Strigolactones and parasitic plants

A parasitic plant is a flowering plant that attaches itself morphologically and physiologically to a host (another plant) by a modified root (the haustorium). Only about 25 out of the 270 genera of parasitic plants have a negative impact in agriculture and forestry, and thus can be considered weeds. Among them, the most damaging root-parasitic weeds belong to the genera Orobanche and Phelipanche (commonly named broomrapes) and Striga (witchweeds) (all belonging to the Orobanchaceae family). Considering the aims of the book, this chapter will focus only on this group of parasitic weeds, as in these plants strigolactones have a key role both in their life cycle, and in management strategies to control them. Distribution, agricultural importance and life cycle of these parasitic weeds are briefly introduced, after which we focus on the role of strigolactones in seed germination, parasite development, host specificity, plant nutrition, and microbiome composition. Furthermore, some weed control approaches involving strigolactones are discussed.