Updating the Impact of Drought on Root Exudation: A Strigolactones Perspective

With the changing global climate, drought is considered one of the most devastating abiotic factors. Drought not only limits plant productivity by changing growth and development but also alters the microbiome in the rhizosphere. In addition to influencing the root microbes, drought modifies the root exudate's composition and profile in the rhizosphere. Plant health, root exudation, and abundance of soil microbes in the rhizosphere are inter-connected. The composition of root exudate is altered in terms of the abundance of primary metabolites such as sugar, amino acids, and organic acids and secondary metabolites like flavonoids, strigolactones, and terpenoids. Here, we discuss how a plethora of soil microbes may be involved in a feedback mechanism by utilizing root exudate constituents to promote drought tolerance in plants. Furthermore, plant drought tolerance is positively associated with strigolactones (SLs) exudation via coordination with ABA hormone signaling. Lastly, while the collection, sampling, and analysis of root exudates are all promising, we attempted to present advanced methodology and the development of novel processes in the review, which benefited greatly.