Strigolactone

Strigolactones are plant hormones that stimulate the branching and growth of symbiotic arbuscular mycorrhizal fungi, increasing the probability of contact and establishment of a symbiotic association between the plant and fungus. Strigolactones also inhibit plant shoot branching, and trigger germination of parasitic plant seeds (for example Striga, from which they gained their name). Strigolactones are carotenoid-derived and contain a labile ether bond that is easily hydrolyzed in the rhizosphere, meaning that there is a large concentration gradient between areas near the root and those further away. In 2009, strigolactone biosynthesis was found to be DWARF27-dependent.

Strigolactones were first discovered in Striga lutea (witchweed), a parasitic weed that lacks the ability to photosynthesize. Such plants use strigolactones exuded from the roots of host plants as a cue for germination. Such mechanism enables them to germinate close to a suitable host.

Strigolactones are terpenoid lactones and are derived from carotenoids.

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