RESUMO
Previous studies have shown that multivesicular bodies (MVBs)/endosomes-mediated vesicular trafficking may play key roles in plant immunity and cell death. However, the molecular regulation is poorly understood in rice. Here we report the identification and characterization of a MVBs-localized AAA ATPase LRD6-6 in rice. Disruption of LRD6-6 leads to enhanced immunity and cell death in rice. The ATPase activity and homo-dimerization of LRD6-6 is essential for its regulation on plant immunity and cell death. An ATPase inactive mutation (LRD6-6E315Q) leads to dominant-negative inhibition in plants. The LRD6-6 protein co-localizes with the MVBs marker protein RabF1/ARA6 and interacts with ESCRT-III components OsSNF7 and OsVPS2. Further analysis reveals that LRD6-6 is required for MVBs-mediated vesicular trafficking and inhibits the biosynthesis of antimicrobial compounds. Collectively, our study shows that the AAA ATPase LRD6-6 inhibits plant immunity and cell death most likely through modulating MVBs-mediated vesicular trafficking in rice.
Assuntos
Adenosina Trifosfatases/biossíntese , Imunidade Celular/genética , Corpos Multivesiculares/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Adenosina Trifosfatases/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Morte Celular/genética , Resistência à Doença/genética , Resistência à Doença/imunologia , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Endossomos/genética , Endossomos/metabolismo , Regulação da Expressão Gênica de Plantas , Corpos Multivesiculares/imunologia , Mutação , Oryza/genética , Oryza/crescimento & desenvolvimento , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Plantas Geneticamente Modificadas/imunologia , Transporte Proteico/genética , Proteínas rab de Ligação ao GTP/genéticaRESUMO
BACKGROUND: Increasing evidence shows that whole genomes of eukaryotes are almost entirely transcribed into both protein coding genes and an enormous number of non-protein-coding RNAs (ncRNAs). Therefore, revealing the underlying regulatory mechanisms of transcripts becomes imperative. However, for a complete understanding of transcriptional regulatory mechanisms, we need to identify the regions in which they are found. We will call these transcriptional regulation regions, or TRRs, which can be considered functional regions containing a cluster of regulatory elements that cooperatively recruit transcriptional factors for binding and then regulating the expression of transcripts. RESULTS: We constructed a hierarchical stochastic language (HSL) model for the identification of core TRRs in yeast based on regulatory cooperation among TRR elements. The HSL model trained based on yeast achieved comparable accuracy in predicting TRRs in other species, e.g., fruit fly, human, and rice, thus demonstrating the conservation of TRRs across species. The HSL model was also used to identify the TRRs of genes, such as p53 or OsALYL1, as well as microRNAs. In addition, the ENCODE regions were examined by HSL, and TRRs were found to pervasively locate in the genomes. CONCLUSION: Our findings indicate that 1) the HSL model can be used to accurately predict core TRRs of transcripts across species and 2) identified core TRRs by HSL are proper candidates for the further scrutiny of specific regulatory elements and mechanisms. Meanwhile, the regulatory activity taking place in the abundant numbers of ncRNAs might account for the ubiquitous presence of TRRs across the genome. In addition, we also found that the TRRs of protein coding genes and ncRNAs are similar in structure, with the latter being more conserved than the former.
Assuntos
Elementos Reguladores de Transcrição , Saccharomyces cerevisiae/genética , Transcrição Gênica , Animais , Sequência Conservada/genética , Células Eucarióticas/metabolismo , Regulação da Expressão Gênica , Genoma Fúngico , Humanos , RNA não Traduzido/genética , Especificidade da Espécie , Proteína Supressora de Tumor p53/genéticaRESUMO
Plant hormones function to coordinate plant growth and development. While the plant hormones, mainly auxin and cytokinin, are exogenously added to various plant tissue cultures, their effects on the organogenesis are apparent, but little is known concerning the molecular mechanisms by which they function in cultured cells. Rice, as a model plant in monocots, is also suitable to tissue culture studies. Here, we used four types of regeneration mediums with different relative concentrations of cytokinin and auxin for rice callus differentiation, the calli at different differentiation stages were collected for proteomic analysis. 2-dimensional electrophoresis revealed that 213 protein spots significantly differentially expressed during callus differentiation under different hormone conditions. By using mass spectrometry, 183 differentially expressed protein spots were identified to match 157 unique proteins. Most of these differential proteins were cellular/metabolic process-related proteins, whose different expression patterns may be correlated with the cytokinin and auxin regulation. Several hormone-related proteins were prominently featured in differentiated calli as compared with the initiated calli, such as alpha-amylase isoforms, mannose-binding rice lectin, putative dehydration stress-induced protein, cysteine endopeptidase and cystatin. All these results provide a novel insight into how the two plant hormones effect the callus differentiation in rice on the proteomic level.