Abstract
Strigolactones (SLs) were originally isolated from plant root exudates as germination stimulants for root parasitic plants and thus were regarded as detrimental to the producing plants. Their role as indispensable chemical signals for root colonization by symbiotic arbuscular mycorrhizal (AM) fungi was subsequently demonstrated, and SLs then became recognized as beneficial plant metabolites. In addition to these functions as communication chemicals for both symbiosis and parasitism in the rhizosphere, it has been recently shown that SLs or their metabolites are a novel class of plant hormones that inhibit shoot branching. Furthermore, SLs are suggested to have other biological functions in rhizosphere communications and in plant growth and development. In this issue, 4 review papers describing SLs as germination stimulants for root parasitic plants, the chemistry, structure-activity relationships and molecular design of SL analogues for practical use, physiological functions of SLs, and development of SL-biosynthetic inhibitors are included.
