATIONALLICENCE 700 1- García-Mendoza Ernesto Departamento de Oceanografía Biológica, Centro de Investigación Científica y de Educación Superior de Ensenada, Km. 107 Carretera Tijuana-Ensenada, 22860, Ensenada, Baja California, Mexico aut NATIONALLICENCE 700 1- Zotz Gerhard Functional Ecology Group, Institute of Biology and Environmental Sciences, University of Oldenburg, Box 2503, 26111, Oldenburg, Germany aut NATIONALLICENCE 700 1- Reyes-García Casandra Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, A. C., Calle 43 Núm. 130, Colonia Chuburná de Hidalgo, 97200, Mérida, Yucatán, Mexico aut NATIONALLICENCE 773 0- Planta Springer Berlin Heidelberg 242/6(2015-12-01), 1425-1438 0032-0935 242:6<1425 2015 242 425