RESUMO
Plant elicitor peptide 1 (Pep1) is one of plant-derived damage-associated molecular patterns (DAMPs) involved in the regulation of multiple biological processes, including immune response and root growth. The exogenous application of Pep1 was shown to inhibit root growth by affecting the auxin content and extracellular pH level in the transition zone (TZ). However, the signaling relationship between extracellular pH and auxin in Pep1-regulated root growth inhibition has not been explored. Our study here suggested that both pH signaling and auxin signaling were responsible for Pep1-regulated root growth inhibition, and the Pep1-induced auxin accumulation in TZ depended on apoplastic acidification. To increase the apoplastic pH in TZ, we mutated the AHA2 and found that the mutants of aha2-4 and pin2aha2-4 both reduced Pep1-induced auxin content in TZ, thereby alleviating root growth inhibition. Thus, our results reveal a new auxin-pH signaling crosstalk mechanism in regulating root growth, and provide new insights into the function of Pep1 in regulating root growth in Arabidopsis.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Raízes de Plantas/metabolismo , Membrana Celular/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
An N-glycosidic polysaccharide-peptide complex CMPS-80 was obtained from the fruiting body of C. militaris. Of importance, CMPS-80 significantly ameliorated formation of atherosclerotic lesions and plasma lipid profiles in apolipoprotein E-deficient mice. Integrated informatics analysis suggested that CMPS-80 can modulate multiple lncRNA-microRNA-mRNA axes. CMPS-80 has a potential application for prevention of hyperlipidemia and atherosclerosis.
Assuntos
Aterosclerose/prevenção & controle , Cordyceps/química , Proteínas Fúngicas/farmacologia , MicroRNAs/genética , Polissacarídeos/farmacologia , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Animais , Aterosclerose/genética , Aterosclerose/metabolismo , Colesterol/sangue , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/prevenção & controle , Proteínas Fúngicas/química , Expressão Gênica , Fígado/metabolismo , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Peptídeos/química , Peptídeos/farmacologia , Polissacarídeos/química , Proteoglicanas , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Triglicerídeos/sangueRESUMO
Cordyceps militaris is a well-known traditional Chinese medicine. Studies have demonstrated that the polysaccharides of C. militaris have various bioactivities. However, their mechanisms of action remain unclear. We previously purified a water-soluble polysaccharide CM1 from C. militaris and found that it has a cholesterol efflux improving capacity. This study further investigates the effect of CM1 in anti-atherosclerosis and its underlying mechanism in apolipoprotein E-deficient mice. Our data indicated that CM1 significantly decreased the total cholesterol and triglyceride in the plasma of mice, and decreased lipid deposition and formation of atherosclerotic plaque in a dose-dependent manner. Integrated bioinformatics analysis revealed that CM1 interacted with multiple signaling pathways, including those involved in lipid metabolism, inflammatory response, oxidoreductase activity and fluid shear stress, to exert its anti-atherosclerotic effect. Molecular technology analysis showed that CM1 enhanced the expression of proteins involved in lipid metabolism, reduced the expression of intercellular adhesion molecule-1 and tumor necrosis factor-α in the aorta, and decreased the content of oxidative products by enhancing the activities of antioxidant enzymes. Microarray analysis and biochemical data indicated that CM1 can improve lipid metabolism, reduce inflammation and oxidative stress. Taken together, CM1 could be used for the treatment of hyperlipidemia and atherosclerotic cardiovascular diseases.
Assuntos
Aterosclerose/tratamento farmacológico , Cordyceps/química , Polissacarídeos/farmacologia , Animais , Antioxidantes/farmacologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aterosclerose/metabolismo , Biologia Computacional , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
The remodeling of root architecture is regarded as a major development to improve the plant's adaptivity to phosphate (Pi)-deficient conditions. The WRKY transcription factors family has been reported to regulate the Pi-deficiency-induced systemic responses by affecting Pi absorption or transportation. Whether these transcription factors act as a regulator to mediate the Pi-deficiency-induced remodeling of root architecture, a typical local response, is still unclear. Here, we identified an Arabidopsis transcription factor, WRKY33, that acted as a negative regulator to mediate the Pi-deficiency-induced remodeling of root architecture. The disruption of WRKY33 in wrky33-2 mutant increased the plant's low Pi sensitivity by further inhibiting the primary root growth and promoting the formation of root hair. Furthermore, we revealed that WRKY33 negatively regulated the remodeling of root architecture by controlling the transcriptional expression of ALMT1 under Pi-deficient conditions, which further mediated the Fe3+ accumulation in root tips to inhibit the root growth. In conclusion, this study demonstrates a previously unrecognized signaling crosstalk between WRKY33 and the ALMT1-mediated malate transport system to regulate the Pi deficiency responses.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ferro/metabolismo , Meristema/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Fosfatos/deficiência , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Homeostase , Meristema/genética , Meristema/fisiologia , Transportadores de Ânions Orgânicos/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologiaRESUMO
Plant elicitor peptides (Peps) are damage/danger-associated molecular patterns (DAMPs) that are derived from precursor proteins PROPEPs and perceived by a pair of leucine-rich repeat receptor-like kinases (LRR-RLKs), PEPR1 and PEPR2, to enhance innate immunity and to inhibit root growth in Arabidopsis thaliana. In this study, we show that Arabidopsis Pep1 inhibits the root growth by interfering with pH signaling, as acidic condition increased, but neutral and alkaline conditions decreased the Pep1 effect on inhibiting the root growth. The perception of Pep1 to PEPRs activated the plasma membrane-localized H+-ATPases (PM H+-ATPases) -the pump proton in plant cell-to extrude the protons into apoplast, and induced an overly acidic environment in apoplastic space, which further promoted the cell swelling in root apex and inhibited root growth. Furthermore, we revealed that pump proton AUTOINHIBITED H+-ATPase 2 (AHA2) physically interacted with PEPR2 and served downstream of the Pep1-PEPRs signaling pathway to regulate Pep1-induced protons extrusion and root growth inhibition. In conclusion, this study demonstrates a previously unrecognized signaling crosstalk between Pep1 and pH signaling to regulate root growth.