**3. Impact of water stress: physiological and biochemical alterations in plants**

Agriculture output is gradually been threatened every year due to drought stress. Drought proves an obtrusive climatic factor for agriculture, livestock and climate. Climate change led to increased temperature and varied environmental conditions globally. So, we need plant varieties that are adapted to these environmental conditions specially drought stress. Water is crucial for plant survival and responsible for various biological, physical and biochemical activities of plant system. Influence of drought desperately hampers plant functioning and limits plant growth at various development stages. Water deficit conditions alter many metabolic activities in plants like reduced photosynthetic rate, increased reactive oxygen species (ROS) accumulation, and production of plant secondary metabolites etc.
