Premium
Some effects of humidity on the light reaction of photosynthesis in the lichens Cladonia impexa and Collema flaccidium
Author(s) -
SIGFRIDSSON BJÖRN
Publication year - 1980
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1980.tb02671.x
Subject(s) - relative humidity , photosynthesis , chlorophyll fluorescence , chlorophyll , chemistry , chlorophyll a , phycocyanin , photosystem i , photochemistry , botany , photosystem ii , biology , cyanobacteria , biochemistry , physics , meteorology , genetics , bacteria
Luminescence and fluorescence were measured at different relative humidities in the lichen Cladonia impexa Harm. Both parameters showed a constant value at relative humidities lower than 80%: thereafter they increased. Low relative humidity was found to decrease energy transfer from chlorophyll b to chlorophyll a. inhibit electron transport, lower electron holding capacity on the reduced side of photosystem two and impair far‐red‐induced afterglow, reflecting photophosphorylation. In Collema flaccidium Ach. Ach. energy transfer from the accessory pigments phycocyanin and phycoerythrin to chlorophyll a was only possible at high relative humidity. The results are interpreted as due to conformational changes caused by changed water content in the lichen.