Excess levels of Al3+ become highly harmful to plant roots. The epidermal and outer cortical layers of root-tips experience more severe damages than the inner tissues from Al toxicity. This project used laser capture microdissection (LCM) technology to isolate the outer and inner cell layers of cells in root-tips. Tomato "MicroTom" plants were grown in hydroponic solution supplemented with Al. Seeds derived from plants previously exposed to four generations of Al-treated solutions were considered stress-acclimated, these seeds were named G4Al+. Seeds harvested from soil-grown plants were also used, these seeds were named G0 seeds. Tandem mass tag (TMT) proteomics was used to identify differential proteomics responses among cells localized at different spaces in root-tips and those between the stress-acclimated and non-acclimated plants.