Figure 4. Overexpression of OsIFL in transgenic tobacco improves its tolerance to salinity stress by maintaining chlorophyll content and favorable K⁺/Na⁺ ratio.

(a) Leaf discs of tobacco (WT, L2 and L3) after 48 hr of incubation in 150 mM NaCl (bottom row) and their corresponding control kept in half MS alone (upper row); (b) Bar graph showing chlorophyll content in leaf discs of tobacco plants obtained from salinity stressed tissue; (c) Pot assay for assessing relative growth of WT and transgenic plants (T₁ generation) in response to salinity stress (150 mM NaCl, 3 weeks); (d) K⁺/Na⁺ ratio; (e) Electrolyte leakage (%); (f) Relative water content (%); (g) Estimated proline levels; (h) Germination assay of T₂ generation seeds of tobacco plants overexpressing OsIFL in comparison to WT tobacco seeds in the presence of 150 mM NaCl. Equal numbers of wild type and OsIFL seeds (Line L2 and L3) were inoculated on MS supplemented with 150 mM NaCl; OsIFL tobacco seeds show higher germination rate as well as better seedling growth as assessed visually. Experiments were repeated thrice and s.d. values are shown as error bars. The asterisk indicates a significant difference from the wild type (WT) groups (p < 0.05, student’s t-test).