Inheritance of organelle DNA sequences in a citrus-poncirus intergeneric cross. (1/21)

Many land plants deviate from the maternal pattern of organelle inheritance. In this study, heterologous mitochondrial and chloroplast probes were used to investigate the inheritance of organelle genomes in the progeny of an intergeneric cross. The seed parent was LB 1-18 (a hybrid of Citrus reticulata Blanco cv. Clementine x C. paradisi Macf. cv. Duncan) and the pollen parent was the cross-compatible species Poncirus trifoliata (L.) Raf. All 26 progeny examined exhibited maternal inheritance of plastid petA and petD loci. However, 17 of the 26 progeny exhibited an apparent biparental inheritance of mitochondrial atpA, cob, coxII, and coxIII restriction fragment length polymorphisms (RFLPs) and maternal inheritance of mitochondrial rrn26 and coxI RFLPs. The remaining nine progeny inherited only maternal mitochondrial DNA (mtDNA) configurations. Investigations of plant mitochondrial genome inheritance are complicated by the multipartite structure of this genome, nuclear gene control over mitochondrial genome organization, and transfer of mitochondrial sequences to the nucleus. In this study, paternal mtDNA configurations were not detected in purified mtDNA of progeny plants, but were present in progeny DNA preparations enriched for nuclear genome sequences. MtDNA sequences in the nuclear genome therefore produced an inheritance pattern that mimics biparental inheritance of mtDNA.  (+info)

Sequence analysis of a 282-kilobase region surrounding the citrus Tristeza virus resistance gene (Ctv) locus in Poncirus trifoliata L. Raf. (2/21)

Citrus tristeza virus (CTV) is the major virus pathogen causing significant economic damage to citrus worldwide, and a single dominant gene, Ctv, provides broad spectrum resistance to CTV in Poncirus trifoliata L. Raf. Ctv was physically mapped to a 282-kb region using a P. trifoliata bacterial artificial chromosome library. This region was completely sequenced to about 8x coverage using a shotgun sequencing strategy and primer walking for gap closure. Sequence analysis predicts 22 putative genes, two mutator-like transposons and eight retrotransposons. This sequence analysis also revealed some interesting features of this region of the P. trifoliata genome: a disease resistance gene cluster with seven members and eight retrotransposons clustered in a 125-kb gene-poor region. Comparative sequence analysis suggests that six genes in the Ctv region have significant sequence similarity with their orthologs in bacterial artificial chromosome clones F7H2 and F21T11 from Arabidopsis chromosome I. However, the analysis of gene colinearity between P. trifoliata and Arabidopsis indicates that Arabidopsis genome sequence information may be of limited use for positional gene cloning in P. trifoliata and citrus. Analysis of candidate genes for Ctv is also discussed.  (+info)

A new flavanone glycoside from the dried immature fruits of Poncirus trifoliata. (3/21)

A new flavanone glycoside, (2R)-5-hydroxy-4'-methoxyflavanone-7-O-{beta-glucopyranosyl-(1-->2)-beta-glucopyr anoside} (1), was isolated from the EtOAc extract of dried immature fruit of Poncirus trifoliata, together with three known compounds, (2S)-poncirin (2), (2S)-naringin (3), and (2S)-poncirenin (4). The structure of compound 1 was elucidated by spectroscopic data analysis, including 1D and 2D NMR experiments. Among the isolates, compound 2 exhibited considerable inhibitory activity against lipopolysaccharide (LPS)-induced prostaglandin E(2) (PGE(2)) and interleukin-6 (IL-6) production, and mRNA expression in RAW 264.7 murine macrophage cells.  (+info)

Inhibition of LPS-induced iNOS, COX-2 and cytokines expression by poncirin through the NF-kappaB inactivation in RAW 264.7 macrophage cells. (4/21)

We previously reported that poncirin, a flavanone glycoside isolated from the EtOAc extract of the dried immature fruits of Poncirus trifoliata, is an anti-inflammatory compound that inhibits PGE(2) and IL-6 production. The present work was undertaken to investigate the molecular actions of poncirin in RAW 264.7 macrophage cell line. Poncirin reduced lipopolysaccharide (LPS)-induced protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and the mRNA expressions of iNOS, COX-2, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in a concentration-dependent manner, as determined by Western blotting and RT-PCR, respectively. Furthermore, poncirin inhibited the LPS-induced DNA binding activity of nuclear factor-kappaB (NF-kappaB). Moreover, this effect was accompanied by a parallel reduction in IkappaB-alpha degradation and phosphorylation that in by nuclear translocations of p50 and p65 NF-kappaB subunits. Taken together, our data indicate that anti-inflammatory properties of poncirin might be the result from the inhibition iNOS, COX-2, TNF-alpha and IL-6 expression via the down-regulation of NF-kappaB binding activity.  (+info)

Terpenoids and coumarins isolated from the fruits of Poncirus trifoliata. (5/21)

Four new triterpenes, 21alpha-methylmelianodiol (1), 21beta-methylmelianodiol (2), hispidol A 25-methyl ether (3) and hispidol B 25-methyl ether (4), and a new coumarin, isoschininallylol (5), were isolated from the fruits of Poncirus trifoliata RAFINESQUE, along with seventeen known compounds. The structures of the new compounds (1 - 5) were elucidated by interpretation of their spectroscopic data.  (+info)

Inhibitory effect of Poncirus trifoliate on acetylcholinesterase and attenuating activity against trimethyltin-induced learning and memory impairment. (6/21)

Various native Korean plants were screened to find an effective acetylcholinesterase (AChE) inhibitor for the treatment of Alzheimer's disease (AD). Among these plants, the ethanol extract of Poncirus trifoliate was selected for isolating the AChE inhibitor because it exhibited the highest inhibitory activity (47.31%). To separate the active compound from Poncirus trifoliate, solvent partition, open column chromatography, thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC) were utilized. The putative chemical structure of the AChE inhibitor was identified as methoxsalen by successive analysis with electron ionization mass spectrometry (EI-MS) and (13)C/(1)H-nuclear magnetic resonance (NMR). To confirm the attenuating effect of the Poncirus trifoliate extract against trimethyltin (TMT)-induced neurotoxicity, in vivo behavior tests were carried out. Our findings suggest that the Poncirus trifoliate extract significantly reversed TMT-induced learning and memory impairment. These results demonstrate that the Poncirus trifoliate extract could possess a wide range of beneficial activities for neurodegenerative disorders, notably AD.  (+info)

Differential gene expression analysis provides new insights into the molecular basis of iron deficiency stress response in the citrus rootstock Poncirus trifoliata (L.) Raf. (7/21)

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MiR-RACE, a new efficient approach to determine the precise sequences of computationally identified trifoliate orange (Poncirus trifoliata) microRNAs. (8/21)

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