Rice tiller production regulated by sustained expression of FON1

Number of tillers is one of the major determinants of yield in rice. MONOCULM1 (MOC1) and MOC3 have been reported to regulate tiller formation by promoting axillary bud formation and elongation of buds. MOC1 interacts with MOC3 and promotes the expression of FLORAL ORGAN NUMBER 1 (FON1), which increases the elongation of buds and ultimately promotes tillering. MOC3 can directly bind to the promoter of FON1, but MOC1 cannot directly bind to FON1 and acts as a co-activator of MOC3. Fan et al. discovered the function of a novel gene DWARF AND LESS TILLER ON CHROMOSOME 3 (DLT3), which interacts with MOC3, recruits MOC1, and binds to the promoter of FON1. They cloned DLT3 from a mutant developed from an EMS mutagenized population and performed Mutmap sequencing to find its candidate gene, whose function was validated by complementation assay and CRISPR genome editing. They found the potential interaction of DLT3 with MOC3 in a yeast two-hybrid screen and validated it through biomolecular fluorescence complementation. This discovery has added a new player, DLT3, to the previously known tiller regulating molecular circuit FON1-MOC3-MOC1. (Summary by Asif Ali @pbgasifkalas) Plant Physiol. 10.1093/plphys/kiae367