Phytoremediation capacity of poplar (Populus spp.) and willow (Salix spp.) clonesin relation to photosynthesis

Abstract

Good photosynthetic features and a favorable water regimes of woody plants improve their survival and remediation potential under unfavorable ecological conditions. Accordingly, we here present results of testing plant tolerance of Pb, Cd, Ni, and diesel fuel based on gas exchange parameters and WUE of four poplar and two willow clones grown in a greenhouse on soil culture. Photosynthesis and transpiration of plants grown on soils with individually applied heavy metals decreased significantly, but this was less obvious in the case of Cd treatment. A heavy metal mixture in the soil induced significant reduction in photosynthesis (by more than 50%). Diesel fuel as the only pollutant in soil caused very strong and significant inhibition of photosynthesis and transpiration of willow clones. The results indicate genotypic specificity of all investigated physiological parameters and mark poplar clones as very useful in phytoextraction technology for the bio-cleaning of chemically polluted soils

Gas exchange responses of two poplar clones (Populus euramericana (Dode) Guinier 561/41 and Populus nigra Linnaeus 63/135) to lead toxicity

“…In contrast, at all Pb treatments, C i of the two poplars remained constant. Similarly, Pajević et al (2009) showed that A and E were significantly decreased in most of the Populus and Salix clones exposed to Pb, Cd, Ni. In addition, the reduction of A, E, g s in different poplar clones under heavy metal stress has been reported by Gu et al (2007), Pietrini et al (2010), and Chandra and Kang (2015).…”

“…The analysis of physiological parameters of woody species is valuable in order to choose genotypes suitable for phytoremediation programs (Pajević et al 2009). On the one hand, physiological responses of A -photosynthetic rate, E -transpiration rate, g s -stomatal conductance, C i -intercellular CO 2 concentration, LWP -leaf water potential, WUE -water use efficiency, g m -mesophyll conductance, **P < 0.01, ns -not significant plants to contaminated soils are a way to evaluate the plant tolerance to heavy metals (Borghi et al 2008), and on the other hand, the high toxicity of heavy metals to overall plant metabolism results in the inhibition of photosynthesis (Pajević et al 2009).…”

“…On the one hand, physiological responses of A -photosynthetic rate, E -transpiration rate, g s -stomatal conductance, C i -intercellular CO 2 concentration, LWP -leaf water potential, WUE -water use efficiency, g m -mesophyll conductance, **P < 0.01, ns -not significant plants to contaminated soils are a way to evaluate the plant tolerance to heavy metals (Borghi et al 2008), and on the other hand, the high toxicity of heavy metals to overall plant metabolism results in the inhibition of photosynthesis (Pajević et al 2009). Also, heavy metal uptake and translocation from roots to aerial parts of plants are controlled by the transpiration process (Adriaensen et al 2003).…”

“…Leaf water potential (LWP) was determined with Plant Moisture Vessel SKPM 1400 (Skye Instruments, Ltd., Powys, UK) using the pressure chamber apparatus (Turnau 1998). WUE was calculated as the ratio of A to E (Pajević et al 2009). Mesophyll conductance (g m ) was defined as the ratio of A to C i (Bernardini et al 2015).…”

“…For example, Kalaji and Loboda (2007) and Han et al (2013) reported that photosynthesis inhibition is a well-recognized symptom of Pb toxicity. In addition, Pajević et al (2009) demonstrated that photosynthesis and transpiration in most of the studied Populus Linnaeus and Salix Linnaeus clones exposed to Pb, Cd and Ni decreased significantly. Also, the decline in gas exchange parameters of different poplar clones in response to heavy metal stress has been shown by Gu et al (2007), Pietrini et al (2010), and Chandra and Kang (2015).…”