Morpho-physiological response and hyperaccumulating ability of Catharanthus roseus (L.) G. Don towards stable Cesium and Strontium isotope through Hydroponic culture

Abstract Stable isotopes of Cesium (Cs) and Strontium (Sr), along with their radioactive isotopes, impose a menace to the populace and environment. For a sustainable decontamination process, the present study focuses on Catharanthus roseus (L.) G.Don, a perennial herb exhibiting effective extraction competence to above-ground biomass, was employed under spiked Cs and Sr treatments. Under modulated plant growth chamber, the hydroponic culture experiments were carried out with Cs dosing as 0-5mM (CsCl) and Sr as 0-3mM (SrCl2. 6H2O) for 21days. Parameters such as chlorophyll content, soluble protein, level of defense enzymatic antioxidants, stable isotope uptake, translocation, and spatial distribution were interpreted. Hyperaccumulation capacity was estimated with transfer factor (TF). The quantification of Cs and Sr in different plant parts was accomplished with atomic absorption spectroscopy (AAS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). With increasing concentration of metals the accumulation increased for Cs ( 255.2- 1828.76 mg/kg.dw) and Sr ( 831.16 - 5383.76 mg/kg.dw) while the transfer factor decreased for Cs (1.84 - 1.07) and Sr ( 9.3-3.2). For Cs and Sr, with increasing concentration, plants exhibited enzymatic expression for defense against metal toxicity by free radicals. With increasing treatments, plant physiology was also relatively affected. Spatial distribution of Cs and Sr in plant leaf was assessed with field emission electron microscopy with Energy dispersive spectroscopy (FE-SEM with EDS), which unveiled the accumulation of Cs, Sr, and their homologous elements in plant leaf.