Photosynthesis in changing environment: Analyzing the role of phytohormones in modulation

Photosynthetic organisms sustain life by converting light energy into chemicalenergy. Photosynthesis is a key phenomenon contributing substantially to plant growthand development. It is a well regulated and multistep process to produce assimilatorypower NADPH and ATP to synthesize carbohydrate. The changing environmentalconditions have forced plant scientists to better understand photosynthetic process moreimportantly for agricultural sustainability. The abiotic stresses such as salt stress, heavymetal stress, water stress, heat stress, chilling stress, nutrient stress etc. adversely affectphotosynthesis because of induced oxidative stress. Various mechanisms may provideprotection to the photosynthetic apparatus under abiotic stress, but phytohormones havepotential to modify biochemical, physiological processes and molecular mechanisms inplants to optimize photosynthesis under optimal and stressful environments. They are astrong tool to protect and alleviate stress by modulating metabolic processes in plants.The present chapter gives an insight into the role of phytohormones in modifyingbiochemical, physiological and molecular responses to adapt plants in stressfulenvironments.