Overexpression of Sorghum plasma membrane-bound Na+/H+ antiporter-like protein (SbNHXLP) enhances salt tolerance in transgenic groundnut (Arachis hypogaea L.)

Soil salinity and water-deficit conditions often affect crop productivity in groundnut. Therefore, developing transgenic groundnut that can grow under such abiotic stress conditions is crucial to stabilize its yield. Sodium proton antiporter-like protein (NHXLP) is a plasma membrane-bound protein associated with Na+ exclusion and helps to maintain ion homeostasis under saline conditions. In the present study, salt tolerant transgenic groundnut variety JL-24 was developed by expressing SbNHXLP gene isolated from Sorghum bicolor. Molecular analysis of transgenics by PCR and Southern blot confirmed the integration of SbNHXLP gene. SbNHXLP expression at the transcript level was checked by reverse transcriptase (RT)-PCR. Homozygous T2 lines along with wild-type (WT) plants were evaluated for 150 mM NaCl stress tolerance. Biochemical analysis of transgenics under salt stress revealed higher chlorophyll content, superoxide dismutase, and catalase activities, accumulation of proline, and K+ accompanied by lower Na+ accumulation compared to WT plants. Additionally, transgenics displayed higher biomass and pod yield when compared with WT plants under stress. Our findings indicate that overexpression of SbNHXLP gene in groundnut results in enhanced tolerance to salinity stress. This highlights the potential of SbNHXLP as a target candidate gene to impart salt stress tolerance in groundnut.