Emilia Labrador

University of Salamanca · Department of Vegetal Physioloy

Main conclusion ST1 and ST6 are possibly involved in primary and lateral root and symbiotic nodule development, but only ST6 participates in the interaction with hemibiotrophic fungi. Abstract Specific tissue (ST) proteins have been shown to be involved in several processes related to plant nutritional status, development, and responses to biotic...

Main conclusion β-(1,4)-galactan determines the interactions between different matrix polysaccharides and cellulose during the cessation of cell elongation. AbstractDespite recent advances regarding the role of pectic β-(1,4)-galactan neutral side chains in primary cell wall remodelling during growth and cell elongation, little is known about the s...

Main conclusion Galactan turnover occurs during cell elongation and affects the cell wall xyloglucan structure which is involved in the interaction between cellulose and xyloglucan. β-(1,4)-Galactan is one of the main side chains of rhamnogalacturonan I. Although the specific function of this polymer has not been completely established, it has been...

In Cicer arietinum, as in several plant species, the β-galactosidases are encoded by multigene families, although the role of the different proteins is not completely elucidated. Here, we focus in 2 members of this family, βIII-Gal and βIV-Gal, with high degree of amino acid sequence identity (81%), but involved in different developmental processes...

In this work, we study the function of the Medicago truncatula ST4, ST5 and ST6 proteins that belong to a protein family of unknown function characterized by the DUF2775 domain. Thus, we analyse their promoter sequence and activity, their transcript accumulation, and their subcellular location. The analysis of the three promoters showed different c...

Background ShooT specific/Specific Tissue (ST) belong to a protein family of unknown function characterized by the DUF2775 domain and produced in specific taxonomic plant families, mainly Fabaceae and Asteraceae, with the Medicago truncatula ST family being the largest. The putative roles proposed for this family are cell elongation, biotic interac...

This work studied the six β-galactosidases (BGALs) of the subfamily a1 of Arabidopsis, that have been proposed to play important roles in the cell wall remodelling during plant development, although their precise functions are still unknown. Knockout mutants bgal1, bgal2, bgal3, bgal4, bgal5, and bgal12 of Arabidopsis and their wild type (WT) plant...

The aim of this work is to gain insight into the six members of the a1 subfamily of the β-galactosidases (BGAL) from Arabidopsis thaliana. First, the subcellular location of all these six BGAL proteins from a1 subfamily has been established in the cell wall by the construction of transgenic plants producing the enhanced green fluorescent protein (e...

The ST (ShooT Specific) proteins are a new family of proteins characterized by a signal peptide, tandem repeats of 25/26 amino acids, and a domain of unknown function (DUF2775), whose presence is limited to a few families of dicotyledonous plants, mainly Fabaceae and Asteraceae. Their function remains unknown, although involvement in plant growth,...

The plant cell wall is a dynamic structure whose constant modification is necessary for plant cells to grow and divide. In the cell walls of chickpea (Cicer arietinum) there are at least four β-galactosidases, whose presence and location in embryonic axes during the first 48 h of seed imbibition are discussed in this paper. We examined their roles...

βIII-Gal, a member of the chickpea β-galactosidase family, is the enzyme responsible for the cell wall autolytic process. This enzyme, whose activity increases during epicotyl growth, displays significant hydrolytic activity against cell wall pectins and its natural substrate has been determined as an arabinogalactan from the pectic fraction of the...

Background Many proteins with tandem repeats in their sequence have been described and classified according to the length of the repeats: I) Repeats of short oligopeptides (from 2 to 20 amino acids), including structural cell wall proteins and arabinogalactan proteins. II) Repeats that range in length from 20 to 40 residues, including proteins with...

Accession numbers of the sequences encoding proteins similar to ST proteins. Sequences were obtained after different searches in EMBL databases as indicated in Methods. Full-length ORFs of chickpea CarST1 and CarST2 nucleotides sequences were used as well as the nucleotide sequences of their conserved repeats.

ST deduced amino acid sequences organized by repeats and sorted by alphabetical order of the plant species. The signal peptide is highlighted in grey; the first repeat is highlighted in green (except when it was chosen for the alignment); in blue, the repeats used for the analysis of alignment; in yellow, the Tyr in the repeats; in dark green, the...

Alphabetical list of plant species were sequences encoding ST proteins were found. The file indicates the number of the different ST sequences found in each species and their names.

Promoter regions of each of the six AtBGAL gene of the subfamily a1 of Arabidopsis thaliana were used to drive the expression of the β-glucuronidase gene. The pattern of promoters (pAtBGAL) activity was followed by histological staining during plant development. pAtBGAL1, pAtBGAL3 and pAtBGAL4 showed a similar activity pattern, being stronger in ce...

We report localisation of the chickpea βI-Gal, a member of the chickpea β-galactosidase family, which contains at least four members. After generation of specific antibodies, the distribution and cellular immunolocalisation of the protein in different organs and developmental stages of the plant was studied. βI-Gal protein is much longer than the o...

On Jan 5, 2011 this sequence version replaced gi:3204133.

In a previous work, the immunolocation of the chickpea XTH1 (xyloglucan endotransglucosylase/hydrolase 1) protein in the cell walls of epicotyls, radicles, and stems was studied, and a role for this protein in the elongation of vascular cells was suggested. In the present work, the presence and the location of the XTH1 protein in embryonic axes dur...

Here, we compare the germination of chickpea seeds when they were imbibed in mannitol and in ABA. Radicle protusion was delayed by both treatments, however, while the negative effect of mannitol, which severely reduced earlier water uptake, was reversed after 24h of treatment, this was not the case of ABA, indicating a specific effect of the hormon...

We report the generation of antibodies against a ß-galactosidase (ßV-Gal) from Cicer arietinum and the subsequent immunolocalization of the protein in different parts and developmental stages of the plant. ßV-Gal is a cell wall protein encoded by the CanBGal-5 gene, which belongs to a family of at least four ß-galactosidase genes in chickpea. We ha...

Two Kunitz trypsin inhibitors TPI-1 and TPI-2, encoded by CaTPI-1 and CaTPI-2, previously identified and characterized, have been detected in chickpea (Cicer arietinum L.) embryonic axes from seeds imbibed up to 48 h. Their gene transcription commenced before germination sensu stricto was completed. The transcript amount of CaTPI-1 remained high un...

Here, we report the identification and characterization of CaTPI-2, which is a member of a Cicer arietinum gene family encoding Kunitz-type proteinase inhibitors with at least two members -CaTPI-1 and CaTPI-2. The widespread mRNA accumulation of CaTPI-2 in all the different organs of 4-day-old etiolated seedlings and in stem internodes differs from...

We report the generation of antibodies against a ß-galactosidase from Cicer arietinum, ßIV-Gal, and the subsequent immunolocalization of the protein in different parts and developmental stages of the plant. The ßIV-Gal protein is encoded by the CanBGal-4 gene, which belongs to a family of at least four ß-galactosidase genes, transcripts of which we...

Kunitz proteinase inhibitors in legumes have mainly been described as defence and storage proteins. Here, we report a Kunitz trypsin inhibitor, encoded by the CaTPI-1 gene from Cicer arietinum. The transcription of this gene mainly occurs in seedling vegetative organs, and is affected by the light and growth stages. The recombinant TPI-1 protein ex...

Cell wall hydrolases have been assumed to be involved in the regulation of seed germination, mostly through their contribution to the cell wall disassembly associated with endosperm cap weakening. In Cicer arietinum (a non-endospermic leguminosae seed), we have focused our research directly on the elongation process of the embryonic axes themselves...

Cell wall proteins were extracted from maize coleoptiles, Zea mays L. B37 x MO 17, with high concentrations of LiCl. Ion-exchange, chromatofocusing and gel-filtration chromatography were employed extensively to purify exo-β-glucanase activity from the extract. The purified enzyme functioned as an exo-(1→3)-β-glucanase (E.C. 3.2.1.58) and as a gluco...

The protein extracted from the cell wall of the epicotyls of Cicer arietinum L. cv. Castellana was separated by ion exchange chromatography in four different fractions with β-D-galactosidase (EC 3.2.1.23) activity. These were called βI, βII, βIII and βIV, according to their order of elution. βII was associated with a particularly high β-D-glucosida...

Sánchez, O.J., Pan, A., Nicolás, G. and Labrador, E. 1989. Relation of cell wall peroxidase activity with growth in epicotyls of Cicer arietinum. Effects of calmodulin inhibitors. Peroxidases are bound ionically to cell walls in epicotyls of Cicer arietinum L. cv. Castellana. The cell wall peroxidase activity increases during the growth of epicotyl...

The inhibition of growth by polyethlene glycol (PEG)-induced osmotic stress led to modifications in the changes taking place in cell wall composition during normal growth of epicotyls of Cicer arietinum L. cv. Castellana. Epicotyls growing under normal conditions showed a decrease in the amount of pectic fractions and an increase in the hemicellulo...

The Hw pectic fraction, extracted with hot water, is the major component of 4 days old epicotyl cell walls of Cicer arietinum L. cv. Castellana and is formed of arabinose and galactose, with smaller amounts of rhamnose, xylose, glucose and mannose. The cell wall 2βIII enzymatic fraction, with β-galactosidase activity (EC 3.2.1.23) and the main enzy...

Oryza sativa L. var. bahia coleoptile cell walls show sufficient autolytic activity for the release into the surrounding medium of amounts up to 60 μg of sugars per mg of dry weight of cell wall. The products released elute in Bio-gel P.2 as mono- and polysaccharides with glucose as the sole component. The polysaccharide component releases tri- and...

Polyclonal antibodies were raised in response to βIII-galactosidase purified from cell wall of Cicer arietinum epicotyls. The antibody preparation generated, bound to βIII protein giving a major protein band in the zone corresponding to Mr 45 000, the molecular mass previously estimated for βIII-galactosidase. These antibodies clearly suppress auto...

The autolytic process in epicotyl cell walls of Cicer arietinum L. cv. Castellana, and also the hydrolysis of heat-inactivated cell walls as mediated by a cell wall β-galactosidase (EC 3.2.1.23) (named βIII and previously characterized as responsible for the autolysis), are maximal on the fourth day of germination and coincide with the maximal grow...

In a previous work, a Cicer arietinum cDNA clone (CaXTH1) encoding a xyloglucan endotransglucosylase/hydrolase (XTH1) protein was isolated and characterized. CaXTH1 showed an expression pattern specific to growing tissue: mostly epicotyls and the upper growing internodes of adult stems. CaXTH1 mRNA was not detected in any other organs of either see...

We report the generation of Solanum tuberosum transformants expressing Cicer arietinum βIII-Gal. βIII-Gal is a β-galactosidase able to degrade cell wall pectins during cell wall loosening that occurs prior to cell elongation. cDNA corresponding to the gene encoding this protein was identified among several chickpea β-galactosidase cDNAs, and named...

We have isolated a Cicer arietinum cDNA clone (CaXTH1) encoding a protein that belongs to the family 16 of glycosyl hydrolases and has all the conserved features of xyloglucan endotransglucosylase/hydrolases (XTH) proteins, including the presence of a highly conserved domain (DEIDFEFLG) and four Cys which suggest the potential for forming disulfide...

In the cell wall of Cicer arietinum epicotyls, there are a family of β-galactosidases, one of them named βIII-Gal is a β-galactosidase able to degrade cell wall pectins. The role of the remainder β-galactosidases has not been established. In this paper, we describe the cloning and expression pattern of a family of three C. arietinum β-galactosidase...

Four different cDNAs encoding alpha-expansins have been identified in Cicer arietinum (Ca-EXPA1, Ca-EXPA2, Ca-EXPA3 and Ca-EXPA4). The shared amino acid sequence similarity among the four alpha-expansin proteins ranged from 67 to 89%. All of them display common characteristics such as molecular mass (around 24 kDa), amino acid numbers, and also the...

On Mar 11, 2004 this sequence version replaced gi:11932088.

On Mar 11, 2004 this sequence version replaced gi:11932091.

The cDNA clone (CanBGal-3) encoding a cell wall pectin-degrading beta-galactosidase (beta III-Gal) from Cicer arietinum L. cv. Castellana has been identified. The identification was carried out by comparing the deduced amino acid sequences of several isolated chickpea beta-galactosidase clones with the purified beta III-Gal protein sequence. The ex...

The cDNA named Cap28 was isolated from an epicotyl cDNA library of Cicer arietinum stressed seedlings as a clone whose transcript abundance decreased under the PEG-induced water stress. Since under this condition epicotyl growth was inhibited, the involvement of the corresponding gene in the growth process was studied. One feature of its encoded pr...

A cDNA clone encoding a cytosolic superoxide dismutase (SOD) was isolated from a cDNA library constructed from poly(A)+RNA from epicotyls of 5-day-old Cicer arietinum L. etiolated seedlings after a differential screening to select clones whose expression decreases with epicotyl growth. Analysis of its deduced amino acid sequence showed all the typi...

Plant lectins are a group of glycoproteins with the ability to recognize and bind carbohydrate ligands. Seed lectins function as storage and defense proteins, but the specific function of vegetative lectins is uncertain. In this paper we describe the characterization of a clone, CanVLEC, encoding a vegetative lectin from chickpea (Cicer arietinum L...

The present study was undertaken to identify and characterize clones whose expression increase during Cicer arietinum epicotyl growth. Two cDNAs encoding two different plant metallothionein (MT)-like proteins have been isolated from a cDNA library from epicotyls of Cicer arietinum L. cv. Castellana. The CanMT-1 deduced protein appears to have the t...

Water stress induces biochemical and physiological responses in plants, such as growth inhibition. A number of genes that respond to drought stress in Cicer arietinum are described and their expression patterns are studied in order to give an approach of their function. Genes coding for lipid transfer proteins (LTP) and late embryogenesis abundant...

Small GTPases of the Rab family are important proteins that take part in the control of vesicular membrane traffic, and the Rab-specific GDP dissociation inhibitor protein is one of the most important accessory proteins that regulate this process. A cDNA clone (CanGDI) encoding a Rab-specific GDP dissociation inhibitor was isolated from a cDNA libr...

Small GTPases of the Rab family are important proteins that take part in the control of vesicular membrane traffic, and the Rab-specific GDP dissociation inhibitor protein is one of the most important accessory proteins that regulate this process. A cDNA clone (CanGDI) encoding a Rab-specific GDP dissociation inhibitor was isolated from a cDNA libr...

A cDNA clone, CanTUB, encoding a putative -tubulin protein was isolated from a cDNA library constructed from 5-day old chickpea (Cicer arietinum) epicotyls. Analysis of its deduced amino acid sequence showed all the typical structural motifs of plant -tubulins. Putative sequences for autoregulation and tubulin mRNA stability, GTP and Ca2+/MAPs (mic...

The proline-rich proteins (PRPs) form a class of plant cell wall structural proteins. The expression of PRP genes is organ- and tissue-specific and it is induced in response to wounding, infection and other stress conditions, but the role of these proteins in the cell wall during development and stress has not yet been established. Our objective wa...

Two cDNAs, CanST-1 and CanST-2, encoding two different growth-related organ-specific sequences have been isolated from a cDNA library from growing epicotyls of Cicer arietinum. An intriguing property of these two clones is the presence in their coding region of a repeated sequence which is highly conserved except for the number of repeats. The corr...

Cell wall glycanhydrolytic enzymes have been related to cell wall loosening and cell growth, although the mechanism of this relationship has not been clarified. Since auxins are plant hormones that stimulate growth in elongating organs, in the present work we studied the effect of auxin on cell wall glycanhydrolytic enzymes, which were extracted wi...

In epicotyls of Cicer arietinum, there is a specific release of sugars when the cell wall is incubated at pH 1 (acid degradation). This process is distinct from the enzymatic cell wall autolysis which takes place at pH 5.5. The release is faster during the acid degradation and the products released are mainly polysaccharides with a high proportion...

Polyclonal antibodies were raised in response to βIII-galactosidase purified from cell wall of Cicer arietinum epicotyls. The antibody preparation generated, bound to βIII protein giving a major protein band in the zone corresponding to Mr 45 000, the molecular mass previously estimated for βIII-galactosidase. These antibodies clearly suppress auto...

Simulation of drought by polyethylene glycol (PEG) inhibited elongation of epicotyls of Cicer arietinum L. cv. Castellana but had no effect on growth capacity since growth was restored once the inhibitory condition had been removed. The amount of proteins in the cell wall was correlated with the elongation of the epicotyls and decreased when elonga...

Fractionation and partial purification of the proteins extracted from cell walls of Cicer arietinum epicotyl reveal the presence of two fractions with peroxidase activity, denominated Px-1 and Px-2 according to their order of elution from a SP-Sephadex chromatography column. The specific activity of the Px-2 fraction increases with the age of the e...

In the cell walls of epicotyls of Cicer arietinum we found β-glucosidase and α-galactosidase activities, the former being predominant. We purified and characterized these enzymatic activities. The β-glucosidase activity is found associated with a protein fraction that also shows β-galactosidase and β-xylosidase activity. It is formed by two subunit...

During the growth of Cicer arietinum epicotyls an increase in specific cell wall β-glucosidase and β-galactosidase activities were observed. In contrast, the amount of cell wall proteins extracted with 3 M LiCl decreased between the third and the fourth day of germination, remaining constant up to the seventh day. Partial purification of the cell w...

β-Galactosidase (EC 3.2.1.23) has been established as the main enzyme involved in the autolytic process. The enzyme extracted from cell walls of epicotyls of Cicer arietinum L. cv. Castellana with 3 M LiCl is a 45 kDa protein composed of a single subunit, having an optimum pH of 4; an optimum temperature of 45°C and Km and Vmax of 1.72 mM and 18.5...

Coleoptile cell wall proteins from Zea mays L. hybrid B 37 × Mo 17 were extracted and fractionated. Three enzymes identified in that extract were examined to determine their role in cell wall hydrolysis with a goal of evaluating the extent to which they participated in autohydrolytic reactions. Two separate proteins were identified as endo- and exo...

Two protein fractions with activity as α-galactosidase (EC 3.2.1.22) and α-arabinosidase (EC 3.2.1.55), respectively, were identified in the proteins of cell wall of Cicer arietinum L. cv. Castellana extracted with 3 M LiCl. These fractions were partially purified by gel filtration chromatography (Bio Gel P-150), increasing the specific arabinosida...

The germination of seeds and growth of embryonic axes of Cicer arietinum L. are retarded or inhibited either by supraoptimal temperatures (30°C or above) or by the presence of abscisic acid (ABA). Both treatments delay the degradation of non-cellulosic cell wall sugars which takes place under normal germination conditions. It seems that this delay...

The products released in cell wall autolysis from 4-day-old epicotyls of Pisum sativum elute in gel filtration chromatography (Bio Gel P.2) as two components, mono and polysaccharides, in a practically constant ratio over the time of incubation. The polysaccharides are mainly composed of arabinose and galactose, with smaller amounts of xylose and g...

Pisum sativum L. (cv. Lincoln) epicotyl cell walls show autohydrolysis and release into the incubation medium up to 120 μg of sugar per mg of cell wall dry weight in 30 h. Cell walls from younger epicotyls with high growth capacity showed higher auto-lytic capacity than older epicotyls. This suggests that both processes, growth and au-tolysis, are...

A fractionation of non-cellulosic sugars of Oryza sativa L. coleoptile cell walls was carried out and the composition of each fraction was studied during coleoptile growth. Percentages of fractions extracted with boiling water and with oxalate (pectic substances) were almost constant throughout development. An increase in the K II hemicellulosic fr...