Screening of Poplar Clones for Cadmium Phytoremediation Using Photosynthesis, Biomass and Cadmium Content Analyses

Abstract

Variability of cadmium tolerance and distribution in plant organs was investigated in ten selected poplar clones from different species, hybrids and genotypes. To this end, plants were exposed for three weeks to 50 microM CdSO4 in hydroponics. Cadmium accumulation in roots, stem and leaves as well as biomass production and photosynthesis maintenance varied greatly among clones. The metal mostly accumulated in roots, up to 80% in some clones, and interestingly, only 50% in some others. In general, metal tolerance reflected the degree of photosynthesis inhibition, which was higher in clones with high cadmium accumulation in leaves. Biomass production, net photosynthesis, transpiration, and pigment content were differently reduced in cadmium-treated clones with respect to control. The variability of cadmium distribution among leaves, stem, and roots provides candidate poplars for specific phytoremediation processes of contaminated waters and soils.

Mapping Cadmium distribution in roots of Salicaceae through scanning electron microscopy with x-ray microanalysis

“…Overall, all the selected clones analyzed in the present experiment showed a considerable potential for Cd uptake in roots. This ability is in agreement with previous results ob tained in companion studies (Zacchini et al 2009, Pietrini et al 2010.…”

“…The relative humidity was 60-70%. Experimental details can be found in Zacchini et al (2009) and Pietrini et al (2010).…”

“…Phytoextrac tion potential of a clone is primarily deter mined by metal concentration and by bio mass production (Laureysens et al 2005). The variability of Cd distribution among leaves, stem, and roots provides candidate Salicaceae for specific phytoremediation processes of contaminated waters and soils (Pietrini et al 2010). Considering the impact of Cd on Salicaceae rooting, Lunácková et al (2003) observed seriously damaged root parts, apex, rhizodermis and cortex, while the structure of central cylinder remained un changed following treatment, showing resi stance of root apical meristem and accumula tion of darkly stained material around the central cylinder.…”

A quick screening to assess the phytoextraction potential of cadmium and copper in Quercus pubescens plantlets

“…Cadmium has a strong carcinogenic potential (García-Esquinas et al 2014) and is also very toxic for plants, affecting water and nutrient uptake, as well as their photosynthetic efficiency (Pietrini et al 2010). Copper (Cu) is a microelement essential for plant growth, though it may become potentially toxic at elevated levels, particularly as a result of agricultural practices, and industrial or municipal waste disposal on land (Ali et al 2004).…”

“…The plant capacity to tolerate metals can rely on a variety of resistance and tolerance mechanisms (Pietrini et al 2010, Wang et al 2014. Plants have evolved avoidance strategies or exclusion processes, which reduce metal accumulation in cells, as well as mechanisms of surviving despite the accumulation of large amounts of metals (Rascio & Navari-Izzo 2011).…”