ABSTRACT
A total of 27 endophytic fungal strains were isolated from Huperzia serrata,which were richly distributed in the stems and leaves while less distributed in roots. The 27 strains were identified by Internal Transcribed Spacer( ITS) r DNA molecular method and one of the strains belongs to Basidiomycota phylum,and other 26 stains belong to 26 species,9 general,6 families,5 orders,3 classes of Ascomycota Phylum. The dominant strains were Colletotrichum genus,belonging to Glomerellaceae family,Glomerellales order,Sordariomycetes class,Ascomycota Phylum,with the percentage of 48. 15%. The inhibitory activities of the crude extracts of 27 endophytic fungal strains against acetylcholinesterase( ACh E) and nitric oxide( NO) production were evaluated by Ellman's method and Griess method,respectively. Crude extracts of four fungi exhibited inhibitory activities against ACh E with an IC50 value of 42. 5-62. 4 mg·L~(-1),and some fungi's crude extracts were found to inhibit nitric oxide( NO) production in lipopolysaccharide( LPS)-activated RAW264. 7 macrophage cells with an IC50 value of 2. 2-51. 3 mg·L~(-1),which indicated that these fungi had potential anti-inflammatory activities.The chemical composition of the Et OAc extract of endophytic fungus HS21 was also analyzed by LCMS-IT-TOF. Seventeen compounds including six polyketides,four diphenyl ether derivatives and seven meroterpenoids were putatively identified.
Subject(s)
Animals , Mice , Acetylcholinesterase , Anti-Inflammatory Agents , Pharmacology , Ascomycota , Chemistry , Classification , Cholinesterase Inhibitors , Metabolism , Endophytes , Classification , Huperzia , MicrobiologyABSTRACT
Objective: To establish the plant tissue culture system of Cistanche tubulosa, and determine the effect of drought stress on accumulation of two respective phenylethanoid glycosides in it. Methods The major chemical constituents of C. tubulosa by tissue culture were analyzed by HPLC-UV and HR-MS. The cell growth curves were also determined. In addition, the effects of drought stress on the phenylethanoid glycosides (echinacoside and acteoside) content in the tissue culture system of C. tubulosa were also studied by using NaCl, mannitol and PEG6000 as osmotic regulators, respectively. Results:Chemical constituents analyses revealed that callus and suspension cultures of C. tubulosa could produce the respective phenylethanoid glycosides of echinacoside and acteoside as in wild plant; Cell growth curves indicated that 30 d were the optimum culture period of callus culture; The cell growth rate and the accumulation of echinacoside and acteoside were mostly inhibited when the callus cells were under drought stress induced by NaCl or mannitol. Meanwhile, the accumulation of echinacoside and acteoside in cell suspension culture of C. tubulosa could be effectively enhanced by treatment with PEG6000. The maximum biomass of echinacoside and acteoside could reach to (1.07 ± 0.10) g/L and (0.12 ± 0.01) g/L 15 d after induction, respectively. And their contents were 20.94% and 2.27% separately based on the cell dry weight (DW) after 15 d of treatment with 6% PEG6000, which were 1.29 and 1.19 fold higher than the control group. Conclusion:Drought stress induced by PEG6000 could effectively enhance the accumulation of echinacoside and acteoside in cell suspension culture of C. tubulosa.
ABSTRACT
S-adenosylmethionine synthetase, a key enzyme in plant metabolism, plays an essential role in the plant defence system. In present study, a full length cDNA sequence of AsSAMS1 gene was cloned by RACE and reverse transcription PCR from Aquilaria sinensis calli. Meanwhile, the bioinformatics, prokaryotic expression, tissue-specific expression analysis, and expression analysis under different abiotic stresses and hormone treatments were performed. The open reading frame (ORF) of AsSAMS1 gene was 1 183 bp, encoding a protein of 393 amino acids with a calculated molecular mass (MW) of 43.13 kDa. Bioinformatic analysis indicated that AsSAMS1 contained 3 SAMS characteristic sequences. The phylogenetic analysis indicated that AsSAMS1 protein had the highest level of homology with SAMS protein from Glycine soja. The recombinant AsSAMS1 protein was successfully expressed in Escherichia coli BL21 (DE3) cells using the prokaryotic expression vector pET28a-AsSAMS1 and the recombinant AsSAMS1 was purified by Ni2+ affinity chromatography. Expression analysis results in different tissues indicated that AsSAMS1 was primarily observed in stems, and then stem tips and leaves, following by roots. The transcript level of AsSAMS1 and the content of S-adenosylmethionine (SAM) were induced by various abiotic stresses including salt, drought, cold, and heavy metal stress. Furthermore, AsSAMS1 expression level was enhanced upon methyl jasmonate (MeJA), salicylic acid (SA), gibberellin (GA3), and abscisic acid (ABA) treatment. These results provided valuable insights for further study on the role of SAMS in the mechanism of agarwood formation and plant resistance.
ABSTRACT
Jasmonic acid (JA) is an important signal molecule involved in plant resistance, and allene oxide synthase (AOS) is a key enzyme in the biosynthesis of jasmonates. In this study, a full-length cDNA of AsAOS1 gene was cloned from Aquilaria sinensis. Meanwhile, the sequence analysis, prokaryotic expression, purification, tissue-specific expression analysis and expression analysis under different abiotic stresses and hormone treatments were performed. The open reading frame (ORF) of AsAOS1 gene was 1 575 bp, encoding a protein of 524 amino acid residues, with a predicted molecular mass of 58.70 kDa. AsAOS1 protein possessed the conserved sequences of cytochrome P450 (CYP450). The phylogenetic analysis indicated that AsAOS1 protein had the highest level of homology with AOS protein of Citrus sinensis. The recombinant AsAOS1 protein was successfully expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-AsAOS1 and the recombinant AsAOS1 was purified by Ni2+ affinity chromatography. Expression analysis results in different tissues showed that AsAOS1 was primarily observed in stems, and then roots, followed by leaves. AsAOS1 transcript level was significantly induced after 12 h treatment of NaCl, cold temperature and CdCl2. Furthermore, AsAOS1 expression level was enhanced upon methyl jasmonate (MeJA), salicylic acid (SA) and abscisic acid (ABA) treatment. However, mannitol and gibberellin (GA3) treatments had little influence on the expression level of AsAOS1. These results provides valuable insights into the role of JA in the mechanism of agarwood formation and plant resistance.
ABSTRACT
The MYB gene family comprises one of the richest groups of transcription factors in plants. The full length of two MYB genes were isolated through heterologous screening of Aquilaria sinensis calli transcriptome data, and the reverse transcription PCR was performed to obstain the corrected MYB clones, named AsMYB1, AsMYB2. The MYB transmembrane domain and phylogenetic analysis were predicted by different software to analyze the bioinformatics of MYB proteins. The transcript level of AsMYB1, AsMYB2 was performed by real-time quantitative RT-PCR in different tissues and in responds to abiotic stresses including salt, cold, metal and drought stress, and hormone treatments including abscisic acid (ABA), salicylic acid (SA), gibberellins (GA3) and methyl jasmonate (MeJA) treatment. The AsMYB1 cDNA sequence had an ORF of 1 063 nucleotides, encoding a protein of 353 amino acids. The largest AsMYB2 ORF was 1 081 nucleotides, and its predicted translation products consisted of 359 amino acids. Two MYB genes had a tissues-specific pattern in A. sinensis. Moreover, the expression level of AsMYB1 and AsMYB2 was regulated by different abiotic stresses and hormone treatments, suggesting the transcription factors AsMYB1 and AsMYB2 play an important role in plant defense and hormone signal transduction in A. sinensis.