Strigolactone biosynthesis and perception

• Carlactone was identified as an endogenous biosynthetic precursor for SLs.
• DAD2/D14, α/β hydrolase family proteins, are likely to be involved in SL perception.
• DAD2/D14 family proteins hydrolyze SLs such as GR24.
• D14 interacts with D53, a repressor of SL signaling, in an SL-dependent manner.

Strigolactones (SLs) are plant hormones that regulate shoot branching as well as known as root-derived signals for parasitic and symbiotic interactions. Since the first discovery of a naturally occurring SL, strigol, more than 40 years ago, the biosynthetic pathway has remained elusive. Recently, it was partially uncovered through the functional analysis of some biosynthetic components that were discovered from genetic studies using SL-deficient mutants. In addition, a perception component was also characterized through genetic and biochemical studies of a rice SL-insensitive mutant, dwarf14. In this review, we describe new findings on SL biosynthesis and focus on a recently identified SL precursor, carlactone. We also describe the perception mechanisms by an α/β-fold hydrolase family protein.