Gene Details:

• MSU gene ID: LOC_Os03g13400
• RAPdb gene ID: Os03g0237250
• Gene Symbol: LPA1
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• LPA1 regulates tiller angle and leaf angle by controlling the adaxial growth of tiller node and lamina joint.
• LPA1 is localized in the nucleus and functions as an active transcriptional repressor, an activity mainly conferred by a conserved ethylene response factor-associated amphiphilic repression-like motif.
• Expression pattern analysis suggested that LPA1 influences plant architecture by affecting the gravitropism of leaf sheath pulvinus and lamina joint.
• Here, we report the cloning and characterization of the Loose Plant Architecture1 (LPA1) gene in rice, the functional ortholog of the AtIDD15/SHOOT GRAVITROPISM5 (SGR5) gene in Arabidopsis (Arabidopsis thaliana).
• LPA1 was also found to affect shoot gravitropism.
• Genetic and biochemical data indicate that LPA1 suppresses the auxin signalling that interacts with C-22-hydroxylated and 6-deoxo BRs, which regulates lamina inclination independently of OsBRI1.
• RNA sequencing analysis and qRT-PCR indicate that LPA1 influences the expression of three OsPIN genes (OsPIN1a, OsPIN1c and OsPIN3a), which suggests that auxin flux might be an important factor in LPA1-mediated lamina inclination in rice.
• Mutant LPA1 plants are hypersensitive to indole-3-acetic acid (IAA) during the lamina inclination response, which is suppressed by the brassinazole (Brz) inhibitor of C-22 hydroxylase involved in BR synthesis.
• This study explores the role of LPA1 in determining lamina inclination in rice.
• LPA1 acts as a positive regulator to suppress lamina bending.
• A strong synergic effect is detected between LPA1 and d2 (the defective mutant for catalysis of C-23-hydroxylated BRs) during IAA-mediated lamina inclination.
• Novel allelic variant of LPA1 gene associated with a significant reduction in seed phytic acid content in rice (Oryza sativa L.).
• LPA1 expressed in pre-vascular cells of leaf primordia regulates genes associated with carbohydrate metabolism and cell enlargement.
• Narrow LPA1 Metaxylems Enhance Drought Tolerance and Optimize Water Use for Grain Filling in Dwarf Rice.
• Narrow metaxylem of LPA1 exhibit leaves curling on sunny day and convey drought tolerance but reduce grain yield in mature plants.
• However, the genetic combination of LPA1 with semi-dwarf mutant (dep1-ko or d2) offer optimal water supply and drought resistance without impacting grain-filling rates.
• We performed genetic combination of LPA1 with semi-dwarf mutant to offer the optimum rice architecture for more efficient water use.

Function-related keywords:

• tiller ,  tiller-angle ,  ethylene ,  sheath ,  leaf ,  growth ,  lamina ,  shoot ,  architecture ,  auxin ,  BR ,  seed ,  grain ,  resistance ,  grain-yield ,  drought ,  tolerance ,  grain-filling ,  yield ,  drought-tolerance ,  dwarf ,  drought-resistance ,  grain-filling

Literature:

• Loose Plant Architecture1, an INDETERMINATE DOMAIN protein involved in shoot gravitropism, regulates plant architecture in rice .  DOI:  10.1104/pp.112.208496 ;  PMID:  23124325
• Loose Plant Architecture1 (LPA1) determines lamina joint bending by suppressing auxin signalling that interacts with C-22-hydroxylated and 6-deoxo brassinosteroids in rice .  DOI:  10.1093/jxb/erw002 ;  PMID:  26826218
• Overexpression of Loose Plant Architecture 1 increases planting density and resistance to sheath blight disease via activation of PIN-FORMED 1a in rice .  DOI:  10.1111/pbi.13072 ;  PMID:  30623557
• Novel allelic variant of Lpa1 gene associated with a significant reduction in seed phytic acid content in rice (Oryza sativa L.) .  DOI:  10.1371/journal.pone.0209636 ;  PMID:  30870429
• Narrow lpa1 Metaxylems Enhance Drought Tolerance and Optimize Water Use for Grain Filling in Dwarf Rice .  DOI:  10.3389/fpls.2022.894545 ;  PMID:  35620680

Related News:

Gene Resources:

• NCBI ID: JQ681528
• UniProt accessions:

Sequences: