RESUMO
A new full-length cDNA encoding strictosidine synthase (designated as OjSTR, GenBank Accession No. 1087598), which catalyzes a committed step in camptothecin biosynthetic pathway, was isolated from young leaves of Ophiorrhiza japonica for the first time. OjSTR was 1,258 bp and contained a 1,062 bp open reading frame encoding a deduced protein of 353 amino acid residues. Sequence analyses showed that OjSTR had high homology with other STRs from some TIA-producing plants. Phylogenetic tree analysis showed that OjSTR had closest relationship with STR from O. pumila. Tissue expression pattern analysis revealed that OjSTR constitutively expressed in all the tested tissues at different levels, which was high in flower, moderate in leaf and root, low in stem. Expression profiles under plant defense signals such as methyl jasmonate and salicylic acid were investigated, and the results revealed that expression of OjSTR was all induced, implying that OjSTR was high elicitor responsive.
Assuntos
Carbono-Nitrogênio Liases/genética , DNA Complementar/genética , Regulação da Expressão Gênica de Plantas , Rubiaceae/enzimologia , Rubiaceae/genética , Acetatos/farmacologia , Sequência de Aminoácidos , Carbono-Nitrogênio Liases/química , Carbono-Nitrogênio Liases/metabolismo , Clonagem Molecular , Biologia Computacional , Ciclopentanos/farmacologia , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Dados de Sequência Molecular , Oxilipinas/farmacologia , Filogenia , Estrutura Secundária de Proteína , Rubiaceae/efeitos dos fármacos , Ácido Salicílico/farmacologia , Alinhamento de Sequência , Análise de Sequência de DNA , Fatores de Tempo , Alcaloides de Vinca/químicaRESUMO
Putrescine N-methyltransferase (PMT; EC. 2.5.1.53) catalyzes the S-adenosylmethionine-dependent N-methylation of putrescine to form N-methylputrescine, which was the first committed step in tropane alkaloid biosynthetic pathway. Two PMT cDNA clones [Anisodus acutangulus putrescine N-methyltransferase 1 (AaPMT1), GenBank Accession No. EU670745; AaPMT2, GenBank Accession No. EU670746] were obtained and characterized together from Anisodus acutangulus for the first time. The full-length cDNA of AaPMT1 was 1322 bp containing a 1014-bp open reading frame (ORF) encoding a polypeptide of 338 amino acids and AaPMT2 was 1219 bp containing a 1041-bp ORF encoding a polypeptide of 347 amino acids. Comparison of the deduced amino acid sequences of AaPMTs with those from tropane alkaloid-producing plants revealed that AaPMTs had high similarity with other plants PMT. Phylogenetic tree analysis displayed that AaPMT1 showed extensive homology with PMT from Anisodus tanguticus, and AaPMT2 had closer relationship with PMT2 from Atropa belladonna, which indicated PMTs belonged to PMT superfamily. Southern hybridization analysis of the genomic DNA revealed the occurrence of two PMT copies in A. acutangulus genome. Tissue expression pattern analysis revealed that AaPMT1 expressed strongly in roots, weakly in steams and leaves, besides, AaPMT2 presented a similar weaker trend. It indicated that AaPMTs were constitutive expression genes, which were the first reported tissue-independent PMT genes compared with other known PMT genes. AaPMT1 expression was upregulated by methyl jasmonate (MeJA) in all tissues, reaching the highest level after 24 h of the treatment. AaPMT2 also exhibited a very similar trend, whereas the expression was much weaker than that in AaPMT1. So, AaPMTs were considered to be MeJA elicitor-responsive genes and could be effectively elicited at least at the transcriptional level. The work would provide useful knowledge for tropane alkaloids biosynthesis and metabolic engineering to increase the production.
Assuntos
Metiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Solanaceae/genética , Acetatos/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Ciclopentanos/metabolismo , DNA Complementar/genética , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Metiltransferases/genética , Dados de Sequência Molecular , Fases de Leitura Aberta , Oxilipinas/metabolismo , Filogenia , Proteínas de Plantas/genética , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , RNA de Plantas/genética , Alinhamento de Sequência , Solanaceae/enzimologiaRESUMO
A new full-length cDNA encoding hyoscyamine 6beta-hydroxylase (designated as aah6h, GenBank Accession No. EF187826), which catalyzes the last committed step in the scopolamine biosynthetic pathway, was isolated from young roots of Anisodus acutangulus by rapid amplification of cDNA ends (RACE) for the first time. The full-length cDNA of aah6h was 1380 bp and contained a 1035 bp open reading frame (ORF) encoding a deduced protein of 344 amino acid residues. The deduced protein had an isoelectric point (pI) of 5.09 and a calculated molecular mass of about 38.7 kDa. Sequence analyses showed that AaH6H had high homology with other H6Hs isolated from some scopolamine-producing plants such as Hyoscyamus niger, Datura metel and Atropa belladonna etc. Bioinformatics analyses results indicated AaH6H belongs to 2-oxoglutarate-dependent dioxygenase superfamily. Phylogenetic tree analysis showed that AaH6H had closest relationship with H6H from A. tanguticus. Southern hybridization analysis of the genomic DNA revealed that aah6h belonged to a multi-copy gene family. Tissue expression pattern analysis firstly founded that aah6h expressed in all the tested tissues including roots, stems and leaves and indicated that aah6h was a constitutive-expression gene, which was the first reported tissue-independent h6h gene compared to other known h6h genes.
Assuntos
DNA Complementar/genética , Oxigenases de Função Mista/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Solanaceae/genética , Sequência de Aminoácidos , Sequência de Bases , Southern Blotting , Clonagem Molecular , DNA Complementar/química , Evolução Molecular , Perfilação da Expressão Gênica , Oxigenases de Função Mista/metabolismo , Dados de Sequência Molecular , Estrutura Molecular , Filogenia , Proteínas de Plantas/metabolismo , Raízes de Plantas/enzimologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Escopolamina/química , Escopolamina/metabolismo , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Solanaceae/enzimologiaRESUMO
OBJECTIVE: To research the hereditary stability of Dendrobium huoshanense which were subcultured 7-8 times in the same tissue culture system. METHOD: Using three primers of arbitrary decamer oligonucleotide sequences from 20 primers for DNA amplification, random amplified polymorphic DNA (RAPD) were performed. RESULT: The genetic similarity coefficient was varied from 85.4% to 98.4%. The variation of protocorm, germination and monoleaf were rather more notable than that of bileaf and inflorescence. CONCLUSION: The variation of the same pod is quite small. It is feasible to set up the rapid propagation system of D. huoshanense
Assuntos
DNA de Plantas/genética , Dendrobium/genética , Variação Genética , Plantas Medicinais/genética , Análise de Variância , Primers do DNA , DNA de Plantas/análise , Dendrobium/crescimento & desenvolvimento , Germinação/genética , Plantas Medicinais/crescimento & desenvolvimento , Técnica de Amplificação ao Acaso de DNA Polimórfico , Fatores de Tempo , Técnicas de Cultura de TecidosRESUMO
The biogenesis of chloroplast from proplastid is the prerequisite of photosynthesis. Using electron microscope, we found that rice albino mutant Osalb23 had no thylakoid inside the chloroplast, only some empty vesicles could be observed (Fig. 2). Genetics analysis showed that albino phenotype was controlled by a single recessive locus. Using map-based cloning technique, OsALB23 has been mapped to a region of 280 kb between molecular markers R2M501 and R2M502 on chromosome 2 (Fig. 4). Homologous analysis indicated that this region contained six chloroplast protein genes.
Assuntos
Cloroplastos/metabolismo , Mapeamento Cromossômico/métodos , Oryza/genética , Proteínas de Plantas/genética , Cromossomos de Plantas/genética , Mutação , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimentoRESUMO
It has been more than a centaury since the identification of ethylene as a gaseous plant hormone, and the effects of ethylene on plants have enabled broad applications in agriculture. Efforts had been made to understand ethylene signal transduction in plants, but it had not been successful until the identification and cloning of the first plant hormone receptor gene, ETR1, in Arabidopsis a decade ago. Comprehensive genetic studies allow the dissecting of the signaling pathway to reveal the components involved, which makes the studies of ethylene signal transduction become one the most-understood signal transduction pathways in plants. The identification of the signaling components and the genetic model of ethylene signal transduction pathway are described in this review.
Assuntos
Arabidopsis/fisiologia , Etilenos/farmacologia , Proteínas de Plantas/fisiologia , Receptores de Superfície Celular/fisiologia , Transdução de Sinais/fisiologia , Arabidopsis/genética , Modelos Genéticos , Proteínas de Plantas/química , Receptores de Superfície Celular/químicaRESUMO
This paper summarizes the studies on improving crop nutritional quality including protein, saccharide and lipid through gene engineering in recent 10 years. Special emphasis is laid upon the improvement of protein contains and amino acid components. The food safety caused probably by gene engineering and some ways to solve the problem are introduced briefly.
