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M Delseny

Publications and source records attributed to M Delseny.

At least 55 records · Page 3Linked to original sources
PubMed1997

cDNA sequence, genomic organization and differential expression of three Arabidopsis genes for germin/oxalate oxidase-like proteins.

Wheat germin is a protein expressed during germination which possesses an oxalate oxidase activity. Germin-type oxalate oxidases have been extensively studied in monocotyledons (wheat and barley) where they are thought to have important functions for development, stress response and defence against pathogens. In contrast, almost nothing is known about the germin-like proteins found in dicotyledons, gymnosperms and myxomycetes. In this work, cDNA clones for three genes (ATGER1, ATGER2 and ATGER3) encoding germin-like proteins, initially characterized as expressed sequence tags (ESTs), from Arabidopsis thaliana cDNA libraries were further characterized. In addition, we isolated and sequenced a Brassica napus cDNA which was strongly homologous to the cDNA for ATGER1. Sequence analysis and secondary structure predictions of the proteins encoded by these cDNAs showed that they possess all the characteristic features of members of the germin family and of the germin/seed globulins/sucrose binding protein superfamily. Sequence comparisons and mapping demonstrated the existence of at least two different gene families in the A. thaliana genome encoding a minimum of three genes for germins. These three genes have been mapped in three different location on the Arabidopsis genome. By northern blot hybridizations we found that these genes are differentially regulated. ATGER1 was expressed during germination, like wheat germin, but also in leaves whereas ATGER2 transcripts were exclusively found in developing embryos, like wheat pseudo-germin. ATGER3 mRNAs were found in leaves and flowers and their abundance was shown to vary during the circadian cycle.

Amino Acid Sequence↗
PubMed1997

A new Arabidopsis nucleic-acid-binding protein gene is highly expressed in dividing cells during development.

An Arabidopsis thaliana cDNA encoding a new RNA-binding protein (RBP37) was cloned from a silique cDNA library. The predicted amino acid sequence corresponds to a RBP containing two RNA recognition motifs (RRM) and a basic domain. An affinity for nucleic acids was confirmed in binding assays using in vitro synthesised AtRBP37 protein. In situ hybridisation experiments on sections of flowers and siliques showed expression only in growing organs: gynoecium, petals, filaments and during early-embryogenesis expression is located in the embryo proper and the suspensor up to late heart stage. Expression is not detected in the embryo during maturation. This results suggests an expression pattern correlated with dividing cells.

Amino Acid Sequence↗
PubMed1997

BANYULS, a novel negative regulator of flavonoid biosynthesis in the Arabidopsis seed coat.

A mutant of Arabidopsis that accumulates a high level of red pigments within the seed coat has been isolated from a population of T-DNA-transformed plants. Genetic analysis revealed that the mutation is recessive and affects maternal seed tissues only. Due to the color of the immature seeds, this mutation was named banyuls (ban). Pigments accumulated continuously from early seed development to the desiccation stage in the seed coat of the mutant. The phenotype of the double mutant banyuls/ transparent testa confirmed the flavonoid nature of the pigments and enabled assignment of the regulatory TT (Transparent Testa) genes to two groups according to their epistatic relationship to ban. The flavonoid content of germinated ban and wild-type seedlings was similar. Plants harbouring the ban mutation had a normal formation of trichomes and root hairs and were not affected in their responses to light. The seeds of ban plants exhibited reduced germination compared to wild-type which may be a direct consequence of the high level of pigments. These results suggest that BANYULS functions as a negative regulator of flavonoid biosynthesis that prevents accumulation of pigments in the seed coat during early embryogenesis in Arabidopsis.

Anthocyanins↗
PubMed1997

Identification of members of gene families in Arabidopsis thaliana by contig construction from partial cDNA sequences: 106 genes encoding 50 cytoplasmic ribosomal proteins.

Partial cDNA sequencing to obtain expressed sequence tags (ESTs) has led to the identification of tags to about 8,000 of the estimated 20,000 genes on Arabidopsis thaliana. This figure represents four to five times the number of complete coding sequences from this organism available in international databases. In contrast to mammals, many proteins are encoded by multigene families in A. thaliana. Using ribosomal protein gene families as an example, it is possible to construct relatively long sequences from overlapping ESTs which are of sufficiently high quality to be able to unambiguously identify tags to individual members of multigene families, even when the sequences are highly conserved. A total of 106 genes encoding 50 different cytoplasmic ribosomal protein types have been identified, most proteins being encoded by at least two and up to four genes. Coding sequences of members of individual gene families are almost always very highly conserved and derived amino acid sequences are almost, if not completely, identical in the vast majority of cases. Sequence divergence is observed in untranslated regions which allows the definition of gene-specific probes. The method can be used to construct high-quality tags to any protein.

Amino Acid Sequence↗
PubMed1996

Genetic and physical mapping in Brassica diploid species of a gene cluster defined in Arabidopsis thaliana.

We report the genetic and physical analysis by pulse field gel electrophoresis (PFGE) in three Brassica diploid genomes for a cluster of five genes characterized in a selected segment of 15 kb on chromosome 3 of Arabidopsis thaliana, encoding a Bradyrhizobium CycJ homologue (At1), a rat p67 translation factor homologue (At2), an Em-like (early methionine) protein (At3), chlorophyll synthase (At4) and a yeast Sac1 homologue (A5). The Arabidopsis gene array was found to be conserved on a single linkage group in each of the Brassica genomes. However, partial complexes were found to be duplicated in other chromosome segments on the same or other linkage groups. Some of the At genes, which could not be genetically mapped because of lack of polymorphism, were assigned to their respective linkage groups by physical mapping. The presence of multiple copies of the A. thaliana gene cluster in the three Brassica genomes further establishes their complex nature, which results from extensive duplication and chromosomal rearrangement. In general, genetic distances between the At genes agreed with values expected for the physical distances determined in Brassica.

Aminopeptidases↗
PubMed1996

Molecular characterization of the gene coding for GPRP, a class of proteins rich in glycine and proline interacting with membranes in Arabidopsis thaliana.

The gene coding for a new class of proteins rich in glycine and proline (GPRP) was cloned in Arabidopsis thaliana. In the protein sequence, five amino acids - glycine, proline, alanine, tyrosine and histidine - account for 79.4% of the total composition. The protein has two different glycine-rich domains interrupted by a hydrophobic segment having a high probability of helix formation. The protein synthesized in vitro interacts with microsomes possibly through the hydrophobic domain. The gene in Arabidopsis has two introns, one in the coding region and the other one in the 5' non-coding region. The later one is 778 bp long. Homologous sequences are found in carrot, tomato and tobacco. GPRP mRNA is found in the different organs of the plant analyzed except in mature seeds and anthers, and mostly in epidermal and vascular tissues. Possible hypotheses about the function of GPRP are discussed.

Amino Acid Sequence↗
PubMed1996

Further progress towards a catalogue of all Arabidopsis genes: analysis of a set of 5000 non-redundant ESTs.

Nearly 7000 Arabidopsis thaliana-expressed sequence tags (ESTs) from 10 cDNA libraries have been sequenced, of which almost 5000 non-redundant tags have been submitted to the EMBL data bank. The quality of the cDNA libraries used is analysed. Similarity searches in international protein data banks have allowed the detection of significant similarities to a wide range of proteins from many organisms. Alignment with ESTs from the rice systematic sequencing project has allowed the detection of amino acid motifs which are conserved between the two organisms, thus identifying tags to genes encoding highly conserved proteins. These genes are candidates for a common framework in genome mapping projects in different plants.

Amino Acid Sequence↗
PubMed1996

Induction and expression of seed-specific promoters in Arabidopsis embryo-defective mutants.

In order to assess the importance of morphogenesis on the induction of promoter markers for storage and Lea programmes, advantage was taken of the emb mutations producing embryos arrested at a wide range of developmental stages in Arabidopsis. These embryos are viable during their stage of developmental arrest and continue to divide further, but apparently without further differentiation into the main organs and tissues of the normal embryos. Eight independent emb mutants arrested in their development prior to the cotyledon stage were selected. These emb embryos lack the normal morphology of the wild-type embryos when the synthesis of storage and Lea proteins are normally initiated. The 2S1-uidA chimeric gene, representative of the maturation programme and the Em 1-uidA chimeric gene, representative of the desiccation programme were introduced by crosses into the emb background. In the eight emb lines, the expression of the GUS reporter gene directed by the 2S1 and Em 1 promoters was observed in the aborted seeds irrespective of their stage of developmental arrest. The time of induction of the expression of both promoters was the same in the arrested embryos as compared with the normal embryos within the same silique. Thus, the activation of these two promoters is triggered by the same signal and can occur in the absence of morphogenesis. However, in the absence of normal organ formation, the expression of the reporter gene under the control of the 2S1 and Em1 promoters was evident throughout the whole seed tissues. In normal seed development, the hormone abscisic acid (ABA) activates the promoters of the 2S1 and Em 1 genes. One of the important members of the signal transduction pathway of ABA is the ABI3 protein. It has been shown previously that this protein is a prerequisite for the induction of Em 1 by ABA in seeds. A good correlation with the expression of the ABI3 promoter and the 2S1 and Em 1 promoters was found in emb seeds tissues. This observation suggests that the promoters of the 2S1 and the Em 1 genes are expressed in the mutant seeds not at a basal level, but are probably induced by ABA, as in normal seed development.

2S Albumins, Plant↗
PubMed1996

Complex arrangement of dispersed repeated DNA sequences in Oryza officinalis.

A 525-bp BglII fragment was isolated from Oryza officinalis DNA (accession W1278) and shown to correspond to a new dispersed repetitive DNA sequence with specificity restricted to a subset of the wild rice with a C genome. The sequence of the fragment was determined but it does not correspond to any sequence already present in databases. It contains several imperfect palindromes. Larger genomic clones (12-18 kbp) were isolated and all contain sequences homologous to the BglII element. Analysis of these clones confirms that the BglII element is dispersed in the O. officinalis genome. From one genomic clone, the sequences adjacent to the BglII element were subcloned and used as probes to demonstrate that the sequences flanking the BglII element are variable in different genomic clones and that some of them are also dispersed repetitive sequences. The genomic specificity of two of these dispersed repeats was evaluated and shown to be different from that of the initial BglII element. This analysis revealed a complex arrangement of various dispersed repeated sequences.

Bacterial Proteins↗
PubMed1996

Sequencing and mapping the Arabidopsis genome: a weed model for real crops.

Arabidopsis is a crucifer weed with a small genome of about 120 Mbp which has been chosen as a model species for plant molecular genetics. Four years ago, a consortium of nine French laboratories, including ours, initiated a project aimed at mapping the transcribed regions of the genome. The strategy employed was to systematically and randomly sequence cDNA clones isolated from libraries made from different tissues and organs of plants grown under various physiological conditions. The consortium released about 7,000 expressed sequenced tags (ESTs) in the dbEST database corresponding to approximately 3,500 unique genes. In the next phase of the programme, a YAC library with average inserts of 500 kbp has been prepared. We have now started to use the EST information to map the cDNA clones on these YACs. The most recent aspect of Arabidopsis sequencing is the ESSA (European Scientists Sequencing Arabidopsis) project, in which the aim is to describe 2.5 Mbp by the end of 1996. Genomic sequencing has revealed a very high gene density. Comparison of present genomic sequencing results with the EST data suggests that up to half of the genes might already be tagged with an EST. In collaboration with Carlos Quiros' group in Davis we have also analysed the conservation of a 30 kbp locus (Em 1, a late embryogenesis abundant protein gene) on chromosome 3 between Arabidopsis and several Brassica species. Progress on these various aspects will be reviewed. We shall also present some sequence comparisons between Arabidopsis and rice ESTs. These results suggest that it should be possible in the very near future to map a pool of common genes onto many different plant genomes. This should provide a common framework to integrate maps from different species and facilitate mapbased cloning of genes of agronomical importance.

Arabidopsis↗
PubMed1995

A chlorophyll synthetase gene from Arabidopsis thaliana.

During the course of an Arabidopsis thaliana genome sequencing project, we identified a gene, G4, with a derived amino acid sequence showing homology to the product of the Rhodobacter capsulatus bchG locus which is involved in the esterification of bacteriochlorophyllide with geranylgeraniol. The relationship between this gene and bchG was confirmed by the isolation and analysis of a corresponding full-length cDNA. Comparison of genomic and cDNA sequences indicated that the gene is made up of 14 exons, some of them being very short. Southern and Northern analyses showed that this sequence represents a single-copy gene and its transcript is detected only in green or greening tissues. Both homologies and expression data suggest that this gene encodes a chlorophyll synthetase, one of the last enzymes of chlorophyll biosynthesis, and thus represents a new example of a nuclear gene encoding an enzyme of this pathway in higher plants.

Amino Acid Sequence↗
PubMed1995

A rapeseed cold-inducible transcript encodes a phosphoenolpyruvate carboxykinase.

We have isolated a clone corresponding to a new cold-regulated gene from a cDNA library made from rapeseed (Brassica napus cv Samourai) cold-acclimated etiolated seedlings. Sequence analysis and homology searches showed that this clone encodes a protein highly homologous to the ATP-dependent phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.49) from Saccharomyces cerevisiae, Trypanosoma, Rhizobium sp., and Escherichia coli; we refer to the B. napus clone as BnPEPCK. A potential ATP-binding site existing in all PEPCK proteins was also found in BnPEPCK. Although there was a basal expression of BnPEPCK in seedlings grown at control, room temperature, the steady-state level of the transcripts increased at 4 degrees C and decreased to normal levels when the seedlings were returned to control temperature (22 degrees C). Using antibodies made against a recombinant histidine-BnPEPCK fusion protein, we demonstrated that BnPEPCK protein level is correlated with the accumulation of the BnPEPCK transcript.

Acclimatization↗
PubMed1995

Characterization of a dispersed repetitive DNA sequence associated with the CCDD genome of wild rice.

A HindII repetitive fragment (pOD3) was isolated and cloned from the genomic DNA of an accession of Oryza latifolia, a wild rice species that possesses a tetraploid CCDD genome. Southern blot analysis using this clone as a probe demonstrated that this repetitive DNA sequence had a dispersed organization in the CCDD genome and seemed to be highly specific for this genome type. This fragment is the first CCDD-specific repeated DNA sequence to be described. The hybridization pattern is similar for most CCDD accessions tested, although a few showed no hybridization signal. The nucleotide sequence of the element cloned in pOD3 was determined and analysed. The 1783 base pair long repeated sequence shows no homology with other known nucleotide sequences. In addition, none of the amino acid sequences deduced from the potential open reading frames contained in the pOD3 repeat is homologous to any known protein. The nucleotide sequence presents several internal repeats, direct or inverted, but their significance remains unknown.

Base Sequence↗
PubMed1994

A pair of genes coding for lipid-transfer proteins in Sorghum vulgare.

Approximately five genes coding for lipid-transfer proteins (LTP) can be detected in Sorghum vulgare by DNA blots using a specific genomic probe. Two of these genes have been identified and sequenced. The two genes (ltp1 and ltp2) code for very similar (91.8% identity) proteins, they are separated by approx. 4 kb of DNA and their open reading frames may be read in the same direction. The gene (ltp1) located upstream has an intron placed in the same position already described for other ltp in maize and rice. Gene ltp2 has no intron. cDNAs corresponding to ltp1 have been identified in a 6-day-old plantlet library, but not for ltp2. The results of the comparison between the two sequences indicate the presence of a gap between the two genes in their promoter region. LTP seem to be coded for in plants by a small family of genes. At least in sorghum, two of its components are tightly clustered in the same genomic region.

Amino Acid Sequence↗
PubMed1994

Plant ribosomal DNA external spacer binding factors: a novel protein binds specifically to a sequence close to the primary pre-rRNA processing site.

Sequence analyses of the ribosomal DNA (rDNA) external spacer region revealed a peculiar structure around the primary pre-rRNA processing site in radish. Using the electrophoretic mobility shift assay, DNAse I footprinting and methylation interference analysis, we have identified in radish extracts a novel nuclear factor, NF B, that recognises this region. NF B binds to a unique CGATTTTGCCCCTGA sequence located 164 bp downstream of the transcription initiation site and immediately upstream of the pre-rRNA processing site. Interestingly, this motif is flanked by four homologous sequences, including the primary pre-rRNA processing site, which are not recognised by NF B. Based on these data and the prediction that alternative hairpin loops can be formed in this region of the nascent pre-rRNA, a putative role for NF B as a factor coupling transcription and pre-rRNA processing is discussed. NF B is unique among plant and animal rDNA-binding proteins and it differs from a previously described radish factor and from other proteins that bind to plant rDNA promoters.

Base Sequence↗
PubMed1994

Characterization of a rice gene coding for a lipid transfer protein.

The cloning and sequence analysis of a gene that encodes a lipid transfer protein (LTP) from rice is reported. A genomic DNA library from Oryza sativa was screened using a cDNA encoding a maize LTP. One genomic clone containing the gene (Ltp) was partially sequenced and analyzed. The open reading frame is interrupted by an 89-bp intron. From the results of Southern hybridizations, Ltp appears to be a member of a small multigenic family. Transcripts of the corresponding gene were detected in several tissues including coleoptile, leaf, endosperm, scutellum and root. The transcription start point was determined by primer extension. The deduced amino-acid sequence of the Ltp product is shown to be homologous to LTPs from other crops.

Amino Acid Sequence↗
PubMed1994

mRNA accumulation and promoter activity of the gene coding for a hydroxyproline-rich glycoprotein in Oryza sativa.

The accumulation of the mRNA corresponding to the gene coding for a hydroxyproline-rich glycoprotein has been studies in rice. The patterns of gene expression obtained are similar to those observed in maize in regions rich in dividing cells such as the meristematic zones of roots. However, the gene does not seem to be induced by wounding as it is the case in maize. This effect is correlated with the absence of sequences present in the promoter of the maize gene and that have been described as responsible for ethylene induction on other plant systems. Instead, the promoter has a sequence that corresponds to abscisic acid-responsive elements and, in fact, HRGP mRNA levels can be two-fold increased in rice leaves by ABA. The genes coding for homologous proteins in two cereal species such as maize and rice appear, therefore, to have distinct mechanisms of gene regulation.

Abscisic Acid↗