ABSTRACT
The swift increase and decrease in temperatures affect the growth and development of the citrus which leads to decreases in its production. Temperature is very much useful for plants to complete their phenological and metabolical pathways. However, an increase and decrease in temperature beyond a certain level will cause a hindrance in its metabolism. The temperature extremities cause oxidative stress to the plants which activate the heat shock proteins and decrease the photosynthetic attributes. Higher temperatures associated with high evaporative losses, combined with increased demand for water, will lead to reduced water availability for agriculture, with some citrus-producing regions expected to experience higher temperatures in the coming decades which can cause moisture loss and decrease productivity and quality of citrus. Citrus grows in tropical and subtropical regions; cold and freezing events only affect specific areas where frost events are infrequent and usually mild. Hence, this chapter comprises the physiological, biochemical, and molecular responses of citrus trees against temperature (heat and cold) extremes.
