Calcium (Ca 2+ ) distribution into relatively low-transpiring fruit versus relatively high-transpiring leaves is of concern to the fruit industry. Ca 2+ uptake is further compromised under salinity through antagonistic competition with sodium (Na + ). Herein, X-Ray Fluorescence (XFM) was applied to elucidate in-situ localization and distribution patterns of Ca 2+ and potassium (K + ) in tomato leaflet and fruit tissues under s...