Strigolactones in Plants: From Development to Abiotic Stress Management

Strigolactones are a group of carotenoid-derived phytohormones which are synthesized in plastids and cytosol. Strigolactones also act as molecular cue that assist plants to liaise with surroundings. These active biomolecules are also called as non-traditional phytohormones or plant growth regulators. Strigolactones are generated in roots mainly and released into rhizosphere, although their synthesis has been reported in other plant parts in trace amount. More than one thousand types of strigolactones are reported in plants but only 30 strigolactones have been identified yet. Strigolactones play a significant role in regulation of biochemical processes such as seed germination, plant growth and development (root system architecture, shoot branching and tillering), and delaying leaf senescence during plant survival under environmental constraints. Strigolactones usually involve oxidative responses in plant cells and promote osmolytes production in stressed cells for maintenance of homeostasis under environmental stress, including salt, light, temperature, drought, nutrient deficiency, and heavy metals. The present review highlights biosynthesis and functions of strigolactones, their crosstalk with other phytohormones and functions in abiotic stress resistance mechanism. Application of strigolactones for plant growth under harsh conditions provides channel for development of novel technologies which are environmentally benign and sustainable. Further in-depth investigations are required about the exogenous treatment or transgenic approaches for the accumulation of strigolactones inside the plants which can be a potential strategy for protection of plants against multiple environmental stresses.