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Light and CO 2 responses of photosynthesis and chlorophyll fluorescence characteristics in bean plants after simulated acid rain
Author(s) -
Velikova Violeta,
Tsonev Tsonko,
Yordanov Ivan
Publication year - 1999
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 - 10.1034/j.1399-3054.1999.100111.x
Subject(s) - photosynthesis , chlorophyll fluorescence , quenching (fluorescence) , chemistry , compensation point , electron transport chain , chlorophyll , acid rain , chlorophyll a , stomatal conductance , carbon dioxide , fluorescence , botany , photochemistry , biophysics , horticulture , biology , biochemistry , transpiration , physics , organic chemistry , quantum mechanics
The effects of simulated acid rain on some chlorophyll fluorescence characteristics and photosynthetic gas exchange at different light intensities and CO 2 concentrations of bean plants were investigated. Measurements were carried out 3, 5 and 24 h after spraying. The results showed that a single acid rain (pH 1.8) treatment of bean plants reduced gas exchange, the maximal carboxylating efficiency and photochemical quenching. This treatment led also to increased CO 2 compensation point and non‐photochemical quenching and changed the shape of CO 2 and light curves of photosynthesis. Both stomatal and non‐stomatal factors contributed to the decreased photosynthetic rate, but their proportion changed with time of recovery of the photosynthetic ampparatus. Three hours after the treatment, the stomatal factors predominated in photosynthesis reduction, while during the next experimental period (5–24 h), mainly non‐stomatal factors determined the decreased photosynthetic rate. It is suggested that the effects observed in consequence of acid rain treatment could be due to an increased intracellular accumulation of H + and harmful ions contained in the cocktail. This probably led to impaired membrane permeability, enhancement of stroma acidity, uncoupled electron transport and insufficient accumulation of ATP and NADPH, which affected carbon metabolism.