Exploring strigolactones for inducing abiotic stress tolerance in plants

Strigolactones (SLs) are a comparatively novel class of phytohormones that are involved in the maintenance of plant architecture with key regulation of lateral branching. They are also reported to play an important role in regulating plant responses to various abiotic stresses. The potential of SLs to improve crop resilience and productivity needs to be effectively translated into agriculture. Therefore, both the endogenous biosynthesis of SLs and their exogenous application need to be thoroughly investigated to understand and exploit the mechanism underlying the alleviation of abiotic stress responses. Although several reviews have emphasised the biosynthesis of SLs in plants under abiotic stress, the mechanism underlying the alleviation of stress responses upon exogenous application has been less explored. Accordingly, in this review, although we have briefly discussed the beneficial effects of endogenous production of SLs in different sections, our main focus is to summarise the influence of exogenous SLs on the growth and development of different plant species grown under various abiotic stresses including drought, nutrient, heavy metal, and salinity stress. Apart from providing an overview of the transcriptomic studies conducted to observe the alleviating effects of SLs on abiotic stress responses, the research gaps in this field were briefly discussed. The review provides insight for researchers to conduct further research on SLs and fill the gap so that they can be effectively used for sustainable agriculture.