Strigolactones: mediators of osmotic stress responses with a potential for agrochemical manipulation of crop resilience

After quickly touching upon general aspects of strigolactones biology and functions, including structure, synthesis and perception, this review focuses on the role and regulation of the strigolactone pathway during osmotic stress, in light of the most recent research developments. We discuss available data on organ-specific dynamics of strigolactone synthesis and interaction with abscisic acid in the acclimatization response, with emphasis on the ecophysiological implications of the effects on the stomatal closure process. We highlight the importance to consider roots and shoots separately as well as combined vs individual stress treatments; and to perform reciprocal grafting experiments to work out organ contributions and long-distance signalling events and components under more realistic conditions. Finally, we elaborate on the question of if and how synthetic or natural strigolactones, alone or in combination with crop management strategies such as grafting, hold potential to maximise crop resilience to abiotic stresses.