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
Allene oxide cyclase (AOC), a key enzyme in biosynthesis of jasmonic acid, plays an essential role in the plant defense system. In present study, a full length cDNA of AsAOC gene was cloned by the reverse transcription PCR from Aquilaria sinensis calli. Meanwhile, the bioinformatics, 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 AsAOC1 gene was 753 bp, encoding a protein of 251 amino acids with a calculated molecular mass (MW) of 27.46 kD. Bioinformatic analysis showed that AsAOC1 protein contains a conserved allene_ox_cyc domain in C-terminus. The phylogenetic analysis indicated that AsAOC1 protein had the highest level of homology with the AOC protein from Morus notabilis. The recombinant AsAOC1 protein was successfully expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-AsAOC1 and was purified by Ni2+ affinity chromatography. Expression analysis in different tissues indicated that AsAOC1 was primarily observed in stems, and then stem tips and roots, following by leaves. The transcript level of AsAOC1 was induced by various abiotic stresses including salt, drought, cold, and heavy metal stress. Furthermore, AsAOC1 expression level was enhanced upon methyl jasmonate (MeJA), salicylic acid (SA), gibberellin (GA3), and abscisic acid (ABA) treatments. These results provide valuable insights into the role of JA in the mechanism of agarwood formation and plant defense system.
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.
ABSTRACT
Objective: To aim at cloning the open reading frame (ORF) of sHSP1 and sHSP2 genes from Aquilaria sinensis and analyzing the bioinformatics and expression of the two genes. Methods: Two unique sequences containing sHSPs domain were discovered in transcriptome dataset of A. sisnensis. The full-length cDNAs of sHSP1 and sHSP2 were cloned by RT-PCR strategy with the specific primers. Subcellular localization, transmembrane domain, three-dimensional structure, and phylogenetic analysis were predicted by different softwares to analyze the bioinformatics of sHSPs protein. The expression different levels of sHSP1 and sHSP2 isoforms in different tissues and in responds to salt and ABA, SA, MJ treatment were measured by real-time quantitative PCR. Results: The sHSP1 and sHSP2 cDNA sequence consisted of 474 bp ORF, encoding 157 amino acids. Tissue expression analysis indicated that sHSP1 and sHSP2 were primarily expressed in roots, followed by stems and leaves. Salt treatment experiments indicated that salt treatment caused a rapid increase in sHSP1and sHSP2 expression within 36 and 24 h, respectively. Exogenous ABA and MJ treatment experiments indicated that sHSP1 and sHSP2 genes were induced by exogenous ABA and MJ, and all reached the highest expression level at 12 h. Simultaneously, the SA treatment experiments indicated that exogenous SA treatment caused a rapid increase in sHSP1 and sHSP2 expression within 12 and 24 h, respectively. Conclusion: The full-length cDNA sequence of sHSP1 and sHSP2 genes from A. sinensis is obtained. sHSP1 and sHSP2 have the different expression level in different tissues. When subjected to high salt, ABA, SA, and MJ treatment, sHSP1 and sHSP2 show the different expression levels in different time. Cloning and analyzing sHSP1 and sHSP2 genes from A. sinensis will play an important role for further study on plant defense response.