Effects of sulfur nutrition on photosynthesis in cadmium‐treated barley seedlings

Abstract

The effects of sulfur (S) nutrition at 0.1 or 1 mM S on cadmium (Cd) toxicity measured by photosynthesis in barley (Hordeum vulgare L. cv. UC 476) seedlings were studied. Eight-day-old seedlings were treated with 25 µM Cd by adding cadmium chloride (CdCl 2 ) to the nutrient solution. Then photosynthetic carboxylation efficiency (ACi curve) and stomatal conductance of the primary and second leaves were measured at four and eight days after Cd treatment. Fluorescence parameters were measured every 24 h for eight days after two days of Cd treatment. At 20 days, plant growth parameters were measured and dry biomass determined. The results showed that ACi was significantly reduced by Cd, but more in the low (0.1 mM) S than in the high (1 mM) S-treated plants. Stomatal conductance of plants was also decreased by Cd, but more in the low S-treated plants. Low S-treated plants exposed to Cd showed an increase in Fo and Fq, and a decrease in Fv/Fm and T 1/2 , indicating photoinhibitory damage to PSII. Analysis of the growth parameters showed that Cd decreased plant size and biomass, but the reduction 1 Corresponding author. 845 Copyright © 1997 by Marcel Dekker, Inc. Downloaded by [University of Nebraska, Lincoln] at 23:38 22 August 2015 846 CHEN AND HUERTAwas more severe in the low S-treated plants. These results support the hypothesis that S is a critical nutritional factor in plants which is important for the reduction of Cd toxicity.Abbreviations: Fo, Fv, and Fm = steady state, variable, and maximal variable fluorescence; Fv/Fm = photochemical fluorescence capacity of PSII; Fq = fluorescence quenching capacity; % t = stomatal conductance; PSII = photosystem II; T I/2 = half-time for fluorescence rise from Fo to Fm.

Effects of silicon nutrition on cadmium uptake, growth and photosynthesis of rice plants exposed to low-level cadmium

“…attained their g smax values when the value of C i was close or similar to what is expected under normal growth conditions (Chen and Huerta 1997).…”

“…Cadmium-induced inhibition of growth has also been demonstrated to result from the accumulation of storage products at the expense of cell growth and elongation (Moya et al 1995;Verma and Dubey 2001). Furthermore, Chen and Huerta (1997) suggested that Cd-induced growth inhibition is due to an inhibition of photosynthesis. Thus, based on our results we suggest that the inhibition of growth due to low-level Cd-stress is most likely coupled to a reduction in photosynthesis (Figs.…”

Effects of sulfur nutrition on the growth and photosynthesis of rice

“…Reduced photosynthesis under sulfur-deficient conditions was observed in barley (Karmaker et al 1991;Chen and Huerta 1997), rapeseed (Leoncini et al 1997), spinach (Dietz and Heilos 1990), soybean (Sexton et al 1997), and tomato (Xu et al 1996). S deprivation decreased the CO 2 assimilation rates in all the leaves of young wheat seedlings (Gilbert et al 1997).…”

Influence of nitrate fertilization on Cd uptake and oxidative stress parameters in alfalfa plants cultivated in presence of Cd

“…Cadmium-induced growth reduction might be explained on the basis of inhibition of carbon fixation due to a decrease in photosynthetic rate and chlorophyll content (Hattab et al, 2009). Cadmium in soils could induce water stress in plants by decreasing stomatal conductance and transpiration (Chen and Huerta 1997).…”