共查询到20条相似文献,搜索用时 15 毫秒
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Berta Alquezar Maria J. Rodrigo Joanna Lado Lorenzo Zacarías 《Tree Genetics & Genomes》2013,9(5):1257-1269
Accumulation of lycopene in citrus fruits is an unusual feature restricted to selected mutants. Grapefruit (Citrus paradisi Macf.) is the Citrus specie with greater number of red-fleshed mutants, but the molecular bases of this alteration are not fully understood. To gain knowledge into the mechanisms implicated in this alteration, we conducted a comparative analysis of carotenoid profile and of the expression of genes related to carotenoid biosynthesis and catabolism in flavedo and pulp of two grapefruit cultivars with marked differences in colouration: the white Marsh and the red Star Ruby. Mature green fruit of Marsh accumulated chloroplastic carotenoids, while mature tissues lacked carotenoids. However, accumulation of downstream products such as abscisic acid (ABA) and expression of its biosynthetic genes, 9-cis-epoxycarotenoid dioxygenase (NCED1 and NCED2), increased after the onset of colouration. In contrast, red grapefruit accumulated lycopene, phytoene and phytofluene, while ABA content and NCED gene expression were lower than in Marsh, suggesting a blockage in the carotenoid biosynthetic pathway. Expression analysis of three genes of the isoprenoid pathway and nine of the carotenoid biosynthetic pathway revealed virtually no differences in flavedo and pulp between both genotypes, except for the chromoplast-specific lycopene cyclase 2 (β-LCY2) which was lower in the pulp of the red grapefruit. The proportion in the expression of the allele with high (β-LCY2a) and low (β-LCY2b) activity was also similar in the pulp of both genotypes. Therefore, results suggest that reduced expression of β-LCY2 appears to be responsible of lycopene accumulation in the red Star Ruby grapefruit. 相似文献
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Chromoplast morphology and ultrastructure of red- and yellow-fleshed papaya (Carica papaya L.) were investigated by light and transmission electron microscopy. Carotenoid analyses by LC–MS revealed striking similarity
of nutritionally relevant carotenoid profiles in both the red and yellow varieties. However, while yellow fruits contained
only trace amounts of lycopene, the latter was found to be predominant in red papaya (51% of total carotenoids). Comparison
of the pigment-loaded chromoplast ultrastructures disclosed tubular plastids to be abundant in yellow papaya, whereas larger
crystalloid substructures characterized most frequent red papaya chromoplasts. Exclusively existent in red papaya, such crystalloid
structures were associated with lycopene accumulation. Non-globular carotenoid deposition was derived from simple solubility
calculations based on carotenoid and lipid contents of the differently colored fruit pulps. Since the physical state of carotenoid
deposition may be decisive regarding their bioavailability, chromoplasts from lycopene-rich tomato fruit (Lycopersicon esculentum L.) were also assessed and compared to red papaya. Besides interesting analogies, various distinctions were ascertained resulting
in the prediction of enhanced lycopene bioavailability from red papaya. In addition, the developmental pathway of red papaya
chromoplasts was investigated during fruit ripening and carotenogenesis. In the early maturation stage of white-fleshed papaya,
undifferentiated proplastids and globular plastids were predominant, corresponding to incipient carotenoid biosynthesis. Since
intermediate plastids, e.g., amyloplasts or chloroplasts, were absent, chromoplasts are likely to emerge directly from proplastids. 相似文献
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Yann Froelicher Wafa Mouhaya Jean-Baptiste Bassene Gilles Costantino Mourad Kamiri Francois Luro Raphael Morillon Patrick Ollitrault 《Tree Genetics & Genomes》2011,7(1):49-61
The aim of this work was to provide a set of mitochondrial markers to reveal polymorphism and to study the maternal phylogeny
in citrus. We first used 44 universal markers previously described in the literature: nine of these markers produced amplification
products but only one revealed polymorphism in citrus. We then designed six conserved pairs of primers using the complete
mitochondrial DNA sequences of Arabidopsis thaliana and Beta vulgaris to amplify polymorphic intergenic and intronic regions. From these six pairs of primers, three from introns of genes coding
for NADH dehydrogenase subunits 2, 5, and 7, revealed polymorphism in citrus. First, we confirmed that citrus have a maternal
mitochondrial inheritance in two populations of 250 and 120 individuals. We then conducted a phylogenic study using four polymorphic
primers on 77 genotypes representing the diversity of Citrus and two related genera. Seven mitotypes were identified. Six mitotypes (Poncirus, Fortunella, Citrus medica, Citrus micrantha, Citrus reticulata, and Citrus maxima) were congruent with previous taxonomic investigations. The seventh mitotype enabled us to distinguish an acidic mandarin
group (‘Cleopatra’, ‘Sunki’ and ‘Shekwasha’) from other mandarins and revealed a maternal relationship with Citrus limonia (‘Rangpur’ lime, ‘Volkamer’ lemon) and Citrus jambhiri (‘Rough’ lemon). This mitotype contained only cultivated species used as rootstocks due to their good tolerances to abiotic
stress. Our results also suggest that two species classified by Swingle and Reece, Citrus limon, and Citrus aurantifolia, have multiple maternal cytoplasmic origins. 相似文献
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W. E. Van de Weg 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(8):1092-1096
Phytophthora fragariae var. fragariae is the causal agent of red stele (red core) root rot in strawberry (Fragaria spp.). The inheritance of resistance to one isolate of this fungus was studied in 12 segregating populations of F.×ananassa derived from crosses between four resistant cultivars (‘Climax’, ‘Redgauntlet’, ‘Siletz’, and ‘Sparkle’) and three susceptible
cultivars (‘Blakemore’, ‘Glasa’, and ‘Senga’ Sengana’). The analysis clearly supports the hypothesis of a single segregating
dominant resistance gene. It is proposed that this gene be designated Rpf2.
Received 12 November 1996 / Accepted: 22 November 1996 相似文献
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Transgenic grapefruit plants (Citrus paradisi cv. ‘Duncan’) with the isopentenyltransferase (ipt) gene under the control of APETALA3 promoter have been produced using Agrobacterium-mediated transformation. The relative expression level of the ipt gene was between 2.3 and 7 times higher in transformed plants than in the wild-type but despite the presence of a tissue-specific
promoter, the expression was not limited only to flower tissue. Increased levels of trans-zeatin riboside between 9.4 and 32-fold found in transgenic grapefruit were considered the consequence of ectopic expression
of the ipt gene. Chlorophyll levels in fully expanded uppermost leaves were also about 30% higher in transgenic than in wild-type plants.
Involvement of cytokinins in control of expression of three pathogenesis-related protein genes: β-1,3-glucanase, a stress
related PR gene 24P220, and an acidic chitinase, 24P262 was examined. Expression of β-1,3-glucanase, and 24P220 gene were
significantly enhanced in transgenic plants while the expression of chitinase was reduced to low levels. Our results confirm
the effect of cytokinins on expression of genes implicated in the response of grapefruit plants to pathogen attack and suggest
a possible role of cytokinins in pathogen resistance. 相似文献
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Xue Gao Zheng-Guo Li Jing Fan Ying-Wu Yang Vasiliki Falara Angelos K. Kanellis 《Plant Growth Regulation》2009,59(1):13-19
In a search for differentially expressed genes in peel pitting of ‘Navel’ orange fruit (Citrus sinensis L. Osbeck), a cDNA subtraction library was constructed and a sequence encoding expansin-like gene was isolated and identified
as pitting related gene. Based on sequence information derived from this fragment, a full-length cDNA (CsEXP, GenBank accession no. FJ769424) of 1,083 nucleotides encoding expansin was isolated from ‘Navel’ orange by RACE approaches. CsEXP encoded a protein of 254 amino acid residues with an open reading frame located in the region between 52 and 816 bp. The
calculated molecular weight of the mature protein was 27.05 kDa and theoretical isoelectric point was 7.93. The deduced protein
contained conserved domains of expansin: the histidine-phenylalanine-aspartate motif in central portion, cysteine residues
in N-terminus, and tryptophan residues in C-terminal region. The expression of CsEXP was higher in pitting than the control. Exposure of fruit to stresses, including wounding, anoxia, low temperature (4°C),
and treatment with ethylene, increased CsEXP mRNA levels in comparison with the control untreated fruit, whereas high temperature (40°C) decreased its mRNA levels. Since
low temperature, low oxygen and wounding were suspected factors inducing peel pitting of citrus fruit. The present results
provided us a clue that CsEXP may play a role in response to peel pitting related stresses. 相似文献
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Thirteen ethylene signaling related genes were isolated and studied during ripening of non-astringent ‘Yangfeng’ and astringent
‘Mopan’ persimmon fruit. Some of these genes were characterized as ethylene responsive. Treatments, including ethylene and
CO2, had different effects on persimmon ripening, but overlapping roles in astringency removal, such as increasing the reduction
in levels of soluble tannins. DkERS1, DkETR2, and DkERF8, may participate in persimmon fruit ripening and softening. The expression patterns of DkETR2, DkERF4, and DkERF5 had significant correlations with decreases in soluble tannins in ‘Mopan’ persimmon fruit, suggesting that these genes might
be key components in persimmon fruit astringency removal and be the linkage between different treatments, while DkERF1 and DkERF6 may be specifically involved in CO2 induced astringency removal. The possible roles of ethylene signaling genes in persimmon fruit astringency removal are discussed. 相似文献
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V. Korzun M. S. Röder M. W. Ganal A. J. Worland C. N. Law 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(8):1104-1109
Two sets of single chromosome recombinant lines comparing 2D chromosomes from the wheat varieties ‘Ciano 67’ and ‘Mara’ with
the common 2D chromosome of ‘Cappelle-Desprez’ in a ‘Cappelle-Desprez’ background were used to detect a diagnostic wheat microsatellite
marker for the dwarfing gene Rht8. The genetic linkage maps place the wheat microsatellite marker WMS 261 0.6 cM distal to Rht8 on the short arm of chromosome 2D. By PCR analysis the WMS 261 alleles of ‘Mara’, ‘Cappelle-Desprez’ and ‘Ciano 67’ could
be distinguished by different fragment sizes of 192 bp, 174 bp and 165 bp, respectively. A screen of over 100 international
varieties of wheat showed that the three allelic variants were all widespread. It also demonstrated that a limited number
of varieties carried novel WMS 261 variants of over 200 bp. Following classification of the individual recombinant lines for
allelic variants at the WMS 261 locus it was possible to attribute a 7- to 8-cm reduction in plant height with the WMS 261-192-bp
allele compared to the WMS 261-174-bp allele in the set of recombinant lines comparing 2D chromosomes of ‘Mara’ and ‘Cappelle-Desprez’.
A height reduction of around 3 cm was detected between the WMS 261-174-bp allele and the WMS 261-165-bp allele in the recombinant
lines comparing 2D chromosomes of ‘Cappelle-Desprez’ and ‘Ciano 67’.
Received: 17 October 1997 / Accepted: 12 November 1997 相似文献
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Rice with LD-type cytoplasmic male sterility (CMS) possesses the cytoplasm of ‘Lead Rice’ and its fertility is recovered by
a nuclear fertility restorer gene Rf1. Rf1 promotes processing of a CMS-associated mitochondrial RNA of atp6–orf79, which consists of atp6 and orf79, in BT-CMS with the cytoplasm of ‘Chinsurah Boro II’. In this study, we found that LD-cytoplasm contained a sequence variant
of orf79 downstream of atp6. Northern blot analysis showed that atp6–orf79 RNA of LD-cytoplasm was co-transcribed and was processed in the presence of Rf1 in the same manner as in BT-cytoplasm. Western blot analysis showed that the ORF79 peptide did not accumulate in an LD-CMS
line, while ORF79 accumulated in a BT-CMS line and was diminished by Rf1. These results suggest that accumulation of ORF79 is not the cause of CMS in LD-cytoplasm and the mechanism of male-sterility
induction/fertility restoration in LD-CMS is different from that in BT-CMS. 相似文献
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Rai M 《Plant molecular biology》2006,61(3):399-414
Citrus tristeza virus (CTV) is a major pathogen of Citrus. A single dominant gene Ctv present in the trifoliate relative of Citrus, Poncirus trifoliata confers broad spectrum resistance against CTV. Refinement of genetic maps has delimited this gene to a 121 kb region, comprising
of ten candidate Ctv resistance genes. The ten candidate genes were individually cloned in Agrobacterium based binary vector and transformed into three CTV susceptible grapefruit varieties. Two of the candidate R-genes, R-2 and R-3 are exclusively expressed in transgenic plants and in Poncirus trifoliata, while five other genes are also expressed in non-transformed Citrus controls. Northern blotting with a CTV derived probe for assessment of infection in virus inoculated plants over a span of
three growth periods, each comprising of six to eight weeks, indicates either an absence of initiation of infection or it’s
slow spread in R-2 plant lines or an initial appearance of infection and it’s subsequent obliteration in some R-1 and R-4 plant lines. Limited genome walk up- and downstream form R-1 gene, based on it’s 100% sequence identity between Poncirus and Citrus, indicates promoter identity of 92% between the two varieties. Further upstream and downstream sequencing indicates the presence
of an O-methyl transferase and a Copia like gene respectively in Citrus instead of the amino acid transporter like gene upstream and a sugar transporter like gene downstream in Poncirus. The possibility of recombinations in the resistance locus of Citrus and the need for consistent monitoring for virus infection and gene expression in the transgenic Citrus trees is discussed.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
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Zhihua Liao Min Chen Yijian Yang Chunxian Yang Yufan Fu Qitang Zhang Qiang Wang 《Biologia》2008,63(2):221-226
Isopentenyl diphosphate isomerase (IDI, EC 5.3.3.2) catalyzes the revisable conversion of 5-carbon isopentenyl diphosphate
and its isomer dimethylallyl diphosphate, which are the essential precursors for isoprenoids, including carotenoids. Here
we report on the cloning and characterization of a novel cDNA encoding IDI from sweet potato. The full-length cDNA is 1155
bp with an ORF of 892 bp encoding a polypeptide of 296 amino acids, which was designated as IbIDI (GenBank Acc. No: DQ150100). The computational molecular weight is 33.8 kDa and the theoretical isoelectric point is 5.76.
The deduced amino acid sequence of IbIDI is similar to the known plant IDIs. The tissue expression analysis revealed that
IbIDI expressed at higher level in sweet-potato’s mature leaves and tender leaves than that in tubers, meanwhile, no expression
signal could be detected in veins. Recombinant IbIDI was heterologously expressed in engineered Escherichia coli which led to the reconstruction of the carotenoid pathway. In the engineered E. coli, IbIDI could take the role of Arabidopsis IDI gene to produce the orange β-carotene. In summary, cloning and characterization of the novel IDI gene from sweet potato will facilitate our understanding
of the molecular genetical mechanism of carotenoid biosynthesis and promote the metabolic engineering studies of carotenoid
in sweet potato. 相似文献