| text |
LOOSE PLANT ARCHITECTURE 1 (LPA1) is a transcriptional repressor involved in the control of tiller angle, and leaf angle by regulating the adaxial growth of tiller node and lamina joint. it is the functional ortholog of the Arabidopsis AtIDD15/SHOOT GRAVITROPISM5 (SGR5) gene. LPA1 is only involved in shoot gravitropism in rice, and the lpa1 mutant does not show any defects in root gravitropism. LPA1 promotes erectness or reduces the tiller and leaf angle, thus giving rise to a more compact plant. LPA1 mutant phenotype is similar to LAZY1, but they work at different steps. LPA1 only influences gravity perception by regulating the sedimentation rate of amyloplasts. LPA1 was highly expressed in the lamina joint and internodes, especially in young tissues, and also expressed in older tiller base, coleoptile, root, seedling, and panicle but not much in the leaf blade and leaf sheath. Both LPA1 and LAZY1 reduce the tiller angle (Wu et al., 2013). ONAC106 is shown to directly down-regulate LPA1 transcription (Sakuraba et al. 2015). Furthermore, the LPA1 promoter has binding sites for OsHOX1 and OsHOX28 transcription factors (analysis carried out by the Plant Reactome curators).
|
