Strigolactone Biosynthesis and Biology

Strigolactones belong to a newly identified class of plant hormones that are involved in the inhibition of shoot branching. Prior to this finding, strigolactones were proven to be root rhizosphere-signaling molecules that mediate plant–parasitic plant, and the symbiotic plant–AM fungi interactions. More recently, strigolactones were shown to have other biological functions as endogenous plant hormones in shoot development, root architecture, and seed germination (also in nonparasitic plants) and to regulate plant developmental processes in interaction with other signaling pathways (i.e., light and senescence signaling) or hormones. Gene discovery in the strigolactone biosynthesis and signal perception pathways is a key step in elucidating the mechanism and mode of action of the existing roles and discovering potential additional roles of strigolactones. Furthermore, insights into strigolactone and strigolactone-associated pathways will provide more knowledge for the control of parasitic weeds and improvement of crop yield. In this chapter, we outline different aspects of the roles that strigolactones play both in the rhizosphere and during plant development. Gene characterization in strigolactone pathways and strigolactone-related hormone cross-talk is also addressed.