Excess levels of Al3+ become highly harmful to plant roots as the toxic ions bind to the surface of root-tips. Plants can acquire tolerance to stress after multiple generations of exposure to stress conditions. After four consecutive generations of Al treatments (G4Al+ seeds), tomato plants appeared more tolerant to the stress condition. This project used laser capture microdissection (LCM) technology to isolate the Al-sensitive epidermal and outer cortical cells of root-tips. Tandem mass tag (TMT) proteomics analysis was conducted to identify proteomics changes related to the physiological properties in root growth under Al treated conditions.