Updated project metadata. Heat stress is a major challenge for crop production. During the reproduction stage, pollen development is the most sensitive process to abnormal environmental conditions. In this project, we have developed a heat treatment system for tomato where plants produce a significantly lower number of pollens and the germination rate of those pollens was also very low. The size of the flower buds and pollen developmental stages were examined under confocal microscope. Pollen cells at different developmental stages were collected from flower buds at corresponding sizes using LCM. The single cell population proteomics analysis was used to identify proteome changes in a distinct group of cells. This information was used to determine the function of proteins that are associated with heat stress on cellular processes/functions during pollen development.