Does zaxinone counteract strigolactones in shaping rice architecture?

The cleavage of plant carotenoids leads to apocarotenoids, a group of metabolites including precursors of the hormones strigolactones (SLs) and abscisic acid, regulatory and signaling molecules. Zaxinone is a recently discovered apocarotenoid growth regulator that improves growth and suppress SL biosynthesis in rice (). To test if zaxinone also counteracts the growth regulatory effects of SLs in rice, we co-supplied zaxinone and the synthetic SL analog -GR24 to the rice SL-deficient ( mutant. Results showed that co-application of GR24 and zaxinone still rescued phenotype, indicating that zaxinone and GR24 act independently in regulating root and shoot growth and development in rice.