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Effects of SO 2 on Photosynthesis and Nitrogen Fixation
Author(s) -
HÄLLGREN JANERIK,
HUSS KERSTIN
Publication year - 1975
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.1399-3054.1975.tb03815.x
Subject(s) - photosynthesis , nitrogen fixation , nitrogenase , nitrogen , botany , chemistry , photosynthetic capacity , biology , organic chemistry
Responses of photosynthesis and nitrogen fixation to NaHSO 3 (10 −5 −5 × 10 −3 M ) were investigated in the lichen Stereocaulon paschale (L.) Fr. and the blue‐green alga Anabaena cylindrica Lemmermann. The treatments were performed in buffered media with varying pH (5.8–8.1) and light conditions (0–32 W × m −2 ). The activities of the intact organisms were investigated, under the same environmental conditions, with 14 C liquid scintillation and acetylene reduction techniques respectively. The nitrogen fixation proved to be more susceptible than photosynthesis, in both organisms, and in all cases treatments at pH 5.8 were more inhibitory than at higher pH‐values. Treatment with 5 × 10 −4 M NaHSO 3 at pH 5.8 caused no reduction of photosynthesis in S. paschale , while the inhibition of nitrogen fixation was 97%. For A. cylindrica the corresponding values were 40% and 75% respectively. Short‐time treatments of A. cylindrica showed that the nitrogen fixation was more rapidly affected than photosynthesis. The inhibition of nitrogenase activity and CO 2 ‐fixation was smaller in the dark and increased at higher light intensities. Both processes showed a good capacity for recovery after removal of the NaHSO 3 solution. Also the clumping ability of A. cylindrica was disturbed by NaHSO 3 treatments.