This reprint aims to introduce the readers to the latest research in plant physiology under the stimulation of various biotic and abiotic stresses. Environmental factors can affect plant primary and secondary metabolite-dependent processes and, consequently, a plant’s physiological state. Therefore, in this reprint, research groups from around the world have investigated physiological aspects of resistance, tolerance, and susceptible responses of plants induced by plant pathogens, i.e., viruses, bacteria, and fungi-causing diseases as well as abiotic factors such as heavy metals, fluctuations in temperature, salinity, and drought. The knowledge gained is a perfect addition to general plant physiology and can be applied for practical use in food production, phytoremediation, and architecture of urban landscapes.