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Thomas Greb - One of the best experts on this subject based on the ideXlab platform.
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computational modelling of Cambium activity provides a regulatory framework for simulating radial plant growth
bioRxiv, 2020Co-Authors: Ivan Lebovka, Bruno Hay Mele, Alexandra Zakieva, Nial Gursanscky, Roeland M H Merks, Thomas GrebAbstract:Abstract Precise organization of growing structures is a fundamental problem in developmental biology. In plants, radial growth is mediated by the Cambium, a stem cell niche continuously producing wood (xylem) and bast (phloem) in a strictly bidirectional manner. While this process contributes large parts to terrestrial biomass, Cambium dynamics eludes direct experimental access due to obstacles in live cell imaging. Here, we present a cell-based computational model visualizing Cambium activity and integrating the function of central Cambium regulators. Performing iterative comparisons of plant and model anatomies, we conclude that an intercellular signaling module consisting of the receptor-like kinase PXY and its ligand CLE41 constitutes a minimal framework sufficient for instructing tissue organization. Employing genetically encoded markers for different Cambium domains in backgrounds with altered PXY/CLE41 activity, we furthermore propose that the module is part of a larger regulatory circuit using the phloem as a morphogenetic center. Our model highlights the importance of intercellular communication along the radial sequence of tissues within the Cambium area and shows that a limited number of factors is sufficient to create a stable bidirectional tissue production.
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bifacial Cambium stem cells generate xylem and phloem during radial plant growth
Development, 2019Co-Authors: Ivan Lebovka, Vadir Lopezsalmeron, Pablo Sanchez, Thomas GrebAbstract:ABSTRACT A reduced rate of stem cell division is considered a widespread feature which ensures the integrity of genetic information during somatic development of plants and animals. Radial growth of plant shoots and roots is a stem cell-driven process that is fundamental for the mechanical and physiological support of enlarging plant bodies. In most dicotyledonous species, the underlying stem cell niche, the Cambium, generates xylem inwards and phloem outwards. Despite the importance and intriguing dynamics of the Cambium, the functional characterization of its stem cells is hampered by the lack of experimental tools for accessing distinct Cambium sub-domains. Here, we use the hypocotyl of Arabidopsis thaliana to map stem cell activity in the proliferating Cambium. Through pulse labeling and genetically encoded lineage tracing, we find that a single bifacial stem cell generates both xylem and phloem cell lineages. This cell is characterized by a specific combination of PXY (TDR), SMXL5 and WOX4 gene activity and a high division rate in comparison with tissue-specific progenitors. Our analysis provides a cellular fate map of radial plant growth, and suggests that stem cell quiescence is not a general prerequisite for life-long tissue production. This article has an associated ‘The people behind the papers’ interview.
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pro Cambium formation and proliferation two sides of the same coin
Current Opinion in Plant Biology, 2015Co-Authors: Thomas Greb, Virginie Jouannet, Klaus BrackmannAbstract:The body of higher plants is usually pervaded by the (pro)Cambium, a reticulate system of meristematic cells harboring the potential for producing vascular tissues at critical times and places. The (pro)Cambium thereby provides the basis for the differential modulation of long-distance transport capacities and plant body stability. Distinct regulatory networks responsible for the initiation and proliferation of (pro)Cambium cells have been identified. However, although a tight interaction between these networks can be expected, connections have been established only sporadically. Here we highlight recent discoveries of how (pro)Cambium development is regulated and discuss possible interfaces between networks regulating two processes: (pro)Cambium formation and Cambium proliferation.
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wox4 imparts auxin responsiveness to Cambium cells in arabidopsis
The Plant Cell, 2011Co-Authors: Stefanie Suer, Pablo Sanchez, Javier Agusti, Martina Schwarz, Thomas GrebAbstract:Multipotent stem cell populations, the meristems, are fundamental for the indeterminate growth of plant bodies. One of these meristems, the Cambium, is responsible for extended root and stem thickening. Strikingly, although the pivotal role of the plant hormone auxin in promoting Cambium activity has been known for decades, the molecular basis of auxin responsiveness on the level of Cambium cells has so far been elusive. Here, we reveal that auxin-dependent Cambium stimulation requires the homeobox transcription factor WOX4. In Arabidopsis thaliana inflorescence stems, 1-N-naphthylphthalamic acid–induced auxin accumulation stimulates Cambium activity in the wild type but not in wox4 mutants, although basal Cambium activity is not abolished. This conclusion is confirmed by the analysis of cellular markers and genome-wide transcriptional profiling, which revealed only a small overlap between WOX4-dependent and Cambium-specific genes. Furthermore, the receptor-like kinase PXY is required for a stable auxin-dependent increase in WOX4 mRNA abundance and the stimulation of Cambium activity, suggesting a concerted role of PXY and WOX4 in auxin-dependent Cambium stimulation. Thus, in spite of large anatomical differences, our findings uncover parallels between the regulation of lateral and apical plant meristems by demonstrating the requirement for a WOX family member for auxin-dependent regulation of lateral plant growth.
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characterization of transcriptome remodeling during Cambium formation identifies mol1 and rul1 as opposing regulators of secondary growth
PLOS Genetics, 2011Co-Authors: Javier Agusti, Martina Schwarz, Raffael Lichtenberger, Lilian Nehlin, Thomas GrebAbstract:Cell-to-cell communication is crucial for the development of multicellular organisms, especially during the generation of new tissues and organs. Secondary growth—the lateral expansion of plant growth axes—is a highly dynamic process that depends on the activity of the Cambium. The Cambium is a stem cell–like tissue whose activity is responsible for wood production and, thus, for the establishment of extended shoot and root systems. Attempts to study Cambium regulation at the molecular level have been hampered by the limitations of performing genetic analyses in trees and by the difficulty of accessing this tissue in model systems such as Arabidopsis thaliana. Here, we describe the roles of two receptor-like kinases, REDUCED IN LATERAL GROWTH1 (RUL1) and MORE LATERAL GROWTH1 (MOL1), as opposing regulators of Cambium activity. Their identification was facilitated by a novel in vitro system in which Cambium formation is induced in isolated Arabidopsis stem fragments. By combining this system with laser capture microdissection, we characterized transcriptome remodeling in a tissue- and stage-specific manner and identified series of genes induced during different phases of Cambium formation. In summary, we provide a means for investigating Cambium regulation in unprecedented depth and present two signaling components that control a process responsible for the accumulation of a large proportion of terrestrial biomass.
Kishore S Rajput - One of the best experts on this subject based on the ideXlab platform.
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structure and ontogeny of intraxylary secondary xylem and phloem development by the internal vascular Cambium in campsis radicans l seem bignoniaceae
Journal of Plant Growth Regulation, 2018Co-Authors: Kishore S Rajput, Amit D Gondaliya, Manoj M Lekhak, Shrirang R. YadavAbstract:Bignoniaceae is known for the presence of different growth forms like trees, shrubs, lianas and herbs that show a wide range of variations in their wood structure. Trees, shrubs and lianas are characterised by the presence of normal secondary growth except the lianoid forms of the tribe Bignonieae that have a unique type of the cambial variant (that is, wedged/furrowed xylem) whereas other lineages lack it. Campsis radicans belongs to tribe Tecomeae and thus is expected to lack the cambial variant but it develops a quantifiable amount of intraxylary secondary xylem and phloem in the pith. Therefore, the main aim of the present investigation is to elucidate the ontogeny of intraxylary phloem and the secondary xylem formed by internal vascular Cambium. Development of intraxylary phloem is delayed significantly as compared to other families of eudicots that show the presence of intraxylary phloem. Subsequently, a functionally bidirectional complete ring of internal vascular Cambium initiates along the pith margin that produces secondary xylem centrifugally and secondary phloem centripetally. In thick stems, an internal vascular Cambium forms quantifiable amounts of inversely oriented secondary xylem and phloem that completely replace the pith. Structurally, this secondary xylem remains similar to the xylem formed by the regular (external) Cambium. It is composed of vessels, fibres, axial and ray parenchyma cells while the secondary phloem consists of sieve elements, companion cells, axial and ray parenchyma cells. The development of internal vascular Cambium completely replaced the parenchyma of the pith by producing intraxylary secondary xylem and phloem. The reason for the occurence of intraxylary phloem in C. radicans remains unknown. However, to the lesser extent it may be playing a secondary role in conductive safety of the conduit.
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FORMATION OF SUCCESSIVE CAMBIA IN THE MENISPERMUM TREE COCCULUS LAURIFOLIUS (MENISPERMACEAE)
IAWA Journal, 2015Co-Authors: Kishore S Rajput, Sangeeta GuptaAbstract:Successive cambia are often associated with the climbing or shrub habit, and is less common in trees. We studied formation of successive cambia and structure of secondary xylem in young stems of Cocculus laurifolius DC., a tree species of Menispermaceae. Cell division in the vascular Cambium ceased in pencil-thick stems. Subsequently, parenchyma cells located outside the perivascular fibre cap re-differentiated and gave rise to several small segments of meristematic cells, of which the central cells divided repeatedly to initiate the first successive Cambium which produces secondary xylem centripetally and phloem centrifugally. Cells located on the inner side of the newly initiated Cambium differentiated into conjunctive tissue while cells on the outer side of it divided further and differentiated into sclereids. Xylem was diffuse porous and composed of vessels, fibre tracheids and ray parenchyma cells, and only differed in vessel diameter from wide-vessel climbing relatives.
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cambial activity in the young branches and peduncles of couroupita guianensis lecythidaceae
Iawa Journal, 2014Co-Authors: Kishore S Rajput, Vidya S Patil, Amreen Saiyed, K S RaoAbstract:Peduncles of Couroupita guianensis Aubl. undergo extensive secondary growth, which is a rare and unexplored feature so far. In the present investigation seasonal behaviour of vascular Cambium was studied in fruit-bearing peduncles and compared with the vegetative branches of similar diameter. In peduncles, the Cambium remained active throughout the year. The number of Cambium cells and differentiating xylem cells increased from May and reached a maximum in July-August. Although cambial growth occurred throughout the year, it was relatively sluggish in February despite the development of new leaves and ongoing extension growth. In contrast, cambial cell division in young branches initiated in February, peaked in the same months as peduncle Cambium while cambial cell division and differentiation of xylem remained suspended from October to January. Cessation of cambial cell division in the branches during this period may be correlated with the presence of mature leaves. In both (branches and peduncle), rapid cell division and increase in the number of differentiating xylem elements in April-May is positively correlated with the development of flower buds and new leaves. The present anatomical investigation revealed that cambial activity in both peduncle and vegetative branches are independent of phenology and climatic conditions. In conclusion, we believe that variations in the number of differentiating Cambium derivatives in peduncles benefits from a dual source of growth hormone supply, i.e. from developing new leaves and flower buds.
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development of intraxylary phloem and internal Cambium in ipomoea hederifolia convolvulaceae
Journal of The Torrey Botanical Society, 2009Co-Authors: Vidya S Patil, K S Rao, Kishore S RajputAbstract:Abstract In Ipomoea hederifolia L. (Convolvulaceae), internal/intraxylary phloem originated as isolated strands from the procambially derived cells after the formation of protoxylem and protophloem. Bands of internal phloem were apparent in the sixth internode after the development of metaCambium. In the relatively thick stems several small arcs/segments of internal Cambium ensues from the parenchyma cells between the protoxylem and internal protophloem. Though all the segments were active, some of them (two of them located opposite to each other) were relatively more active. Bidirectional differentiation of these segments gave rise to secondary xylem centrifugally and secondary phloem centripetally, resulting inverted vascular bundles. Rest of the internal Cambium segments were unidirectional and formed only secondary phloem centripetally. Like external vascular Cambium, the internal Cambium was non-storied. Structurally, secondary xylem and phloem was composed of axial and radial system in which rays we...
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structure and development of secondary thickening meristem in mirabilis jalapa nyctaginaceae
Polish Botanical Journal, 2009Co-Authors: Kishore S Rajput, Vidya S Patil, Kailash K KapadneAbstract:The structure and development of vascular Cambium and its derivatives were studied in normal and experimentally injured stems of Mirabilis jalapa L. (Nyctaginaceae). In normal stems the Cambium was semi-storied and composed exclusively of fusiform cambial cells with no rays. Several collateral vascular bundles were joined by interfascicular Cambium and formed a complete ring of activity. After a defi nite period a small segment of Cambium that produced conducting elements of xylem and phloem ceased to divide. A new segment of Cambium was developed from the parenchyma cells outside the phloem of previous Cambium. This newly formed cambial segment replaced the nonfunctional segment by joining with other functional segments to form a continuous ring. Each successive segment of Cambium followed a similar pattern of development. Functionally the Cambium was bidirectional, producing both xylem and phloem on opposite sides, but the rate of cell division towards phloem was very slow, thus making the Cambium appear functionally unidirectional. Functional sieve elements were observed in all the phloem islands; nonfunctional sieve elements showed heavy accumulation of callose. Experimentally we tried to induce the formation of rays by injuring the Cambium, but instead of forming wound meristem it formed cork Cambium around the wounds. The meristematic segments present between the xylem and phloem of medullary bundles also remained active even at the senescent stage.
Laigeng Li - One of the best experts on this subject based on the ideXlab platform.
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a xylem produced peptide ptrcle20 inhibits vascular Cambium activity in populus
Plant Biotechnology Journal, 2020Co-Authors: Dongliang Song, Cheng Huang, Rui Zhang, Laigeng LiAbstract:: In trees, lateral growth of the stem occurs through cell divisions in the vascular Cambium. Vascular Cambium activity is regulated by endogenous developmental programmes and environmental cues. However, the underlying mechanisms that regulate Cambium activity are largely unknown. Genomic, biochemical and genetic approaches were used here to elucidate the role of PtrCLE20, a CLAVATA3 (CLV3)/embryo surrounding region (ESR)-related peptide gene, in the regulation of lateral growth in Populus. Fifty-two peptides encoded by CLE genes were identified in the genome of Populus trichocarpa. Among them PtrCLE20 transcripts were detected in developing xylem while the PtrCLE20 peptide was mainly localized in vascular Cambium cells. PtrCLE20 acted in repressing vascular Cambium activity indicated by that upregulation of PtrCLE20 resulted in fewer layers of vascular Cambium cells with repressed expression of the genes related to cell dividing activity. PtrCLE20 peptide also showed a repression effect on the root growth of Populus and Arabidopsis, likely through inhibiting meristematic cell dividing activity. Together, the results suggest that PtrCLE20 peptide, produced from developing xylem cells, plays a role in regulating lateral growth by repression of Cambium activity in trees.
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A HD‐ZIP III gene, PtrHB4, is required for interfascicular Cambium development in Populus
Plant Biotechnology Journal, 2017Co-Authors: Dongliang Song, Peng Xu, Laigeng LiAbstract:Summary Wood production is dependent on the activity of the vascular Cambium, which develops from the fascicular and interfascicular cambia. However, little is known about the mechanisms controlling how the vascular Cambium is developed in woody species. Here, we show that PtrHB4, belonging to the Populus HD-ZIP III family, plays a critical role in the process of vascular Cambium development. PtrHB4 was specifically expressed in shoot tip and stem vascular tissue at an early developmental stage. Repression of PtrHB4 caused defects in the development of the secondary vascular system due to failures in interfascicular Cambium formation. By contrast, overexpression of PtrHB4 induced Cambium activity and xylem differentiation during secondary vascular development. Transcriptional analysis of PtrHB4 repressed plants indicated that auxin response and cell proliferation were affected in the formation of the interfascicular Cambium. Taken together, these results suggest that PtrHB4 is required for interfascicular Cambium formation to develop the vascular Cambium in woody species.
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diverse roles of ptrduf579 proteins in populus and ptrduf579 1 function in vascular Cambium proliferation during secondary growth
Plant Molecular Biology, 2014Co-Authors: Dongliang Song, Laigeng LiAbstract:DUF579 (domain of unknown function 579) family proteins contain a DUF579 domain structure but vary greatly in their overall sequence similarity. Several DUF579 proteins have been found to play a role in cell wall biosynthesis in Arabidopsis, while DUF579 family genes have not yet been systematically investigated in Populus. In this study, the Populus DUF579 family proteins were found to be localized in different cell types and subcellular locations. The diverse expression patterns of the proteins indicate that they may perform different functions in Populus. Among the DUF579 family members, PtrDUF579-1 is found to be specifically expressed in vascular Cambium zone cells where it is localized in the Golgi apparatus. Suppression of PtrDUF579-1 expression reduced plant height and stem diameter size. Cambium cell division and xylem tissue growth was inhibited while secondary cell wall formation was unchanged in PtrDUF579-1 suppressed plants. Cell walls analysis showed that the composition of the pectin fraction of the Cambium cell wall was altered while other polysaccharides were not affected in PtrDUF579-1 suppressed plants. This observation suggest Cambium expressed PtrDUF579-1 may affect cell wall biosynthesis and be involved in Cambium cell proliferation in Populus. Overall, DUF579 family proteins play a diverse set of roles in Populus.
Javier Agusti - One of the best experts on this subject based on the ideXlab platform.
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strigolactone signaling is required for auxin dependent stimulation of secondary growth in plants
Proceedings of the National Academy of Sciences of the United States of America, 2011Co-Authors: Javier Agusti, Pablo Sanchez, Martina Schwarz, Silvia Herold, Karin Ljung, Elizabeth A Dun, Philip B Brewer, Christine A Beveridge, Tobias Sieberer, Eva M SehrAbstract:Long distance cell-to-cell communication is critical for the development of multicellular organisms. In this respect, plants are especially demanding as they constantly integrate environmental inputs to adjust growth processes to different conditions. One example is thickening of shoots and roots, also designated as secondary growth. Secondary growth is mediated by the vascular Cambium, a stem cell-like tissue whose cell-proliferating activity is regulated over a long distance by the plant hormone auxin. How auxin signaling is integrated at the level of Cambium cells and how Cambium activity is coordinated with other growth processes are largely unknown. Here, we provide physiological, genetic, and pharmacological evidence that strigolactones (SLs), a group of plant hormones recently described to be involved in the repression of shoot branching, positively regulate cambial activity and that this function is conserved among species. We show that SL signaling in the vascular Cambium itself is sufficient for Cambium stimulation and that it interacts strongly with the auxin signaling pathway. Our results provide a model of how auxin-based long-distance signaling is translated into Cambium activity and suggest that SLs act as general modulators of plant growth forms linking the control of shoot branching with the thickening of stems and roots.
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wox4 imparts auxin responsiveness to Cambium cells in arabidopsis
The Plant Cell, 2011Co-Authors: Stefanie Suer, Pablo Sanchez, Javier Agusti, Martina Schwarz, Thomas GrebAbstract:Multipotent stem cell populations, the meristems, are fundamental for the indeterminate growth of plant bodies. One of these meristems, the Cambium, is responsible for extended root and stem thickening. Strikingly, although the pivotal role of the plant hormone auxin in promoting Cambium activity has been known for decades, the molecular basis of auxin responsiveness on the level of Cambium cells has so far been elusive. Here, we reveal that auxin-dependent Cambium stimulation requires the homeobox transcription factor WOX4. In Arabidopsis thaliana inflorescence stems, 1-N-naphthylphthalamic acid–induced auxin accumulation stimulates Cambium activity in the wild type but not in wox4 mutants, although basal Cambium activity is not abolished. This conclusion is confirmed by the analysis of cellular markers and genome-wide transcriptional profiling, which revealed only a small overlap between WOX4-dependent and Cambium-specific genes. Furthermore, the receptor-like kinase PXY is required for a stable auxin-dependent increase in WOX4 mRNA abundance and the stimulation of Cambium activity, suggesting a concerted role of PXY and WOX4 in auxin-dependent Cambium stimulation. Thus, in spite of large anatomical differences, our findings uncover parallels between the regulation of lateral and apical plant meristems by demonstrating the requirement for a WOX family member for auxin-dependent regulation of lateral plant growth.
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characterization of transcriptome remodeling during Cambium formation identifies mol1 and rul1 as opposing regulators of secondary growth
PLOS Genetics, 2011Co-Authors: Javier Agusti, Martina Schwarz, Raffael Lichtenberger, Lilian Nehlin, Thomas GrebAbstract:Cell-to-cell communication is crucial for the development of multicellular organisms, especially during the generation of new tissues and organs. Secondary growth—the lateral expansion of plant growth axes—is a highly dynamic process that depends on the activity of the Cambium. The Cambium is a stem cell–like tissue whose activity is responsible for wood production and, thus, for the establishment of extended shoot and root systems. Attempts to study Cambium regulation at the molecular level have been hampered by the limitations of performing genetic analyses in trees and by the difficulty of accessing this tissue in model systems such as Arabidopsis thaliana. Here, we describe the roles of two receptor-like kinases, REDUCED IN LATERAL GROWTH1 (RUL1) and MORE LATERAL GROWTH1 (MOL1), as opposing regulators of Cambium activity. Their identification was facilitated by a novel in vitro system in which Cambium formation is induced in isolated Arabidopsis stem fragments. By combining this system with laser capture microdissection, we characterized transcriptome remodeling in a tissue- and stage-specific manner and identified series of genes induced during different phases of Cambium formation. In summary, we provide a means for investigating Cambium regulation in unprecedented depth and present two signaling components that control a process responsible for the accumulation of a large proportion of terrestrial biomass.
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analysis of secondary growth in the arabidopsis shoot reveals a positive role of jasmonate signalling in Cambium formation
Plant Journal, 2010Co-Authors: Eva M Sehr, Javier Agusti, Martina Schwarz, Reinhard Lehner, Edward E Farmer, Thomas GrebAbstract:After primary growth, most dicotyledonous plants undergo secondary growth. Secondary growth involves an increase in the diameter of shoots and roots through formation of secondary vascular tissue. A hallmark of secondary growth initiation in shoots of dicotyledonous plants is the initiation of meristematic activity between primary vascular bundles, i.e. in the interfascicular regions. This results in establishment of a cylindrical meristem, namely the vascular Cambium. Surprisingly, despite its major implications for plant growth and the accumulation of biomass, the molecular regulation of secondary growth is only poorly understood. Here, we combine histological, molecular and genetic approaches to characterize interfascicular Cambium initiation in the Arabidopsis thaliana inflorescence shoot. Using genome-wide transcriptional profiling, we show that stress-related and touch-inducible genes are up-regulated in stem regions where secondary growth takes place. Furthermore, we show that the products of COI1, MYC2, JAZ7 and the touch-inducible gene JAZ10, which are components of the JA signalling pathway, are Cambium regulators. The positive effect of JA application on Cambium activity confirmed a stimulatory role of JA in secondary growth, and suggests that JA signalling triggers cell divisions in this particular context.
Dongliang Song - One of the best experts on this subject based on the ideXlab platform.
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a xylem produced peptide ptrcle20 inhibits vascular Cambium activity in populus
Plant Biotechnology Journal, 2020Co-Authors: Dongliang Song, Cheng Huang, Rui Zhang, Laigeng LiAbstract:: In trees, lateral growth of the stem occurs through cell divisions in the vascular Cambium. Vascular Cambium activity is regulated by endogenous developmental programmes and environmental cues. However, the underlying mechanisms that regulate Cambium activity are largely unknown. Genomic, biochemical and genetic approaches were used here to elucidate the role of PtrCLE20, a CLAVATA3 (CLV3)/embryo surrounding region (ESR)-related peptide gene, in the regulation of lateral growth in Populus. Fifty-two peptides encoded by CLE genes were identified in the genome of Populus trichocarpa. Among them PtrCLE20 transcripts were detected in developing xylem while the PtrCLE20 peptide was mainly localized in vascular Cambium cells. PtrCLE20 acted in repressing vascular Cambium activity indicated by that upregulation of PtrCLE20 resulted in fewer layers of vascular Cambium cells with repressed expression of the genes related to cell dividing activity. PtrCLE20 peptide also showed a repression effect on the root growth of Populus and Arabidopsis, likely through inhibiting meristematic cell dividing activity. Together, the results suggest that PtrCLE20 peptide, produced from developing xylem cells, plays a role in regulating lateral growth by repression of Cambium activity in trees.
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A HD‐ZIP III gene, PtrHB4, is required for interfascicular Cambium development in Populus
Plant Biotechnology Journal, 2017Co-Authors: Dongliang Song, Peng Xu, Laigeng LiAbstract:Summary Wood production is dependent on the activity of the vascular Cambium, which develops from the fascicular and interfascicular cambia. However, little is known about the mechanisms controlling how the vascular Cambium is developed in woody species. Here, we show that PtrHB4, belonging to the Populus HD-ZIP III family, plays a critical role in the process of vascular Cambium development. PtrHB4 was specifically expressed in shoot tip and stem vascular tissue at an early developmental stage. Repression of PtrHB4 caused defects in the development of the secondary vascular system due to failures in interfascicular Cambium formation. By contrast, overexpression of PtrHB4 induced Cambium activity and xylem differentiation during secondary vascular development. Transcriptional analysis of PtrHB4 repressed plants indicated that auxin response and cell proliferation were affected in the formation of the interfascicular Cambium. Taken together, these results suggest that PtrHB4 is required for interfascicular Cambium formation to develop the vascular Cambium in woody species.
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diverse roles of ptrduf579 proteins in populus and ptrduf579 1 function in vascular Cambium proliferation during secondary growth
Plant Molecular Biology, 2014Co-Authors: Dongliang Song, Laigeng LiAbstract:DUF579 (domain of unknown function 579) family proteins contain a DUF579 domain structure but vary greatly in their overall sequence similarity. Several DUF579 proteins have been found to play a role in cell wall biosynthesis in Arabidopsis, while DUF579 family genes have not yet been systematically investigated in Populus. In this study, the Populus DUF579 family proteins were found to be localized in different cell types and subcellular locations. The diverse expression patterns of the proteins indicate that they may perform different functions in Populus. Among the DUF579 family members, PtrDUF579-1 is found to be specifically expressed in vascular Cambium zone cells where it is localized in the Golgi apparatus. Suppression of PtrDUF579-1 expression reduced plant height and stem diameter size. Cambium cell division and xylem tissue growth was inhibited while secondary cell wall formation was unchanged in PtrDUF579-1 suppressed plants. Cell walls analysis showed that the composition of the pectin fraction of the Cambium cell wall was altered while other polysaccharides were not affected in PtrDUF579-1 suppressed plants. This observation suggest Cambium expressed PtrDUF579-1 may affect cell wall biosynthesis and be involved in Cambium cell proliferation in Populus. Overall, DUF579 family proteins play a diverse set of roles in Populus.
