Drought stress affects plant growth and overall yield. Following drought, stomata close, leading to a decline in net photosynthesis. Stomatal conductance is controlled by soil moisture availability as well as a complex interaction of intrinsic and extrinsic factors. Depending on the severity of drought, the activities of enzymes involved in carbon assimilation and adenosine triphosphate synthesis decrease and sometimes are even inhibited. The main factors reducing plant growth and productivity during drought are the production of reactive oxygen species in organelles, including chloroplasts, mitochondria and peroxisomes. Reactive oxygen species target cell membrane lipid peroxidation and enzymatic and nucleic protein degradation.