Anatomical characteristics and nutrient uptake and distribution associated with the Cd-phytoremediation capacity of Eucalyptus camaldulenses Dehnh

Abstract

Cadmium (Cd) is a hazardous heavy metal whose concentrations have been increasing in Brazilian soils, largely due to mining activities. Eucalyptus species are widely planted in Brazil to produce raw materials, and the confirmation of their phytoremediation potential would link their economic and environmental roles. We examined the Cd-tolerance of Eucaliptus camaldulenses Dehnh and the anatomical and physiological features associated with that capacity. Plants were grown under greenhouse conditions in nutrient solutions with increasing concentrations of Cd (0, 15, 25, 45, 90 μmol m -3 ). Shoot biomass production was less sensitive to the phytotoxic effects of cadmium than root biomass production due to low Cd transport rates from roots to shoots. Increases in epidermal and endodermal thickness, changes in the vascular conductive elements of the roots, as well as differential nutrient distributions between roots and shoots are features of Cd tolerance in this species. The Cd tolerance of E. camaldulenses and its high biomass production support its potential use in Cd phytoremediation programs.

Analysis of biometric, physiological, and biochemical traits to evaluate the cadmium phytoremediation ability of eucalypt plants under hydroponics

“…In fact, in plant-based water decontamination systems the root biomass can be totally harvested, thus removing the absorbed metal. The accumulation of Cd in the roots of eucalypt plants is in agreement with findings by Gomes et al (2012) and Fine et al (2013).…”

“…6). Consistent with the limited literature present on the matter (Gomes et al 2012, Fine et al 2013), the two clones showed a low capability to translocate Cd in the aerial parts, and no differences were observed between the clones with respect to this physiological process.…”

“…Among the physiological processes associated with heavy metal tolerance in plants, the restriction of metal transport to the aerial parts has been highlighted in non hyperaccumulating plants (Lux et al 2004, Gomes et al 2012, Iori et al 2013. In fact, in leaves, Cd represents a very toxic agent, as it severely interferes with the photosynthetic processes (Pietrini et al 2005).…”

Assessment of physiological and biochemical responses, metal tolerance and accumulation in two eucalypt hybrid clones for phytoremediation of cadmium-contaminated waters

“…In plants, cadmium (Cd) exposure affects several morphological and physiological processes, altering water balance, nitrogen metabolic activities, and nutrient uptake and distribution (Dal Corso et al, 2010;Diwan et al, 2010;Gomes et al, 2012). Cadmium can also interact with photosynthesis by competing for root absorption with other metals (i.e., Mg, Fe, Mn, Zn) that are important cofactors of enzymes, pigments and structural components of the photosynthetic apparatus, reducing metabolic capacity for CO 2 fixation (Pietrini et al, 2010a;Basa et al, 2014).…”

The potential of wild vegetation species of Eleusine indica L., and Sonchus arvensis L. for phytoremediation of Cd-contaminated soil

“…According to Gomes et al (2012), dry weight (DW) production was negatively affected by Cd concentrations. Cd had inhibiting effects on growth up to concentrations of 45 µmol Cd; at higher concentrations, dry biomass production of both shoots and roots showed only slight changes.…”