The document summarizes plant responses to different types of stress. It discusses how plants can avoid or tolerate stress through mechanisms like osmotic adjustment, accumulation of compatible solutes like proline and glycine betaine, and expression of heat shock proteins. Stress can be biotic, imposed by other organisms, or abiotic arising from environmental deficits or excesses. Abiotic stresses discussed in detail include drought, salinity, temperature extremes, and oxidative stress from pollutants.