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Marcella Holsters - One of the best experts on this subject based on the ideXlab platform.
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suppression subtractive hybridization to enrich low abundance and submergence enhanced transcripts of adventitious Root Primordia of sesbania rostrata
Plant Science, 2002Co-Authors: Merce Caturla, Katrien Schroeyers, Cristian Chaparro, Marcella HolstersAbstract:Upon waterlogging, the tropical legume Sesbania rostrata activates dormant meristems of stem-located Root Primordia, leading to adventitious Root outgrowth. By suppression subtractive hybridization (SSH), cDNA clones were collected that were enriched for low-abundant and water-induced transcripts. From 192 sequenced SSH clones, ranging from 64 to 1064 bp in size, 66 unigenes were obtained. Complex cDNA probes were generated to screen cDNA macro-arrays. Sequence homologies of putative up-regulated unigenes and of non-induced unigenes will be briefly discussed.
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srchi13 a novel early nodulin from sesbania rostrata is related to acidic class iii chitinases
The Plant Cell, 1998Co-Authors: Sofie Goormachtig, Willem Van De Velde, Sam Lievens, Marc Van Montagu, Marcella HolstersAbstract:On the tropical legume Sesbania rostrata, stem-borne nodules develop after inoculation of adventitious Root Primordia with the microsymbiont Azorhizobium caulinodans. A cDNA clone, Srchi13, with homology to acidic class III chitinase genes, corresponds to an early nodulin gene with transiently induced expression during nodule ontogeny. Srchi13 transcripts accumulated strongly 2 days after inoculation, decreased from day 7 onward, and disappeared in mature nodules. Induction was dependent on Nod factor-producing bacteria. Srchi13 was expressed around infection pockets, in infection centra, around the developing nodule and its vascular bundles, and in uninfected cells of the central tissue. The specific and transient transcript accumulation together with the lipochitooligosaccharide degradation activity of the recombinant protein hint at a role of Srchi13 in normal nodule ontogeny by limiting the action of Nod factors.
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patterns of enod40 gene expression in stem borne nodules of sesbania rostrata
Plant Molecular Biology, 1998Co-Authors: Viviana Corich, Sam Lievens, Marc Van Montagu, Sofie Goormachtig, Marcella HolstersAbstract:At the base of adventitious Root Primordia, located on the stem of the tropical legume Sesbania rostrata, nitrogen-fixing nodules are formed upon inoculation with the microsymbiont Azorhizobium caulinodans. This pattern of nodule development presents features of indeterminate and determinate nodules in early and later stages, respectively. A S. rostrata cDNA clone homologous to early nodulin ENOD40 genes was isolated from a cDNA library of developing stem nodules. SrENOD40-1 contained the conserved regions I and II of other ENOD40 genes. By reverse transcriptase PCR, enhanced SrENOD40-1 expression was observed in the adventitious Root Primordia between 4 and 8 h after inoculation with A. caulinodans. In situ hybridization showed that SrENOD40-1 transcripts, present around the central vascular bundle of the uninfected Root Primordia, were strongly enhanced upon induction of nodule development. De novo SrENOD40-1 expression was observed in the initiating and growing nodule Primordia and around vascular bundles. When cell type specification sets in, the expression became pronounced in cells derived from the meristematic regions. In other parts of the plant, weak SrENOD40-1 expression was associated with vascular bundles and was observed in leaf and stipule Primordia.
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chitinase gene expression during stem nodulation on sesbania rostrata
Archives of Physiology and Biochemistry, 1998Co-Authors: Sofie Goormachtig, Willem Van De Velde, Sam Lievens, Marc Van Montagu, Marcella HolstersAbstract:Stem nodules on the tropical legume Sesbania rostrata develop after intercellular infection of adventitious Root Primordia by the microsymbiont Azorhizobium caulinodans strain ORS571. Development of these nodules is dependent on Nod factors and shows hybrid features with a brief indeterminate phase followed by maturation, resulting in the formation of determinate nodules.
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early gene expression during stem nodule formation on sesbania rostrata
Current Plant Science and Biotechnology in Agriculture, 1998Co-Authors: Sam Lievens, Willem Van De Velde, Sylvia Herman, Marc Van Montagu, Sofie Goormachtig, Marcella HolstersAbstract:Sesbania rostrata is a tropical legume that can be nodulated on the stem as well as on the Root. Dormant adventitious Root Primordia present along the stem can develop into adventitious Roots upon immersion in water or into nitrogen fixing stem nodules upon inoculation with the microsymbiont Azorhizohium caulinodans. In a quest for new genes of which the expression is changed during stem nodule development, RNA populations from non-infected Root Primordia were compared with RNA populations from infected Root Primordia. This resulted in the isolation of several interesting genes.
Emile Duhoux - One of the best experts on this subject based on the ideXlab platform.
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Root to shoot primordium conversion on sesbania rostrata brem stem explants
Journal of Experimental Botany, 1994Co-Authors: M M Spencerbarreto, Emile DuhouxAbstract:The morphogenetic responses of cultured stem explants of Sesbania rostrata Brem. from various positions along the stem axis were analysed after treatment with four growth regulators (BAP, NAA, kinetin, and GA 3 ). Internodal explants formed adventitious shoot buds when cultured on a Murashige and Skoog basal medium without added growth regulators. Histological studies of regenerated shoot buds revealed that approximately 30% of the buds resulted from the conversion of a preformed Root primordium (characteristic of this species) into a shoot bud without a callogenesis phase. Each bud which originated from a single Root primordium grew into a leafy shoot. Preformed Root Primordia of stem explants of Sesbania rostrata may constitute an excellent model for physiological research on plant differentiation
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Root to shoot primordium conversion on sesbania rostrata brem stem explants
Journal of Experimental Botany, 1994Co-Authors: M M Spencerbarreto, Emile DuhouxAbstract:The morphogenetic responses of cultured stem explants of Sesbania rostrata Brem. from various positions along the stem axis were analysed after treatment with four growth regulators (BAP, NAA, kinetin, and GA 3 ). Internodal explants formed adventitious shoot buds when cultured on a Murashige and Skoog basal medium without added growth regulators. Histological studies of regenerated shoot buds revealed that approximately 30% of the buds resulted from the conversion of a preformed Root primordium (characteristic of this species) into a shoot bud without a callogenesis phase. Each bud which originated from a single Root primordium grew into a leafy shoot. Preformed Root Primordia of stem explants of Sesbania rostrata may constitute an excellent model for physiological research on plant differentiation
Benjamin Peret - One of the best experts on this subject based on the ideXlab platform.
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floral organ abscission peptide ida and its hae hsl2 receptors control cell separation during lateral Root emergence
Proceedings of the National Academy of Sciences of the United States of America, 2013Co-Authors: Robert P Kumpf, Benjamin Peret, Antoine Larrieu, Malcolm J Bennett, Chunlin Shi, Ida M Sto, Melinka A Butenko, Even Sannes Riiser, Reidunn B AalenAbstract:Throughout their life cycle, plants produce new organs, such as leaves, flowers, and lateral Roots. Organs that have served their purpose may be shed after breakdown of primary cell walls between adjacent cell files at the site of detachment. In Arabidopsis, floral organs abscise after pollination, and this cell separation event is controlled by the peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA), which signals through the leucine-rich repeat receptor-like kinases HAESA (HAE) and HAESA-LIKE2 (HSL2). Emergence of new lateral Root Primordia, initiated deep inside the Root under the influence of auxin, is similarly dependent on cell wall dissolution between cells in the overlaying endodermal, cortical, and epidermal tissues. Here we show that this process requires IDA, HAE, and HSL2. Mutation in these genes constrains the passage of the growing lateral Root Primordia through the overlaying layers, resulting in altered shapes of the lateral Root Primordia and of the overlaying cells. The HAE and HSL2 receptors are redundant in function during floral organ abscission, but during lateral Root emergence they are differentially involved in regulating cell wall remodeling genes. In the Root, IDA is strongly auxin-inducible and dependent on key regulators of lateral Root emergence--the auxin influx carrier LIKE AUX1-3 and AUXIN RESPONSE FACTOR7. The expression levels of the receptor genes are only transiently induced by auxin, suggesting they are limiting factors for cell separation. We conclude that elements of the same cell separation signaling module have been adapted to function in different developmental programs.
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sequential induction of auxin efflux and influx carriers regulates lateral Root emergence
Molecular Systems Biology, 2013Co-Authors: Benjamin Peret, Antoine Larrieu, Alistair M Middleton, Andrew P French, Antony Bishopp, Maria Fransiska Njo, Darren M. WellsAbstract:In Arabidopsis, lateral Roots originate from pericycle cells deep within the primary Root. New lateral Root Primordia ( LRP) have to emerge through several overlaying tissues. Here, we report that auxin produced in new LRP is transported towards the outer tissues where it triggers cell separation by inducing both the auxin influx carrier LAX3 and cell-wall enzymes. LAX3 is expressed in just two cell files overlaying new LRP. To understand how this striking pattern of LAX3 expression is regulated, we developed a mathematical model that captures the network regulating its expression and auxin transport within realistic three-dimensional cell and tissue geometries. Our model revealed that, for the LAX3 spatial expression to be robust to natural variations in Root tissue geometry, an efflux carrier is required-later identified to be PIN3. To prevent LAX3 from being transiently expressed in multiple cell files, PIN3 and LAX3 must be induced consecutively, which we later demonstrated to be the case. Our study exemplifies how mathematical models can be used to direct experiments to elucidate complex developmental processes.
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Auxin regulates aquaporin function to facilitate lateral Root emergence.
Nature Cell Biology, 2012Co-Authors: Ute Voß, Benjamin Peret, Olivier Postaire, Olivier Da Ines, Ilda Casimiro, Mikael Lucas, Leah R Band, Jin Zhao, Doan-trung Luu, Darren M. WellsAbstract:Aquaporins are membrane channels that facilitate water movement across cell membranes. In plants, aquaporins contribute to water relations. Here, we establish a new link between aquaporin-dependent tissue hydraulics and auxin-regulated Root development in Arabidopsis thaliana. We report that most aquaporin genes are repressed during lateral Root formation and by exogenous auxin treatment. Auxin reduces Root hydraulic conductivity both at the cell and whole-organ levels. The highly expressed aquaporin PIP2;1 is progressively excluded from the site of the auxin response maximum in lateral Root Primordia (LRP) whilst being maintained at their base and underlying vascular tissues. Modelling predicts that the positive and negative perturbations of PIP2;1 expression alter water flow into LRP, thereby slowing lateral Root emergence (LRE). Consistent with this mechanism, pip2;1 mutants and PIP2;1-overexpressing lines exhibit delayed LRE. We conclude that auxin promotes LRE by regulating the spatial and temporal distribution of aquaporin-dependent Root tissue water transport.
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short Root regulates primary lateral and adventitious Root development in arabidopsis
Plant Physiology, 2011Co-Authors: Mikael Lucas, Ranjan Swarup, Benjamin Peret, Ilda Casimiro, Kamal Swarup, Ivan A Paponov, David Lake, Susan Zappala, Stefan Mairhofer, Morag WhitworthAbstract:SHORT-Root (SHR) is a well-characterized regulator of radial patterning and indeterminacy of the Arabidopsis (Arabidopsis thaliana) primary Root. However, its role during the elaboration of Root system architecture remains unclear. We report that the indeterminate wild-type Arabidopsis Root system was transformed into a determinate Root system in the shr mutant when growing in soil or agar. The Root growth behavior of the shr mutant results from its primary Root apical meristem failing to initiate cell division following germination. The inability of shr to reactivate mitotic activity in the Root apical meristem is associated with the progressive reduction in the abundance of auxin efflux carriers, PIN-FORMED1 (PIN1), PIN2, PIN3, PIN4, and PIN7. The loss of primary Root growth in shr is compensated by the activation of anchor Root Primordia, whose tissues are radially patterned like the wild type. However, SHR function is not restricted to the primary Root but is also required for the initiation and patterning of lateral Root Primordia. In addition, SHR is necessary to maintain the indeterminate growth of lateral and anchor Roots. We conclude that SHR regulates a wide array of Arabidopsis Root-related developmental processes.
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Lateral Root emergence: a difficult birth.
Journal of Experimental Botany, 2009Co-Authors: Benjamin Peret, Antoine Larrieu, Malcolm J BennettAbstract:Lateral Root initiation takes place deep within the parental Root, requiring new Primordia to break through the overlying tissues before they emerge into the soil. Lateral Root emergence has been well described at the cellular level but, until recently, the molecular mechanisms involved were unclear. Scientists in the 19th and 20th centuries hypothesized that the cell wall of the overlying tissues was modified by enzymes released by cells within the primordium. Recent studies in the model plant Arabidopsis thaliana revealed the existence of a complex transcellular signalling network regulated by auxin that controls cell wall remodelling in cells overlying lateral Root Primordia. In the first part of this review, early observations on the cell biology of lateral Root formation and emergence are summarized, and in the following two sections recent observations in Arabidopsis that led to the identification of the molecular mechanism regulating lateral Root emergence are described.
Sofie Goormachtig - One of the best experts on this subject based on the ideXlab platform.
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srchi13 a novel early nodulin from sesbania rostrata is related to acidic class iii chitinases
The Plant Cell, 1998Co-Authors: Sofie Goormachtig, Willem Van De Velde, Sam Lievens, Marc Van Montagu, Marcella HolstersAbstract:On the tropical legume Sesbania rostrata, stem-borne nodules develop after inoculation of adventitious Root Primordia with the microsymbiont Azorhizobium caulinodans. A cDNA clone, Srchi13, with homology to acidic class III chitinase genes, corresponds to an early nodulin gene with transiently induced expression during nodule ontogeny. Srchi13 transcripts accumulated strongly 2 days after inoculation, decreased from day 7 onward, and disappeared in mature nodules. Induction was dependent on Nod factor-producing bacteria. Srchi13 was expressed around infection pockets, in infection centra, around the developing nodule and its vascular bundles, and in uninfected cells of the central tissue. The specific and transient transcript accumulation together with the lipochitooligosaccharide degradation activity of the recombinant protein hint at a role of Srchi13 in normal nodule ontogeny by limiting the action of Nod factors.
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patterns of enod40 gene expression in stem borne nodules of sesbania rostrata
Plant Molecular Biology, 1998Co-Authors: Viviana Corich, Sam Lievens, Marc Van Montagu, Sofie Goormachtig, Marcella HolstersAbstract:At the base of adventitious Root Primordia, located on the stem of the tropical legume Sesbania rostrata, nitrogen-fixing nodules are formed upon inoculation with the microsymbiont Azorhizobium caulinodans. This pattern of nodule development presents features of indeterminate and determinate nodules in early and later stages, respectively. A S. rostrata cDNA clone homologous to early nodulin ENOD40 genes was isolated from a cDNA library of developing stem nodules. SrENOD40-1 contained the conserved regions I and II of other ENOD40 genes. By reverse transcriptase PCR, enhanced SrENOD40-1 expression was observed in the adventitious Root Primordia between 4 and 8 h after inoculation with A. caulinodans. In situ hybridization showed that SrENOD40-1 transcripts, present around the central vascular bundle of the uninfected Root Primordia, were strongly enhanced upon induction of nodule development. De novo SrENOD40-1 expression was observed in the initiating and growing nodule Primordia and around vascular bundles. When cell type specification sets in, the expression became pronounced in cells derived from the meristematic regions. In other parts of the plant, weak SrENOD40-1 expression was associated with vascular bundles and was observed in leaf and stipule Primordia.
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chitinase gene expression during stem nodulation on sesbania rostrata
Archives of Physiology and Biochemistry, 1998Co-Authors: Sofie Goormachtig, Willem Van De Velde, Sam Lievens, Marc Van Montagu, Marcella HolstersAbstract:Stem nodules on the tropical legume Sesbania rostrata develop after intercellular infection of adventitious Root Primordia by the microsymbiont Azorhizobium caulinodans strain ORS571. Development of these nodules is dependent on Nod factors and shows hybrid features with a brief indeterminate phase followed by maturation, resulting in the formation of determinate nodules.
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early gene expression during stem nodule formation on sesbania rostrata
Current Plant Science and Biotechnology in Agriculture, 1998Co-Authors: Sam Lievens, Willem Van De Velde, Sylvia Herman, Marc Van Montagu, Sofie Goormachtig, Marcella HolstersAbstract:Sesbania rostrata is a tropical legume that can be nodulated on the stem as well as on the Root. Dormant adventitious Root Primordia present along the stem can develop into adventitious Roots upon immersion in water or into nitrogen fixing stem nodules upon inoculation with the microsymbiont Azorhizohium caulinodans. In a quest for new genes of which the expression is changed during stem nodule development, RNA populations from non-infected Root Primordia were compared with RNA populations from infected Root Primordia. This resulted in the isolation of several interesting genes.
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expression of cell cycle genes during sesbania rostrata stem nodule development
Molecular Plant-microbe Interactions, 1997Co-Authors: Sofie Goormachtig, Marcio Alvesferreira, Marc Van Montagu, Gilbert Engler, Marcella HolstersAbstract:Upon infection of Sesbania rostrata with Azorhizobium caulinodans, nodules are formed on Roots and stems. Stem nodules develop from abundantly distributed dormant Root Primordia. To acquire more insight into the meristem organization during stem nodule development, the expression patterns of a mitotic B1-type cyclin gene (Sesro; CycB1;1), a cyclin-dependent kinase gene (Cdc2-1Sr), and a histone H4 gene (H4-1Sr) of S. rostrata were followed by in situ hybridization. Cdc2-1Sr transcripts were found in all cells of uninfected and infected Root Primordia. In uninfected Root Primordia, Sesro;CycB1;1 transcripts were detected in a few cells of the apical Root meristem whereas H4-1Sr transcripts were abundant in this region. Interestingly, after inoculation with A. caulinodans, H4-1Sr transcripts disappeared in the Root meristem and a patchy pattern of Sesro;CycB1;1 and H4-1Sr expression appeared in the cortex of the Root primordium, reflecting the formation of globular nodule Primordia. When bacterial invasion ...
Malcolm J Bennett - One of the best experts on this subject based on the ideXlab platform.
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Quiescent center initiation in the Arabidopsis lateral Root Primordia is dependent on the SCARECROW transcription factor
Development (Cambridge England), 2016Co-Authors: Tatsuaki Goh, Darren M. Wells, Laurent Laplaze, Dolf Weijers, Hidehiro Fukaki, Kamal Swarup, Koichi Toyokura, Mayuko Yamamoto, Tetsuro Mimura, Malcolm J BennettAbstract:Lateral Root formation is an important determinant of Root system architecture. In Arabidopsis, lateral Roots originate from pericycle cells, which undergo a program of morphogenesis to generate a new lateral Root meristem. Despite its importance for Root meristem organization, the onset of quiescent center (QC) formation during lateral Root morphogenesis remains unclear. Here, we used live 3D confocal imaging to monitor cell organization and identity acquisition during lateral Root development. Our dynamic observations revealed an early morphogenesis phase and a late meristem formation phase as proposed in the bi-phasic growth model. Establishment of lateral Root QCs coincided with this developmental phase transition. QC precursor cells originated from the outer layer of stage II lateral Root Primordia, within which the SCARECROW (SCR) transcription factor was specifically expressed. Disrupting SCR function abolished periclinal divisions in this lateral Root Primordia cell layer and perturbed the formation of QC precursor cells. We conclude that de novo QC establishment in lateral Root Primordia operates via SCR-mediated formative cell division and coincides with the developmental phase transition.
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floral organ abscission peptide ida and its hae hsl2 receptors control cell separation during lateral Root emergence
Proceedings of the National Academy of Sciences of the United States of America, 2013Co-Authors: Robert P Kumpf, Benjamin Peret, Antoine Larrieu, Malcolm J Bennett, Chunlin Shi, Ida M Sto, Melinka A Butenko, Even Sannes Riiser, Reidunn B AalenAbstract:Throughout their life cycle, plants produce new organs, such as leaves, flowers, and lateral Roots. Organs that have served their purpose may be shed after breakdown of primary cell walls between adjacent cell files at the site of detachment. In Arabidopsis, floral organs abscise after pollination, and this cell separation event is controlled by the peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA), which signals through the leucine-rich repeat receptor-like kinases HAESA (HAE) and HAESA-LIKE2 (HSL2). Emergence of new lateral Root Primordia, initiated deep inside the Root under the influence of auxin, is similarly dependent on cell wall dissolution between cells in the overlaying endodermal, cortical, and epidermal tissues. Here we show that this process requires IDA, HAE, and HSL2. Mutation in these genes constrains the passage of the growing lateral Root Primordia through the overlaying layers, resulting in altered shapes of the lateral Root Primordia and of the overlaying cells. The HAE and HSL2 receptors are redundant in function during floral organ abscission, but during lateral Root emergence they are differentially involved in regulating cell wall remodeling genes. In the Root, IDA is strongly auxin-inducible and dependent on key regulators of lateral Root emergence--the auxin influx carrier LIKE AUX1-3 and AUXIN RESPONSE FACTOR7. The expression levels of the receptor genes are only transiently induced by auxin, suggesting they are limiting factors for cell separation. We conclude that elements of the same cell separation signaling module have been adapted to function in different developmental programs.
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Lateral Root emergence: a difficult birth.
Journal of Experimental Botany, 2009Co-Authors: Benjamin Peret, Antoine Larrieu, Malcolm J BennettAbstract:Lateral Root initiation takes place deep within the parental Root, requiring new Primordia to break through the overlying tissues before they emerge into the soil. Lateral Root emergence has been well described at the cellular level but, until recently, the molecular mechanisms involved were unclear. Scientists in the 19th and 20th centuries hypothesized that the cell wall of the overlying tissues was modified by enzymes released by cells within the primordium. Recent studies in the model plant Arabidopsis thaliana revealed the existence of a complex transcellular signalling network regulated by auxin that controls cell wall remodelling in cells overlying lateral Root Primordia. In the first part of this review, early observations on the cell biology of lateral Root formation and emergence are summarized, and in the following two sections recent observations in Arabidopsis that led to the identification of the molecular mechanism regulating lateral Root emergence are described.
