Inhibition of electron flow around photosystem I in chloroplasts of Cd-treated maize plants is due to Cd-induced iron deficiency

Abstract

T. 1993. Inhibition of electron flow around photosystem I in chloroplasts of Cd-treated maize plants is due to Cd-indueed iron deficiency. Photosystem I activity of ehloroplasts isolated from 21 days old maize seedlings {Zeu mays L. ev. Hidosil) cultivated in a nutrient solution containing different concentrations of Cd (10, 20, 30 \i.M) was investigated. Cd markedly decreased ferredoxin(Fd)dependent NADP* photoreduetion, while it had no effect on electron transport from 2,6-diehlorophenolindophenol to methyl viologen, indicating that the metal interferred with electron transport on the reducing side of photosystem I. The decrease in electron transport correlated with a low Fd content, which in turn was correlated with a low Fe concentration, suggesting Cd-indueed Fe deficiency. In in vitro experiments direet Cd inhibition of Fd-dependent NADP* photoreduetion required much higher Cd coneentrations than those observed in Cd-treated plants.

Genetic Control of Cadmium Concentration in Soybean Seeds

“…Cd stress can affect enzyme activities [3,7], alter membrane permeability [6], and disrupt cell transport processes [8]. Cd stress can also disturb cellular redox control [9], damage the light-harvesting complex II [10] and photosystems I and II [11], and decrease carbon assimilation and chlorophyll content [12]. Soybean has long been a staple food for Asians, especially as soymilk, tofu, and oil [13].…”

Potential of Trichoderma spp. on Growth Promotion and Mitigating Cadmium Uptake in Rice Plant under the Metal Stress Ecosystem

“…Cadmium damages the photosynthetic apparatus (Sidlecka and Baszynsky, 1993), lowers chlorophyll content (Larsson et al, 1998), and inhibits the stomatal opening (Barcelo and Poschenrieder, 1990). With increase in metal contamination in Trichoderma non-treated treatment there was a significant reduction in chlorophyll content.…”

Chlorophyll a Fluorescence as a Probe of Heavy Metal Ion Toxicity in Plants

“…Cadmium inhibits Mn uptake (Hernandez et al, 1998) and frequently results in Fe deficiency (Wallace etal, 1992;Siedlecka and Baszynski, 1993;Siedlecka et al, 1997). The Cd mediated effects correlate well not to tissue Fe content, but to Chls (Lang et al, 1998).…”