Strigolactones: Discovery, Biological Activity, Biosynthesis, and Applications

Strigolactones (SLs) are carotenoid derivatives found in a variety of plants. Since the discovery of the first SL, strigol, from root exudates of cotton in 1966, more than 30 SLs have been characterized to date. The SLs are derived from all- trans - β -carotene by the action of β -carotene isomerase, carotenoid cleavage dioxygenases, and a series of CYP450 oxygenases. SLs were originally identified as signal molecules between plant roots and parasitic seeds/fungi. Recently, SLs have been found to be involved in regulating root and shoot architecture, leaf senescence, and stress tolerance. SLs hold great potency in agricultural applications, such as controlling root parasite weeds, regulating plant responses to abiotic stress, and enhancing plant nutrient acquisition. In the chapter, we summarize the recent advances of SLs in biosynthesis and agricultural applications.