Project description:Sesuvium portulacastrum (L.) is a halophyte, adapted to grow naturally under high-saline environments. Under control conditions, an inverse correlation was seen between Na and K accumulation, suggesting its facultative nature and ability to use Na-K interchangeably. No significant growth reduction was seen in seedlings upto 250 mM NaCl, except for youngest leaf-curling. Significantly higher accumulation of proline (4.3/1.8-folds), glycine betaine (1.4/1.4-folds) and selected amino-acids (1.4-4.2/1.4-2.3-folds) were seen in root/shoot of seedlings within 8 h stress duration. Inspite of having higher Na-accumulation, significantly lower number of differentially expressed genes (DEGs) were identified at 24 h than 8 h stress duration, indicating transcriptional restoration. As initial hours after NaCl stress are dominated by osmotic-component, 8h-specific DEGs, which are mainly transporters and transcription factors, reflect plant’s response towards NaCl-induced osmotic challenge. Most of the growth-related pathways including photosynthesis and ribosome-associated biogenesis gets suppressed, to support the activation of stress defence. Overexpression of SpRAB18 (an ABA-responsive dehydrin), one of the top-ranked DEGs, was found to impart salt-tolerance in soybean, indicating gene-function level conservation between halophyte and glycophyte. An open-access transcriptome database “SesuviumKB” (https:/ /cb.imsc.res.in/sesuviumkb) was developed to enable wide-scale gene function studies in S. portulacastrum, that could pave the way to engineer salt-tolerance in crops.