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1.
Front Plant Sci ; 13: 919299, 2022.
Article in English | MEDLINE | ID: mdl-35937324

ABSTRACT

The impact of global warming on transpiration and photosynthesis would compromise plant fitness, impacting on crop yields and ecosystem functioning. In this frame, we explored the performance of a set of Arabidopsis mutants carrying partial or total loss-of-function alleles of stomatal development genes and displaying distinct stomatal abundances. Using microscopy and non-invasive imaging techniques on this genotype collection, we examined anatomical leaf and stomatal traits, plant growth and development, and physiological performance at optimal (22°C) and supra-optimal (30°C) temperatures. All genotypes showed thermomorphogenetic responses but no signs of heat stress. Data analysis singled out an extremely low stomatal abundance mutant, spch-5. At 22°C, spch-5 had lower transpiration and warmer leaves than the wild type. However, at 30°C, this mutant developed larger stomata and thinner leaves, paralleled by a notable cooling capacity, similar to that of the wild type. Despite their low stomatal density (SD), spch-5 plants grown at 30°C showed no photosynthesis or growth penalties. The behavior of spch-5 at supra-optimal temperature exemplifies how the effect of very low stomatal numbers can be counteracted by a combination of larger stomata and thinner leaves. Furthermore, it provides a novel strategy for coping with high growth temperatures.

2.
Front Plant Sci ; 11: 584471, 2020.
Article in English | MEDLINE | ID: mdl-33154763

ABSTRACT

Mitogen-activated protein kinases (MAPK) play pivotal roles in transducing developmental cues and environmental signals into cellular responses through pathways initiated by MAPK kinase kinases (MAP3K). AtYODA is a MAP3K of Arabidopsis thaliana that controls stomatal development and non-canonical immune responses. Arabidopsis plants overexpressing a constitutively active YODA protein (AtCA-YDA) show broad-spectrum disease resistance and constitutive expression of defensive genes. We tested YDA function in crops immunity by heterologously overexpressing AtCA-YDA in Solanum lycopersicum. We found that these tomato AtCA-YDA plants do not show developmental phenotypes and fitness alterations, except a reduction in stomatal index, as reported in Arabidopsis AtCA-YDA plants. Notably, AtCA-YDA tomato plants show enhanced resistance to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 and constitutive upregulation of defense-associated genes, corroborating the functionality of YDA in tomato immunity. This function was further supported by generating CRISPR/Cas9-edited tomato mutants impaired in the closest orthologs of AtYDA [Solyc08g081210 (SlYDA1) and Solyc03g025360 (SlYDA2)]. Slyda1 and Slyda2 mutants are highly susceptible to P. syringae pv. tomato DC3000 in comparison to wild-type plants but only Slyda2 shows altered stomatal index. These results indicate that tomato orthologs have specialized functions and support that YDA also regulates immune responses in tomato and may be a trait for breeding disease resistance.

3.
Front Plant Sci ; 10: 1300, 2019.
Article in English | MEDLINE | ID: mdl-31736989

ABSTRACT

Stomatal abundance determines the maximum potential for gas exchange between the plant and the atmosphere. In Arabidopsis, it is set during organ development through complex genetic networks linking epidermal differentiation programs with environmental response circuits. Three related bHLH transcription factors, SPCH, MUTE, and FAMA, act as positive drivers of stomata differentiation. Mutant alleles of some of these genes sustain different stomatal numbers in the mature organs and have potential to modify plant performance under different environmental conditions. However, knowledge about stomatal genes in dicotyledoneous crops is scarce. In this work, we identified the Solanum lycopersicum putative orthologs of these three master regulators and assessed their functional orthology by their ability to complement Arabidopsis loss-of-function mutants, the epidermal phenotypes elicited by their conditional overexpression, and the expression patterns of their promoter regions in Arabidopsis. Our results indicate that the tomato proteins are functionally equivalent to their Arabidopsis counterparts and that the tomato putative promoter regions display temporal and spatial expression domains similar to those reported for the Arabidopsis genes. In vivo tracking of tomato stomatal lineages in developing cotyledons revealed cell division and differentiation histories similar to those of Arabidopsis. Interestingly, the S. lycopersicum genome harbors a FAMA-like gene, expressed in leaves but functionally distinct from the true FAMA orthologue. Thus, the basic program for stomatal development in S. lycopersicum uses key conserved genetic determinants. This opens the possibility of modifying stomatal abundance in tomato through previously tested Arabidopsis alleles conferring altered stomata abundance phenotypes that correlate with physiological traits related to water status, leaf cooling, or photosynthesis.

4.
Front Plant Sci ; 10: 1392, 2019.
Article in English | MEDLINE | ID: mdl-31781138

ABSTRACT

Stomatal abundance varies widely across natural populations of Arabidopsis thaliana, and presumably affects plant performance because it influences water and CO2 exchange with the atmosphere and thence photosynthesis and transpiration. In order to determine the genetic basis of this natural variation, we have analyzed a recombinant inbred line (RIL) population derived from the wild accession Ll-0 and the reference strain Landsberg erecta (Ler), which show low and high stomatal abundance, respectively. Quantitative trait locus (QTL) analyses of stomatal index, stomatal density, and pavement cell density measured in the adaxial cotyledon epidermis, identified five loci. Three of the genomic regions affect all traits and were named MID (Modulator of Cell Index and Density) 1 to 3. MID2 is a large-effect QTL overlapping with ERECTA (ER), the er-1 allele from Ler increasing all trait values. Additional analyses of natural and induced loss-of-function er mutations in different genetic backgrounds revealed that ER dysfunctions have differential and opposite effects on the stomatal index in adaxial and abaxial cotyledon epidermis and confirmed that ER is the gene underlying MID2. Ll-0 alleles at MID1 and MID3 displayed moderate and positive effects on the various traits. Furthermore, detailed developmental studies tracking primary and satellite stomatal lineages show that MID3-Ll-0 allele promotes the spacing divisions that initiate satellite lineages, while the ER allele limits them. Finally, expression analyses suggest that ER and MID3 modulate satellization through partly different regulatory pathways. Our characterization of MID3 indicates that genetic modulation of satellization contributes to the variation for stomatal abundance in natural populations, and subsequently that this trait might be involved in plant adaptation.

5.
Nature ; 563(7732): 574-578, 2018 11.
Article in English | MEDLINE | ID: mdl-30429609

ABSTRACT

Stomatal cell lineage is an archetypal example of asymmetric cell division (ACD), which is necessary for plant survival1-4. In Arabidopsis thaliana, the GLYCOGEN SYNTHASE KINASE3 (GSK3)/SHAGGY-like kinase BRASSINOSTEROID INSENSITIVE 2 (BIN2) phosphorylates both the mitogen-activated protein kinase (MAPK) signalling module5,6 and its downstream target, the transcription factor SPEECHLESS (SPCH)7, to promote and restrict ACDs, respectively, in the same stomatal lineage cell. However, the mechanisms that balance these mutually exclusive activities remain unclear. Here we identify the plant-specific protein POLAR as a stomatal lineage scaffold for a subset of GSK3-like kinases that confines them to the cytosol and subsequently transiently polarizes them within the cell, together with BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL), before ACD. As a result, MAPK signalling is attenuated, enabling SPCH to drive ACD in the nucleus. Moreover, POLAR turnover requires phosphorylation on specific residues, mediated by GSK3. Our study reveals a mechanism by which the scaffolding protein POLAR ensures GSK3 substrate specificity, and could serve as a paradigm for understanding regulation of GSK3 in plants.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/cytology , Arabidopsis/metabolism , Asymmetric Cell Division , Cell Cycle Proteins/metabolism , Cell Polarity , Multiprotein Complexes/metabolism , Signal Transduction , Arabidopsis/enzymology , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Lineage , Cytosol/enzymology , Cytosol/metabolism , Glycogen Synthase Kinase 3/metabolism , MAP Kinase Signaling System , Multiprotein Complexes/chemistry , Phenotype , Phosphorylation , Plant Stomata/cytology , Protein Binding , Protein Kinases/metabolism , Substrate Specificity
6.
Front Plant Sci ; 9: 940, 2018.
Article in English | MEDLINE | ID: mdl-30022991

ABSTRACT

Stomata are microscopic valves formed by two guard cells flanking a pore, which are located on the epidermis of most aerial plant organs and are used for water and gas exchange between the plant and the atmosphere. The number, size and distribution of stomata are set during development in response to changing environmental conditions, allowing plants to minimize the impact of a stressful environment. In Arabidopsis, STOMATAL DENSITY AND DISTRIBUTION 1 (AtSDD1) negatively regulates stomatal density and optimizes transpiration and water use efficiency (WUE). Despite this, little is known about the function of AtSDD1 orthologs in crop species and their wild stress-tolerant relatives. In this study, SDD1-like from the stress-tolerant wild tomato Solanum chilense (SchSDD1-like) was identified through its close sequence relationship with SDD1-like from Solanum lycopersicum and AtSDD1. Both Solanum SDD1-like transcripts accumulated in high levels in young leaves, suggesting that they play a role in early leaf development. Arabidopsis sdd1-3 plants transformed with SchSDD1-like under a constitutive promoter showed a significant reduction in stomatal leaf density compared with untransformed sdd1-3 plants. Additionally, a leaf dehydration shock test demonstrated that the reduction in stomatal abundance of transgenic plants was sufficient to slow down dehydration. Overexpression of SchSDD1-like in cultivated tomato plants decreased the stomatal index and density of the cotyledons and leaves, and resulted in higher dehydration avoidance. Taken together, these results indicate that SchSDD1-like functions in a similar manner to AtSDD1 and suggest that Arabidopsis and tomatoes share this component of the stomatal development pathway that impinges on water status.

7.
Plant Physiol ; 174(2): 823-842, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28507175

ABSTRACT

The asymmetric cell divisions necessary for stomatal lineage initiation and progression in Arabidopsis (Arabidopsis thaliana) require the function of the basic helix-loop-helix (bHLH) transcription factor SPEECHLESS (SPCH). Mutants lacking SPCH do not produce stomata or lineages. Here, we isolated a new spch-5 allele carrying a point mutation in the bHLH domain that displayed normal growth, but had an extremely low number of sometimes clustered stomata in the leaves, whereas the hypocotyls did not have any stomata. In vivo tracking of leaf epidermal cell divisions, combined with marker lines and genetic analysis, showed that the spch-5 leaf phenotype is dosage dependent and results from the decreased ability to initiate and amplify lineages, defects in asymmetric cell fate allocation, and misorientation of asymmetric division planes. Notably, application of brassinosteroids (BRs) partly rescued the stomatal leaf phenotype of spch-5 Transcriptomic analysis combining spch-5 with BR treatments revealed that the expression of a set of SPCH target genes was restored by BRs. Our results also show that BR-dependent stomata formation and expression of some, but not all, SPCH target genes require the integrity of the bHLH domain of SPCH.


Subject(s)
Arabidopsis Proteins/genetics , Basic Helix-Loop-Helix Transcription Factors/genetics , Brassinosteroids/metabolism , Mutation , Plant Stomata/physiology , Arabidopsis/drug effects , Arabidopsis/genetics , Arabidopsis/physiology , Arabidopsis Proteins/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism , Brassinosteroids/pharmacology , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Differentiation , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Plant , Hypocotyl/cytology , Plant Leaves/cytology , Plant Leaves/genetics , Plant Stomata/cytology , Plant Stomata/drug effects , Plants, Genetically Modified , Protein Domains , Transcription Factors/genetics , Transcription Factors/metabolism
9.
Front Plant Sci ; 6: 456, 2015.
Article in English | MEDLINE | ID: mdl-26157447

ABSTRACT

Loss of function of the positive stomata development regulators SPCH or MUTE in Arabidopsis thaliana renders stomataless plants; spch-3 and mute-3 mutants are extreme dwarfs, but produce cotyledons and tiny leaves, providing a system to interrogate plant life in the absence of stomata. To this end, we compared their cotyledon transcriptomes with that of wild-type plants. K-means clustering of differentially expressed genes generated four clusters: clusters 1 and 2 grouped genes commonly regulated in the mutants, while clusters 3 and 4 contained genes distinctively regulated in mute-3. Classification in functional categories and metabolic pathways of genes in clusters 1 and 2 suggested that both mutants had depressed secondary, nitrogen and sulfur metabolisms, while only a few photosynthesis-related genes were down-regulated. In situ quenching analysis of chlorophyll fluorescence revealed limited inhibition of photosynthesis. This and other fluorescence measurements matched the mutant transcriptomic features. Differential transcriptomes of both mutants were enriched in growth-related genes, including known stomata development regulators, which paralleled their epidermal phenotypes. Analysis of cluster 3 was not informative for developmental aspects of mute-3. Cluster 4 comprised genes differentially up-regulated in mute-3, 35% of which were direct targets for SPCH and may relate to the unique cell types of mute-3. A screen of T-DNA insertion lines in genes differentially expressed in the mutants identified a gene putatively involved in stomata development. A collection of lines for conditional overexpression of transcription factors differentially expressed in the mutants rendered distinct epidermal phenotypes, suggesting that these proteins may be novel stomatal development regulators. Thus, our transcriptome analysis represents a useful source of new genes for the study of stomata development and for characterizing physiology and growth in the absence of stomata.

10.
Appl Microbiol Biotechnol ; 99(7): 3057-68, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25324130

ABSTRACT

The TM1072 gene from Thermotoga maritima codifies for a putative form of a rhamnulose-1-phosphate aldolase (Rha-1PA Tm). To investigate this enzyme further, its gene was cloned and expressed in Escherichia coli. The purified enzyme was activated by Co(2+) as a divalent metal ion cofactor, instead of Zn(2+) as its E. coli homologue, and exhibited a maximum of activity at 95 °C. Furthermore, the enzyme displayed a high stability against extreme reaction conditions, retaining 90 % of its activity in the presence of 40 % of acetonitrile and showing a half-life greater than 3 h at 115 °C. The kinetic parameters at room temperature (R/T) were also studied; the K M was calculated to be 3.6 ± 0.33 mM, while k cat/K M was found to be 0.7 × 10(3) s(-1) M(-1). Given these characteristics, Rha-1PA Tm is an attractive enzyme for use as a biocatalyst for industrial applications, offering intriguing possibilities for practical biocatalysis.


Subject(s)
Aldehyde-Lyases/genetics , Aldehyde-Lyases/metabolism , Thermotoga maritima/enzymology , Aldehyde-Lyases/chemistry , Amino Acid Sequence , Catalysis , Cloning, Molecular , Enzyme Stability , Escherichia coli/genetics , Half-Life , Hydrogen-Ion Concentration , Kinetics , Molecular Sequence Data , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Temperature , Thermotoga maritima/genetics
11.
Plant J ; 75(5): 808-22, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23662679

ABSTRACT

Epidermal differentiation in Arabidopsis thaliana aerial organs involves stomatal lineage development. Lineages derive from meristemoids, which arise from asymmetric divisions of protodermal cells. Each meristemoid divides repeatedly in an inward spiral before it transits to a guard mother cell (GMC) that produces the stoma, leaving a trail of surrounding stomatal lineage ground cells (SLGCs) that eventually differentiate into endoreplicated pavement cells. MUTE is a bHLH transcription factor that is expressed in late meristemoids and drives their transition to GMCs. Loss-of-function mute mutants are stomata-less dwarf plants with arrested lineages, in which stunted putative SLGCs surround a halted meristemoid. We analysed MUTE functions using a chemically inducible system for mute-3 complementation based on conditional MUTE expression in its normal domain. Continuous induction from germination produced stomata-bearing, normal-sized plants with viable mute-3 seeds. In 2-week-old mute-3 cotyledons, meristemoids appeared to retain their identity and synchronously formed stomata in response to induced MUTE expression. However, arrested SLGCs were not complemented: many produced stomata, leading to stomatal clusters, and others remained unexpanded and diploid. In contrast, non-lineage pavement cells, which are under-endoreplicated in mute-3, expanded and increased their ploidy level upon induction, showing that the lack of response of SLGCs is specific to this arrested cell type. Leaf phenotypic mosaics include wild-type lineages and adjacent mute-3 lineages, whose meristemoids and putative SLGCs remained arrested, indicating that the role of MUTE in SLGC fate is strictly lineage-autonomous. These results show that timely MUTE expression is essential to prevent stomatal fate in SLGCs and to promote their differentiation as pavement cells.


Subject(s)
Arabidopsis Proteins/physiology , Arabidopsis/growth & development , Basic Helix-Loop-Helix Transcription Factors/physiology , Cell Differentiation/genetics , Plant Stomata/growth & development , Arabidopsis/cytology , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Estradiol/pharmacology , Gene Expression Profiling , Gene Expression Regulation, Plant , Genetic Markers , Phenotype , Plant Stomata/genetics , Plant Stomata/ultrastructure , Ploidies
12.
Plant Signal Behav ; 7(8): 990-3, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22836493

ABSTRACT

Stomata are epidermal bi-celled structures that differentiate within special cell lineages initiated by a subset of protodermal cells. Recently, we showed that the Arabidopsis photomorphogenic repressor COP10 controls specific cell-lineage and cell-signaling developmental mechanisms in stomatal lineages. Loss-of-function cop10-1 mutant cotyledons and leaves produced (in the light and in the dark) abundant stomatal clusters, but nonlineage epidermal cells were not affected. Here we examine COP10 role in hypocotyls, cylindrical organs displaying a distinct epidermal organization with alternate files of protruding and non-protruding cells, with the latter producing a limited number of stomata. COP10 prevents stomatal clusters and restricts stomata production in hypocotyls; these roles are specific to lineage cells as in cotyledons, since COP10 loss of function does not elicit stomatal fate in nonlineage cells; COP10 also sustains the directional cell expansion of all hypocotyl epidermal cell types, and seems necessary for the differentiation between protruding and non-protruding cell files.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/growth & development , Arabidopsis/metabolism , Plant Stomata/growth & development , Plant Stomata/metabolism , Ubiquitin-Conjugating Enzymes/metabolism , Arabidopsis/cytology , Arabidopsis/radiation effects , Hypocotyl/cytology , Hypocotyl/metabolism , Hypocotyl/radiation effects , Light , Phenotype , Plant Stomata/cytology , Plant Stomata/radiation effects
13.
Planta ; 236(2): 447-61, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22407427

ABSTRACT

Stomatal development in Arabidopsis thaliana has been linked to photoreceptor-perceived light through several components of the photomorphogenic switch, whose lack of function is often seedling-lethal. CONSTITUTIVE PHOTOMORPHOGENIC 10 (COP10) is an important component of this switch, its loss of function producing stomatal clusters. Exploiting the reduced lethality of the cop10-1 mutant we characterized the developmental basis of its stomatal phenotype. Constitutive, light-independent stomata overproduction accounts for half of cop10-1 stomatal abundance and appears very early in development. Clusters are responsible for the remaining stomata excess and build-up progressively at later stages. Serial impressions of living cotyledon epidermis allowed a dynamic, quantitative analysis of stomatal lineage types by reconstructing their division histories. We found that COP10 adjusts the initiation frequency and extension of stomatal lineages (entry and amplifying asymmetric divisions) and represses stomatal fate in lineage cells; COP10 also supervises the orientation of spacing divisions in satellite lineages, preventing the appearance of stomata in contact. Aberrant accumulation of the proliferating stomatal lineage cell marker TMMpro::TMM-GFP showed that the abundant cop10-1 stomatal lineages maintained extended and ectopic competence for stomatal fate. Expression of stomatal development master genes suggests that the mutant does not bypass major molecular actors in this process. cop10-1 first leaf produces trichomes and apparently normal pavement cells, but functionally and morphologically aberrant stomata; COP10 operates genetically in parallel to the stomatal repressor SDD1 and does not generally affect epidermal cell differentiation, but seems to operate on stomatal lineages where it controls specific cell-lineage and cell-signaling developmental mechanisms.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/genetics , Gene Expression Regulation, Developmental/genetics , Plant Epidermis/cytology , Plant Stomata/genetics , Signal Transduction/genetics , Ubiquitin-Conjugating Enzymes/metabolism , Arabidopsis/cytology , Arabidopsis/growth & development , Arabidopsis/physiology , Arabidopsis Proteins/genetics , Cell Differentiation , Cell Division , Cotyledon/cytology , Cotyledon/genetics , Cotyledon/growth & development , Cotyledon/physiology , Gene Expression Regulation, Plant/genetics , Microscopy, Confocal , Mutation , Phenotype , Plant Epidermis/genetics , Plant Epidermis/growth & development , Plant Epidermis/physiology , Plant Leaves/cytology , Plant Leaves/genetics , Plant Leaves/growth & development , Plant Leaves/physiology , Plant Stomata/cytology , Plant Stomata/growth & development , Plant Stomata/physiology , Recombinant Fusion Proteins , Seedlings/cytology , Seedlings/genetics , Seedlings/growth & development , Seedlings/physiology , Ubiquitin-Conjugating Enzymes/genetics
14.
Ann Bot ; 107(8): 1247-58, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21447490

ABSTRACT

BACKGROUND AND AIMS: Current understanding of stomatal development in Arabidopsis thaliana is based on mutations producing aberrant, often lethal phenotypes. The aim was to discover if naturally occurring viable phenotypes would be useful for studying stomatal development in a species that enables further molecular analysis. METHODS: Natural variation in stomatal abundance of A. thaliana was explored in two collections comprising 62 wild accessions by surveying adaxial epidermal cell-type proportion (stomatal index) and density (stomatal and pavement cell density) traits in cotyledons and first leaves. Organ size variation was studied in a subset of accessions. For all traits, maternal effects derived from different laboratory environments were evaluated. In four selected accessions, distinct stomatal initiation processes were quantitatively analysed. KEY RESULTS AND CONCLUSIONS: Substantial genetic variation was found for all six stomatal abundance-related traits, which were weakly or not affected by laboratory maternal environments. Correlation analyses revealed overall relationships among all traits. Within each organ, stomatal density highly correlated with the other traits, suggesting common genetic bases. Each trait correlated between organs, supporting supra-organ control of stomatal abundance. Clustering analyses identified accessions with uncommon phenotypic patterns, suggesting differences among genetic programmes controlling the various traits. Variation was also found in organ size, which negatively correlated with cell densities in both organs and with stomatal index in the cotyledon. Relative proportions of primary and satellite lineages varied among the accessions analysed, indicating that distinct developmental components contribute to natural diversity in stomatal abundance. Accessions with similar stomatal indices showed different lineage class ratios, revealing hidden developmental phenotypes and showing that genetic determinants of primary and satellite lineage initiation combine in several ways. This first systematic, comprehensive natural variation survey for stomatal abundance in A. thaliana reveals cryptic developmental genetic variation, and provides relevant relationships amongst stomatal traits and extreme or uncommon accessions as resources for the genetic dissection of stomatal development.


Subject(s)
Arabidopsis/growth & development , Genetic Variation/genetics , Plant Stomata/growth & development , Arabidopsis/cytology , Arabidopsis/genetics , Cotyledon/cytology , Cotyledon/growth & development , Environment , Genotype , Phenotype , Plant Epidermis/cytology , Plant Leaves/cytology , Plant Leaves/genetics , Plant Stomata/cytology , Plant Stomata/genetics , Plant Transpiration/physiology , Quantitative Trait Loci
16.
Mol Plant Pathol ; 6(3): 321-5, 2005 May 01.
Article in English | MEDLINE | ID: mdl-20565660

ABSTRACT

SUMMARY Promoter activity of ABI3 and of three LEA genes was monitored in Arabidopsis transgenics infected with Heterodera schachtii and Meloidogyne incognita. ABI3::GUS expression was induced (in four different promoter deletion constructs) during early infection stages with H. schachtii. Similar GUS expression patterns, though slightly later in time compared with ABI3, were observed for one of the LEA promoter constructs, whereas the other two were not induced by H. schachtii. Expression was mainly observed in the syncytia. In contrast, little or no reporter gene expression was observed upon infection with M. incognita. The data suggest a role for ABI3 during the formation and active growth of the syncytium and demonstrate a marked difference between syncytium and giant cell ontogenesis.

17.
Pediátrika (Madr.) ; 24(3): 80-82, mar. 2004. tab
Article in Es | IBECS | ID: ibc-31513

ABSTRACT

Se realizó una investigación en 21 niños con asma bronquial y enuresis nocturna de edades comprendidas entre 5 y 15 años, con una media de 11.A todos se les aplicó durante cuatro semanas el método de tratamiento consistente en inducir propósitos. Se registró un aumento progresivo de pacientes que dejaron de orinarse a partir de la primera semana de tratamiento, cifra que llegó al 80.9 por ciento de curados en la cuarta semana (n=17). Con relación al asma bronquial hubo una mejor relación médico-paciente-familia, lo que propició un mejor tratamiento (AU)


Subject(s)
Adolescent , Female , Child, Preschool , Male , Child , Humans , Asthma/complications , Asthma/psychology , Asthma/therapy , Enuresis/complications , Enuresis/psychology , Enuresis/therapy , Mother-Child Relations , Physician-Patient Relations , Cuba
18.
Plant J ; 33(2): 329-40, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12535346

ABSTRACT

Functional analysis of hydrolase gene promoters, induced by gibberellin (GA) in aleurone cells following germination, has identified a GA-responsive complex (GARC) as a tripartite element containing a pyrimidine-box motif 5'-CCTTTT-3'. We describe here the characterization of a new barley gene (Sad gene) encoding a transcription factor (SAD) of the DNA binding with One Finger (DOF) class that binds to the pyrimidine box in vitro and activates transcription of a GA-induced protease promoter in bombarded aleurone layers. RT-PCR and in situ hybridization analyses showed that the Sad transcripts accumulated in all tissues analysed, being especially abundant in the scutellum and aleurone cells upon seed germination. The SAD protein, expressed in bacteria, binds in a specific manner to two oligonucleotides containing the sequence 5'-G/CCTTTT/C-3', derived from the promoter region of the Al21 gene encoding a cathepsin B-like cysteine protease. Although the Sad transcript accumulation did not respond to external GA-incubation in aleurone cells, in transient expression experiments in co-bombarded aleurone layers, SAD trans-activated transcription from the Al21 promoter in a similar manner as did GAMYB, a MYB protein previously shown to respond to GA and to activate several hydrolase gene promoters in barley aleurone cells. In vivo interaction between the GAMYB and SAD proteins was shown in the yeast two-hybrid system, where GAMYB potentiates the SAD trans-activation capacity through interaction with its C-terminal domain.


Subject(s)
Cathepsin B/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Plant , Germination/genetics , Hordeum/genetics , Plant Proteins/metabolism , Seeds/genetics , Amino Acid Sequence , Base Sequence , Cloning, Molecular , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , Genes, Plant/genetics , Hordeum/enzymology , Hordeum/growth & development , Hordeum/metabolism , Molecular Sequence Data , Plant Proteins/chemistry , Plant Proteins/genetics , Promoter Regions, Genetic/genetics , Protein Binding , Protein Structure, Tertiary , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Plant/genetics , RNA, Plant/metabolism , Seeds/enzymology , Seeds/growth & development , Transcription, Genetic
19.
Plant Physiol ; 130(1): 111-9, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12226491

ABSTRACT

Functional analyses of a number of hydrolase gene promoters, induced by gibberellin (GA) in aleurone cells following germination, have identified a GA-responsive complex as a tripartite element containing a pyrimidine box motif 5'-CCTTTT-3'. We describe here that BPBF, a barley (Hordeum vulgare) transcription factor of the DOF (DNA-Binding with One Finger) class, previously shown to be an activator of reserve protein encoding genes during development, also has a role in the control of hydrolase genes following seed germination. Northern-blot, reverse transcriptase-polymerase chain reaction, and in situ hybridization analyses evidenced that the transcripts of the BPBF-encoding gene (Pbf), besides being present during endosperm development, are also expressed in aleurone cells of germinated seeds where they are induced by GA, an effect counteracted by abscisic acid. Electrophoretic mobility shift assays have shown that the BPBF protein binds specifically to the pyrimidine box motif in vitro within the different sequence contexts that naturally occur in the promoters of genes encoding a cathepsin B-like protease (Al21) and a low-isoelectric point alpha-amylase (Amy2/32b), both induced in the aleurone layers in response to GA. In transient expression experiments, BPBF repressed transcription of the Al21 promoter in GA-treated barley aleurone layers and reverted the GAMYB-mediated activation of this protease promoter.


Subject(s)
DNA-Binding Proteins/physiology , Gibberellins/pharmacology , Hordeum/genetics , Plant Proteins/genetics , Proto-Oncogene Proteins c-myb/genetics , Transcription Factors/physiology , Abscisic Acid/pharmacology , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , DNA-Binding Proteins/genetics , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Plant/drug effects , Germination/drug effects , Germination/physiology , Hordeum/drug effects , Hordeum/growth & development , Hydrolases/genetics , Hydrolases/metabolism , In Situ Hybridization , Plant Growth Regulators/pharmacology , Plant Proteins/metabolism , Promoter Regions, Genetic/genetics , Protein Binding , Proto-Oncogene Proteins c-myb/metabolism , Seeds/drug effects , Seeds/genetics , Seeds/growth & development , Transcription Factors/genetics
20.
Medicina (Guayaquil) ; 6(4): 257-259, 2000.
Article in Spanish | LILACS | ID: lil-652351

ABSTRACT

Se realizó una investigación en 108 niños asmáticos de las edades comprendidas entre 5 y 15 años, con una media de 11 que presentaban enuresis nocturna. A la mitad de ellos se le aplicó por asignación aleatoria durante cuatro semanas el método de tratamiento consistente en inducir propósitos. Se percibió un aumento progresivo de los pacientes que dejaron de orinarse a partir de la primera semana de tratamiento, llegando hasta un 75.9% los curados en la cuarta semana (n=41). Con relación al asma bronquial hubo una mejor relación médico – paciente – familia lo que propició un mejor manejo de la enfermedad. El 70.3% de los tratados con inducción de propósitos mejoraron los síntomas de asma (RM = 0.39, IC 95% 0.35-0.93, p=0.019), en la cuarta semana de tratamiento.


We developed a research in 108 asthmatic children between 5 – 15 years of age (average of 11), suffering from nocturnal enuresis. A prospective randomized study was realized with the treatment of proposal induction for four weeks. There was an increment of patients that stopped their urinary incontinence during the first week of treatment. Healed patients reached a 75.9% at the fourth week. There was a better doctor – patient – family relationship concerning bronchial asthma, which brought about a better handling of the disease. There was a notable improvement, clinically demonstrated by an important decrease in the quantity of asthmatic crisis and answer to proposal induction (OR= 0.39, IC 95% 0.35-0.93, p = 0.19).


Subject(s)
Male , Adolescent , Female , Child , Asthma , Nocturnal Enuresis , Allergy and Immunology , Antidiuretic Agents , Deamino Arginine Vasopressin
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