Gene Details:

Functional Descriptions:

  • Here we show that the constitutively active OsRac1 (i) causes HR-like responses and greatly reduces disease lesions against a virulent race of the rice blast fungus; (ii) causes resistance against a virulent race of bacterial blight; and (iii) causes enhanced production of a phytoalexin and alters expression of defense-related genes.
  • Taken together, our findings strongly suggest that OsRac1 has a general role in disease resistance of rice.
  • The constitutively active (CA) G19V mutation of OsRac1 was previously shown to induce reactive oxygen species production, phytoalexin synthesis and defense gene activation, leading to resistance to rice blast infection.
  • Proteins involved in redox regulation, chaperones such as heat shock proteins, BiP, and chaperonin 60, proteases and protease inhibitors, cytoskeletal proteins, subunits of proteasomes, and enzymes involved in the phenylpropanoid and ethylene biosynthesis pathways were found to be induced by CA-OsRac1 or SE.
  • We have previously shown that a human small GTPase Rac homolog, OsRac1, from rice (Oryza sativa) induces cascades of defense responses in rice plants and cultured cells.
  • Interestingly, of 100 proteins that were up-regulated by a SE, 87 were also induced by CA-OsRac1, suggesting that OsRac1 plays a pivotal role in defense responses induced by SE in cultured rice cells.
  • Results of our proteomic analysis revealed that OsRac1 is able to induce many proteins in various signaling and metabolic pathways and plays a predominant role in the defense response in cultured rice cells.
  • We have previously shown that the Rac homolog of rice, OsRac1, is a regulator of ROI production and cell death in rice.
  • We found that the expression of a metallothionein gene (OsMT2b) was synergically down-regulated by OsRac1 and rice (Oryza sativa) blast-derived elicitors.
  • In the CA-gOsRac1 plants, a number of genes previously shown to be induced by Magnaporthe oryzae and Xanthomonas oryzae pv.
  • Expression of the constitutively active OsRac1, a small GTPase Rac of rice, in d1 mutants restored SE-dependent defense signaling and resistance to rice blast.
  • We have proposed a model for the defense signaling of rice in which the heterotrimeric G protein functions upstream of the small GTPase OsRac1 in the early steps of signaling.
  • To study the precise localization of OsRac1 in the PM and its possible association with other signaling components, we performed proteomic analysis of DRMs (detergent-resistant membranes) isolated from rice suspension-cultured cells transformed with myc-tagged constitutively active (CA) OsRac1.
  • Proteome analysis of detergent-resistant membranes (DRMs) associated with OsRac1-mediated innate immunity in rice.
  • We introduced the constitutively active and the dominant negative forms of the small GTP-binding protein OsRac1, a rice homolog of human Rac, into the wild type and a lesion mimic mutant of rice and analyzed H(2)O(2) production and cell death in transformed cell cultures and plants.
  • OsRac1, one of the Rac/Rop family of small GTPases, plays important roles in defense responses, including a role in the production of reactive oxygen species mediated by NADPH oxidase.
  • Thus, it is likely that OsRac1 controls lignin synthesis through regulation of both NADPH oxidase and OsCCR1 activities during defense responses in rice.
  • In the leaf blade of homozygous CA-gOsRac1 plants, mutant transcript levels were much lower than in those of wild-type plants.
  • We have established a plant version of a F<U+00F6>rster resonance energy transfer (FRET) probe called Ras and interacting protein chimeric unit (Raichu) that can successfully monitor activation of the rice small GTPase OsRac1 during various defence responses in cells.
  • Importance of OsRac1 and RAI1 in signalling of NLR protein-mediated resistance to rice blast disease.
  • We also identified RAI1, a transcriptional activator, as a PID3 interactor required for PID3-mediated blast resistance and showed that RAI1 expression is induced by PID3 via a process mediated by OsRac1.
  • This study describes a new signalling pathway for NLR protein-mediated blast resistance and shows that OsRac1 and RAI1 act together to play a critical role in this process.
  • We identified OsRac1, a known GTPase, as a signaling molecule in PID3-mediated blast resistance, implicating OsRac1 as a possible common factor downstream of rice NLR proteins.
  • The Rho-family GTPase OsRac1 controls rice grain size and yield by regulating cell division.
  • As a result, OsRac1 overexpression improves grain yield in O.
  • Interestingly, OsRac1 interacts with and regulates the phosphorylation level of OsMAPK6, which is known to regulate cell division and grain size in rice.
  • Thus, our findings suggest OsRac1 modulates rice grain size and yield by influencing cell division.
  • This study provides insights into the molecular mechanisms underlying the control of rice grain size and suggests that OsRac1 could serve as a potential target gene for breeding high-yield crops.
  • RNA-seq and cell cycle analyses suggest that OsRac1 promotes cell division.
  • We have previously found that the small GTPase OsRac1 plays key roles in the signaling of OsCERK1, a PRR for fungal chitin, and of Pit, an NLR for rice blast fungus, and associates directly and indirectly with both of these immune receptors.
  • These findings illuminate how the PRR OsCERK1 and the NLR Pit orchestrate rice immunity through the small GTPase OsRac1.

Literature:

Gene Resources:

Sequences:

cDNA Sequence
  • >LOC_Os01g12900.3
    GGCAAGTTCAAACGGAGCTGGAGGCAGAGCTAGAGTGAGACTGTGAGAGTGAACAAGAGATAAGCTAAGCTAGTACAGCAACCAGCAAGAACAAAGAAGAGTGGCCGGAGTGGGCGGGGGAGATGAGCTCGGCGGCGGCGGCGACGAGGTTCATCAAGTGCGTCACCGTGGGGGACGGCGCGGTGGGGAAGACGTGCATGCTCATCTGCTACACCTGCAACAAGTTCCCCACCGGATTACATCCCCACCGTGTTCGACAACTTCAGCGCCAATGTCTCCGTGGACGGGAGCGTCGTCAACCTCGGCCTCTGGGACACTGCAGGTCAGGAGGATTACAGCAGGTTGAGGCCTCTGAGCTACAGGGGAGCCGATGTGTTCATCCTGTCCTTCTCCCTGATAAGCAGGGCGAGCTATGAGAATGTTCAGAAGAAGTGGATGCCAGAGCTTCGCCGGTTTGCGCCTGGTGTTCCTGTAGTTCTTGTTGGAACCAAGTTGGGTATGCTATGCTATTCATTAATTCACCCTTTACCTTCTGAAATTTCTTAATTTTTTGAACGCCATTCAACCCCACGAAGATATTTGATACAGTAACCACAGCCCAGTGACATTCTTTGCTGATGCTGCATTACCGATTTCCTGTCTGTTCAGATCTCCGTGAAGATAGGGCCTATCTTGCTGATCATCCAGCTTCTTCCATAATAACAACGGAGCAGGGAGAAGAACTGAGGAAGCTAATAGGAGCGGTCGCCTACATCGAATGCAGCTCCAAGACACAGAGAAACATTAAAGCTGTTTTCGACACTGCCATCAAAGTGGTGCTTCAACCTCCAAGACATAAGGATGTAACCAGAAAGAAACTCCAATCAAGCTCCAATCGGCCAGTAAGGCGGTACTTTTGCGGAAGCGCTTGTTTCGCGTAGTCAATAACCAAGAAGAAAAAAATGTGGTTTTTGTTCCATCACCATGATGTTCAGATGGCCCCATGGATCTACTCAGAATGGGATAGAAGATCATGGTTGAATCAACATTGCTTGCAGCTAGGAGGAACTTCTAGTTCTCTTTTTTTCTGCAGTGGAGCTCCTTTTGTTTCTCCTTTCTCTTTTTTTCTTATGTTGTAAAAGCTCCAGAAAGTTTTACCCTTGGTAATAAGATGTGCTCTTCTGGATGGCTACCTTTACCCGTATCTCCTTTCACTTTGCGAAATGTTGGAAACTACTGGACCTAACAGACCTAACAGACAAACAAAAAAGAAGCCACATGCTTCAACCTTTTCTTATATACTTTGGATTGAATACATAGGAAGTTAATTACA
  • >LOC_Os01g12900.1
    GGCAAGTTCAAACGGAGCTGGAGGCAGAGCTAGAGTGAGACTGTGAGAGTGAACAAGAGATAAGCTAAGCTAGTACAGCAACCAGCAAGAACAAAGAAGAGTGGCCGGAGTGGGCGGGGGAGATGAGCTCGGCGGCGGCGGCGACGAGGTTCATCAAGTGCGTCACCGTGGGGGACGGCGCGGTGGGGAAGACGTGCATGCTCATCTGCTACACCTGCAACAAGTTCCCCACCGGATTACATCCCCACCGTGTTCGACAACTTCAGCGCCAATGTCTCCGTGGACGGGAGCGTCGTCAACCTCGGCCTCTGGGACACTGCAGGTCAGGAGGATTACAGCAGGTTGAGGCCTCTGAGCTACAGGGGAGCCGATGTGTTCATCCTGTCCTTCTCCCTGATAAGCAGGGCGAGCTATGAGAATGTTCAGAAGAAGTGGATGCCAGAGCTTCGCCGGTTTGCGCCTGGTGTTCCTGTAGTTCTTGTTGGAACCAAGTTGGGTATGCTATGCTATTCATTAATTCACCCTTTACCTTCTGAAATTTCTTAATTTTTTGAACGCCATTCAACCCCACGAAGATATTTGATACAGTAACCACAGCCCAGTGACATTCTTTGCTGATGCTGCATTACCGATTTCCTGTCTGTTCAGATCTCCGTGAAGATAGGGCCTATCTTGCTGATCATCCAGCTTCTTCCATAATAACAACGGAGCAGGGAGAAGAACTGAGGAAGCTAATAGGAGCGGTCGCCTACATCGAATGCAGCTCCAAGACACAGAGAAACATTAAAGCTGTTTTCGACACTGCCATCAAAGTGGTGCTTCAACCTCCAAGACATAAGGATGTAACCAGAAAGAAACTCCAATCAAGCTCCAATCGGCCAGTAAGGCGGTACTTTTGCGGAAGCGCTTGTTTCGCGTAGTCAATAACCAAGAAGAAAAAAATGTGGTTTTTGTTCCATCACCATGATGTTCAGATGGCCCCATGGATCTACTCAGAATGGGATAGAAGATCATGGTTGAATCAACATTGCTTGCAGCTAGGAGGAACTTCTAGTTCTCTTTTTTTCTGCAGTGGAGCTCCTTTTGTTTCTCCTTTCTCTTTTTTTCTTATGTTGTAAAAGCTCCAGAAAGTTTTACCCTTGGTAATAAGATGTGCTCTTCTGGATGGCTACCTTTACCCGTATCTCCTTTCACTTTGCGAAATGTTGGAAACTACTGGACCTAACAGACCTAACAGACAAACAAAAAAGAAGCCACATGCTTCAACCTTTTCTTATATACTTTGGATTGAATACATAGGAAGTTAATTACA
  • >LOC_Os01g12900.2
    GGCAAGTTCAAACGGAGCTGGAGGCAGAGCTAGAGTGAGACTGTGAGAGTGAACAAGAGATAAGCTAAGCTAGTACAGCAACCAGCAAGAACAAAGAAGAGTGGCCGGAGTGGGCGGGGGAGATGAGCTCGGCGGCGGCGGCGACGAGGTTCATCAAGTGCGTCACCGTGGGGGACGGCGCGGTGGGGAAGACGTGCATGCTCATCTGCTACACCTGCAACAAGTTCCCCACCGGATTACATCCCCACCGTGTTCGACAACTTCAGCGCCAATGTCTCCGTGGACGGGAGCGTCGTCAACCTCGGCCTCTGGGACACTGCAGGTCAGGAGGATTACAGCAGGTTGAGGCCTCTGAGCTACAGGGGAGCCGATGTGTTCATCCTGTCCTTCTCCCTGATAAGCAGGGCGAGCTATGAGAATGTTCAGAAGAAGTGGATGCCAGAGCTTCGCCGGTTTGCGCCTGGTGTTCCTGTAGTTCTTGTTGGAACCAAGTTGGGTATGCTATGCTATTCATTAATTCACCCTTTACCTTCTGAAATTTCTTAATTTTTTGAACGCCATTCAACCCCACGAAGATATTTGATACAGTAACCACAGCCCAGTGACATTCTTTGCTGATGCTGCATTACCGATTTCCTGTCTGTTCAGATCTCCGTGAAGATAGGGCCTATCTTGCTGATCATCCAGCTTCTTCCATAATAACAACGGAGCAGGGAGAAGAACTGAGGAAGCTAATAGGAGCGGTCGCCTACATCGAATGCAGCTCCAAGACACAGAGAAACATTAAAGCTGTTTTCGACACTGCCATCAAAGTGGTGCTTCAACCTCCAAGACATAAGGATGTAACCAGAAAGAAACTCCAATCAAGCTCCAATCGGCCAGTAAGGCGGTACTTTTGCGGAAGCGCTTGTTTCGCGTAGTCAATAACCAAGAAGAAAAAAATGTGGTTTTTGTTCCATCACCATGATGTTCAGATGGCCCCATGGATCTACTCAGAATGGGATAGAAGATCATGGTTGAATCAACATTGCTTGCAGCTAGGAGGAACTTCTAGTTCTCTTTTTTTCTGCAGTGGAGCTCCTTTTGTTTCTCCTTTCTCTTTTTTTCTTATGTTGTAAAAGCTCCAGAAAGTTTTACCCTTGGTAATAAGATGTGCTCTTCTGGATGGCTACCTTTACCCGTATCTCCTTTCACTTTGCGAAATGTTGGAAACTACTGGACCTAACAGACCTAACAGACAAACAAAAAAGAAGCCACATGCTTCAACCTTTTCTTATATACTTTGGATTGAATACATAGGAAGTTAATTACA
CDS Sequence
  • >LOC_Os01g12900.3
    ATGCTGCATTACCGATTTCCTGTCTGTTCAGATCTCCGTGAAGATAGGGCCTATCTTGCTGATCATCCAGCTTCTTCCATAATAACAACGGAGCAGGGAGAAGAACTGAGGAAGCTAATAGGAGCGGTCGCCTACATCGAATGCAGCTCCAAGACACAGAGAAACATTAAAGCTGTTTTCGACACTGCCATCAAAGTGGTGCTTCAACCTCCAAGACATAAGGATGTAACCAGAAAGAAACTCCAATCAAGCTCCAATCGGCCAGTAAGGCGGTACTTTTGCGGAAGCGCTTGTTTCGCGTAG
  • >LOC_Os01g12900.1
    ATGCTGCATTACCGATTTCCTGTCTGTTCAGATCTCCGTGAAGATAGGGCCTATCTTGCTGATCATCCAGCTTCTTCCATAATAACAACGGAGCAGGGAGAAGAACTGAGGAAGCTAATAGGAGCGGTCGCCTACATCGAATGCAGCTCCAAGACACAGAGAAACATTAAAGCTGTTTTCGACACTGCCATCAAAGTGGTGCTTCAACCTCCAAGACATAAGGATGTAACCAGAAAGAAACTCCAATCAAGCTCCAATCGGCCAGTAAGGCGGTACTTTTGCGGAAGCGCTTGTTTCGCGTAG
  • >LOC_Os01g12900.2
    ATGCTGCATTACCGATTTCCTGTCTGTTCAGATCTCCGTGAAGATAGGGCCTATCTTGCTGATCATCCAGCTTCTTCCATAATAACAACGGAGCAGGGAGAAGAACTGAGGAAGCTAATAGGAGCGGTCGCCTACATCGAATGCAGCTCCAAGACACAGAGAAACATTAAAGCTGTTTTCGACACTGCCATCAAAGTGGTGCTTCAACCTCCAAGACATAAGGATGTAACCAGAAAGAAACTCCAATCAAGCTCCAATCGGCCAGTAAGGCGGTACTTTTGCGGAAGCGCTTGTTTCGCGTAG
Protein Sequence
  • >LOC_Os01g12900.3
    MLHYRFPVCSDLREDRAYLADHPASSIITTEQGEELRKLIGAVAYIECSSKTQRNIKAVFDTAIKVVLQPPRHKDVTRKKLQSSSNRPVRRYFCGSACFA*
  • >LOC_Os01g12900.1
    MLHYRFPVCSDLREDRAYLADHPASSIITTEQGEELRKLIGAVAYIECSSKTQRNIKAVFDTAIKVVLQPPRHKDVTRKKLQSSSNRPVRRYFCGSACFA*
  • >LOC_Os01g12900.2
    MLHYRFPVCSDLREDRAYLADHPASSIITTEQGEELRKLIGAVAYIECSSKTQRNIKAVFDTAIKVVLQPPRHKDVTRKKLQSSSNRPVRRYFCGSACFA*