Potassium ion (K+) constitutes one of the six macronutrients and is implicated in several processes that aid cell survival and growth. Optimal intracellular K+ level is achieved through the combination of low and high-affinity transport systems allowing uptake over a wide range (millimolar (mM) to micromolar (mu M)) of external K+ concentration and is impacted by both biotic and abiotic stress conditions. Plants growing in K+-deficient soil are more susceptible to disease and damage caused due to abiotic stress factors like frost, drought, and salinity. The severity decreases with an increase in exogenous K+. Exposure to high saline conditions results in an increase in intracellular sodium (Na+) and a concurrent decrease in K+ levels. Thus, intracellular K+ levels are crucially linked to specific uptake and efflux mechanisms operational during a particular stress regime. While molecular pathway(s) operative in K+-mediated endurance to multiple stress conditions are not fully understood, studies suggest a positive correlation between capacity for incremented K+ levels and survival advantages. In this article we review: K+ uptake systems and mechanisms available across life domains with special reference to plant systems. Recent emerging evidence on the involvement of K+ in stress management, and the role of K+ uptake systems during pathogenicity and symbiotic associations. Approaches aimed at optimizing intracellular K+ levels through modulation of (influx and efflux mechanisms) and (vacuole pools) as a viable strategy to support plant growth under stress conditions.