Uptake-related parameters as indices of phytoremediation potential

Abstract

Phytoremediation is emerging as an alternative agriculture-based technology because remediation of metalpolluted sites can be brought about utilizing the ability of plants to uptake and store contaminants in them. A field study was conducted to assess the role of Indian mustard in phytoremediation of chromium-contaminated substrata. Uptake parameters, namely, bio-concentration factor, translocation index, Cr distribution within plant, and tolerance index were used in determining the remediation potential of the crop. A significant increase in Cr accumulation (0.64-4.19 mg g −1 DW, stem; and 0.77-1.1 mg Cr g −1 DW, root), coupled with high tolerance indices, was observed in response to Cr stress, thus showing that Indian mustard is a potential hyperaccumulator. Movement and subsequent distribution of metal ions in the plant were assessed by studying the translocation index which showed a consistent increase (27-87% at T5) with time, and bioconcentration factor, where also an increase over a time period was observed in stem (1.3-11.4, T1) and root (1.96-5.56, T1), thereby, depicting the strong ability of Indian mustard for phytoextraction. A significant decline, however, was observed in the bioconcentration factor with increase in the dose of Cr application.

Morphophysiological Responses, Heavy Metal Accumulation and Phytoremoval Ability in Four Willow Clones Exposed to Cadmium Under Hydroponics

“…The reduction of root biomass observed in clones 2-03 and 6-03 might be due both to competition in the uptake between Cd and some micronutrients essential for plant growth and to the inhibition of root cell division as has been suggested by several authors (Ernst et al 1992 ;Gaudet et al 2011 ;Zhivotovsky et al 2011 ). The metal bioaccumulation capability is a crucial trait to screen plants for phytoremediation, and the metal uptake parameters are reported as very relevant to the understanding of the plant responses to heavy metal stress (Diwan et al 2010 ). Data for Cd accumulation and distribution among organs of willow clones are shown in Fig.…”

“…In this context, metal translocation to the aerial part can be considered as a crucial biochemical process ) and root-to-shoot ratio in willow clones grown for 3 weeks in the presence of 0 μM (control, black bars ) and 50 μM ( grey bars ) CdSO 4 in hydroponics (mean ± S.E., n = 5). In column, different letters correspond to statistical different values (Duncan's test, for the P value see Table 7.1 ) for an effective utilisation of plants to remediate polluted substrates (Zacchini et al 2009 ;Diwan et al 2010 ). In fact, the accumulation of Cd in the above-ground woody tissues could reduce the damaging effects exerted by this pollutant on root physiology and biochemistry, resulting in a higher metal removal effi ciency, as these plant parts are commonly harvested and stored.…”

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).…”

Lithium, Vanadium and Chromium Uptake Ability ofBrassica junceafrom Lithium Mine Tailings

“…Usually, a TI > 1 reveals the suitability of the hyperaccumulator plant to translocate the heavy metals to its upper physiological sites (Lasat et al 1997;Salt et al 1995). Theoretically, the accumulated metals in hyperaccumulator plant shoots are more easily recovered, recycled, or stored as opposed to its roots; therefore, a higher value of translocation index is always more desirable than a successful phytoremediation or phytomining process (Belouchi et al 1997;Williams et al 2000;Salt et al 1995;Diwan et al 2010;Zu et al 2005). However; in this study the Brassica juncea's translocation indexes for the three metals were 67% Li > 7% Cr > 6% V, which clearly reveals its overwhelmingly enhanced ability to translocate and accumulate lithium (but not chromium and vanadium) inside its upper above ground physiological sites, despite a relatively low growth rate.…”