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Water Status of Green and Blue‐green Phycobionts in Lichen Thalli after Hydration by Water Vapor Uptake: Do They Become Turgid?
Author(s) -
Büdel B.,
Lange O. L.
Publication year - 1991
Publication title -
botanica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 0932-8629
DOI - 10.1111/j.1438-8677.1991.tb00242.x
Subject(s) - thallus , lichen , water vapor , nostoc , botany , algae , humidity , chemistry , environmental science , environmental chemistry , biology , cyanobacteria , physics , genetics , organic chemistry , bacteria , thermodynamics
Abstract It is known from previous investigations that dry lichens with green algae are able to recover net photosynthesis through rehydration with water vapor, whereas all blue‐green lichens tested so far lack this ability. The REM micrographs of the present study show that the green phycobionts ( Trebouxia spec.) of Ramalina maciformis become turgid only after water vapor uptake. In contrast, the blue‐green phycobionts ( Nostoc spec.) of Peltigera rufescens do not differ in appearance from the dry state, even when the thallus has reached equilibrium with the water vapor‐saturated air; they require liquid water for turgidity. It is hypothesized that, after humidity hydration, water content is not sufficient for reestablishment of a functioning osmotic cell system in the blue‐green phycobiont.