Sodium selenate na2seo4

The Se concentration in L. paracasei CCFM 1089 strain was determined by hydride atomic fluorescence spectrometry (AFS-8520, Beijing Haiguang Instrument Co., Ltd., Beijing, China), as reported by Li. et al. [21 (link)].
The Se forms in the strains were detected using high-performance liquid chromatography (HPLC, Ultimate3000, Thermo Fisher Scientific, Waltham, MA, USA) and inductively coupled plasma mass spectrometry (ICP-MS, NexION 350D, Perkin-Elmer, Waltham, MA, USA) according to Micaela Pescuma et al. [22 (link)]. Standard samples of SeCys (98%), methylselenocysteine (MeSeCys; 95%), SeMet (99%), sodium selenate (Na₂SeO₄; 98%), and sodium selenite (Na₂SeO₃; 98%) were purchased from Sigma-Aldrich LLC., Saint Louis, MO, USA.

EBL was procured from Sigma-Aldrich India Ltd. Chemicals, Bangalore, Karnataka, India. A required quantity of the hormone was dissolved in 5 mL of ethanol and placed in a 100 mL volumetric flask to create stock solutions (10⁻⁴ M) of EBL. The final volume was maintained at the desired level by adding double-distilled water. Sodium selenate (Na₂SeO₄) was procured from Sigma-Aldrich India Ltd. Chemicals and was used as the source of Se in this study. Na₂SeO₄ was dissolved in deionized water to prepare the stock solution (1 mM), and the final volume was increased to the required level by adding double deionized water. The requisite concentrations (10 μM) of Se were prepared by diluting the stock solution and 24-EBL at a certain concentration based on our earlier study [16 (link)]. Prior to the treatments, a desired concentration of 0.5 mL of Tween-20 was applied as a surfactant to all the plants.

Propanolan titanium (Ti(OCH₂CH₂CH₃)₄) 98%, sodium selenite (Na₂SeO₃) 99%, and sodium selenate (Na₂SeO₄) 98% were purchased from Sigma-Aldrich (Germany); propan-2-ol (C₃H₇OH) was purchased from Chempur (Poland); nitric acid (HNO₃) 65% and ammonia solution (NH₃·H₂O) 30% p.a. were purchased from POCH (Poland); standard solutions (1 mg mL⁻¹): Se(IV), As(III), and As(V) were purchased from Sigma-Aldrich (Germany), and Cr(III), Cr(VI), Cu(II), Pb(II), Zn(II), and Fe(III) were purchased from Merck (Germany); re-destilated water was from Milli-Q System of Millipore (France); filters Whatman 3MM were purchased from GE Healthcare Life Sciences (United Kingdom); Certified Reference Material (CRM) of natural water, NIST 1640a, was purchased from Sigma-Aldrich (Germany).
The following equipment were used for the research: FEI Nova NanoSEM 230 microscope (FEI Company, Hillsboro, Oregon, USA), x-ray powder diffractometer (XRD) (PANalytical, The Netherlands), energy-dispersive x-ray fluorescence spectrometer (EDXRF) XDV-SD model (Helmut Fischer GmbH, Sindelfingen, Germany), energy-dispersive x-ray fluorescence spectrometer (EDXRF) Epsilon 3 model (PANalytical, Almelo, The Netherlands), and inductively coupled plasma optical emission spectrometer (ICP-OES) SpectroBlue FMS16a model (Spectro Analytical Instruments GmbH, Germany). The apparatus is described in detail in ESM.