Differential ozone sensitivity interferes with cadmium stress in poplar clones

Abstract

Information on plant responses to combined ozone and cadmium stresses are scarce and limited to herbaceous species. In this research, two poplar clones (I-214 and Eridano), differently sensitive to O 3 , were grown for 5 weeks in pots supplied with 0, 53.5, and 160.5 mg(Cd) kg -1 (soil d.m.) and then exposed to 15-d O 3 fumigation (0.06 mm 3 dm -3 , 5 h a day). The effects of the two stressors, alone or in combination, on Cd, Ca, Fe, and Zn accumulation in above-and below-ground organs, photosynthesis, leaf pigments, and accumulation of H 2 O 2 and NO were investigated. Cadmium induced a reduction in stomatal conductance and a significant accumulation of H 2 O 2 and NO in both clones and negatively affected the carotenoid content in I-214. Ozone, on the other hand, counteracted Cd accumulation in the above-ground organs and significantly increased the xanthophyll de-epoxidation state indicating photoinhibition in O 3 -treated plants. Surprisingly, O 3 alone or in combination with Cd decreased H 2 O 2 accumulation in I-214. The NO production was generally stimulated by Cd, whereas it decreased following O 3 exposure in I-214. The overall data indicate that Cd and O 3 induced clone specific responses. Moreover, when they were applied in combination, antagonistic rather than synergistic effects were observed.

Effects of high Zn and Pb concentrations onPhragmites australis(Cav.) Trin. Ex. Steudel: Photosynthetic performance and metal accumulation capacity under controlled conditions

“…Photosynthesis is known to be one of the most sensitive processes to heavy metals stress, since both light and dark photosynthetic reactions can be affected, directly or indirectly (Todeschini et al 2011;Castagna et al 2013;Zurek et al 2014). …”

Physiological effects of short acute UVB treatments in Chenopodium quinoa Willd

“…Chlorophyll and carotenoids were extracted and analyzed as reported by Castagna et al . 39 . Carotenoids included β-carotene, neoxanthin, lutein, violaxanthin, antheraxanthin and zeaxanthin.…”

Overexpression of bacterial γ‐glutamylcysteine synthetase mediates changes in cadmium influx, allocation and detoxification in poplar

“…However, the biomass of these herbaceous species is low, thus the total amount of Cd accumulated in the biomass is limited. Recently, Populus species have been proposed for phytoremediation because poplars are fast-growing woody plants with a large aboveground biomass and they are able to accumulate intermediate Cd concentrations in their aerial tissues (Peuke & Rennenberg, 2005;Merkle, 2006;Di Lonardo et al, 2011;Castagna et al, 2013;Luo et al, 2014).…”