Ribosomal RNA genes of Phaseolus coccineus. I

Maggini, F.; Tucci, G. F.; Demartis, Anna; Gelati, M. T.; Avanzi, S.

doi:10.1007/bf00047710

Cited by 29 publications

(14 citation statements)

References 51 publications

(15 reference statements)

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“…are concerned, an ability to enhance transcription from the rDNA promoter has been hypothesized in several plants (Flavell 1986;Maggini et al 1992;Sardana et al 1993;Hemleben and Zentgraf 1994), in some cases only on the basis of the analogy with animal systems (Reeder 1989); this is the case of the s.r. in wheat that have been considered as enhancers because of sequence homology with its own promoter and with Xenopus promoter region (Flavell 1986;Barker et al 1988).…”

Section: Discussionmentioning

confidence: 98%

The intergenic spacer region of the rDNA in Olea europaea L.

Maggini

Gelati

Spolverini

et al. 2007

Tree Genetics & Genomes

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The intergenic spacer (IGS) region of rDNA in Olea europaea is 5,629 bp long and it can be subdivided, on the basis of the different features, into six regions; two of them, located upstream and downstream of the putative transcription initiation site (TIS), respectively, contain prominent and unrelated subrepeats (s.r.). The upstream s.r. are 75-86 bp in length and the downstream ones are about 160 bp in length. The first type is represented by a high number (36) of iterations, which share a mutual similarity of 82.5%. A single sequence (TATTATAGGGGGGAGG) is found, which fits the reported TIS of plants and the position +1 would correspond to the adenine at position 3,622 after the 3′ end of 25 S ribosomal RNA (rDNA) genes. Moreover, in Olea IGS region some unusual features are observed and discussed in relation to analogous data present in the literature.

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Section: Discussionmentioning

confidence: 98%

The intergenic spacer region of the rDNA in Olea europaea L.

Maggini

Gelati

Spolverini

et al. 2007

Tree Genetics & Genomes

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“…The lack of promoter duplication in Ginkgo, and its associated enhancement of transcription, might be counteracted by the presence of large repeat units (comprising several AT-rich motifs that are duplicated throughout the entire B box), which occur proximal to the promoter region. They have been hypothesized to serve as additional specificity enhancers for protein binding, playing an important role in enhancing transcription activity (Maggini et al, 1992;Bauer et al, 2009). A short sequence, CACAAACACAAA, found 98 nucleotides upstream of the TIS, was similar to the angiosperm motif CCAAAAAAGA, which has been implicated in protein binding (Bauer et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba

2012

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In seed plants, the colocalization of the 5S loci within the intergenic spacer (IGS) of the nuclear 45S tandem units is restricted to the phylogenetically derived Asteraceae family. However, fluorescent in situ hybridization (FISH) colocalization of both multigene families has also been observed in other unrelated seed plant lineages. Previous work has identified colocalization of 45S and 5S loci in Ginkgo biloba using FISH, but these observations have not been confirmed recently by sequencing a 1.8 kb IGS. In this work, we report the presence of the 45S-5S linkage in G. biloba, suggesting that in seed plants the molecular events leading to the restructuring of the ribosomal loci are much older than estimated previously. We obtained a 6.0 kb IGS fragment showing structural features of functional sequences, and a single copy of the 5S gene was inserted in the same direction of transcription as the ribosomal RNA genes. We also obtained a 1.8 kb IGS that was a truncate variant of the 6.0 kb IGS lacking the 5S gene. Several lines of evidence strongly suggest that the 1.8 kb variants are pseudogenes that are present exclusively on the satellite chromosomes bearing the 45S-5S genes. The presence of ribosomal IGS pseudogenes best reconciles contradictory results concerning the presence or absence of the 45S-5S linkage in Ginkgo. Our finding that both ribosomal gene families have been unified to a single 45S-5S unit in Ginkgo indicates that an accurate reassessment of the organization of rDNA genes in basal seed plants is necessary.

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“…RNA quantification was checked by means of both ethidium bromide staining of agarose gels and hybridization with a 25S rRNA probe (not shown) from Phaseolus coccineus [22]. Total RNA samples were separated in 6~o formaldehyde-1.2~o agarose gels and blotted onto Hybond N membranes (Amersham) using 20 x SSC as blotting buffer.…”

Section: Rna Extraction and Northern Blot Analysismentioning

confidence: 99%

Differential ethylene-inducible expression of cellulase in pepper plants

et al. 1995

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Ethylene promotes the abscission of leaves and the ripening of fruits in pepper plants, and in both events an increase in cellulase activity is observed. However, two enzyme isoforms (pI 7.2 and 8.5, respectively) are differentially involved in the two physiological phenomena. The pI 8.5 form has been purified from ripe fruits. It is a glycoprotein with an apparent molecular mass of 54 kDa. Two short peptides were sequenced and a very high homology to a tomato cellulase was observed. Polyclonal antibodies, raised against the purified enzyme, have allowed us to demonstrate that the observed ethylene-induced increase in cellulase activity is paralleled by de novo synthesis of protein. Three cDNAs (CX1, CX2 and CX3), encoding different cellulases, were obtained and characterized and their expression investigated. Accumulation of all three mRNAs is induced by ethylene treatment, though to different levels. CX1 is mainly expressed in ripe fruits while CX2 is especially found in abscission zones. CX3 accumulates at very low levels in activated abscission zones. Comparisons with other known cellulases demonstrate clear heterogeneity within the higher plant cellulases. Differences in ethylene inducibility and molecular structure suggest different physiological roles for cellulase in pepper plants.

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Ribosomal RNA genes of Phaseolus coccineus. I

Cited by 29 publications

References 51 publications

The intergenic spacer region of the rDNA in Olea europaea L.

The intergenic spacer region of the rDNA in Olea europaea L.

Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba

Differential ethylene-inducible expression of cellulase in pepper plants

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