Fine Mapping of the Affecting Tillering and Plant Height Gene in Rice.

The plant architecture of rice is an important factor affecting yield. Strigolactones (SLs) are newly discovered carotenoid-derived plant hormones that play an important role in rice plant architecture. In this study, a high-tillering dwarf mutant, was identified by spatial mutagenesis. was located in the region of 31.52-31.55 MB on chromosome 1 by map-based cloning. Compared with the wild-type THZ, the mutant showed that ACCAC replaced TGGT in the coding region of the candidate gene , leading to premature termination of expression. Genetic complementation experiments proved that was , which encodes a putative member of Class III lipase. Expression analysis showed that was constitutively expressed in various organs of rice. Compared with those in THZ, the expression levels of the and genes were significantly downregulated in the . In addition, the concentrations of ent-2'-epi-5-deoxystrigol (epi-5DS) in the root exudates of the mutant was significantly reduced compared with that of THZ, and exogenous application of GR24 inhibited the tillering of the mutant. These results suggest that influences rice architecture by affecting SL biosynthesis.