The effect of abscisic acid on chlorophyll fluorescence in lichens under extreme water regimes |
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Authors: | S DIETZ & W HARTUNG |
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Institution: | Julius-von-Sachs-Institut für Biowissenschaften, Lehrstuhl für Botanik I, Julius von Sachs Platz 2, D-97082 Würzburg, Germany; Author for correspondence (fax +49 931 8886158;e-mail;). |
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Abstract: | Chlorophyll fluorescence measurements were used to test whether externally applied abscisic acid (ABA) has an effect on the desiccation tolerance of lichens and their sensitivity to constant water saturation. A surplus of ABA did not decrease the time required to regain full photosynthetic capacity after prolonged dry periods. However, an effect of ABA could be observed when lichens were permanently hydrated at moderately high temperatures. Lichens suffered less from constant saturation if ABA was added to the incubation medium. These results suggest a positive effect of ABA on membrane function. |
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Keywords: | abscisic acid ABA chlorophyll fluorescence constant water saturation desiccation tolerance lichens |
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