Visualization of Na+ ions through confocal
laser scanning microscopy (CLSM)
Freshly collected leaves and roots were segmented into 1 cm sections and
incubated with 2.5% glutaraldehyde solution in 0.1 M MOPS buffer
overnight at 4°C. For sodium illumination, tissues were stained with 5µ M Na+ specific probe CoroNa-Green AM
(Invitrogen) in the presence of 0.02% pluronic acid in 50 mM MOPS (pH
7.0) for overnight at room temperature. Further, the segments of leaves
and roots were thoroughly washed with 50 mM MOPS (pH 7.0) several times.
Thin sections were performed with razor blade and quickly immersed in
cell wall stain propidium iodide (Invitrogen) for 15 min. The sections
were examined under CSLM (Leica TCS SP2 with AOBS, Heidelberg, GmbH,
Germany). All measurements were performed as described by Marriboina &
Attipalli, (2020b) with some minor modifications. The cytosolic and
vacuolar Na+ fluorescence were calculated by LCS
software (Heidelberg, GmbH, Germany).