Assessment of natural low molecular weight organic acids in facilitating cadmium phytoextraction by Lepidium didymus (Brassicaceae).

The present study examined the ability of three naturally occurring low molecular weight organic acids (tartaric, TA; citric, CA; and oxalic, OA) to improve the efficiency of cadmium (Cd) phytoextraction in Lepidium didymus L. (Brassicaceae). The plants were grown in soil containing three different concentrations, i.e., 35, 105, and 175 mg kg ^-1 , of total Cd and 10 mM of TA, CA, and OA. After 6 weeks, plant height, dry biomass, photosynthetic traits, and metal accumulation were determined. All three organic chelants significantly increased the Cd accumulation in L. didymus plants; however, the greatest accumulation was seen with TA (TA > OA > CA). In general, Cd accumulation was the highest in the roots, followed by the stems, and the leaves. Highest BCF _Stem was observed upon the addition of TA (7.02) and CA (5.90) at Cd ₃₅ , compared to Cd-alone (3.52) treatment. The BCF was the highest in the stem (7.02) and leaves (3.97) under Cd ₃₅ treatment supplemented with TA. The BCF _Root in the plants under different chelant treatments were in the following order: Cd ₃₅  + TA (~ 100) > Cd ₃₅  + OA (~ 84) > Cd ₃₅  + TA (~ 83). The stress tolerance index and translocation factor (root-stem) were maximal at Cd ₁₇₅ with TA and OA supplementation, respectively. The study concludes that L. didymus could be a viable option for Cd-remediation projects, and the addition of TA improved its phytoextraction efficiency.
(© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)