During their biological cycle, plants are often exposed to adverse conditions that negatively affect both their growth and their survival. The term stress refers to the impact of unfavorable environmental factors that tend to hinder the proper functioning of physiological mechanisms.

Therefore, the appearance of dysfunctions in a plant organism (deviations from normal operating levels) indicates the presence of stress factors in its environment. In most cases, stress is assessed through the agricultural product produced, the survival of the plant, the accumulation of biomass, or the rate of assimilation (CO2 or nutrients).

Each plant organism has adapted through evolution to grow without problems within defined environmental condition limits (optimal conditions). If these optimal limits are violated, the plant organism will experience stress and show the first symptoms of stress. This condition will occur when, for example, a plant is exposed to temperature conditions to which it has not genetically adapted.

Under conditions of intense stress, significant deviations from optimal growth conditions are observed, as well as temporary and/or permanent effects on all levels of function within a plant organism. Typically, one stress factor affects more than one physiological function. On the other hand, the interaction of multiple stress factors creates extremely complex physiological reactions in plants.

The presence of stress factors in the environment of a plant organism usually does not exhibit a uniform distribution in space and time. Stresses play a significant role at the agricultural production level, as it has been estimated that under field conditions, deviations from ideal growth conditions result in the net product representing a small percentage (approximately 20-30%) of what could potentially be produced, taking into account the genetically determined maximum yield of each cultivated plant.