Isolation And Functional Characterization Of HTDF, A Gene Controlling High Tillering, Dwarf And Low Fertility In Rice

Abstract:Rice architecture is an important agronomic trait that affects grain yield. In the papers, we characterized a high tillering dwarf mutant htdf (high tillering and dwarf with low fertility, named htdf). The mutant had excessive high tillers, dwarf and low fertility compared to the wild-type. Histological analysis showed that mutation in htdf resulted in anisotropic cell expansion and cell division.Genetic analysis showed that both high tiller and dwarf phenotypes of htdf were controlled by single recessive nuclear gene. By means of molecular marker technique, the htdf gene was mapped between two CAPS markers C1and C2on chromosome1within90kilobases. By comparing sequences and complementation test to determine htdf encode an lipase and the gene was expressed in most rice organs, with especially high levels in the cllus and panicles. Homologue search revealed that htdf is conserved in both the monocots and eudicots. In addition, the change in marker gene (IAA1, D10et) expression showed that HTDF is involved in strigolactone and auxin signaling though exogenous application of auxin and strigolactone did not restore the phenotype. These findings imply that htdf might be a critical step in regulation role of branch, as well as other developmental control.