WorldWideScience

Sample records for cambium

  1. Cambium

    Science.gov (United States)

    Savidge, Rodney

    2009-01-01

    The Cambium investigation is one in a pair of investigations which utilizes the Advanced Biological Research System (ABRS). Cambium seeks definitive evidence that gravity has a direct effect on cambial cells (cells located under the inner bark where secondary growth occurs) in willow, Salix babylonica. The Cambium investigation uses willow plants flown on the International Space Station to better understand the fundamental processes by which plants produce cellulose and lignin, the two main structural materials found in plant matter. On Earth, the nature of wood within tree stems varies depending on position, and that within-tree variation includes differences in cell types and chemistry including lignin and cellulose, two major components of wood influencing wood strength, usefulness and carbon content. Reaction wood is an extreme example of such variation, and it is believed that reaction wood develops as a reaction to the influence of gravity. For the Cambium experiment, young willow plants will be launched to the ISS where their stems will be looped in an attempt to induce reaction wood formation. After on-orbit growth, the plants will be preserved and returned to Earth for analysis. Understanding the role of gravity in wood formation is expected to enable wiser management of forests for carbon sequestration as well as better utilization of trees for wood products. Detailed Research Description: The Cambium experiment will provide an understanding of physiological processes such as gene expression, metabolism and general plant development that are affected in plant systems exposed to space flight. Cambium seeks definitive evidence that gravity has a direct effect on the cambial cells (cells located under the inner bark where secondary growth occurs) that contribute to xylogenesis (reaction wood formation) in willow plants, Salix babylonica. Tension wood fibers differentiate on the upper sides of stems when the stem is altered from its normal (vertical) growth

  2. Modeling hormonal control of cambium proliferation.

    Science.gov (United States)

    Oles, Vladyslav; Panchenko, Alexander; Smertenko, Andrei

    2017-01-01

    Rise of atmospheric CO2 is one of the main causes of global warming. Catastrophic climate change can be avoided by reducing emissions and increasing sequestration of CO2. Trees are known to sequester CO2 during photosynthesis, and then store it as wood biomass. Thus, breeding of trees with higher wood yield would mitigate global warming as well as augment production of renewable construction materials, energy, and industrial feedstock. Wood is made of cellulose-rich xylem cells produced through proliferation of a specialized stem cell niche called cambium. Importance of cambium in xylem cells production makes it an ideal target for the tree breeding programs; however our knowledge about control of cambium proliferation remains limited. The morphology and regulation of cambium are different from those of stem cell niches that control axial growth. For this reason, translating the knowledge about axial growth to radial growth has limited use. Furthermore, genetic approaches cannot be easily applied because overlaying tissues conceal cambium from direct observation and complicate identification of mutants. To overcome the paucity of experimental tools in cambium biology, we constructed a Boolean network CARENET (CAmbium REgulation gene NETwork) for modelling cambium activity, which includes the key transcription factors WOX4 and HD-ZIP III as well as their potential regulators. Our simulations predict that: (1) auxin, cytokinin, gibberellin, and brassinosteroids act cooperatively in promoting transcription of WOX4 and HD-ZIP III; (2) auxin and cytokinin pathways negatively regulate each other; (3) hormonal pathways act redundantly in sustaining cambium activity; (4) individual cambium cells can have diverse molecular identities. CARENET can be extended to include components of other signalling pathways and be integrated with models of xylem and phloem differentiation. Such extended models would facilitate breeding trees with higher wood yield.

  3. Modeling hormonal control of cambium proliferation.

    Directory of Open Access Journals (Sweden)

    Vladyslav Oles

    Full Text Available Rise of atmospheric CO2 is one of the main causes of global warming. Catastrophic climate change can be avoided by reducing emissions and increasing sequestration of CO2. Trees are known to sequester CO2 during photosynthesis, and then store it as wood biomass. Thus, breeding of trees with higher wood yield would mitigate global warming as well as augment production of renewable construction materials, energy, and industrial feedstock. Wood is made of cellulose-rich xylem cells produced through proliferation of a specialized stem cell niche called cambium. Importance of cambium in xylem cells production makes it an ideal target for the tree breeding programs; however our knowledge about control of cambium proliferation remains limited. The morphology and regulation of cambium are different from those of stem cell niches that control axial growth. For this reason, translating the knowledge about axial growth to radial growth has limited use. Furthermore, genetic approaches cannot be easily applied because overlaying tissues conceal cambium from direct observation and complicate identification of mutants. To overcome the paucity of experimental tools in cambium biology, we constructed a Boolean network CARENET (CAmbium REgulation gene NETwork for modelling cambium activity, which includes the key transcription factors WOX4 and HD-ZIP III as well as their potential regulators. Our simulations predict that: (1 auxin, cytokinin, gibberellin, and brassinosteroids act cooperatively in promoting transcription of WOX4 and HD-ZIP III; (2 auxin and cytokinin pathways negatively regulate each other; (3 hormonal pathways act redundantly in sustaining cambium activity; (4 individual cambium cells can have diverse molecular identities. CARENET can be extended to include components of other signalling pathways and be integrated with models of xylem and phloem differentiation. Such extended models would facilitate breeding trees with higher wood yield.

  4. Heat transfer and vascular cambium necrosis in the boles of trees during surface fires

    Science.gov (United States)

    M. B. Dickinson

    2002-01-01

    Heat-transfer and cell-survival models are used to link surface fire behavior with vascular cambium necrosis from heating by flames. Vascular cambium cell survival was predicted with a numerical model based on the kinetics of protein denaturation and parameterized with data from the literature. Cell survival was predicted for vascular cambium temperature regimes...

  5. Temperature-dependent rate models of vascular cambium cell mortality

    Science.gov (United States)

    Matthew B. Dickinson; Edward A. Johnson

    2004-01-01

    We use two rate-process models to describe cell mortality at elevated temperatures as a means of understanding vascular cambium cell death during surface fires. In the models, cell death is caused by irreversible damage to cellular molecules that occurs at rates that increase exponentially with temperature. The models differ in whether cells show cumulative effects of...

  6. Transition areas in the domain patterns of storeyed cambium of Tilia cordata Mill.

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    Wiesław Włoch

    2014-01-01

    Full Text Available The occurrence of interlocked grain, generated by storeyed cambium, was observed in the wood of linden. The inclination of the grain changed periodically every two to four years. In general, the direction of the change of grain was compatible with the occurrence of configuration Z or S of cellular events. 1f, in the cambium during the generation of a growth ring, the domain border did not pass the examined area, the events were of one configuration type only, otherwise, there were two types of events aggregated into microareas. The microareas were the result of unsynchronous activities of groups of cambium cells. A growth ring area through which a domain border passed during the year under consideration was called the transition area.

  7. Time-variable frequency of events in domains of Tilia cambium

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    Wiesław Włoch

    2014-01-01

    Full Text Available In the cambium of linden, producing xylem with interlocked grain, domains active, as regards the occurrence of events, and inactive ones can be distinguished. The area of the cambium investigated was an assemblage of small domains among which at certain periods domains Z, and, at another period, domains S were active. The inclination of the grain was changing in the direction corresponding to the type of the active domains. Alternative occurrence of periods of activity of Z and S domains led to the formation of interlocked grain in the xylem, with a much longer wave than the height of a pair domains.

  8. The Populus Class III HD ZIP, popREVOLUTA, influences cambium initiation and patterning of woody stems

    Science.gov (United States)

    Marcel Robischon; Juan Du; Eriko Miura; Andrew Groover

    2011-01-01

    The secondary growth of a woody stem requires the formation of a vascular cambium at an appropriate position and proper patterning of the vascular tissues derived from the cambium. Class III homeodomain-leucine zipper (HD ZIP) transcription factors have been implicated in polarity determination and patterning in lateral organs and primary vascular tissues and in the...

  9. Gum spots caused by cambium miners in black cherry in West Virginia

    Science.gov (United States)

    Charles O. Rexrode; John E. Baumgras

    1980-01-01

    Six types of gum spots in black cherry, Prunus serotina Ehrh. were associated with parenchyma flecks caused by the cambium miner Phytobia pruni (Gross). The number of parenchyma flecks and associated gum spots increased with the height of the tree. Four percent of the flecks produced gum spots in the first 18 to 20 feet of the...

  10. Seasonal activity of cambium in some tropical trees. 111. Salvadora persica L.

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    G. S. Paliwal

    2015-01-01

    Full Text Available Seasonal activity of cambium has been investigated in Salvadora persica L., one of the commonest evergrenn tree of northern India, from March, 1974 to February, 1975 in the main stem and the branch. Secondary vascular cambium behaves abnormally on the xylem side, by producing xylem and phloem in succession, resulting in the formation of interxylary phloem. It has a storied (sitratified cambium organization, comprising short fusiform and isodiametric ray initials. The fusiform initials show characteristically beaded cell walls due to the presence of primary pit fields and are uninucleate. These are highly vacuolate during the active period. The cambial activity starts in the month of March, reaches the peak in August and finally slows down in the main stem. In an young branch, however, it is initiated in March-April and reaches the peak in July and then declines till November. It once again showed an upward trend gradually. It appears that the initiation of the combial activity in this tree takes place by a hormone produced in the newly formed leaves, coupled with the high rainfall, enhanced relative humidity, optimum temperature, and short-day conditions. Size measurements for the fusiform initials showed considerable variations during the span of a year. A comparision of the organization of three types of phloem 'normal', 'included' and 'internal' occurring in this plant has also bean presented.

  11. Moving beyond the cambium necrosis hypothesis of post-fire tree mortality: cavitation and deformation of xylem in forest fires

    Science.gov (United States)

    S.T. Michaletz; E.A. Johnson; M.T. Tyree

    2012-01-01

    It is widely assumed that post-fire tree mortality results from necrosis of phloem and vascular cambium in stems, despite strong evidence that reduced xylem conductivity also plays an important role. In this study, experiments with Populus balsamifera were used to demonstrate two mechanisms by which heat reduces the hydraulic conductivity of xylem:...

  12. [Impact of salt stress on peroxidase activity in Populus deltoides cambium and its consequence].

    Science.gov (United States)

    Li, Guoqi; An, Shuqing; Zhang, Jilin; Li, Jin; Wang, Yunjing; Sun, Jinglin

    2003-06-01

    Studies on the impact of salt stress on the peroxidase (POD) activity in Populus deltoides cambium and on the anatomic characteristics of its secondary xylem indicated that the changes of POD activity caused by soil salinity stress behaved differently in dormant and growing period. In low salinity soil, the POD activity of dormant Populus deltoides showed the trend of increasing first, and then, decreasing as the soil salinity was rising gradually. Namely, with the rising of soil salinity in the range of 0.024-->0.094-->0.145%, the POD activity varied in the range of 83.7-->132.1-->63.2 units.min-1.g-1FW accordingly. However, in growing season, with the gradual increase of soil salinity from 0.036 to 0.289%, the POD activity decreased gradually from 405.2 to 107.2 units.min-1.g-1FW. There were regular changes in wood anatomic characteristics of Populus deltoides. Namely, with the increase of soil salinity 0.036-->0.125-->0.289%, the vessel diameters (VD) of both early wood and late wood varied accordingly in the range of 41.8-->56.6-->43.4 microns, and 29.1-->33.1-->33.1 microns, respectively. The vessel frequencies (VF) were 141.8-->113.8-->144.2 and 160.0-->134.8-->206.7 entries mm-2, respectively. Along with the gradual increase of soil salinity from 0.036 to 0.289%, the fiber length gradually decreased from 693.8 to 570.4 microns, and the fiber width decreased from 14.9 to 13.5 microns.

  13. Diverse roles of PtrDUF579 proteins in Populus and PtrDUF579-1 function in vascular cambium proliferation during secondary growth.

    Science.gov (United States)

    Song, Dongliang; Sun, Jiayan; Li, Laigeng

    2014-08-01

    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.

  14. The parenchymo-vascular cambium and its derivative tissues in stems and roots of Bougainvillaea glabra Choisy (Nyctaginaceae

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    Z. Puławska

    2015-01-01

    Full Text Available In the shoots and roots of Bougainmllaea, the parenchymo-vascular cambium produces thinwalled secondary parenchyma to one side and the secondary vascular bundles embedded in the "conjunctive tissue" to the other. Periclinal division of a single cambial cell in one radial row brings about periclinal divisions of the adjacent cells of the neighbouring rows. Anticlinal division of a single cambial cell at one level, on the other hand, causes anticlinal. divisions of the adjacent cells of the overlying and underlying tiers.

  15. APEX-CAMBIUM: A Case Study in Advantages and Challenges of International Cooperation for the International Space Station

    Science.gov (United States)

    Cox, David; Buckley, Nicole

    2008-01-01

    It is generally agreed that space science benefits from an international collaboration. There are different mechanisms to make this happen but to recognize opportunities requires a keen awareness of the activities, people and respective strengths. Apex- Cambium is a joint Canadian Space Agency (CSA)-National Aeronautics and Space Administration (NASA) initiative. It was made possible in large part through the good relations and shared willingness to meet a common objective, that of doing exciting science in space. The actual mechanics of bringing an international project together can be divided into two perspectives: programmatic and implementation. The programmatic component includes recognizing complementarities, bringing science together, and the need to have Agencies approve and accept joint responsibility for the mission. The implementation component involves working to define science requirements, available resources and assigning individual responsibilities while keeping the overall success criteria as a collective objective. The APEX-CAMB11.JM mission will be described from the point of view of both CSA and NASA. Suggestions on how to facilitate these types of initiatives will be provided and highlights of the APEX-Cambium collaboration will be provided.

  16. The Populus Class III HD ZIP, popREVOLUTA, Influences Cambium Initiation and Patterning of Woody Stems1[W][OA

    Science.gov (United States)

    Robischon, Marcel; Du, Juan; Miura, Eriko; Groover, Andrew

    2011-01-01

    The secondary growth of a woody stem requires the formation of a vascular cambium at an appropriate position and proper patterning of the vascular tissues derived from the cambium. Class III homeodomain-leucine zipper (HD ZIP) transcription factors have been implicated in polarity determination and patterning in lateral organs and primary vascular tissues and in the initiation and function of shoot apical meristems. We report here the functional characterization of a Populus class III HD ZIP gene, popREVOLUTA (PRE), that demonstrates another role for class III HD ZIPs in regulating the development of cambia and secondary vascular tissues. PRE is orthologous to Arabidopsis (Arabidopsis thaliana) REVOLUTA and is expressed in both the shoot apical meristem and in the cambial zone and secondary vascular tissues. Transgenic Populus expressing a microRNA-resistant form of PRE presents unstable phenotypic abnormalities affecting both primary and secondary growth. Surprisingly, phenotypic changes include abnormal formation of cambia within cortical parenchyma that can produce secondary vascular tissues in reverse polarity. Genes misexpressed in PRE mutants include transcription factors and auxin-related genes previously implicated in class III HD ZIP functions during primary growth. Together, these results suggest that PRE plays a fundamental role in the initiation of the cambium and in regulating the patterning of secondary vascular tissues. PMID:21205615

  17. The intrusive growth of initial cells in re-arangement of cells in cambium of Tilia cordata Mill.

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    Wiesław Włoch

    2014-01-01

    Full Text Available In the cambium of linden producing wood with short period of grain inclination change (2-4 years, the intensive reorientation of cells takes place. This is possible mainly through an intrusive growth of cell ends from one radial file entering space between tangential walls of neighboring file and through unequal periclinal divisions that occur in the "initial surface". The intrusive growth is located on the longitudinal edge of a fusiform cell close to the end, and causes deviation of cell ends in a neighbouring file from the initial surface. Unequal periclinal division divides a cell with a deviated end into two derivatives, unequal in size. The one of them, which inherits the deviated end, leaves the initial surface becoming a xylem or phloem mother cell. This means that the old end is eliminated. The intensity of intrusive growth and unequal periclinal divisions is decisive for the velocity of cambial cell reorientation. The oriented intrusive growth occurs only in the initial cells. For that reason, changes in cell-ends position do not occur within one packet of cells but are distinct between neighbouring packets.

  18. Identification and expression analyses of new potential regulators of xylem development and cambium activity in cassava (Manihot esculenta).

    Science.gov (United States)

    Siebers, Tyche; Catarino, Bruno; Agusti, Javier

    2017-03-01

    We have identified new potential regulators of xylem cell-type determination and cellular proliferation in cassava and studied their expression in roots. Results are highly relevant for cassava biotechnology. Cassava's root system is composed of two types of root that coexist in every individual: the fibrous and the storage roots. Whether a root becomes fibrous or storage depends on the xylem cell types that it develops: fibrous roots develop xylem fibres and vessels while storage roots develop parenchyma xylem, the starch-storing tissue. A crucial question in cassava root development is how the specific xylem cell types differentiate and proliferate in the fibrous and storage roots. Using phylogenetic, protein sequence and synteny analyses we identified (1) MeVND6, MeVND7.1, MeVND7.2, MeNST3.1 and MeNST3.2 as the potential cassava orthologues of the Arabidopsis regulators of xylem cell type determination AtVND6, AtVND7 and AtNST3; and (2) MeWOX4.1 and MeWOX4.2 as the potential cassava orthologues of the Arabidopsis cambium regulator AtWOX4. Fibrous and storage roots were anatomically characterised and tested for the expression of the identified genes. Results revealed that (1) MeVND7.1 and MeVND7.2 are expressed in the fibrous but not in the storage roots; (2) MeVND6 shows low expression in both root types; (3) MeNST3.1 is not expressed in the fibrous or storage roots, while MeNST3.2 is highly expressed in both root-types and (4) MeWOX4.1 and, to a higher level, MeWOX4.2 are expressed in both the fibrous and storage roots. Results open new avenues for research in cassava root development and for food security-oriented biotechnology programmes.

  19. A meta-analysis of cambium phenology and growth: linear and non-linear patterns in conifers of the northern hemisphere

    Science.gov (United States)

    Rossi, Sergio; Anfodillo, Tommaso; Čufar, Katarina; Cuny, Henri E.; Deslauriers, Annie; Fonti, Patrick; Frank, David; Gričar, Jožica; Gruber, Andreas; King, Gregory M.; Krause, Cornelia; Morin, Hubert; Oberhuber, Walter; Prislan, Peter; Rathgeber, Cyrille B. K.

    2013-01-01

    Background and Aims Ongoing global warming has been implicated in shifting phenological patterns such as the timing and duration of the growing season across a wide variety of ecosystems. Linear models are routinely used to extrapolate these observed shifts in phenology into the future and to estimate changes in associated ecosystem properties such as net primary productivity. Yet, in nature, linear relationships may be special cases. Biological processes frequently follow more complex, non-linear patterns according to limiting factors that generate shifts and discontinuities, or contain thresholds beyond which responses change abruptly. This study investigates to what extent cambium phenology is associated with xylem growth and differentiation across conifer species of the northern hemisphere. Methods Xylem cell production is compared with the periods of cambial activity and cell differentiation assessed on a weekly time scale on histological sections of cambium and wood tissue collected from the stems of nine species in Canada and Europe over 1–9 years per site from 1998 to 2011. Key Results The dynamics of xylogenesis were surprisingly homogeneous among conifer species, although dispersions from the average were obviously observed. Within the range analysed, the relationships between the phenological timings were linear, with several slopes showing values close to or not statistically different from 1. The relationships between the phenological timings and cell production were distinctly non-linear, and involved an exponential pattern Conclusions The trees adjust their phenological timings according to linear patterns. Thus, shifts of one phenological phase are associated with synchronous and comparable shifts of the successive phases. However, small increases in the duration of xylogenesis could correspond to a substantial increase in cell production. The findings suggest that the length of the growing season and the resulting amount of growth could respond

  20. OnPLS integration of transcriptomic, proteomic and metabolomic data shows multi-level oxidative stress responses in the cambium of transgenic hipI- superoxide dismutase Populus plants.

    Science.gov (United States)

    Srivastava, Vaibhav; Obudulu, Ogonna; Bygdell, Joakim; Löfstedt, Tommy; Rydén, Patrik; Nilsson, Robert; Ahnlund, Maria; Johansson, Annika; Jonsson, Pär; Freyhult, Eva; Qvarnström, Johanna; Karlsson, Jan; Melzer, Michael; Moritz, Thomas; Trygg, Johan; Hvidsten, Torgeir R; Wingsle, Gunnar

    2013-12-17

    Reactive oxygen species (ROS) are involved in the regulation of diverse physiological processes in plants, including various biotic and abiotic stress responses. Thus, oxidative stress tolerance mechanisms in plants are complex, and diverse responses at multiple levels need to be characterized in order to understand them. Here we present system responses to oxidative stress in Populus by integrating data from analyses of the cambial region of wild-type controls and plants expressing high-isoelectric-point superoxide dismutase (hipI-SOD) transcripts in antisense orientation showing a higher production of superoxide. The cambium, a thin cell layer, generates cells that differentiate to form either phloem or xylem and is hypothesized to be a major reason for phenotypic perturbations in the transgenic plants. Data from multiple platforms including transcriptomics (microarray analysis), proteomics (UPLC/QTOF-MS), and metabolomics (GC-TOF/MS, UPLC/MS, and UHPLC-LTQ/MS) were integrated using the most recent development of orthogonal projections to latent structures called OnPLS. OnPLS is a symmetrical multi-block method that does not depend on the order of analysis when more than two blocks are analysed. Significantly affected genes, proteins and metabolites were then visualized in painted pathway diagrams. The main categories that appear to be significantly influenced in the transgenic plants were pathways related to redox regulation, carbon metabolism and protein degradation, e.g. the glycolysis and pentose phosphate pathways (PPP). The results provide system-level information on ROS metabolism and responses to oxidative stress, and indicate that some initial responses to oxidative stress may share common pathways. The proposed data evaluation strategy shows an efficient way of compiling complex, multi-platform datasets to obtain significant biological information.

  1. Size variation in the vascular cambium and its derivatives in two Alstonia species Variação em tamanho do cambio vascular e seus tecidos derivados em duas espécies de Alstonia

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    Moin A. Khan

    2007-09-01

    Full Text Available Two tropical tree species viz. Alstonia venenata Br. and Alstonia neriifolia Don. (Apocynaceae were investigated to detect size variation in different elements of the cambium and its derivative tissues. Although these two species were grown under identical climatic and edaphic conditions, fusiform initial dimensions and the elements derived from them were larger in A. venenata than in A. neriifolia. Ray initials are rectangular in A. venenata but isodiametric in A. neriifolia. An appreciable increase in length was observed in the phloem and xylem ray cells when compared to the mother cells. Maximum elongation was observed in xylem fibers during differentiation from the respective fusiform initials.Duas espécies de árvores tropicais (Alstonia venenata Br. e Alstonia neriifolia Don. - Apocynaceae foram estudadas para detectar variação em tamanho de diversos elementos do cambio e seus tecidos derivados. Embora as condições de clima e edaficas destas duas espécies fossem identicas, as dimensões das iniciais fusiformes e os elementos derivados destas foram maiores em A. venenata do que em A. neriifolia. As iniciais radiais são retangulares em A. venenata porem são isodiamêtricas em A. neriifolia. Foi observado aumento substancial no comprimento das células do floema e xilema quando comparadas com as células mãe. Alongamento máximo foi observado nas fibras do xilema durante a diferenciação das respectivas iniciais fusiformes.

  2. Isolation of high quality DNA and RNA from cambium of the East ...

    African Journals Online (AJOL)

    The genus Warburgia belongs to the Canellaceae, a small family of tropical aromatic tree species important for their antibacterial and antifungal medicinal qualities amongst many other functions. Many published protocols for nucleic acid isolation failed to yield sufficiently good quality amounts for analysis. We have ...

  3. Isolation of high quality DNA and RNA from cambium of the East ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... Key words: Nucleic acid extraction, polyphenols, polysaccharides, medicinal plants. INTRODUCTION. Traditional medicine .... dium bromide and visualized under UV light. DNA PCR analysis. Polymerase ... SDS and then exposed to Kodak X-ray film, stored at -80°C for 3 days and subsequently developed.

  4. Duff mound consumption and cambium injury for centuries-old western larch from prescribed burning in western Montana

    Science.gov (United States)

    Michael G. Harrington

    2012-01-01

    Western larch is one of the most fire-adapted conifers in western North America. Its historical perpetuation depended upon regular fire disturbances, which creates open stand conditions and mineral seedbeds. A stand of 200- to 500-year-old larch in western Montana with deep duff mounds resulting from an unusually long 150-year fire-free period was mechanically thinned...

  5. Intra-annual dynamics of non-structural carbohydrates in the cambium of mature conifer trees reflects radial growth demands.

    Science.gov (United States)

    Simard, Sonia; Giovannelli, Alessio; Treydte, Kerstin; Traversi, Maria Laura; King, Gregory M; Frank, David; Fonti, Patrick

    2013-09-01

    The presence of soluble carbohydrates in the cambial zone, either from sugars recently produced during photosynthesis or from starch remobilized from storage organs, is necessary for radial tree growth. However, considerable uncertainties on carbohydrate dynamics and the consequences on tree productivity exist. This study aims to better understand the variation in different carbon pools at intra-annual resolution by quantifying how cambial zone sugar and starch concentrations fluctuate over the season and in relation to cambial phenology. A comparison between two physiologically different species growing at the same site, i.e., the evergreen Picea abies Karst. and the deciduous Larix decidua Mill., and between L. decidua from two contrasting elevations, is presented to identify mechanisms of growth limitation. Results indicate that the annual cycle of sugar concentration within the cambial zone is coupled to the process of wood formation. The highest sugar concentration is observed when the number of cells in secondary wall formation and lignification stages is at a maximum, subsequent to most radial growth. Starch disappears in winter, while other freeze-resistant non-structural carbohydrates (NSCs) increase. Slight differences in NSC concentration between species are consistent with the differing climate sensitivity of the evergreen and deciduous species investigated. The general absence of differences between elevations suggests that the cambial activity of trees growing at the treeline was not limited by the availability of carbohydrates at the cambial zone but instead by environmental controls on the growing season duration.

  6. OnPLS integration of transcriptomic, proteomic and metabolomic data shows multi-level oxidative stress responses in the cambium of transgenic hipI- superoxide dismutase Populus plants

    OpenAIRE

    Srivastava, Vaibhav; Obudulu, Ogonna; Bygdell, Joakim; Löfstedt, Tommy; Ryden, Patrik; Nilsson, Robert; Ahnlund, Maria; Johansson, Annika; Jonsson, Pär; Freyhult, Eva; Qvarnström, Johanna; Karlsson, Jan; Melzer, Michael; Moritz, Thomas; Trygg, Johan

    2013-01-01

    BACKGROUND: Reactive oxygen species (ROS) are involved in the regulation of diverse physiological processes in plants, including various biotic and abiotic stress responses. Thus, oxidative stress tolerance mechanisms in plants are complex, and diverse responses at multiple levels need to be characterized in order to understand them. Here we present system responses to oxidative stress in Populus by integrating data from analyses of the cambial region of wild-type controls and plants expressi...

  7. Dicty_cDB: Contig-U12722-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ) GQ02809.SP6_D22 GQ028 - Cambium / phloem scrappin... 48 0.63 1 ( EX315666 ) GQ02809.B7_D22 GQ028 - Cambium / phloem scrap...ping... 48 0.63 1 ( EX312653 ) GQ02804.SP6_F06 GQ028 - Cambium / phloem scrap...pin... 48 0.63 1 ( EX312312 ) GQ02804.B7_F06 GQ028 - Cambium / phloem scrapping... 48 0.63 1 ( AC

  8. Dicty_cDB: Contig-U11082-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 58 ) GQ02811.B7_D08 GQ028 - Cambium / phloem scrapping... 46 3e-05 3 ( EX312195 ) GQ02804.B7_A02 GQ028 - Cambium / phloem scrap...ping... 46 3e-05 3 ( EX313127 ) GQ02805.B7_M12 GQ028 - Cambium / phloem scrapping... 46 3...GQ031 - Xylem Scrapings (Normalize... 46 3e-05 3 ( EX317077 ) GQ02811.B7_E03 GQ028 - Cambium / phloem scrapp

  9. Dicty_cDB: Contig-U11967-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 9.SP6_A14 GQ028 - Cambium / phloem scrappin... 42 9e-05 2 ( EX328735 ) GQ02829.B7..._A14 GQ028 - Cambium / phloem scrapping... 42 9e-05 2 ( EX326205 ) GQ02824.SP6_M13 GQ028 - Cambium / phloem scrap

  10. Dicty_cDB: Contig-U15927-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ondary xylem of girdled... 54 0.031 1 ( EX318935 ) GQ02813.SP6_N02 GQ028 - Cambium / phloem scrappin... 54 0....031 1 ( EX318604 ) GQ02813.B7_N02 GQ028 - Cambium / phloem scrapping... 54 0.031 1 ( EX317857 ) GQ02812.B7_...I07 GQ028 - Cambium / phloem scrapping... 54 0.031 1 ( EX314053 ) GQ02806.SP6_H13... GQ028 - Cambium / phloem scrappin... 54 0.031 1 ( EX313703 ) GQ02806.B7_H13 GQ028 - Cambium / phloem scrapp

  11. Dicty_cDB: Contig-U06545-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available GQ02803.SP6_N23 GQ028 - Cambium / phloem scrappin... 58 4e-04 1 ( EX311897 ) GQ0...2803.B7_N23 GQ028 - Cambium / phloem scrapping... 58 4e-04 1 ( EX310949 ) GQ02801.SP6_H09 GQ028 - Cambium / phloem scrap...pin... 58 4e-04 1 ( EX310884 ) GQ02801.SP6_E04 GQ028 - Cambium / phloem scrappin... 58 4e-04 1 (... EX310628 ) GQ02801.B7_H09 GQ028 - Cambium / phloem scrapping... 58 4e-04 1 ( EX3...10566 ) GQ02801.B7_E04 GQ028 - Cambium / phloem scrapping... 58 4e-04 1 ( AL929353 ) Plasmodium falciparum s

  12. Dicty_cDB: Contig-U04603-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available appin... 44 8.6 1 ( EX318360 ) GQ02813.B7_B23 GQ028 - Cambium / phloem scrap...ping... 44 8.6 1 ( EX315990 ) GQ02809.SP6_C18 GQ028 - Cambium / phloem scrappin... 44 8....6 1 ( EX315638 ) GQ02809.B7_C18 GQ028 - Cambium / phloem scrapping... 44 8.6 1 ( EX315442 ) GQ02808.SP6_J18 ...GQ028 - Cambium / phloem scrappin... 44 8.6 1 ( EX315097 ) GQ02808.B7_J18 GQ028 - Cambium / phloem scrap... ( EX344349 ) GQ03102.B7_I10 GQ031 - Xylem Scrapings (Normalize... 44 8.6 1 ( EX318692 ) GQ02813.SP6_B23 GQ028 - Cambium / phloem scr

  13. Dicty_cDB: Contig-U10553-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available abelii mRNA; EST DKFZp470M2011_r1 (from clo... 48 0.34 1 ( EX328636 ) GQ02828.SP6_M06 GQ028 - Cambium / phloem scrap...pin... 48 0.34 1 ( EX328273 ) GQ02828.B7_M06 GQ028 - Cambium / phloem scrapping... 48 0.34 1 ( EX327...971 ) GQ02827.SP6_O02 GQ028 - Cambium / phloem scrappin... 48 0.34 1 ( EX327671 )... GQ02827.B7_O02 GQ028 - Cambium / phloem scrapping... 48 0.34 1 ( BX936281 ) Zebrafish DNA sequence *** SEQU

  14. Dicty_cDB: Contig-U05088-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Shoot tip (Normalized li... 44 6.9 1 ( EX314035 ) GQ02806.SP6_G17 GQ028 - Cambium / phloem scrappin... 44 6....9 1 ( EX313684 ) GQ02806.B7_G17 GQ028 - Cambium / phloem scrapping... 44 6.9 1 ( EV276953 ) GLMCY94TF JCVI-

  15. Dicty_cDB: Contig-U05055-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 8.SP6_G24 GQ030 - Xylem planings - daytime ... 44 10.0 1 ( EX316108 ) GQ02809.SP6_I08 GQ028 - Cambium / phloem scrap...pin... 44 10.0 1 ( EX315761 ) GQ02809.B7_I08 GQ028 - Cambium / phloem scrapping... 44 10.0 1 ( DQ074

  16. Dicty_cDB: Contig-U13795-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ) GQ03212.B7_H17 GQ032 - Shoot tip (Normalized libr... 54 0.006 1 ( EX320896 ) GQ02816.SP6_L13 GQ028 - Cambium / phloem scrap...pin... 54 0.006 1 ( EX320527 ) GQ02816.B7_L13 GQ028 - Cambium / phloem scrap

  17. Dicty_cDB: Contig-U10652-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available WS03820.C21_M12 SS-B-23 Picea sitchensis cDNA clo... 62 3e-05 1 ( EX321390 ) GQ02817.SP6_A20 GQ028 - Cambium / phloem scrap...pin... 62 3e-05 1 ( EX321020 ) GQ02817.B7_A20 GQ028 - Cambium / phloem scrap

  18. Dicty_cDB: Contig-U15912-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available P5323RG8.T0 Acorn worm normalized juvenile pE... 56 3e-10 4 ( EX320945 ) GQ02816.SP6_N15 GQ028 - Cambium / phloem scrap...pin... 68 5e-09 2 ( EX320576 ) GQ02816.B7_N15 GQ028 - Cambium / phloem scrap

  19. Dicty_cDB: Contig-U14675-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available P(XYZ) lettuce perennis Lac... 46 2e-15 6 ( EX317051 ) GQ02811.B7_D01 GQ028 - Cambium / phloem scrapping... ...) WS0099.B21.1_L03 IS-B-N-A-10 Picea engelmannii x ... 74 5e-13 3 ( EX317416 ) GQ02811.SP6_D01 GQ028 - Cambium / phloem scrap

  20. Dicty_cDB: Contig-U10799-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 66 2e-11 2 ( EX313750 ) GQ02806.B7_J14 GQ028 - Cambium / phloem scrapping... 50 2e-11 3 ( AF026545 ) Pneumoc...ive growth ... 50 3e-11 3 ( EX314098 ) GQ02806.SP6_J14 GQ028 - Cambium / phloem scrap

  1. Dicty_cDB: Contig-U02375-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Cryptomeria japonica cDNA clone: CMFL031_P02, 5'e... 44 4.9 1 ( EX314727 ) GQ02807.SP6_I05 GQ028 - Cambium / phloem scrap...pin... 44 4.9 1 ( EX314403 ) GQ02807.B7_I05 GQ028 - Cambium / phloem scrap

  2. Dicty_cDB: Contig-U15039-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Q02828.SP6_G20 GQ028 - Cambium / phloem scrappin... 40 1e-07 3 ( DR476779 ) WS00968.C21_G22 IS-B-N-A-10 Pice...6_M13 GQ028 - Cambium / phloem scrappin... 40 2e-07 3 ( CB089832 ) gp29d06.g1 Cycad Leaf Library (NYBG) Cyca... 3 ( EX328280 ) GQ02828.B7_M13 GQ028 - Cambium / phloem scrapping... 40 2e-07 3 (...: Clean ROOTS systems - P trea... 40 2e-07 3 ( EX312157 ) GQ02803.SP6_N22 GQ028 - Cambium / phloem scrappin...... 40 2e-07 3 ( EX311896 ) GQ02803.B7_N22 GQ028 - Cambium / phloem scrapping... 4

  3. Dicty_cDB: Contig-U06838-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available .SP6_M18 GQ029 - Xylem scrapings - AT NITE... 48 0.29 1 ( EX332407 ) GQ02904.B7_M18 GQ029 - Xylem scrapings ...- AT NITE ... 48 0.29 1 ( EX320804 ) GQ02816.SP6_H13 GQ028 - Cambium / phloem scrap...pin... 48 0.29 1 ( EX320433 ) GQ02816.B7_H13 GQ028 - Cambium / phloem scrapping... 48 0.29 1 ( EX318356 ) ...GQ02813.B7_B18 GQ028 - Cambium / phloem scrapping... 48 0.29 1 ( EX316825 ) GQ02810.SP6_J03 GQ028 - Cambium / phloem scrap...pin... 48 0.29 1 ( EX316470 ) GQ02810.B7_J03 GQ028 - Cambium / phloem scrap

  4. Dicty_cDB: Contig-U04870-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Q032 - Shoot tip (Normalized libr... 46 0.17 2 ( EX311742 ) GQ02803.B7_F05 GQ028 - Cambium / phloem scrappin...820.B7_F01 GQ028 - Cambium / phloem scrapping... 46 0.17 2 ( EX373838 ) GQ03228.B7_N08 GQ032 - Shoot tip (No...Normalized libr... 46 0.18 2 ( EX314238 ) GQ02807.B7_A02 GQ028 - Cambium / phloem scrapping... 46 0.19 2 ( E... ) GQ03203.B7_A07 GQ032 - Shoot tip (Normalized libr... 46 2.6 1 ( EX323619 ) GQ02820.SP6_F01 GQ028 - Cambium / phloem scrap...pin... 46 2.6 1 ( EX314565 ) GQ02807.SP6_A02 GQ028 - Cambium / phloem scrap

  5. Role of emerald ash borer (Coleoptera: Buprestidae) larval vibrations in host-quality assessments by Tetrastichus planipennisi (Hymenoptera: Eulophidae)

    Science.gov (United States)

    Michael D. Ulyshen; Richard W. Mankin; Yigen Chen; Jian J. Duan; Therese M. Poland; Leah S. Bauer

    2011-01-01

    The biological control agent Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) is a gregarious larval endoparasitoid of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive cambium-feeding species responsible for recent, widespread mortality of ash (Fraxinus spp.) in...

  6. Cytokinins Are Central Regulators of Cambial Activity

    National Research Council Canada - National Science Library

    Miho Matsumoto-Kitano; Takami Kusumoto; Petr Tarkowski; Kaori Kinoshita-Tsujimura; Katerina Václavíková; Kaori Miyawaki; Tatsuo Kakimoto

    2008-01-01

    .... The quadruple Arabidopsis thaliana mutant atipt1;3;5;7, in which 4 genes encoding cytokinin biosynthetic isopentenyltransferases are disrupted by T-DNA insertion, was unable to form cambium and showed reduced thickening of the root and stem...

  7. Dicty_cDB: Contig-U09330-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ylem planings - daytime a... 60 1e-04 1 ( EX331539 ) GQ02903.B7_A06 GQ029 - Xylem scrapings - AT NITE ... 60... 1e-04 1 ( EX323057 ) GQ02819.SP6_M07 GQ028 - Cambium / phloem scrappin... 60 1e-04 1 ( EX322713 ) GQ02819.B...7_M07 GQ028 - Cambium / phloem scrapping... 60 1e-04 1 ( AV999726 ) Ciona intesti

  8. Cambial variants of liana species (Fabaceae) in Taiwan

    OpenAIRE

    Sheng-Zehn YANG; Po-Hao CHEN; Kung-Cheng LIN

    2016-01-01

    In order to better understand variation in cambium in lianas in Taiwan and to aid identification of liana species, we examined the stem structure of ten species of lianas belonging to the family Fabaceae. Samples were collected mainly from southern and eastern Taiwan and were selected from plants with different stem diameters in order to compare the structural similarities of plants. The results showed that cambium had a normal appearance and stems were round in Caesalpinia bonduc (L.) Roxb.,...

  9. GROWTH ANALYSIS OF SUGAR BEET IN DIFFERENT SOWING DENSITY DURING VEGETATION

    Directory of Open Access Journals (Sweden)

    Ivana Varga

    2015-06-01

    Full Text Available The aim of this study was to analyse sugar beet growth in field conditions during 2014 growing season. Sugar beet (hybrid Serenade, KWS was sown on March 18th at inter–row spacing of 50 cm and four different intra–row spacings: 13 cm, 15 cm,17 cm and 19 cm. During the growing season sugar beet plants samples were taken in eight terms from June to September. In each sampling term sugar beet leaf and root fresh weight (g/plant were determined. Also, diameter, number and distance between cambium rings and the number of cambium rings of 1 cm diameter were determined at the cross section of the widest hypocotyl part. Sowing density had a significant effect (P≤0.05 on all observed parameters. Average fresh leaf weight for all densities of 717.84 g/plant was the highest in late July and early August. Generally, during the growing season the plants sown at wider intra–row spacings (17 and 19 cm had on average higher root weight compared to average root weight in narrower intra–row spacings (13 and 15 cm. Average root diameter of all sowing densities increases from 4.13 cm in the first decade of June to 12.51 cm in the second decade of September wherein the diameter varied from 11.55 cm (intra–row spacing 13 cm to 14.79 cm (intra–row spacing 19 cm. Intensive formation of cambium rings for all densities was found out in June, where at the beginning of the June, the average number of cambium rings was 4.9, while and at the end of it was 7.3. In September, sugar beet root had on average of 8.4 cambium rings. On July 30th the largest number of cambium rings at 1 cm root diameter was on the average 1.52.

  10. [Anatomy of Aconitum finetianum Hand.-Mazz].

    Science.gov (United States)

    Qin, M

    1998-02-01

    The primary xylem of plump taproot of Aconitum finetianum is the diarch with xylem in the center. In the action of the secondary structure of the herb, the meristem is first produced in the secondary phloem, then the anomalous cambium is produced in the secondary xylem forms a new and splits into anomalous structure. In the action of anomalous structure of the herb, the meristem in the secondary phloem sinks inwardly from many sites, and forms many rings with the anomalous cambium. One of these rings forms a special endodermis and the protostele turns into the schizogenous stele.

  11. Movement of the cambial domain pattern and mechanism of formation of interlocked grain in Platanus

    Directory of Open Access Journals (Sweden)

    J. Krawczyszyn

    2015-01-01

    Full Text Available The orientation of splitting and uniting of rays, which served as an indicator of the orientation of morphogenic events occurring in cambium, was determined on series of veneers covering large tangential faces of Platanus trunks. It has been shown that cambium consists of orientational domains of Z- and S-type. They are perpendicular to, or slightly inclined with respect to, the trunk axis. Axial dimensions of domains are 8-28 cm. They move upward along the trunk, at a rate 6,5—12 mm, per radial mm of xylem porduced. Migration domain patterns are responsible for the formation of the interlocked grain.

  12. Comparative Root and Stem Anatomy of Four Rare Onobrychis Mill. (Fabaceae Taxa Endemic in Turkey

    Directory of Open Access Journals (Sweden)

    Mehmet TEKİN

    2015-09-01

    Full Text Available Four endemic taxa of Onobrychis Mill. genus, some of them being classified in the endangered threat category, were investigated for root and stem anatomy. Onobrychis quadrijuga, O. argyrea subsp. argyrea, O. tournefortii and O. albiflora were studied in regard to specific anatomy for the first time within the hereby study. Anatomical characters as the size and shape of the periderm, cortex, cambium cells in root and epidermis, collenchyma, cortex, cambium and pith cells in stem belonging to these four Onobrychis taxa were determined in detail. Based on the roots and stems measurements and analysis, specific anatomical differences between species were revealed.

  13. Tree rings and the local environment

    Science.gov (United States)

    Kevin T. Smith

    2011-01-01

    The amount of wood produced by a tree each year depends on tree condition, genetic programming, and growing conditions. Wood is mature xylem, the result of inward cell divisions by the vascular cambium, the new cell generator located between the wood and the inner bark (phloem). In temperate climatic zones, where a spring and summer growing season alternates with...

  14. Dicty_cDB: Contig-U09222-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available . 50 0.071 1 ( EX330315 ) GQ02901.B7_H16 GQ029 - Xylem scrapings - AT NITE ... 50... 0.071 1 ( EX312476 ) GQ02804.B7_M18 GQ028 - Cambium / phloem scrapping... 50 0.071 1 ( CE507331 ) tigr-gss-

  15. Dicty_cDB: Contig-U14381-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available _J09 GQ031 - Xylem Scrapings (Normaliz... 44 9.0 1 ( EX331458 ) GQ02902.SP6_M12 GQ029 - Xylem scrapings - AT... NITE... 44 9.0 1 ( EX316044 ) GQ02809.SP6_F04 GQ028 - Cambium / phloem scrappin... 44 9.0 1 >( AU038582 ) D

  16. Dicty_cDB: Contig-U15294-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ngs (Normalize... 46 5.5 1 ( EX334633 ) GQ02907.SP6_G12 GQ029 - Xylem scrapings - AT NITE... 46 5.5 1 ( EX31...6004 ) GQ02809.SP6_D08 GQ028 - Cambium / phloem scrappin... 46 5.5 1 ( EX309517 )

  17. Dicty_cDB: Contig-U15059-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 689 ) GQ02819.B7_L06 GQ028 - Cambium / phloem scrapping... 56 1e-13 2 ( EX426360 ) GQ03813.B7_B24 GQ038 - St...-13 4 ( EX332277 ) GQ02904.B7_G20 GQ029 - Xylem scrapings - AT NITE ... 54 2e-12 2 ( BJ400850 ) Dictyosteliu

  18. Hagelbui veroorzaakt grootschalige dennensterfte

    NARCIS (Netherlands)

    Moraal, L.G.

    2003-01-01

    Alterra onderzocht de grootschalige verbruining en sterfte van vliegdennen in het Houtdorper en Speulderwold in de gemeente Ermelo in de zomer van 2003. Op grond van de waargenomen symptomen (bastschade en afsterven van cambium) is de conclusie dat een zware hagelbui de oorzaak is geweest. Douglas

  19. Missing and dark rings associated with drought in Pinus halepensis

    Science.gov (United States)

    Klemen Novak; Martin De Luis; Jozica Gricar; Peter Prislan; Maks Merela; Kevin T. Smith; Katarina. Cufar

    2016-01-01

    The responses of the vascular cambium and tracheid differentiation to extreme drought in Aleppo pine (Pinus halepensis Mill.) were investigated. The research focused on the drought year of 2005, in the primary study area at Maigmo (MAI) in southeastern Spain, with comparisons in Jarafuel (JAL) and Guardamar (GUA). The climate in this region is...

  20. Repellence of the red bud borer (Resseliella oculiperda) to grafted apple trees by impregnation of budding tape with essential oils

    NARCIS (Netherlands)

    Tol, van R.W.H.M.; Linden, van der A.; Swarts, H.J.; Visser, J.H.

    2007-01-01

    The red bud borer Resseliella oculiperda (Rübs.) is a pest insect of apple trees when rootstocks are grafted with scion buds by shield budding. The female midges are attracted to the wounds of the grafted buds where they lay their eggs. The larvae feed on the cambium and destroy the buds completely

  1. Emerald Ash Borer

    Science.gov (United States)

    Deborah G. McCullough; Steven A. Katovich

    2004-01-01

    An exotic beetle from Asia was discovered in July 2002 feeding on ash (Fraxinus spp.) trees in southeastern Michigan. It was identified as Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Larvae feed in the cambium between the bark and wood, producing galleries that eventually girdle and kill branches and entire trees. Evidence suggests that A. planipennis has...

  2. Verification of a useful character for separating the sexes of the goldspotted oak borer, Agrilus coxalis auroguttatus (Coleoptera: Buprestidae)

    Science.gov (United States)

    T.W. Coleman; S.J. Seybold

    2010-01-01

    The goldspotted oak borer, Agrilus coxalis auroguttatus Schaeffer (Coleoptera: Buprestidae), is a new threat to several native oak species in California (CA) (Coleman & Seybold 2008a, b). The beetle larvae feed in and damage the outer xylem, cambium, and phloem of coast live oak, Quercus agrifolia Née (Fagaceae),...

  3. Fire-induced wounding elicits changes in the wood anatomy of North American conifers

    Science.gov (United States)

    Estelle Arbellay; Markus Stoffel; Elaine K. Sutherland; Kevin T. Smith; Donald A. Falk

    2013-01-01

    Fire is a major disturbance agent in North American forests. Fires injure trees when heat transfer through the bark partially kills the cambium and the compartmentalization process results in a fire scar. Dendrochronologists use these scars in the xylem to reconstruct fire regimes. However, little information exists on the wood anatomy of fire scars. Consequently, this...

  4. Efficacy of fipronil for protecting individual pines from mortality attributed to attack by western pine beetle and mountain pine beetle (Coleoptera: Curculionidae, Scolytinae)

    Science.gov (United States)

    C.J. Fettig; A.S. Munson; C.I. Jorgenson; D.M. and Grosman

    2010-01-01

    Bark beetles (Coleoptera: C~rculionidae, Scolytinae) are commonly recognized as important tree mortality agents in coniferous forests of the western U.S. Most species feed on the phloem and cambium, or xylem tissue of woody plants; and a few are recognized as the most destructive of all forest insect pests. The last decade has seen elevated levels of bark beetle caused...

  5. Reliability assessment of selected indicators of tree health

    Science.gov (United States)

    Pawel M. Lech

    2000-01-01

    The measurements of electrical resistance of near-cambium tissues, selected biometric features of needles and shoots, and the annual radial increment as well as visual estimates of crown defoliation were performed on about 100 Norway spruce trees in three 60- to 70-year-old stands located in the Western Sudety Mountains. The defoliation, electrical resistance, and...

  6. The Populus homeobox gene ARBORKNOX2 regulates cell differentiation during secondary growth

    Science.gov (United States)

    Juan Du; Shawn D. Mansfield; Andrew T. Groover

    2009-01-01

    The stem cells of the vascular cambium divide to produce daughter cells, which in turn divide before undergoing differentiation during the radial growth of woody stems. The genetic regulation of these developmental events is poorly understood, however. We report here the cloning and functional characterization of a Populus class-I KNOX...

  7. Fire, ice, and metabolism

    Science.gov (United States)

    Kevin T. Smith

    2015-01-01

    Evaluation of tree injury often begins with a loss assessment. For winter storm injury, percent crow loss or branch breakage is often estimated. For injury from fire or some mechanical source to the lower trunk, the height and width of the killed vascular cambium and resulting scar are often measured. Both crown breakage and stem wounds provide the opportunity for...

  8. Cytokinins are central regulators of cambial activity.

    Science.gov (United States)

    Matsumoto-Kitano, Miho; Kusumoto, Takami; Tarkowski, Petr; Kinoshita-Tsujimura, Kaori; Václavíková, Katerina; Miyawaki, Kaori; Kakimoto, Tatsuo

    2008-12-16

    The roots and stems of dicotyledonous plants thicken by the cell proliferation in the cambium. Cambial proliferation changes in response to environmental factors; however, the molecular mechanisms that regulate cambial activity are largely unknown. The quadruple Arabidopsis thaliana mutant atipt1;3;5;7, in which 4 genes encoding cytokinin biosynthetic isopentenyltransferases are disrupted by T-DNA insertion, was unable to form cambium and showed reduced thickening of the root and stem. The atipt3 single mutant, which has moderately decreased levels of cytokinins, exhibited decreased root thickening without any other recognizable morphological changes. Addition of exogenously supplied cytokinins to atipt1;3;5;7 reactivated the cambium in a dose-dependent manner. When an atipt1;3;5;7 shoot scion was grafted onto WT root stock, both the root and shoot grew normally and trans-zeatin-type (tZ-type) cytokinins in the shoot were restored to WT levels, but isopentenyladenine-type cytokinins in the shoot remained unchanged. Conversely, when a WT shoot was grafted onto an atipt1;3;5;7 root, both the root and shoot grew normally and isopentenyladenine-type cytokinins in the root were restored to WT levels, but tZ-type cytokinins were only partially restored. Collectively, it can be concluded that cytokinins are important regulators of cambium development and that production of cytokinins in either the root or shoot is sufficient for normal development of both the root and shoot.

  9. Long- and short-distance signaling in the regulation of lateral plant growth.

    Science.gov (United States)

    Brackmann, Klaus; Greb, Thomas

    2014-06-01

    Lateral growth of shoot and root axes by the formation of secondary vascular tissues is an instructive example for the plasticity of plant growth processes. Being purely postembryonic, lateral growth strongly depends on environmental input and is tightly regulated by long- and short-distance signaling. In general, plant vasculature represents the main route for long-distance transport of compounds throughout the plant body, thereby providing also a fast and efficient signaling pipeline for the coordination of growth and development. The vasculature consists of three major tissues; the xylem conducts water and nutrients, the phloem transports mainly organic compounds and the vascular cambium is a group of undifferentiated stem cells responsible for the continuous production of secondary vascular tissues. Notably, the close proximity to functional vascular tissues makes the vascular cambium especially accessible for the regulation by long-distance-derived signaling molecules as well as by the physical and physiological properties of transport streams. Thus, the vascular cambium offers unique opportunities for studying the complex regulation of plant growth processes. In this review, we focus on recent findings about long- and short-distance signaling mechanisms regulating cambium activity and, thereby, lateral expansion of plant growth axes by the formation of additional vascular tissues. © 2013 The Authors. Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.

  10. Developmental mechanisms regulating secondary growth in woody plants

    Science.gov (United States)

    Andrew Groover; Marcel Robischon

    2006-01-01

    Secondary growth results in the radial expansion of woody stems, and requires the coordination of tissue patterning, cell differentiation, and the maintenance of meristematic stem cells within the vascular cambium. Advances are being made towards describing molecular mechanisms that regulate these developmental processes, thanks in part to the application of new...

  11. Kutenai Indian Subsistence and Settlement Patterns.

    Science.gov (United States)

    1984-09-01

    task because a strip had previously been removed from a test tree to allow sampling its cambium for sweetness. The bark was now remoed from the trees...Eleventh - printing. Macmillan. Baillie-Grohman, W. A. 1907 Fifteen Years’ Sport and Life in the Hunting Grounds of Western America and British Columbia. 2d

  12. Dicty_cDB: SHH135 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available and phloem from mature trees Picea glauca cDNA clone GenomeQuebec_Id:GQ00610_L03 5', mRNA sequence. 44 1e-0...RNA, partial cds. 1265 0.0 1 DV977319 |DV977319.1 GQ00610.B3.1_L03 GQ006: Cambium

  13. Fulltext PDF

    Indian Academy of Sciences (India)

    diseases. Inner to the bark is the cortex. Inner to the cortex is the secondary phloem followed by a fascicular cambium (a meristem dedicated to produce the vascular tissues, the secondary phloem ..... following factors: i) Age-related growth processes due to normal physiological state; ii) Climate of that year; iii) Occurrence of ...

  14. Identification of cyst nematode B-type CLE peptides and modulation of the vascular stem cell pathway for feeding cell formation

    Science.gov (United States)

    Stem cells are important in the continuous formation of various tissues during postembryonic organogenesis. Stem cell pools in the SAM (shoot apical meristem), RAM (root apical meristem) and vascular procambium/cambium are regulated by CLE-receptor kinase-WOX signaling modules. Previous data showed ...

  15. Pruning Allegheny hardwoods

    Science.gov (United States)

    W. D. Zeedyk; A. F. Hough

    1958-01-01

    The continuing heavy demand for high-quality Allegheny hardwoods, particularly black cherry and sugar maple, impresses on us the need for more information responses of hardwoods to pruning. Pruning may have beneficial effects: it may increase quality without sacrificing growth. Or it may have detrimental effects: it may cause dieback of cambium, decay, staining and...

  16. Strigolactone analogues and their use

    KAUST Repository

    Al-Babili, Salim

    2015-03-17

    Novel compounds of formula (I) their use as germination trap for parasitic weeds, for the regulation of branching, tillering and root development, for enhancement of cambium growth, for the regulation of hyphal growth of mycorrhizal fungi and compositions comprising compounds of formula (I) and insecticides and/or fungicides.

  17. Physiological girdling of pine trees via phloem chilling: proof of concept

    Science.gov (United States)

    Kurt Johnsen; Chris Maier; Felipe Sanchez; Peter Anderson; John Butnor; Richard Waring; Sune Linder

    2007-01-01

    Quantifying below-ground carbon (C) allocation is particularly difficult as methods usually disturb the root– mycorrhizal–soil continuum. We reduced C allocation below ground of loblolly pine trees by: (1) physically girdling trees and (2) physiologically girdling pine trees by chilling the phloem. Chilling reduced cambium temperatures by approximately 18 °C. Both...

  18. The Populus ARBORKNOX1 homeodomain transcription factor regulates woody growth through binding to evolutionarily conserved target genes of diverse function

    Science.gov (United States)

    Lijun Liu; Matthew S. Zinkgraf; H. Earl Petzold; Eric P. Beers; Vladimir Filkov; Andrew Groover

    2014-01-01

    The class I KNOX homeodomain transcription factor ARBORKNOX1 (ARK1) is a key regulator of vascular cambium maintenance and cell differentiation in Populus. Currently, basic information is lacking concerning the distribution, functional characteristics, and evolution of ARK1 binding in the Populus genome.

  19. Last millennium northern hemisphere summer temperatures from tree rings: Part I: The long term context

    Czech Academy of Sciences Publication Activity Database

    Wilson, R.; Anchukaitis, K.; Briffa, K. R.; Büntgen, Ulf; Cook, E.; D'Arrigo, R.; Davi, N.; Esper, J.; Frank, D.; Gunnarson, B.; Hegerl, G.; Helama, S.; Klesse, S.; Krusic, P. J.; Linderholm, H. W.; Myglan, V. S.; Osborn, T. J.; Rydval, M.; Schneider, L.; Schurer, A.; Wiles, G.; Zhang, P.; Zorita, E.

    2016-01-01

    Roč. 134, FEB (2016), s. 1-18 ISSN 0277-3791 Institutional support: RVO:67179843 Keywords : high-resolution paleoclimatology * stable carbon isotopes * medieval warm period * past 600 years * blue intensity * volcanic-eruptions * density data * ice-age * dendroclimatic reconstruction * cambium phenology * Tree-rings * Northern hemisphere * Last millennium * Summer temperatures * Reconstruction * CMIP5 models Subject RIV: EH - Ecology, Behaviour Impact factor: 4.797, year: 2016

  20. Dendroclimatological potential of the Australian red cedar

    OpenAIRE

    Heinrich, Ingo; Banks, J. C. G.

    2005-01-01

    We examined Toona ciliata M.Roemer (Australian red cedar) for its potential to deliver annually resolved tree-ring proxy data. Such proxies are valuable and sought-after sources for reconstructing climate beyond instrumental records, especially in Australia. T. ciliata was chosen because it is one of the few deciduous tree species in Australia experiencing a seasonally dormant period of the cambium. This was confirmed by a preliminary tree-ring analysis which revealed distinct growth rings. B...

  1. Gene family structure, expression and functional analysis of HD-Zip III genes in angiosperm and gymnosperm forest trees

    OpenAIRE

    C?t?, Caroline L; Boileau, Francis; Roy, Vicky; Ouellet, Mario; Levasseur, Caroline; Morency, Marie-Jos?e; Cooke, Janice EK; S?guin, Armand; MacKay, John J

    2010-01-01

    Abstract Background Class III Homeodomain Leucine Zipper (HD-Zip III) proteins have been implicated in the regulation of cambium identity, as well as primary and secondary vascular differentiation and patterning in herbaceous plants. They have been proposed to regulate wood formation but relatively little evidence is available to validate such a role. We characterised and compared HD-Zip III gene family in an angiosperm tree, Populus spp. (poplar), and the gymnosperm Picea glauca (white spruc...

  2. Cytokinin-dependent secondary growth determines root biomass in radish (Raphanus sativus L.).

    Science.gov (United States)

    Jang, Geupil; Lee, Jung-Hun; Rastogi, Khushboo; Park, Suhyoung; Oh, Sang-Hun; Lee, Ji-Young

    2015-08-01

    The root serves as an essential organ in plant growth by taking up nutrients and water from the soil and supporting the rest of the plant body. Some plant species utilize roots as storage organs. Sweet potatoes (Ipomoea batatas), cassava (Manihot esculenta), and radish (Raphanus sativus), for example, are important root crops. However, how their root growth is regulated remains unknown. In this study, we characterized the relationship between cambium and radial root growth in radish. Through a comparative analysis with Arabidopsis root expression data, we identified putative cambium-enriched transcription factors in radish and analysed their expression in representative inbred lines featuring distinctive radial growth. We found that cell proliferation activities in the cambium positively correlated with radial growth and final yields of radish roots. Expression analysis of candidate transcription factor genes revealed that some genes are differentially expressed between inbred lines and that the difference is due to the distinct cytokinin response. Taken together, we have demonstrated for the first time, to the best of our knowledge, that cytokinin-dependent radial growth plays a key role in the yields of root crops. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Development of successive cambia and wood structure in stem of Rivea hypocriteriformis (Convolvulaceae

    Directory of Open Access Journals (Sweden)

    Rajput Kishore S.

    2016-07-01

    Full Text Available This study examined the formation of successive rings of cambia in Rivea hypocriteriformis Choisy (Convolvulaceae. The mature stem is composed of four to five rings of xylem alternating with phloem. Successive cambia originate as smaller and larger segments; union and anastomosing of small cambial segments often leads to the formation of discontinuous rings. In the initial stage of growth, several vascular bundles interconnect to form the first ring of vascular cambium. The cambium remains functional for one complete season and becomes dormant during summer; a new ring of cambium is completed prior to the subsequent monsoon season and sprouting of new leaves. Successive cambia are initiated from the pericyclic parenchyma situated three to four cell layers outside of the protophloem. Functionally, all the successive cambia are bidirectional and produce secondary xylem centripetally and phloem centrifugally. The secondary xylem is diffuse-porous, with indistinct growth rings and consisting of wide fibriform vessels, fibre tracheids, and axial and ray parenchyma cells. The xylem rays are uni- to multiseriate and heterocellular. The multiseriate rays contain lignified marginal ray cells and thin-walled, unlignified central cells. The central ray cells also show accumulations of starch and druses. Discrete strands of intraxylary phloem occur at the periphery of the pith, and additional intraxylary phloem develops from adjacent cells as secondary growth progresses. Earlier-formed phloem shows heavy accumulation of callose, followed by its compaction. The development of successive cambia is correlated with extension growth and with the phenology of the plant.

  4. Cambial variants of liana species (Fabaceae in Taiwan

    Directory of Open Access Journals (Sweden)

    Sheng-Zehn YANG

    2016-08-01

    Full Text Available In order to better understand variation in cambium in lianas in Taiwan and to aid identification of liana species, we examined the stem structure of ten species of lianas belonging to the family Fabaceae. Samples were collected mainly from southern and eastern Taiwan and were selected from plants with different stem diameters in order to compare the structural similarities of plants. The results showed that cambium had a normal appearance and stems were round in Caesalpinia bonduc (L. Roxb., Caesalpinia crista L., and Caesalpinia minax Hance. We noted a combination of furrowed xylem and dissected xylem in Bauhinia championii (Benth. Benth., shallowly furrowed xylem in Acacia caesia (L. Willd., Centrosema pubescens Benth., and Mimosa diplotricha C. Wright ex Sauvalle, a combination of flattened stem and interxylary phloem in Entada koshunensis Hayata & Kaneh. and Entada phaseoloides (L. Merr., and a combination of external vascular cylinder and flattened stem in Pueraria montana (Lour. Merr. Of these lianas, three species, -A. caesia, B. championii, and C. crista, -experienced two distinct developmental growth phases. We concluded that variations in cambium and xylem deposition are associated with the size of the stems. Medullary bundles occurred in the pith of P. montana, an observation that has not previously been recorded. We present the first description and photographs of these bundles and the external vascular cylinder in the pith, and it is recommended that further study of this species be conducted.

  5. PHYSICAL, MORPHOLOGICAL PROPERTIES AND RAMAN SPECTROSCOPY OF CHESTNUT BLIGHT DISEASED CASTANEA SATIVA MILL. WOOD

    Directory of Open Access Journals (Sweden)

    Gokhan Gunduz

    2016-03-01

    Full Text Available In this study, some of the physical and anatomical properties of Chestnut Blight Diseased (CBD wood were investigated, and the study also included observations using Raman spectroscopy. The objective of these investigations was to determine the extent of the damage that is done to the wood of the diseased chestnut trees, which must be removed from the forest and used in the manufacture of industrial products. It was indicated that most of the adverse effects of the disease were in the vascular cambium. There was a clear indication of deterioration of the wood in the last growth ring next to vascular cambium. In the diseased secondary xylem region next to vascular cambium; vessel diameter, vessel frequency and vessel element length had a decrease, and vessel and other cells were irregular compared to healthy wood. Spores were detected and identified as Cryphonectria parasitica (Murrill. Annual ring properties (annual growth ring width, latewood percentage, etc. were similar in diseased wood compared to healthy wood. The Raman spectroscopy results showed no significant changes in the structure of the cell wall or its components. After removing the diseased parts, unlimited usage of formerly wood is possible. Heat treatment of the wood is suggested before use in the interest of sanitation and dimensional stability.

  6. Immunohistochemical and molecular characterization of the human periosteum.

    Science.gov (United States)

    Frey, Sönke Percy; Jansen, Hendrik; Doht, Stefanie; Filgueira, Luis; Zellweger, Rene

    2013-01-01

    The aim of the present study was to characterize the cell of the human periosteum using immunohistological and molecular methods. Phenotypic properties and the distribution of the cells within the different layers were investigated with immunohistochemical staining techniques and RT-PCR, focussing on markers for stromal stem cells, osteoblasts, osteoclasts and immune cells. Immunohistochemical results revealed that all stained cells were located in the cambium layer and that most cells were positive for vimentin. The majority of cells consisted of stromal stem cells and osteoblastic precursor cells. The density increased towards the deeper layers of the cambium. In addition, cells positive for markers of the osteoblast, chondrocyte, and osteoclast lineages were found. Interestingly, there were MHC class II-expressing immune cells suggesting the presence of dendritic cells. Using lineage-specific primer pairs RT-PCR confirmed the immunofluorescence microscopy results, supporting that human periosteum serves as a reservoir of stromal stem cells, as well as cells of the osteoblastic, and the chondroblastic lineage, osteoclasts, and dendritic cells. Our work elucidates the role of periosteum as a source of cells with a high regenerative capacity. Undifferentiated stromal stem cells as well as osteoblastic precursor cells are dominating in the cambium layer. A new outlook is given towards an immune response coming from the periosteum as MHC II positive immune cells were detected.

  7. Impact of warming and drought on carbon balance related to wood formation in black spruce.

    Science.gov (United States)

    Deslauriers, Annie; Beaulieu, Marilène; Balducci, Lorena; Giovannelli, Alessio; Gagnon, Michel J; Rossi, Sergio

    2014-08-01

    Wood formation in trees represents a carbon sink that can be modified in the case of stress. The way carbon metabolism constrains growth during stress periods (high temperature and water deficit) is now under debate. In this study, the amounts of non-structural carbohydrates (NSCs) for xylogenesis in black spruce, Picea mariana, saplings were assessed under high temperature and drought in order to determine the role of sugar mobilization for osmotic purposes and its consequences for secondary growth. Four-year-old saplings of black spruce in a greenhouse were subjected to different thermal conditions with respect to the outside air temperature (T0) in 2010 (2 and 5 °C higher than T0) and 2011 (6 °C warmer than T0 during the day or night) with a dry period of about 1 month in June of each year. Wood formation together with starch, NSCs and leaf parameters (water potential and photosynthesis) were monitored from May to September. With the exception of raffinose, the amounts of soluble sugars were not modified in the cambium even if gas exchange and photosynthesis were greatly reduced during drought. Raffinose increased more than pinitol under a pre-dawn water potential of less than -1 Mpa, presumably because this compound is better suited than polyol for replacing water and capturing free radicals, and its degradation into simple sugar is easier. Warming decreased the starch storage in the xylem as well the available hexose pool in the cambium and the xylem, probably because of an increase in respiration. Radial stem growth was reduced during drought due to the mobilization of NSCs for osmotic purposes and due to the lack of cell turgor. Thus plant water status during wood formation can influence the NSCs available for growth in the cambium and xylem. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Properties of sweet potato starches from different tissue zones

    Energy Technology Data Exchange (ETDEWEB)

    Noda, T.; Takahata, Y.; Nagata, T. (Kyushu National Agricultural Experiment Station, Ministry of Agriculture, Forestry and Fisheries, Kumamoto (Japan))

    1992-10-01

    Sweet potato starches prepared from the peel (P), cambium (C), and inner-tissue (IT) were tested for physicochemical properties. The average granule sizes of the IT starches were tended to be larger than those of the P and C starches. Amylose contents of starches from the different tissue zones did not differ significantly. The onset and peak temperatures (T[sub o], T[sub p]) of the P starches determined by differential scanning calorimetry (DSC) were somewhat high. The C starches were readily digested by the four glucoamylases. (orig.).

  9. [Pharmacognosy identification of Embelia parviflora].

    Science.gov (United States)

    Lu, Sen-hua; Liang, Xiao-le; Chen, Yong; Zeng, Hai-sheng; Wei, Yu-yan; Wu, Fan-jing

    2012-02-01

    To study the morphological character and microscopic identification of Embelia parviflora. Researches on the morphological character and microscopic identification of roots and stems of Embelia parviflora were carried on respectively. Significant microscopic characteristics of Embelia parviflora were confirmed. Such as single stone cells scattered in the root cortical, lots of stone cell groups and fiber bundles scattered in the column parts and became ring intermittently. Stem phloem was broad, large scale secretory cells scattered near cambium region and stone cell groups in ray parts. Crystal stone cells of thick and thin could be seen in powder. These features can be used as the reference for quality standard of Embelia parviflora.

  10. Potential of enzymes for wood debarking

    Energy Technology Data Exchange (ETDEWEB)

    Raettoe, M.; Kantelinen, A.; Bailey, M.; Viikari, L. (VTT Biotechnical Lab., Espoo (Finland))

    1993-02-01

    The effect of enzymatic pretreatment on the energy consumption of wood debarking was studied on the laboratory scale using enzymes to degrade the cambial layer. The energy consumed in debarking spruce was decreased as much as 80% after pretreatment with pectinolytic enzymes. In addition to polygalacturonase activity, pectin lyase and xylanase activities were also present in the most efficient enzyme preparation. Due to the complex composition of the cambium and inner phloem, these and other enzymes that hydrolyze the various inner bark components are probably needed for efficient debarking.

  11. Classifying Taiwan Lianas with Radiating Plates of Xylem

    Directory of Open Access Journals (Sweden)

    Sheng-Zehn Yang

    2015-12-01

    Full Text Available Radiating plates of xylem are a lianas cambium variation, of which, 22 families have this feature. This study investigates 15 liana species representing nine families with radiating plates of xylem structures. The features of the transverse section and epidermis in fresh liana samples are documented, including shapes and colors of xylem and phloem, ray width and numbers, and skin morphology. Experimental results indicated that the shape of phloem fibers in Ampelopsis brevipedunculata var. hancei is gradually tapered and flame-like, which is in contrast with the other characteristics of this type, including those classified as rays. Both inner and outer cylinders of vascular bundles are found in Piper kwashoense, and the irregularly inner cylinder persists yet gradually diminishes. Red crystals are numerous in the cortex of Celastrus kusanoi. Aristolochia shimadai and A. zollingeriana develop a combination of two cambium variants, radiating plates of xylem and a lobed xylem. The shape of phloem in Stauntonia obovatifoliola is square or truncate, and its rays are numerous. Meanwhile, that of Neoalsomitra integrifolia is blunt and its rays are fewer. As for the features of a stem surface within the same family, Cyclea ochiaiana is brownish in color and has a deep vertical depression with lenticels, Pericampylus glaucus is greenish in color with a vertical shallow depression. Within the same genus, Aristolochia shimadai develops lenticels, which are not in A. zollingeriana; although the periderm developed in Clematis grata is a ring bark and tears easily, that of Clematis tamura is thick and soft.

  12. Determining the Composition of Lignins in Different Tissues of Silver Birch

    Directory of Open Access Journals (Sweden)

    Kurt V. Fagerstedt

    2015-04-01

    Full Text Available Quantitative and qualitative lignin analyses were carried out on material from the trunks of silver birch (Betula pendula Roth trees. Two types of material were analyzed. First, whole birch trunk pieces were cryosectioned into cork cambium, non-conductive phloem, the cambial zone (conductive phloem, cambium and differentiating xylem, lignified xylem and the previous year’s xylem; material that would show differences in lignin amount and quality. Second, clonal material from one natural birch population was analyzed to show variations between individuals and between the lignin analysis methods. The different tissues showed marked differences in lignin amount and the syringyl:guaiacyl (S/G ratio. In the non-conductive phloem tissue containing sclereids, the S/G ratio was very low, and typical for phloem fibers and in the newly-formed xylem, as well as in the previous year’s xylem, the ratio lay between five and seven, typical for broadleaf tree xylem. Clonal material consisting of 88 stems was used to calculate the S/G ratios from the thioacidolysis and CuO methods, which correlated positively with an R2 value of 0.43. Comparisons of the methods indicate clearly that the CuO method is a good alternative to study the monomeric composition and S/G ratio of wood lignins.

  13. HISTOPATOLOGÍA DEL PINO DE LAS ALTURAS (Pinus hartwegii Lindl. INOCULADO CON TRES HONGOS OPHIOSTOMATOIDES

    Directory of Open Access Journals (Sweden)

    Omar Alejandro Pérez-Vera

    2011-01-01

    Full Text Available El objetivo de este estudio fue identificar las alteraciones histológicas en el pino de las alturas (Pinus hartwegii causadas por tres especies de hongos ophiostomatoides, por medio de microscopia de luz. En Pinus hartwegii hubo acumulación de resina en la zona de inoculación a los diez días, y el follaje se tornó de amarillo a café rojizo a los 60 días. En las inoculaciones con Leptographium guttulatum y Ophiostoma olivaceapinii se observó que inducen la metabolización de polifenoles, depositándose en las paredes de las células de la corteza, el floema, cambium vascular y en la médula se necrosaron. O. ips causó necrosis más severa en corteza, floema, cambium vascular y médula. En xilema, las hifas de los tres hongos penetran en las traqueidas y avanzan longitudinalmente por las puntuaciones aeroladas y se distribuyen radialmente por células parenquimatosas y radios.

  14. Development of Successive Cambia and Structure of Secondary Xylem of Ipomoea Obscura (Convolvulaceae

    Directory of Open Access Journals (Sweden)

    Rajput Kishore S.

    2014-07-01

    Full Text Available Stems of Ipomoea obscura Ker Gawl., increase in thickness by forming multiple rings of cambia. Stems 5-6 mm thick produce parenchymatous derivatives which divide repeatedly to form small arcs of cambium. Several such small arcs initiate simultaneously and form a ring of small cambial arcs. After the formation of a few xylem and phloem elements, all these arcs are interconnected by transdifferentiation of parenchyma cells present between the cambial arcs and constitute a complete cambial cylinder. This newly formed cambium is functionally bidirectional: earlier- formed arcs produce xylem centripetally and phloem centrifugally, while later-formed segments exclusively produce thin-walled parenchyma cells on either side. Young stems are circular in cross section but as stem thickness increases they become oval to elliptic or lobed and dumbbell-shaped. Xylem rays are mostly uni- or biseriate and thin-walled, but multiseriate rays characteristic for a climbing habit are observed occasionally. In thick stems, the marginal ray parenchyma in most of the samples becomes meristematic and develops ray cambia which exclusively produce sieve elements. Similarly, parenchyma cells produced from later-formed cambial segments give rise to several irregularly oriented vascular bundles. The secondary xylem is diffuse porous, with indistinct growth rings and is composed of fibriform and wider vessels, fibres, and axial and ray parenchyma cells, while phloem consists of sieve elements, companion cells, and axial and ray parenchyma cells.

  15. Biological basis of tree-ring formation: a crash course

    Directory of Open Access Journals (Sweden)

    Cyrille Barthélémy Karl Rathgeber

    2016-05-01

    Full Text Available Wood is of crucial importance for man and biosphere. In this mini review, we present the fundamental processes involved in tree-ring formation and intra-annual dynamics of cambial activity, along with the influences of the environmental factors. During wood formation, new xylem cells produced by the cambium are undergoing profound transformations, passing through successive differentiation stages, which enable them to perform their functions in trees. Xylem cell formation can be divided in five major phases: (1 the division of a cambial mother cell that creates a new cell; (2 the enlargement of this newly formed cell; (3 the deposition of its secondary wall; (4 the lignification of its cell wall; and finally, (5 its programmed cell death. In most regions of the world cambial activity follows a seasonal cycle. At the beginning of the growing season, when temperature increases, the cambium resumes activity, producing new xylem cells. These cells are disposed along radial files, and start their differentiation program according to their birth date, creating typical developmental strips in the forming xylem. The width of these strips smoothly changes along the growing season. Finally, when climatic conditions deteriorate (temperature or water availability in particular, cambial activity stops, soon followed by cell enlargement, and later on by secondary wall deposition. Without a clear understanding of the xylem formation process, it is not possible to comprehend how annual growth rings and typical wood structures are formed, recording seasonal variations of the environment as well as extreme climatic events.

  16. Antiproliferative effect of the hydroalcoholic extract of Hymenaea stigonocarpa Mart. ex Hayne (Fabaceae, Caesalpinioideae on the meristematic cells of Allium cepa L. roots

    Directory of Open Access Journals (Sweden)

    Layana Menezes da Silva

    2014-11-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n1p45 This study evaluates the hydroalcoholic extract obtained from the cork cambium of Hymenaea stigonocarpa (jatobá-do-cerrado on the meristematic cells of Allium cepa roots, at 3 concentrations, 0.5, 1.0, and 1.5 mg/mL, and 2 exposure times, 24 h and 48 h. The slides were made through the crushing technique. Cells were analyzed throughout the cell cycle, totaling 5,000 for each control and concentration group. We found that the 3 concentrations significantly decreased the cell division rate at the exposure time of 48 h when compared to their respective controls. The mitotic index of the exposure time of 48 h was statistically different when compared to the cell division rate of the exposure time of 24 h for all concentrations. The number of cell abnormalities observed was not statistically significant by means of the chi-square test used. Therefore, under the conditions analyzed, the 3 concentrations tested for the cork cambium of jatobá-do-cerrado significantly decreased, in statistical terms, the cell division rate in the meristematic cells of A. cepa roots.

  17. Antiproliferative effect of the hydroalcoholic extract of Hymenaea stigonocarpa Mart. ex Hayne (Fabaceae, Caesalpinioideae on the meristematic cells of Allium cepa L. roots

    Directory of Open Access Journals (Sweden)

    Layana Menezes da Silva

    2015-02-01

    Full Text Available This study evaluates the hydroalcoholic extract obtained from the cork cambium of Hymenaea stigonocarpa (jatobá-do-cerrado on the meristematic cells of Allium cepa roots, at 3 concentrations, 0.5, 1.0, and 1.5 mg/mL, and 2 exposure times, 24 h and 48 h. The slides were made through the crushing technique. Cells were analyzed throughout the cell cycle, totaling 5,000 for each control and concentration group. We found that the 3 concentrations significantly decreased the cell division rate at the exposure time of 48 h when compared to their respective controls. The mitotic index of the exposure time of 48 h was statistically different when compared to the cell division rate of the exposure time of 24 h for all concentrations. The number of cell abnormalities observed was not statistically significant by means of the chi-square test used. Therefore, under the conditions analyzed, the 3 concentrations tested for the cork cambium of jatobá-do-cerrado significantly decreased, in statistical terms, the cell division rate in the meristematic cells of A. cepa roots.

  18. Cell wall modifications in Arabidopsis plants with altered alpha-L-arabinofuranosidase activity.

    Science.gov (United States)

    Chávez Montes, Ricardo A; Ranocha, Philippe; Martinez, Yves; Minic, Zoran; Jouanin, Lise; Marquis, Mélanie; Saulnier, Luc; Fulton, Lynette M; Cobbett, Christopher S; Bitton, Frédérique; Renou, Jean-Pierre; Jauneau, Alain; Goffner, Deborah

    2008-05-01

    Although cell wall remodeling is an essential feature of plant growth and development, the underlying molecular mechanisms are poorly understood. This work describes the characterization of Arabidopsis (Arabidopsis thaliana) plants with altered expression of ARAF1, a bifunctional alpha-L-arabinofuranosidase/beta-D-xylosidase (At3g10740) belonging to family 51 glycosyl-hydrolases. ARAF1 was localized in several cell types in the vascular system of roots and stems, including xylem vessels and parenchyma cells surrounding the vessels, the cambium, and the phloem. araf1 T-DNA insertional mutants showed no visible phenotype, whereas transgenic plants that overexpressed ARAF1 exhibited a delay in inflorescence emergence and altered stem architecture. Although global monosaccharide analysis indicated only slight differences in cell wall composition in both mutant and overexpressing lines, immunolocalization experiments using anti-arabinan (LM6) and anti-xylan (LM10) antibodies indicated cell type-specific alterations in cell wall structure. In araf1 mutants, an increase in LM6 signal intensity was observed in the phloem, cambium, and xylem parenchyma in stems and roots, largely coinciding with ARAF1 expression sites. The ectopic overexpression of ARAF1 resulted in an increase in LM10 labeling in the secondary walls of interfascicular fibers and xylem vessels. The combined ARAF1 gene expression and immunolocalization studies suggest that arabinan-containing pectins are potential in vivo substrates of ARAF1 in Arabidopsis.

  19. Cell Wall Modifications in Arabidopsis Plants with Altered α-l-Arabinofuranosidase Activity[C][W

    Science.gov (United States)

    Chávez Montes, Ricardo A.; Ranocha, Philippe; Martinez, Yves; Minic, Zoran; Jouanin, Lise; Marquis, Mélanie; Saulnier, Luc; Fulton, Lynette M.; Cobbett, Christopher S.; Bitton, Frédérique; Renou, Jean-Pierre; Jauneau, Alain; Goffner, Deborah

    2008-01-01

    Although cell wall remodeling is an essential feature of plant growth and development, the underlying molecular mechanisms are poorly understood. This work describes the characterization of Arabidopsis (Arabidopsis thaliana) plants with altered expression of ARAF1, a bifunctional α-l-arabinofuranosidase/β-d-xylosidase (At3g10740) belonging to family 51 glycosyl-hydrolases. ARAF1 was localized in several cell types in the vascular system of roots and stems, including xylem vessels and parenchyma cells surrounding the vessels, the cambium, and the phloem. araf1 T-DNA insertional mutants showed no visible phenotype, whereas transgenic plants that overexpressed ARAF1 exhibited a delay in inflorescence emergence and altered stem architecture. Although global monosaccharide analysis indicated only slight differences in cell wall composition in both mutant and overexpressing lines, immunolocalization experiments using anti-arabinan (LM6) and anti-xylan (LM10) antibodies indicated cell type-specific alterations in cell wall structure. In araf1 mutants, an increase in LM6 signal intensity was observed in the phloem, cambium, and xylem parenchyma in stems and roots, largely coinciding with ARAF1 expression sites. The ectopic overexpression of ARAF1 resulted in an increase in LM10 labeling in the secondary walls of interfascicular fibers and xylem vessels. The combined ARAF1 gene expression and immunolocalization studies suggest that arabinan-containing pectins are potential in vivo substrates of ARAF1 in Arabidopsis. PMID:18344421

  20. Stem cell function during plant vascular development.

    Science.gov (United States)

    Elo, A; Immanen, J; Nieminen, K; Helariutta, Y

    2009-12-01

    While many regulatory mechanisms controlling the development and function of root and shoot apical meristems have been revealed, our knowledge of similar processes in lateral meristems, including the vascular cambium, is still limited. Our understanding of even the anatomy and development of lateral meristems (procambium or vascular cambium) is still relatively incomplete, let alone their genetic regulation. Research into this particular tissue type has been mostly hindered by a lack of suitable molecular markers, as well as the fact that thus far very few mutants affecting plant secondary development have been described. The development of suitable molecular markers is a high priority in order to help define the anatomy, especially the location and identity of cambial stem cells and the developmental phases and molecular regulatory mechanisms of the cambial zone. To date, most of the advances have been obtained by studying the role of the major plant hormones in vascular development. Thus far auxin, cytokinin, gibberellin and ethylene have been implicated in regulating the maintenance and activity of cambial stem cells; the most logical question in research would be how these hormones interact during the various phases of cambial development.

  1. Identification, expression, and functional analysis of CLE genes in radish (Raphanus sativus L.) storage root.

    Science.gov (United States)

    Gancheva, Maria S; Dodueva, Irina E; Lebedeva, Maria A; Tvorogova, Varvara E; Tkachenko, Alexandr A; Lutova, Ludmila A

    2016-01-27

    Radish (Raphanus sativus L.) is a widespread agricultural plant forming storage root due to extensive secondary growth which involves cambium proliferation and differentiation of secondary conductive tissues. Closely related to the model object Arabidopsis thaliana, radish is a suitable model for studying processes of secondary growth and storage root development. CLE peptides are a group of peptide phytohormones which play important role in the regulation of primary meristems such as SAM, RAM, and procambium, as well as secondary meristems. However, the role of CLE peptides in lateral growth of root during storage root formation has not been studied to date. In present work we studied the role of CLE peptides in the development of storage root in radish. We have identified 18 CLE genes of radish (RsCLEs) and measured their expression in various plant organs and also at different stages of root development in R. sativus and Raphanus raphanistrum-its close relative which does not form storage root. We observed significant decline of expression levels for genes RsCLE1, 2, 11, 13, and 16, and also multifold increase of expression levels for genes RsCLE19, and 41 during secondary root growth in R. sativus but not in R. raphanistrum. Expression of RsCLE 2, 19, and 41 in R. sativus root was confined to certain types of tissues while RsCLE1, 11, 13, and 16 expressed throughout the root. Experiments on overexpression of RsCLE2, 19 and 41 or treatment of radish plants with synthetic CLE peptides revealed that CLE19 and CLE2 increase the number of xylem elements, and CLE41 induces the formation of extra cambium foci in secondary xylem. Expression levels of RsCLE2 and 19 strongly decrease in response to exogenous cytokinin, while auxin causes dramatic increase of RsCLE19 expression level and decrease of RsCLE41 expression. Our data allow us to hypothesize about the role of RsCLE2, 19 and 41 genes in the development of storage root of Raphanus sativus, e.g. RsCLE19 may play a

  2. Genetic and environmental modification of the mechanical properties of wood

    Science.gov (United States)

    Sederoff, R.; Allona, I.; Whetten, R.

    1996-02-01

    Wood is one of the nation's leading raw materials and is used for a wide variety of products, either directly as wood, or as derived materials in pulp and paper. Wood is a biological material and evolved to provide mechanical support and water transport to the early plants that conquered the land. Wood is a tissue that results from the differentiation and programmed cell death of cells that derive from a tissue known as the vascular cambium. The vascular cambium is a thin cylinder of undifferentiated tissue in plant stems and roots that gives rise to several different cell types. Cells that differentiate on the internal side of the cambium form xylem, a tissue composed in major part, of long thin cells that die leaving a network of interconnected cell walls that serve to transport water and to provide mechanical support for the woody plant. The shape and chemical composition of the cells in xylem are well suited for these functions. The structure of cells in xylem determines the mechanical properties of the wood because of the strength derived from the reinforced matrix of the wall. The hydrophobic phenolic surface of the inside of the cell walls is essential to maintain surface tension upon which water transport is based and to resist decay caused by microorganisms. The properties of wood derived from the function of xylem also determine its structural and chemical properties as wood and paper products. Therefore, the physical and chemical properties of wood and paper products also depend on the morphology and composition of the cells from which they are derived. Wood (xylem cell walls) is an anisotropic material, a composite of lignocellulose. It is a matrix of cellulose microfibrils, complexed with hemicelluloses, (carbohydrate polymers which contain sugars other than glucose, both pentoses and hexoses), embedded together in a phenolic matrix of lignin. The high tensile strength of wood in the longitudinal direction, is due to the structure of cellulose and the

  3. Transcriptome characteristics and six alternative expressed genes positively correlated with the phase transition of annual cambial activities in Chinese Fir (Cunninghamia lanceolata (Lamb. Hook.

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    Zhanjun Wang

    Full Text Available BACKGROUND: The molecular mechanisms that govern cambial activity in angiosperms are well established, but little is known about these molecular mechanisms in gymnosperms. Chinese fir (Cunninghamia lanceolata (Lamb. Hook, a diploid (2n  = 2x  = 22 gymnosperm, is one of the most important industrial and commercial timber species in China. Here, we performed transcriptome sequencing to identify the repertoire of genes expressed in cambium tissue of Chinese fir. METHODOLOGY/PRINCIPAL FINDINGS: Based on previous studies, the four stage-specific cambial tissues of Chinese fir were defined using transmission electron microscopy (TEM. In total, 20 million sequencing reads (3.6 Gb were obtained using Illumina sequencing from Chinese fir cambium tissue collected at active growth stage, with a mean length of 131 bp and a N50 of 90 bp. SOAPdenovo software was used to assemble 62,895 unigenes. These unigenes were further functionally annotated by comparing their sequences to public protein databases. Expression analysis revealed that the altered expression of six homologous genes (ClWOX1, ClWOX4, ClCLV1-like, ClCLV-like, ClCLE12, and ClPIN1-like correlated positively with changes in cambial activities; moreover, these six genes might be directly involved in cambial function in Chinese fir. Further, the full-length cDNAs and DNAs for ClWOX1 and ClWOX4 were cloned and analyzed. CONCLUSIONS: In this study, a large number of tissue/stage-specific unigene sequences were generated from the active growth stage of Chinese fir cambium. Transcriptome sequencing of Chinese fir not only provides extensive genetic resources for understanding the molecular mechanisms underlying cambial activities in Chinese fir, but also is expected to be an important foundation for future genetic studies of Chinese fir. This study indicates that ClWOX1 and ClWOX4 could be possible reverse genetic target genes for revealing the molecular mechanisms of cambial activities in

  4. Does the structure of wood contribute to understanding the oaks decline phenomenon?

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    Mirela Tulik

    2014-04-01

    Full Text Available Vascular cambium is a meristematic tissue which produces wood centriphugaly and phloem centripetaly. In the structure of wood and phloem, data concerning developmental processes taking place in the cambium is recorded. The history of the cambium is encoded in the dimensions, numbers and arrangements of the wood and phloem cells. For investigations, the wood is usually preferred because it is durable and such data could remain unchanged for centuries, whereas in the phloem due to distorted processes, it deranges after a few years. In broadleaves, the wood is composed of vessels, tracheids, fibers and parenchyma cells. The process of the wood formation consists of the cambial cell derivatives expansion, lignification of its walls and programmed cell death. Since the seventies of the nineteenth century, the process of declining oaks taking place in Europe on a regular basis has been observed. Oak decline is a complex process that involves interactions of both biotic and abiotic factors leading to increased trees mortality. The main goal of the studies is the examination of the structure of wood in declining oaks (Quercus robur L. in respect to physiological (conductive role of this tissue. It is known that on the level of the wood structure, water transport efficiency depends on the diameter of vessels - the main elements of the hydraulic conductivity system. Any reduction of the vessels lumen causes the reduction of the water transport to the organs of the trees body and, therefore, influences organisms survival rate. Anatomical analyses were carried out on wood samples (comprising all annual rings formed during the 30-40 years life of the analyzed trees collected at breast height from the main stem of healthy, weakened and dead oaks. The anatomical traits of the wood like as the width of the annual increments, the diameter and density of early wood vessels were measured. The results which are described in the paper by Tulik (2014 revealed that

  5. Transcriptome changes in the cambial region of poplar (Populus alba L.) in response to water deficit.

    Science.gov (United States)

    Berta, M; Giovannelli, A; Sebastiani, F; Camussi, A; Racchi, M L

    2010-03-01

    A transcriptome analysis of the Populus alba cambial region was performed with the aim of elucidating the gene network underlying the response to water deficit within the cambium and differentiating derivative cambial cells. Water stress was induced in 1-year-old P. alba plants by withholding water for 9 days. At that time, leaf predawn water potential fell to -0.8 MPa, resulting in a significant reduction in stomatal conductance, CO(2) assimilation and a consistent increment of stem shrinkage. These effects were almost fully reversed by re-hydration. The water deficit resulted in changes in gene expression that affected several functional categories, such as protein metabolism, cell wall metabolism, stress response, transporters and transcriptional regulation. The function of up- and down-regulated genes is discussed considering the physiological response of the plants to water deficit.

  6. Crecimiento secundario inusual en raíz principal de Pfaffia gnaphalioides (L. Fil. Mart. (Amaranthaceae Secondary and unusual growth in main root of Pfaffia gnaphalioides (L. Fil. Mart. (Amaranthaceae

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    Mónica Alicia Grosso

    2007-03-01

    Full Text Available Raíces de Pfaffia se comercializan como "ginseng brasilero" y extractos crudos de raíces de Pfaffia glomerata tienen actividad analgésica y desinflamatoria. Pfaffia gnaphalioides es herbácea perenne y crece en el área serrana del sur de la Provincia de Córdoba, Argentina. El objetivo de este trabajo es estudiar el crecimiento secundario inusual en raíz principal de Pfaffia gnaphalioides. Se estudió en invernáculo la forma de crecimiento durante los dos primeros años relacionando la parte aérea y subterránea. Se realizaron calicatas in situ para analizar el sistema radical. La raíz principal desarrolla raíces laterales, plagiótropas, con yemas que forman brotes aéreos de innovación. En cortes transversales de raíz principal se observa desarrollo secundario inusual. Un meristema lateral produce corteza secundaria hacia afuera y tejido conjuntivo y una sucesión de cambia vascular hacia adentro. Cuando cada cambium vascular es producido, el meristema lateral que se encuentra hacia afuera de éste tiende a permanecer quiescente, retornando a la actividad cuando el cambium vascular interno a éste permanece menos activo. Los cordones vasculares secundarios están dispuestos en anillos concéntricos sin radios parenquimáticos. La presencia de abundante parénquima conteniendo almidón en la estructura inusual de raíz en Pfaffia gnaphalioides, constituye una buena adaptación a condiciones xéricas.Pfaffia roots have been commercialized as "brazilian ginseng" and crude extracts of Pfaffia glomerata roots have analgesic and disinflamatory activity. Pfaffia gnaphalioides is a perennial herb and grows in southern Córdoba, Argentina. The objective of this work is to analyze root systems in Pfaffia gnaphalioides. Growth of above and belowground organs was observed for two years in a greenhouse. Belowground organs were analyzed in situ in hillcountry shrublands, by digging soil pits. The root system is characterized by presence of a main

  7. Socio-ecological implications of modifying rotation lengths in forestry.

    Science.gov (United States)

    Roberge, Jean-Michel; Laudon, Hjalmar; Björkman, Christer; Ranius, Thomas; Sandström, Camilla; Felton, Adam; Sténs, Anna; Nordin, Annika; Granström, Anders; Widemo, Fredrik; Bergh, Johan; Sonesson, Johan; Stenlid, Jan; Lundmark, Tomas

    2016-02-01

    The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today's major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns.

  8. ANATOMY OF GYNURA AURANTIACA (BLUME SCH.BIP. EX DC. (ASTERACEAE

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    Rodica BERCU

    2014-06-01

    Full Text Available The paper presents a detailed histoanatomical description, of the vegetative organs (root, stem and leaf and photographs as well of Gynura aurantiaca (Blume Sch.Bip. ex DC. It was observed that the root have typical primary dictos structure. The stem has a differentiated in two regions cortex and the stele comprise one ring of open collateral vascular bundles with secondary xylem due to the cambium activity. The petiole anatomy is quite similar in its basic structure with the stem. The blade presents a heterogenous and hypostomatic mesophyll and a number of vascular bundles in the midrib zone. Remarkable is the presence of the filamentous, uniseriate non-glandular hairs in the stem, petiole and leaf blade. The mechanical tissue is present in the stem, petiole and blade as well.

  9. Dicty_cDB: Contig-U04515-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available _L3A_SL1 Nippo... 46 0.008 2 ( FG287049 ) 1108770728167 New World Screwworm Egg 9261 ESTs C... 46 0.009 2 ( ...FG294927 ) 1108770721339 New World Screwworm Larvae 9387 EST... 46 0.009 2 ( FG28...9781 ) 1108793305302 New World Screwworm Egg 9261 ESTs C... 46 0.009 2 ( CK096156 ) UA48BPF09.3pR Populus do...09 1 ( BU819882 ) UA48BPF09 Populus tremula cambium cDNA library Po... 54 0.009 1 ( FG288449 ) 1108793271723 New World... Screwworm Egg 9261 ESTs C... 46 0.010 2 ( FG299008 ) 1108793324740 New World Screwworm Larvae 938

  10. Dicty_cDB: Contig-U11030-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 5 ) GQ00611.TB_L13 GQ006: Cambium and phloem from mat... 54 0.013 1 ( FK136381 ) XABT171675.b1 Gateway compa...one:dda11f04, 3' ... 40 2.6 2 ( FK061521 ) XABT124781.b1 Gateway compatible cien ...cDNA librar... 40 2.7 2 ( FF775353 ) XABT76119.fwd Gateway compatible cien cDNA librar... 40 2.7 2 ( FF690866 ) XABT103520.fwd Gatewa... clone:dda23m22, 3' ... 40 2.7 2 ( FF766735 ) XABT70515.fwd Gateway compatible ci...131367 ) XABT168717.b1 Gateway compatible cien cDNA librar... 40 2.3 2 ( FC760810

  11. Morphoregulatory role of thidiazuron: morphogenesis of root outgrowths in thidiazuron-treated geranium (Pelargonium x hortorum Bailey).

    Science.gov (United States)

    Sanago, M H; Murch, S J; Slimmon, T Y; Krishnaraj, S; Saxena, P K

    1995-12-01

    Root outgrowths formed on the root tissue of geranium (Pelargonium x hortorum Bailey cv. Kim and cv. Shone Helena) plants in response to treatment with the phenylurea derivative, thidiazuron (N-phenyl-N'-1,2,3-thiadiazol-5'-ylurea; TDZ). Treatment with the cytokinin N(6)-benzylaminopurine (BAP) or the auxin α-naphthaleneacetic acid (NAA) did not result in stimulation of similar abnormal structures on the root tissue. Significantly more outgrowths developed on roots of plants treated with 10 μM and 20 μM TDZ than on control plants or those treated with 1 μM TDZ for the eight-week treatment period. Some outgrowths produced shoots and plantlets while still attached to roots, and regenerants were easily separated from the root tissue and transferred to soil in the greenhouse where they grew to maturity. Histological observations suggested these outgrowths originated from the vascular cambium region of the root.

  12. A new reconstruction algorithm of the cell production kinetics for conifer species

    Science.gov (United States)

    Popkova, Margarita; Shishov, Vladimir; Tychkov, Ivan

    2017-04-01

    Tree-rings are important to reconstruct past environmental conditions. To describe and to understand development of tree-ring formation and predict the wood characteristics, a process-based modeling of wood formation have great potentials. Seasonal dynamics of tree growth can be explained by tree-ring growth, individual features of tree and external climatic conditions. The main anatomical characteristics of tree ring structure, e.g. the number of cells, the radial cell size and cell walls thickness are closely related to the kinetic characteristics of seasonal tree-ring formation, especially with the kinetics of cell production. Due to specificity of these processes and complexity of labor-intensive experimental methods (reference) mathematical modeling can be considered as an one possible approach, which requires to develop adequate mathematical methods and corresponded software components. In modern times the most process-based models simulate biomass production only with no possibility to determine the processes of cell production by cambium and differentiation cambial derivatives. A new block of the Vaganov-Shashkin model was proposed to estimate a cell production in tree rings and transfer it into time scale based on the simulated integral growth rates of the model. Here the VS-modeling is extremely important step because the simulated daily tree-ring growth rate is a basis to evaluate intra-seasonal variation of cambial production. The comparative analysis of the growth rates with one of the main tree-ring anatomical characteristics of conifers - radial cells size was carried out to provide a new procedure of timing cambium cell production during the season. Based on the previous research experience when the seasonal tree-growth dynamics were analyzed by direct (cutting, etc.) and indirect methods, the new proposed method is free from any complexity and limitations accompanying previous methods. The work was supported by the Russian Science Foundation (RSF

  13. Annual Cambial Rhythm in Pinus halepensis and Pinus sylvestris as Indicator for Climate Adaptation.

    Science.gov (United States)

    Prislan, Peter; Gričar, Jožica; de Luis, Martin; Novak, Klemen; Martinez Del Castillo, Edurne; Schmitt, Uwe; Koch, Gerald; Štrus, Jasna; Mrak, Polona; Žnidarič, Magda T; Čufar, Katarina

    2016-01-01

    To understand better the adaptation strategies of intra-annual radial growth in Pinus halepensis and Pinus sylvestris to local environmental conditions, we examined the seasonal rhythm of cambial activity and cell differentiation at tissue and cellular levels. Two contrasting sites differing in temperature and amount of precipitation were selected for each species, one typical for their growth and the other represented border climatic conditions, where the two species coexisted. Mature P. halepensis trees from Mediterranean (Spain) and sub-Mediterranean (Slovenia) sites, and P. sylvestris from sub-Mediterranean (Slovenia) and temperate (Slovenia) sites were selected. Repeated sampling was performed throughout the year and samples were prepared for examination with light and transmission electron microscopes. We hypothesized that cambial rhythm in trees growing at the sub-Mediterranean site where the two species co-exist will be similar as at typical sites for their growth. Cambium in P. halepensis at the Mediterranean site was active throughout the year and was never truly dormant, whereas at the sub-Mediterranean site it appeared to be dormant during the winter months. In contrast, cambium in P. sylvestris was clearly dormant at both sub-Mediterranean and temperate sites, although the dormant period seemed to be significantly longer at the temperate site. Thus, the hypothesis was only partly confirmed. Different cambial and cell differentiation rhythms of the two species at the site where both species co-exist and typical sites for their growth indicate their high but different adaptation strategies in terms of adjustment of radial growth to environmental heterogeneity, crucial for long-term tree performance and survival.

  14. Expression of the KNOTTED HOMEOBOX Genes in the Cactaceae Cambial Zone Suggests Their Involvement in Wood Development

    Science.gov (United States)

    Reyes-Rivera, Jorge; Rodríguez-Alonso, Gustavo; Petrone, Emilio; Vasco, Alejandra; Vergara-Silva, Francisco; Shishkova, Svetlana; Terrazas, Teresa

    2017-01-01

    The vascular cambium is a lateral meristem that produces secondary xylem (i.e., wood) and phloem. Different Cactaceae species develop different types of secondary xylem; however, little is known about the mechanisms underlying wood formation in the Cactaceae. The KNOTTED HOMEOBOX (KNOX) gene family encodes transcription factors that regulate plant development. The role of class I KNOX genes in the regulation of the shoot apical meristem, inflorescence architecture, and secondary growth is established in a few model species, while the functions of class II KNOX genes are less well understood, although the Arabidopsis thaliana class II KNOX protein KNAT7 is known to regulate secondary cell wall biosynthesis. To explore the involvement of the KNOX genes in the enormous variability of wood in Cactaceae, we identified orthologous genes expressed in species with fibrous (Pereskia lychnidiflora and Pilosocereus alensis), non-fibrous (Ariocarpus retusus), and dimorphic (Ferocactus pilosus) wood. Both class I and class II KNOX genes were expressed in the cactus cambial zone, including one or two class I paralogs of KNAT1, as well as one or two class II paralogs of KNAT3-KNAT4-KNAT5. While the KNOX gene SHOOTMERISTEMLESS (STM) and its ortholog ARK1 are expressed during secondary growth in the Arabidopsis and Populus stem, respectively, we did not find STM orthologs in the Cactaceae cambial zone, which suggests possible differences in the vascular cambium genetic regulatory network in these species. Importantly, while two class II KNOX paralogs from the KNAT7 clade were expressed in the cambial zone of A. retusus and F. pilosus, we did not detect KNAT7 ortholog expression in the cambial zone of P. lychnidiflora. Differences in the transcriptional repressor activity of secondary cell wall biosynthesis by the KNAT7 orthologs could therefore explain the differences in wood development in the cactus species. PMID:28316604

  15. A contribution to understanding the structure of amphivasal secondary bundles in monocotyledons

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    Joanna Jura-Morawiec

    2014-04-01

    Full Text Available Secondary growth of monocotyledonous plants is connected with the activity of the monocot cambium that accumulates most of the derivatives inner to the cambial cylinder. These derivatives differentiate into (a secondary bundles with the amphivasal arrangement, i.e. xylem composed of tracheids surrounds the phloem cells and (b the parenchymatous secondary conjunctive tissue in which the bundles are embedded. The amphivasal secondary bundles differ in the arrangement of xylem cells as visible on single cross sections through the secondary body of the monocots. Apart from the bundles with typical ring of tracheids also the bundles where tracheids do not quite surround the phloem are present. We aimed to elucidate the cross sectional anatomy of the amphivasal secondary bundles with the use of the serial sectioning method which allowed us to follow very precisely the bundle structure along its length. The studies were carried out with the samples of secondary tissues collected from the stem of Dracaena draco L. growing in the greenhouses of the Polish Academy of Sciences Botanical Garden – CBDC in Powsin and the Adam Mickiewicz University Botanical Garden. The material was fixed in a mixture of glycerol and ethanol (1:1; v/v, dehydrated stepwise with graded ethanol series and finally embedded in epon resin. Afterwards, the material was sectioned with microtome into continuous series of thin (3 μm sections, stained with PAS/toluidine blue and examined under the light microscope. The results, described in details in Jura‑Morawiec & Wiland-Szymańska (2014, revealed novel facts about tracheids arrangement. Each amphivasal bundle is composed of sectors where tracheids form a ring as well as of such where tracheids are separated by vascular parenchyma cells. We hypothesize that strands of vascular parenchyma cells locally separating the tracheids enable radial transport of assimilates from sieve elements of the bundle towards the sink tissues, e

  16. Living on the Edge: Contrasted Wood-Formation Dynamics in Fagus sylvatica and Pinus sylvestris under Mediterranean Conditions.

    Science.gov (United States)

    Martinez Del Castillo, Edurne; Longares, Luis A; Gričar, Jožica; Prislan, Peter; Gil-Pelegrín, Eustaquio; Čufar, Katarina; de Luis, Martin

    2016-01-01

    Wood formation in European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) was intra-annually monitored to examine plastic responses of the xylem phenology according to altitude in one of the southernmost areas of their distribution range, i.e., in the Moncayo Natural Park, Spain. The monitoring was done from 2011 to 2013 at 1180 and 1580 m a.s.l., corresponding to the lower and upper limits of European beech forest in this region. Microcores containing phloem, cambium and xylem were collected biweekly from twenty-four trees from the beginning of March to the end of November to assess the different phases of wood formation. The samples were prepared for light microscopy to observe the following phenological phases: onset and end of cell production, onset and end of secondary wall formation in xylem cells and onset of cell maturation. The temporal dynamics of wood formation widely differed among years, altitudes and tree species. For Fagus sylvatica, the onset of cambial activity varied between the first week of May and the third week of June. Cambial activity then slowed down and stopped in summer, resulting in a length of growing season of 48-75 days. In contrast, the growing season for P. sylvestris started earlier and cambium remained active in autumn, leading to a period of activity varying from 139-170 days. The intra-annual wood-formation pattern is site and species-specific. Comparison with other studies shows a clear latitudinal trend in the duration of wood formation, positive for Fagus sylvatica and negative for P. sylvestris.

  17. Living on the edge: contrasted wood-formation dynamics in Fagus sylvatica and Pinus sylvestris under Mediterranean conditions

    Directory of Open Access Journals (Sweden)

    Edurne eMartinez Del Castillo

    2016-03-01

    Full Text Available Wood formation in European beech (Fagus sylvatica L. and Scots pine (Pinus sylvestris L. was intra-annually monitored to examine plastic responses of the xylem phenology according to altitude in one of the southernmost areas of their distribution range, i.e. in the Moncayo Natural Park, Spain. The monitoring was done from 2011 to 2013 at 1180 and 1580 m a.s.l., corresponding to the lower and upper limits of European beech forest in this region. Microcores containing phloem, cambium and xylem were collected biweekly from twenty-four trees from the beginning of March to the end of November to assess the different phases of wood formation. The samples were prepared for light microscopy to observe the following phenological phases: onset and end of cell production, onset and end of secondary wall formation in xylem cells and onset of cell maturation. The temporal dynamics of wood formation widely differed among years, altitudes and tree species. For Fagus sylvatica, the onset of cambial activity varied between the first week of May and the third week of June. Cambial activity then slowed down and stopped in summer, resulting in a length of growing season of 48–75 days. In contrast, the growing season for Pinus sylvestris started earlier and cambium remained active in autumn, leading to a period of activity varying from 139-170 days. The intra-annual wood-formation pattern is site and species-specific. Comparison with other studies shows a clear latitudinal trend in the duration of wood formation, positive for Fagus sylvatica and negative for Pinus sylvestris.

  18. Bayesian phylogeny of sucrose transporters: Ancient origins, differential expansion and convergent evolution in monocots and dicots

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    Duo ePeng

    2014-11-01

    Full Text Available Sucrose transporters (SUTs are essential for the export and efficient movement of sucrose from source leaves to sink organs in plants. The angiosperm SUT family was previously classified into three or four distinct groups, Types I, II (subgroup IIB and III, with dicot-specific Type I and monocot-specific Type IIB functioning in phloem loading. To shed light on the underlying drivers of SUT evolution, Bayesian phylogenetic inference was undertaken using 41 sequenced plant genomes, including seven basal lineages at key evolutionary junctures. Our analysis supports four phylogenetically and structurally distinct SUT subfamilies, originating from two ancient groups (AG1 and AG2 that diverged early during terrestrial colonization. In both AG1 and AG2, multiple intron acquisition events in the progenitor vascular plant established the gene structures of modern SUTs. Tonoplastic Type III and plasmalemmal Type II represent evolutionarily conserved descendants of AG1 and AG2, respectively. Type I and Type IIB were previously thought to evolve after the dicot-monocot split. We show, however, that divergence of Type I from Type III SUT predated basal angiosperms, likely associated with evolution of vascular cambium and phloem transport. Type I SUT was subsequently lost in monocots along with vascular cambium, and independent evolution of Type IIB coincided with modified monocot vasculature. Both Type I and Type IIB underwent lineage-specific expansion. In multiple unrelated taxa, the newly-derived SUTs exhibit biased expression in reproductive tissues, suggesting a functional link between phloem loading and reproductive fitness. Convergent evolution of Type I and Type IIB for SUT function in phloem loading and reproductive organs supports the idea that differential vascular development in dicots and monocots is a strong driver for SUT family evolution in angiosperms.

  19. Cytokinin and Auxin Display Distinct but Interconnected Distribution and Signaling Profiles to Stimulate Cambial Activity.

    Science.gov (United States)

    Immanen, Juha; Nieminen, Kaisa; Smolander, Olli-Pekka; Kojima, Mikiko; Alonso Serra, Juan; Koskinen, Patrik; Zhang, Jing; Elo, Annakaisa; Mähönen, Ari Pekka; Street, Nathaniel; Bhalerao, Rishikesh P; Paulin, Lars; Auvinen, Petri; Sakakibara, Hitoshi; Helariutta, Ykä

    2016-08-08

    Despite the crucial roles of phytohormones in plant development, comparison of the exact distribution profiles of different hormones within plant meristems has thus far remained scarce. Vascular cambium, a wide lateral meristem with an extensive developmental zonation, provides an optimal system for hormonal and genetic profiling. By taking advantage of this spatial resolution, we show here that two major phytohormones, cytokinin and auxin, display different yet partially overlapping distribution profiles across the cambium. In contrast to auxin, which has its highest concentration in the actively dividing cambial cells, cytokinins peak in the developing phloem tissue of a Populus trichocarpa stem. Gene expression patterns of cytokinin biosynthetic and signaling genes coincided with this hormonal gradient. To explore the functional significance of cytokinin signaling for cambial development, we engineered transgenic Populus tremula × tremuloides trees with an elevated cytokinin biosynthesis level. Confirming that cytokinins function as major regulators of cambial activity, these trees displayed stimulated cambial cell division activity resulting in dramatically increased (up to 80% in dry weight) production of the lignocellulosic trunk biomass. To connect the increased growth to hormonal status, we analyzed the hormone distribution and genome-wide gene expression profiles in unprecedentedly high resolution across the cambial zone. Interestingly, in addition to showing an elevated cambial cytokinin content and signaling level, the cambial auxin concentration and auxin-responsive gene expression were also increased in the transgenic trees. Our results indicate that cytokinin signaling specifies meristematic activity through a graded distribution that influences the amplitude of the cambial auxin gradient. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Starch Grain Distribution in Taproots of Defoliated Medicago sativa L. 1

    Science.gov (United States)

    Habben, Jeffrey E.; Volenec, Jeffrey J.

    1990-01-01

    Defoliation of alfalfa (Medicago sativa L.) results in a cyclic pattern of starch degradation followed by reaccumulation in taproots. Characterization of changes in anatomical distribution of starch grains in taproots will aid our understanding of biochemical and physiological mechanisms involved in starch metabolism in taproots of this species. Our objectives were to determine the influence of defoliation on starch grain distribution and size variation in taproots of two alfalfa lines selected for contrasting concentrations of taproot starch. In addition, we used electron microscopy to examine the cellular environment of starch grains, and computer-based image optical analysis to determine how cross-sectional area of tissues influenced starch accumulation. Taproots of field-grown plants were sampled at defoliation and weekly thereafter over a 28-day period. Taproot segments were fixed in glutaraldehyde and prepared for either light or electron microscopy. Transverse sections were examined for number and size of starch grains and tissue areas were measured. Starch grains were located throughout bark tissues, but were confined primarily to ray parenchyma cells in wood tissues. During the first week of foliar regrowth after defoliation, starch grains in ray cells near the cambium disappeared first, while degradation of those near the center of the taproot was delayed. During the third and fourth weeks of regrowth, there was a uniform increase in number of starch grains per cell profile across the rays, but by 28 days after defoliation there were more starch grains in ray cells near the cambium than in cells near the center of the taproot (low starch line only). Bark tissues from both lines showed synchronous degradation and synthesis of starch grains that was not influenced greatly by cell location. Diameter of starch grains varied with cell location in medullary rays during rapid starch degradation, but was not influenced by cell position in bark tissues. Therefore

  1. [Radial variation and time lag of sap flow of Populus gansuensis in Minqin Oasis, Northwest].

    Science.gov (United States)

    Dang, Hong-Zhong; Yang, Wen-Bin; Li, Wei; Zhang, You-Yan; Li, Chang-Long

    2014-09-01

    Sap flow of tree trunk is very important to reflect the dynamics of physiological activities, as well as to estimate the water consumption of individual plant. In the present study, we used the thermal dissipation technique to monitor the sap flow velocity (J) at four depth loci (i. e. 2 cm, 3 cm, 5 cm, 8 cm) of three Populus gansuensis trees (30 year-old) in Minqin Oasis for two consecutive growing seasons. The results showed that there were significant differences among J values at four depth loci under tree trunk cambium. J value at the 3 cm depth locus (J3) of the tree trunk was the highest, and then in sequences, were 2 cm, 5 cm and 8 cm depth loci (J2, J5 and J8). J value (J3) on typical sunny days in June with the highest atmospheric potential evapotranspiration (ET0) was up to 28.53 g · cm(-2) · h(-1), which was 1.42, 2.74 and 4.4 times of J2, J5 and J8, respectively. In the process of diurnal variation of sap flow velocity, the peak value time of J at the four depth loci of the tree trunk was different, but the differences among them were within 20 min. Furthermore, the peak value time of sap flow velocity was very different to that of solar radiation (Rs) and air vapour pressure deficit (VPD). The time lag between J and Rs was from 55 to 88 min on typical sunny days during the main growing seasons (from June to August), and, positively related to the depth of the locus under tree trunk cambium, while the time lag between J and VPD reached 60-96 min, and was negatively related to the depth of the locus. The seasonal variation patterns of J were consistent with ET0. With the increase of tree physiological activities, there was a trend that the major water transportation layer extended to the interior sapwood. The most important meteorological factor was the solar radiation, which primarily drove sap flow at different depths of tree trunk. However, the secondary factor changed along with the depth, and VPD became increasingly important with increasing the

  2. Analysis of Differentially Expressed Genes Associated with Coronatine-Induced Laticifer Differentiation in the Rubber Tree by Subtractive Hybridization Suppression.

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    Shi-Xin Zhang

    Full Text Available The secondary laticifer in the secondary phloem is differentiated from the vascular cambia of the rubber tree (Hevea brasiliensis Muell. Arg.. The number of secondary laticifers is closely related to the rubber yield potential of Hevea. Pharmacological data show that jasmonic acid and its precursor linolenic acid are effective in inducing secondary laticifer differentiation in epicormic shoots of the rubber tree. In the present study, an experimental system of coronatine-induced laticifer differentiation was developed to perform SSH identification of genes with differential expression. A total of 528 positive clones were obtained by blue-white screening, of which 248 clones came from the forward SSH library while 280 clones came from the reverse SSH library. Approximately 215 of the 248 clones and 171 of the 280 clones contained cDNA inserts by colony PCR screening. A total of 286 of the 386 ESTs were detected to be differentially expressed by reverse northern blot and sequenced. Approximately 147 unigenes with an average length of 497 bp from the forward and 109 unigenes with an average length of 514 bp from the reverse SSH libraries were assembled and annotated. The unigenes were associated with the stress/defense response, plant hormone signal transduction and structure development. It is suggested that Ca2+ signal transduction and redox seem to be involved in differentiation, while PGA and EIF are associated with the division of cambium initials for COR-induced secondary laticifer differentiation in the rubber tree.

  3. Analysis of Differentially Expressed Genes Associated with Coronatine-Induced Laticifer Differentiation in the Rubber Tree by Subtractive Hybridization Suppression.

    Science.gov (United States)

    Zhang, Shi-Xin; Wu, Shao-Hua; Chen, Yue-Yi; Tian, Wei-Min

    2015-01-01

    The secondary laticifer in the secondary phloem is differentiated from the vascular cambia of the rubber tree (Hevea brasiliensis Muell. Arg.). The number of secondary laticifers is closely related to the rubber yield potential of Hevea. Pharmacological data show that jasmonic acid and its precursor linolenic acid are effective in inducing secondary laticifer differentiation in epicormic shoots of the rubber tree. In the present study, an experimental system of coronatine-induced laticifer differentiation was developed to perform SSH identification of genes with differential expression. A total of 528 positive clones were obtained by blue-white screening, of which 248 clones came from the forward SSH library while 280 clones came from the reverse SSH library. Approximately 215 of the 248 clones and 171 of the 280 clones contained cDNA inserts by colony PCR screening. A total of 286 of the 386 ESTs were detected to be differentially expressed by reverse northern blot and sequenced. Approximately 147 unigenes with an average length of 497 bp from the forward and 109 unigenes with an average length of 514 bp from the reverse SSH libraries were assembled and annotated. The unigenes were associated with the stress/defense response, plant hormone signal transduction and structure development. It is suggested that Ca2+ signal transduction and redox seem to be involved in differentiation, while PGA and EIF are associated with the division of cambium initials for COR-induced secondary laticifer differentiation in the rubber tree.

  4. INTELLIGENCE, COGNITION AND LANGUAGE OF GREEN PLANTS

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    Anthony eTrewavas

    2016-04-01

    Full Text Available A summary definition of some 70 descriptions of intelligence provides a definition for all other organisms including plants that stresses fitness. Barbara McClintock, a plant biologist, posed the notion of the ‘ thoughtful cell’ in her Nobel prize address. The systems structure necessary for a thoughtful cell is revealed by comparison of the interactome and connectome. The plant root cap, a group of some 200 cells that act holistically in responding to numerous signals, likely possesses a similar systems structure agreeing with Darwin’s description of acting like the brain of a lower organism. Intelligent behaviour requires assessment of different choices and taking the beneficial one. Decisions are constantly required to optimise the plant phenotype to a dynamic environment and the cambium is the assessing tissue diverting more or removing resources from different shoot and root branches through manipulation of vascular elements. Environmental awareness likely indicates consciousness. Spontaneity in plant behaviour, ability to count to five and error correction indicate intention. Volatile organic compounds are used as signals in plant interactions and being complex in composition may be the equivalent of language accounting for self and alien recognition by individual plants. Game theory describes competitive interactions. Interactive and intelligent outcomes emerge from application of various games between plants themselves and interactions with microbes. Behaviour profiting from experience, another simple definition of intelligence, requires both learning and memory and is indicated in the priming of herbivory, disease and abiotic stresses.

  5. Members of the LATERAL ORGAN BOUNDARIES DOMAIN transcription factor family are involved in the regulation of secondary growth in Populus.

    Science.gov (United States)

    Yordanov, Yordan S; Regan, Sharon; Busov, Victor

    2010-11-01

    Regulation of secondary (woody) growth is of substantial economic and environmental interest but is poorly understood. We identified and subsequently characterized an activation-tagged poplar (Populus tremula × Populus alba) mutant with enhanced woody growth and changes in bark texture caused primarily by increased secondary phloem production. Molecular characterization of the mutation through positioning of the tag and retransformation experiments shows that the phenotype is conditioned by activation of an uncharacterized gene that encodes a novel member of the LATERAL ORGAN BOUNDARIES DOMAIN (LBD) family of transcription factors. Homology analysis showed highest similarity to an uncharacterized LBD1 gene from Arabidopsis thaliana, and we consequently named it Populus tremula × Populus alba (Pta) LBD1. Dominant-negative suppression of Pta LBD1 via translational fusion with the repressor SRDX domain caused decreased diameter growth and suppressed and highly irregular phloem development. In wild-type plants, LBD1 was most highly expressed in the phloem and cambial zone. Two key Class I KNOTTED1-like homeobox genes that promote meristem identity in the cambium were downregulated, while an Altered Phloem Development gene that is known to promote phloem differentiation was upregulated in the mutant. A set of four LBD genes, including the LBD1 gene, was predominantly expressed in wood-forming tissues, suggesting a broader regulatory role of these transcription factors during secondary woody growth in poplar.

  6. Intrusive growth of primary and secondary phloem fibres in hemp stem determines fibre-bundle formation and structure

    Science.gov (United States)

    Snegireva, Anastasia; Chernova, Tatyana; Ageeva, Marina; Lev-Yadun, Simcha; Gorshkova, Tatyana

    2015-01-01

    Plant fibres—cells with important mechanical functions and a widely used raw material—are usually identified in microscopic sections only after reaching a significant length or after developing a thickened cell wall. We characterized the early developmental stages of hemp (Cannabis sativa) stem phloem fibres, both primary (originating from the procambium) and secondary (originating in the cambium), when they still had only a primary cell wall. We gave a major emphasis to the role of intrusive elongation, the specific type of plant cell growth by which fibres commonly attain large cell length. We could identify primary phloem fibres at a distance of only 1.2–1.5 mm from the shoot apical meristem when they grew symplastically with the surrounding tissues. Half a millimeter further downwards along the stem, fibres began their intrusive elongation, which led to a sharp increase in fibre numbers visible within the stem cross-sections. The intrusive elongation of primary phloem fibres was completed within the several distal centimetres of the growing stem, before the onset of their secondary cell wall formation. The formation of secondary phloem fibres started long after the beginning of secondary xylem formation. Our data indicate that only a small portion of the fusiform cambial initials (hemp, but may be applied to many other species. PMID:26019229

  7. Functional network analysis of genes differentially expressed during xylogenesis in soc1ful woody Arabidopsis plants.

    Science.gov (United States)

    Davin, Nicolas; Edger, Patrick P; Hefer, Charles A; Mizrachi, Eshchar; Schuetz, Mathias; Smets, Erik; Myburg, Alexander A; Douglas, Carl J; Schranz, Michael E; Lens, Frederic

    2016-06-01

    Many plant genes are known to be involved in the development of cambium and wood, but how the expression and functional interaction of these genes determine the unique biology of wood remains largely unknown. We used the soc1ful loss of function mutant - the woodiest genotype known in the otherwise herbaceous model plant Arabidopsis - to investigate the expression and interactions of genes involved in secondary growth (wood formation). Detailed anatomical observations of the stem in combination with mRNA sequencing were used to assess transcriptome remodeling during xylogenesis in wild-type and woody soc1ful plants. To interpret the transcriptome changes, we constructed functional gene association networks of differentially expressed genes using the STRING database. This analysis revealed functionally enriched gene association hubs that are differentially expressed in herbaceous and woody tissues. In particular, we observed the differential expression of genes related to mechanical stress and jasmonate biosynthesis/signaling during wood formation in soc1ful plants that may be an effect of greater tension within woody tissues. Our results suggest that habit shifts from herbaceous to woody life forms observed in many angiosperm lineages could have evolved convergently by genetic changes that modulate the gene expression and interaction network, and thereby redeploy the conserved wood developmental program. © 2016 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.

  8. Transformation of Sugar Maple Bark through Catalytic Organosolv Pulping

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    Georges Koumba-Yoya

    2017-09-01

    Full Text Available The catalytic organosolv pulping of sugar maple bark was performed adopting the concept of forest biorefinery in order to transform bark into several valuable products. Our organosolv process, consisting of pre-extracting the lignocellulosic material followed by pulping with ferric chloride as a catalyst, was applied to sugar maple bark. The pre-extraction step has yielded a mixture of phenolic extractives, applicable as antioxidants. The organosolv pulping of extractives-free sugar maple bark yielded a solid cellulosic pulp (42.3% and a black liquor containing solubilized bark lignin (24.1% and products of sugars transformation (22.9% of hemicelluloses, mainly represented by furfural (0.35% and 5-hydroxymethyl furfural (HMF, 0.74%. The bark cellulosic pulp was determined to be mainly constituted of glucose, with a high residual lignin content, probably related to the protein content of the original bark (containing cambium tissue. The biorefinery approach to the transformation of a solid bark residue into valuable biopolymers (lignin and cellulose along with phenolic antioxidants from pre-extraction and the HMF derivatives from black liquor (applicable for 2,5-diformylfuran production is an example of a catalytic process reposing on sustainable engineering and green chemistry concepts.

  9. [Influence of measurement position on calculating pear tree stem sap flow].

    Science.gov (United States)

    Sun, Huizhen; Kang, Sha-Ozhong; Gong, Daozhi

    2006-11-01

    By the method of heat pulse, this paper studied the influence of different measurement positions on calculating the stem sap flow velocity and quantity of pear trees. The results showed that at definite depths, the directional variation of the volume fraction of water and wood was lower than the seasonal change of wood physical parameters. The directional and seasonal variation of the volumetric water and wood was 0.01 - 0.03 and 0 - 0.02, and 0.02 - 0.09 and 0.02 -0.08, respectively. The sap flow velocity at definite depth, which was calculated by different depths wood physical parameters measured at the same time, had no significant difference, but that calculated by the same depth wood parameters measured at different time was significantly different. The sap flow quantity measured at the inner two points and four points was underestimated 1.5 and 4.9 times of that measured at the outer corresponding measurement positions, relative to the estimation obtained from a multi-point measurement. The sap flow quantity measured by four-point at the position of 0 - 0.6 from the cambium could represent the water consumption of whole tree.

  10. Variability with xylem depth in sap flow in trunks and branches of mature olive trees.

    Science.gov (United States)

    Nadezhdina, Nadezhda; Nadezhdin, Valeriy; Ferreira, Maria Isabel; Pitacco, Andrea

    2007-01-01

    Knowledge of sap flow variability in tree trunks is important for up-scaling transpiration from the measuring point to the whole-tree and stand levels. Natural variability in sap flow, both radial and circumferential, was studied in the trunks and branches of mature olive trees (Olea europea L., cv Coratina) by the heat field deformation method using multi-point sensors. Sapwood depth ranged from 22 to 55 mm with greater variability in trunks than in branches. Two asymmetric types of sap flow radial patterns were observed: Type 1, rising to a maximum near the mid-point of the sapwood; and Type 2, falling continuously from a maximum just below cambium to zero at the inner boundary of the sapwood. The Type 1 pattern was recorded more often in branches and smaller trees. Both types of sap flow radial patterns were observed in trunks of the sample trees. Sap flow radial patterns were rather stable during the day, but varied with soil water changes. A decrease in sap flow in the outermost xylem was related to water depletion in the topsoil. We hypothesized that the variations in sap flow radial pattern in a tree trunk reflects a vertical distribution of water uptake that varies with water availability in different soil layers.

  11. A survey of Populus PIN-FORMED family genes reveals their diversified expression patterns.

    Science.gov (United States)

    Liu, Bobin; Zhang, Jin; Wang, Lin; Li, Jianbo; Zheng, Huanquan; Chen, Jun; Lu, Mengzhu

    2014-06-01

    The plant hormone auxin is a key regulator of plant development, and its uneven distribution maintained by polar intercellular auxin transport in plant tissues can trigger a wide range of developmental processes. Although the roles of PIN-FORMED (PIN) proteins in intercellular auxin flow have been extensively characterized in Arabidopsis, their roles in woody plants remain unclear. Here, a comprehensive analysis of PIN proteins in Populus is presented. Fifteen PINs are encoded in the genome of Populus, including four PIN1s, one PIN2, two PIN3s, three PIN5s, three PIN6s, and two PIN8s. Similar to Arabidopsis AtPIN proteins, PtPINs share conserved topology and transmembrane domains, and are either plasma membrane- or endoplasmic reticulum-localized. The more diversified expansion of the PIN family in Populus, comparing to that in Arabidopsis, indicates that some auxin-regulated developmental processes, such as secondary growth, may exhibit unique features in trees. More importantly, different sets of PtoPINs have been found to be strongly expressed in the roots, leaves, and cambium in Populus; the dynamic expression patterns of selected PtoPINs were further examined during the regeneration of shoots and roots. This genome-wide analysis of the Populus PIN family provides important cues for their potential roles in tree growth and development. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. The Populus ARBORKNOX1 homeodomain transcription factor regulates woody growth through binding to evolutionarily conserved target genes of diverse function.

    Science.gov (United States)

    Liu, Lijun; Zinkgraf, Matthew; Petzold, H Earl; Beers, Eric P; Filkov, Vladimir; Groover, Andrew

    2015-01-01

    The class I KNOX homeodomain transcription factor ARBORKNOX1 (ARK1) is a key regulator of vascular cambium maintenance and cell differentiation in Populus. Currently, basic information is lacking concerning the distribution, functional characteristics, and evolution of ARK1 binding in the Populus genome. Here, we used chromatin immunoprecipitation sequencing (ChIP-seq) technology to identify ARK1 binding loci genome-wide in Populus. Computational analyses evaluated the distribution of ARK1 binding loci, the function of genes associated with bound loci, the effect of ARK1 binding on transcript levels, and evolutionary conservation of ARK1 binding loci. ARK1 binds to thousands of loci which are highly enriched proximal to the transcriptional start sites of genes of diverse functions. ARK1 target genes are significantly enriched in paralogs derived from the whole-genome salicoid duplication event. Both ARK1 and a maize (Zea mays) homolog, KNOTTED1, preferentially target evolutionarily conserved genes. However, only a small portion of ARK1 target genes are significantly differentially expressed in an ARK1 over-expression mutant. This study describes the functional characteristics and evolution of DNA binding by a transcription factor in an undomesticated tree, revealing complexities similar to those shown for transcription factors in model animal species. No claim to original US Government works. New Phytologist © 2014 New Phytologist Trust.

  13. Morphophysiological Behavior and Cambial Activity in Seedlings of Two Amazonian Tree Species under Shade

    Directory of Open Access Journals (Sweden)

    Monyck Jeane dos Santos Lopes

    2015-01-01

    Full Text Available Variations in light intensity can lead to important anatomical and morphophysiological changes in plants. Aiming to increase knowledge about the Amazonian tree species, this study examines the influence of shade on the cambial activity and development of Parkia gigantocarpa Ducke and Schizolobium parahyba var. amazonicum (Huber ex Ducke Barneby seedlings. Seedlings of the two species were grown in a nursery under four shade intensities (treatments: full sun, low, moderate, and high shade (resp., 0%, 23%, 67%, and 73% of shade, or 2000, 1540, 660, and 540 µmol·m−2·s−1 obtained with polyethylene screens. We measured plant height, stem diameter, biomass production, stomatal conductance (gs, transpiration (E, photosynthesis (A, and cambial activity (CA (xylem, cambium, and phloem. Also, we calculated the Dickson Quality Index (DQI. The highest values of biomass production, gs,  E, A, and DQI, were found under full sun, in P. gigantocarpa, and under low shade intensity in S. parahyba. In both species high shade intensity reduced CA. We concluded that the CA and the physiological and morphological attributes work together, explaining the radial growth and increasing seedlings quality, which optimized efficient seedling production under full sun, in P. gigantocarpa, and under low shade intensity in S. parahyba.

  14. Directional fluid flow enhances in vitro periosteal tissue growth and chondrogenesis on poly-ε-caprolactone scaffolds

    Science.gov (United States)

    Tarng, Yih-Wen; Casper, Michelle E.; Fitzsimmons, James S.; Stone, James J.; Bekkers, Joris; An, Kai-Nan; Su, Fong-Chin; O'Driscoll, Shawn W.; Reinholz, Gregory G.

    2010-01-01

    The purpose of this study was to investigate the effect of directional fluid flow on periosteal chondrogenesis. Periosteal explants were harvested from two-month-old rabbits and sutured onto poly-ε-caprolactone (PCL) scaffolds with the cambium layer facing away from the scaffolds. The periosteum/PCL composites were cultured in suspension in spinner flask bioreactors and exposed to various fluid flow velocities: 0, 20, 60, 150 rpm for 4 hours each day for 6 weeks. The application of fluid flow significantly increased percent cartilage yield in periosteal explants from 17% in the static controls to 65-75% under fluid flow (there was no significant difference between 20, 60, or 150 rpm). The size of the neocartilage was also significantly greater in explants exposed to fluid flow compared to static culture. The development of zonal organization within the engineered cartilage was observed predominantly in the tissue exposed to flow conditions. The Young's modulus of the engineered cartilage exposed to 60 rpm was significantly greater than the samples exposed to 150 rpm and 20 rpm. These results demonstrate that application of directional fluid flow to periosteal explants secured onto PCL scaffolds enhances cell proliferation, chondrogenic differentiation, cell organization, and alters the biomechanical properties of the engineered cartilage. PMID:20540101

  15. Repression of BLADE-ON-PETIOLE genes by KNOX homeodomain protein BREVIPEDICELLUS is essential for differentiation of secondary xylem in Arabidopsis root.

    Science.gov (United States)

    Woerlen, Natalie; Allam, Gamalat; Popescu, Adina; Corrigan, Laura; Pautot, Véronique; Hepworth, Shelley R

    2017-06-01

    Repression of boundary genes by KNOTTED1-like homeodomain transcription factor BREVIPEDICELLUS promotes the differentiation of phase II secondary xylem in Arabidopsis roots. Plant growth and development relies on the activity of meristems. Boundaries are domains of restricted growth that separate forming organs and the meristem. Class I KNOX homeodomain transcription factors are important regulators of meristem maintenance. Members of this class including BREVIDICELLUS also called KNOTTED-LIKE FROM ARABIDOPSIS THALIANA1 (BP/KNAT1) fulfill this function in part by spatially regulating boundary genes. The vascular cambium is a lateral meristem that allows for radial expansion of organs during secondary growth. We show here that BP/KNAT1 repression of boundary genes plays a crucial role in root secondary growth. In particular, exclusion of BLADE-ON-PETIOLE1/2 (BOP1/2) and other members of this module from xylem is required for the differentiation of lignified fibers and vessels during the xylem expansion phase of root thickening. These data reveal a previously undiscovered role for boundary genes in the root and shed light on mechanisms controlling wood development in trees.

  16. Anatomy of recent and peatified Calluna vulgaris stems: implications for coal maceral formation

    Energy Technology Data Exchange (ETDEWEB)

    Heijden, E. van der; Bouman, F.; Boon, J.J. [FOM Institute for Atomic and Molecular Physics, Amsterdam (Netherlands). Unit for Mass Spectrometry of Macromolecular Systems

    1994-01-01

    Anatomical characteristics of peatified {ital Calluna vulgaris} stems isolated from a selection of North-West European raised bog peat deposits were compared with intact stems in order to reveal anatomical modifications caused by the peatification process. Four main decomposition processes were discerned: loss of structural integrity of cell walls and cell inclusions; gelification and swelling of cell walls; discolouration of cell walls; and deposition of matter in cell lumina. Fibre-tracheids and wood parenchyma appear to be the most affected cell types. The two main decomposition trends discerned in these tissues were related to different fungal types. Precipitation of decay products was mainly observed in vessels. Bark tissues, primary xylem and medullary parenchyma were characterized by an excellent anatomical preservation. In the first stages of peatification a rapid decrease in cell contents was observed in bark tissues. Swelling and gelification was mainly seen in cell walls of the cambium and vessels. It is concluded that different types of cell walls respond differently to decay conditions. This is probably related to differences in the original cell wall chemistry. A high intra- and intercellular variability in degree of preservation was sometimes observed in identical tissues. The microscopic variability arising during peatification of wood and bark testifies to the heterogeneity of coal macerals derived from these tissues. 53 refs., 2 figs., 4 plates.

  17. Monitoring of sap flow, leaf water potential, stomatal conductance, and latex yield of rubber trees under irrigation management

    Directory of Open Access Journals (Sweden)

    Prapaporn Tongsawang

    2008-08-01

    Full Text Available To investigate the physiological responses and latex yield of rubber trees under irrigation management, an experiment was established at Songkhla Province, southern Thailand. The sap flow of rubber trees was measured by heat-pulse technique. First, the anatomy of sapwood and the optimum depth for implanting the sap flow sensor probe were determined. Then, the diurnal changes of the physiological responses (sap flow, leaf water potential, and stomatal conductance and latex yield under three regimes of irrigation (T1: no irrigation, T2: irrigation at 1.0 crop evapotranspiration (ETc and T3: irrigation at0.5 ETc were determined. The results showed that xylem vessels in sapwood were homogeneous and the optimum depth for implanting the sap flow sensor probes was 10 mm beneath the cambium. In the measurements of diurnal changes of the physiological responses, it was found that stomatal conductance and sap flow rates were related to radiation. Sap flow and stomatal conductance increased from the morning to the midday. Then they decreased slowly during the afternoon. However,leaf water potential changes showed an opposite effect. Among the three treatments, the results showed that sap flow, leaf water potential and stomatal conductance in T2 were highest. The trees in T2 also exhibited the highest latex yield from April to July 2006, which was significantly different from those of T3 and T1. This implied that latex yield increased with an increase of sap flow.

  18. Vegetative anatomy of Lophophytum mirabile subsp. bolivianum (Balanophoraceae and the effect of its parasitism in the anatomy of the roots of its host Anadenanthera colubrina var. cebil

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    Ana María González

    2016-12-01

    Full Text Available The objectives of this work were to study the structure of the vegetative body of Lophophytum mirabile subsp. bolivianum (Wedd. B. Hansen, to analyze the change on roots of Anadenanthera colubrina var. cebil (Griseb. Altschul when they are infected by this parasitic plant, and to identify the anatomical changes produced by that parasitism. L. mirabile subsp. bolivianum plants are formed by a spheroidal-narrower underground vegetative body or tuber, that externally has a dark warty surface;epidermis, stomata or trichomes are lacking. The central matrix of tuber consists of reserving parenchyma and vascular bundles. Parasitic cells located at the level of root cambium initiate the tuber formation. On the infected root of A. colubrina var.cebil, the identity of radial and axial growth of the secondary system are lost. This leads to the formation of xylem loops that affect the xylem transport and root development, which stops length growth and develops a woody gall. Infection of L. mirabile subsp. bolivianum causes profound anatomical changes in timber developing of A. colubrina var. cebil, which favor the parasite success.

  19. An early origin of secondary growth: Franhueberia gerriennei gen. et sp. nov. from the Lower Devonian of Gaspé (Quebec, Canada).

    Science.gov (United States)

    Hoffman, Laurel A; Tomescu, Alexandru M F

    2013-04-01

    Secondary xylem (wood) produced by a vascular cambium supports increased plant size and underpins the most successful model of arborescence among tracheophytes. Woody plants established the extensive forest ecosystems that dramatically changed the Earth's biosphere. Secondary growth evolved in several lineages in the Devonian, but only two occurrences have been reported previously from the Early Devonian. The evolutionary history and phylogeny of wood production are poorly understood, and Early Devonian plants are key to illuminating them. A fossil plant preserved anatomically by cellular permineralization in the Lower Devonian (Emsian, ca. 400-395 million years old) Battery Point Formation of Gaspé Bay (Quebec, Canada) is described using the cellulose acetate peel technique. The plant, Franhueberia gerriennei Hoffman et Tomescu gen. et sp. nov., is a basal euphyllophyte with a centrarch protostele and metaxylem tracheids with circular and oval to scalariform bordered multiaperturate pits (P-type tracheids). The outer layers of xylem, consisting of larger-diameter P-type tracheids, exhibit the features diagnostic of secondary xylem: radial files of tracheids, multiplicative divisions, and a combination of axial and radial components. Franhueberia is one of the three oldest euphyllophytes exhibiting secondary growth documented in the Early Devonian. Within the euphyllophyte clade, these plants represent basal lineages that predate the evolution of stem-leaf-root organography and indicate that underlying mechanisms for secondary growth became part of the euphyllophyte developmental toolkit very early in the clade's evolution.

  20. Omics and modelling approaches for understanding regulation of asymmetric cell divisions in arabidopsis and other angiosperm plants.

    Science.gov (United States)

    Kajala, Kaisa; Ramakrishna, Priya; Fisher, Adam; Bergmann, Dominique C; De Smet, Ive; Sozzani, Rosangela; Weijers, Dolf; Brady, Siobhan M

    2014-06-01

    Asymmetric cell divisions are formative divisions that generate daughter cells of distinct identity. These divisions are coordinated by either extrinsic ('niche-controlled') or intrinsic regulatory mechanisms and are fundamentally important in plant development. This review describes how asymmetric cell divisions are regulated during development and in different cell types in both the root and the shoot of plants. It further highlights ways in which omics and modelling approaches have been used to elucidate these regulatory mechanisms. For example, the regulation of embryonic asymmetric divisions is described, including the first divisions of the zygote, formative vascular divisions and divisions that give rise to the root stem cell niche. Asymmetric divisions of the root cortex endodermis initial, pericycle cells that give rise to the lateral root primordium, procambium, cambium and stomatal cells are also discussed. Finally, a perspective is provided regarding the role of other hormones or regulatory molecules in asymmetric divisions, the presence of segregated determinants and the usefulness of modelling approaches in understanding network dynamics within these very special cells. Asymmetric cell divisions define plant development. High-throughput genomic and modelling approaches can elucidate their regulation, which in turn could enable the engineering of plant traits such as stomatal density, lateral root development and wood formation.

  1. Concentration of radiocesium in the wild Japanese monkey (Macaca fuscata over the first 15 months after the Fukushima Daiichi nuclear disaster.

    Directory of Open Access Journals (Sweden)

    Shin-ichi Hayama

    Full Text Available Following the massive earthquake that struck eastern Japan on March 11, 2011, a nuclear reactor core meltdown occurred at the Fukushima Daiichi Nuclear Power Plant, operated by Tokyo Electric Power Company, and was followed by the release of large amounts of radioactive materials. The objective of this study was to measure the concentration of radiocesium (134Cs and (137Cs in the muscle of Japanese monkeys (Macaca fuscata inhabiting the forest area of Fukushima City and to determine the change in concentration over time as well as the relationship with the level of soil contamination. Cesium concentrations in the muscle of monkeys captured at locations with 100,000-300,000 Bq/m(2 were 6,000-25,000 Bq/kg in April 2011 and decreased over 3 months to around 1,000 Bq/kg. However, the concentration increased again to 2,000-3,000 Bq/kg in some animals during and after December 2011 before returning to 1,000 Bq/kg in April 2012, after which it remained relatively constant. This pattern of change in muscle radiocesium concentration was similar to that of the change in radiocesium concentration in atmospheric fallout. Moreover, the monkeys feed on winter buds and the cambium layer of tree bark potentially containing higher concentrations of radiocesium than that in the diet during the rest of the year. The muscle radiocesium concentration in the monkeys related significantly with the level of soil contamination at the capture locations.

  2. Resin secretory structures of Boswellia papyrifera and implications for frankincense yield.

    Science.gov (United States)

    Tolera, Motuma; Menger, David; Sass-Klaassen, Ute; Sterck, Frank J; Copini, Paul; Bongers, Frans

    2013-01-01

    Frankincense, a gum-resin, has been tapped from Boswellia papyrifera trees for centuries. Despite the intensive tapping and economic interest of B. papyrifera, information on the resin secretory structures, which are responsible for synthesis, storage and transport of frankincense, is virtually absent. This study describes the type, architecture and distribution of resin secretory structures of B. papyrifera and its relevance for the ecophysiology and economic use of the tree. The type and architecture of resin secretory structures present in bark and wood was investigated from transversal, tangential and radial sections of bark and wood samples. The diameter and density (number of resin canals mm(-2)) of axial resin canals were determined from digital images of thin sections across the different zones of inner bark. Resin canals form a three-dimensional network within the inner bark. Yet, the intact resin-conducting and producing network is on average limited to the inner 6·6 mm of the inner bark. Within the inner bark, the density of non-lignified axial resin canals decreases and the density of lignified resin canals increases from the vascular cambium towards the outer bark. In the wood, only radial resin canals were encountered. Frankincense tapping techniques can be improved based on knowledge of bark anatomy and distribution and architecture of resin secretory structures. The suggested new techniques will contribute to a more sustainable frankincense production that enhances the contribution of frankincense to rural livelihoods and the national economy.

  3. Coexistence and Competition between Tomicus yunnanensis and T. minor (Coleoptera: Scolytinae in Yunnan Pine

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    Rong Chun Lu

    2012-01-01

    Full Text Available Competition and cooperation between bark beetles, Tomicus yunnanensis Kirkendall and Faccoli and Tomicus minor (Hartig (Coleoptera: Scolytinae were examined when they coexisted together in living Yunnan pine trees (Pinus yunnanensis Franchet in Yunnan province in Southwest China. T. yunnanensis bark beetles were observed to initiate dispersal from pine shoots to trunks in November, while the majority of T. minor begins to transfer in December. T. yunnanensis mainly attacks the top and middle parts of the trunk, whereas T. minor mainly resides in the lower and middle parts of the trunk. The patterns of attack densities of these two species were similar, but with T. yunnanensis colonizing the upper section of the trunk and T. minor the lower trunk. The highest attack density of T. Yunnanensis was 297 egg galleries/m2, and the highest attack density of T. minor was 305 egg galleries/m2. Although there was significant overlap for the same bark areas, the two species generally colonize different areas of the tree, which reduces the intensity of competition for the relatively thin layer of phloem-cambium tissues where the beetles feed and reside.

  4. Lebensspuren holzzerstörender Organismen an fossilen Hölzern aus dem Tertiär der Insel Lesbos, Griechenland

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    H. Süss

    2001-01-01

    Full Text Available Lebensspuren (Schadbilder holzzerstörender Organismen an fossilen Holzresten aus dem Untermiozän von Lesbos (Griechenland werden beschrieben. Von pflanzlichen Holzzerstörern konnten Bakterien, imperfekte Pilze, Weiß- und Braunfäulepilze und in das Holz eingewachsene Wurzeln nachgewiesen werden. Von tierischen Holzzerstörern wurden Termitenfraß, durch Pflanzensauger (Homopteren verursachtes Wundgewebe, Larvenfraß der Kambium-Minierfliege Palaeophytobia (Agromyzidae, Diptera und Fraßgänge mit Koprolithen verschiedener Käferarten (Anobiiden? und Milben (Acari gefunden. Außerdem werden durch Kristallisationsvorgänge im Holz verursachte kugelförmige Gebilde beschrieben. Traces of wood destroying organisms on fossil wood from the Lower Miocene of Lesbos (Greece are described. Among nonanimal wood destroyers evidence is presented of bacteria, Fungi imperfecti, whiterot and brownrot fungus and penetrating roots. Animal wood destroyers include termite feeding traces, wound tissues produced by plant suckers (Homoptera, larval feeding traces of the cambium miner Palaeophytobia (Agromyzidae, Diptera and feeding channels, with coprolites, of several beetle species (Anobiidae? and Mites (Acari. In addition globe-like structures produced in the wood through crystallization processes are described. doi:10.1002/mmng.20010040105

  5. Traumatic resin ducts in Larix decidua stems impacted by debris flows.

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    Bollschweiler, Michelle; Stoffel, Markus; Schneuwly, Dominique M; Bourqui, Karin

    2008-02-01

    Following mechanical injury, stems of many conifers produce tangential rows of traumatic resin ducts (TRDs), the distribution of which has been used to date geomorphic events. However, little is known about how far TRD formation extends tangentially and axially from the point of injury or what the time course of TRD appearance is. We analyzed 28 injuries in eight Larix decidua Mill. tree stems resulting from debris flows in October 2000 and November 2004. Injuries occurred outside the period of cambial activity, and TRD formation occurred in the first layers of the growth ring formed in the year following that of injury. The axial extent of TRD formation averaged 74 cm and was greater above the injury than below it. At the height of the wound center, TRDs extended horizontally to a mean of 18% of the stem circumference excluding that portion where the cambium had been destroyed. In subsequent growth rings, TRDs, if present, were confined mainly to the height of the center of injury. Both the vertical and horizontal extent of TRD formation was related to the injury size. Within growth rings, the position of TRD formation changed with increasing distance from the wound progressing from early earlywood to later portions of the growth ring.

  6. Tapping the tree-ring archive for studying effects of resin extraction on the growth and climate sensitivity of Scots pine

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    Ernst van der Maaten

    2017-06-01

    Full Text Available Background In the German Democratic Republic (GDR, resin tapping in Scots pine (Pinus sylvestris L. forests was a major economic activity, and resin-tapped stands are frequently found up until this day. In this study, we investigate how the mechanical damage caused by resin tapping affects the growth and climate sensitivity of Scots pine using a dendroecological approach. Methods Tree-ring samples were collected from resin-tapped and non-tapped trees in two forest areas in northeastern Germany, and tree-growth patterns were analyzed. For elucidating effects of resin tapping on the climate sensitivity of pine growth, climate-growth relationships and pointer years were studied. Results We observed that resin tapping positively affects tree growth at breast height, likely as wood formation is concentrated on the living part of the bole (i.e. after tapping there is no growth taking place on the tapping face due to the mechanical damage done to the cambium. We observed no differences in the climate sensitivity of tapped and non-tapped trees, nor in the occurrence of extreme growth responses. Conclusion Our results highlight that resin extraction is, apart from inflicting mechanical damage, not altering the sensitivity of Scots pine growth to climatic conditions.

  7. Verifying the geographic origin of mahogany (Swietenia macrophylla King) with DNA-fingerprints.

    Science.gov (United States)

    Degen, B; Ward, S E; Lemes, M R; Navarro, C; Cavers, S; Sebbenn, A M

    2013-01-01

    Illegal logging is one of the main causes of ongoing worldwide deforestation and needs to be eradicated. The trade in illegal timber and wood products creates market disadvantages for products from sustainable forestry. Although various measures have been established to counter illegal logging and the subsequent trade, there is a lack of practical mechanisms for identifying the origin of timber and wood products. In this study, six nuclear microsatellites were used to generate DNA fingerprints for a genetic reference database characterising the populations of origin of a large set of mahogany (Swietenia macrophylla King, Meliaceae) samples. For the database, leaves and/or cambium from 1971 mahogany trees sampled in 31 stands from Mexico to Bolivia were genotyped. A total of 145 different alleles were found, showing strong genetic differentiation (δ(Gregorious)=0.52, F(ST)=0.18, G(ST(Hedrick))=0.65) and clear correlation between genetic and spatial distances among stands (r=0.82, Pdatabase and Bayesian assignment testing to determine the geographic origins of two sets of mahogany wood samples, based on their multilocus genotypes. In both cases the wood samples were assigned to the correct country of origin. We discuss the overall applicability of this methodology to tropical timber trading. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. Reassessing the cultural and psychopharmacological significance of Banisteriopsis caapi: preparation, classification and use among the Piaroa of Southern Venezuela.

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    Rodd, Robin

    2008-09-01

    Recent attention to the monoamine oxidase inhibiting properties of Banisteriopsis caapi's harmala alkaloids has precluded a balanced assessment of B. caapi's overall significance to indigenous South American societies. Relatively little attention has been paid to the cultural contexts, local meanings and patterns of use of B. caapi among snuff-using societies, such as the Piaroa, who do not prepare decoctions containing N,N-dimethyltryptamine (DMT) admixtures. This article reviews the psychopharmacological literature on B. caapi in light of recent ethnographic work conducted among the Piaroa of southern Venezuela. Piaroa shamans use only B. caapi's cambium, identify at least five distinct varieties of B. caapi, and emphasise the plant's importance for heightening empathy. Some Piaroa people also attribute a range of extra-shamanic uses to B. caapi, including as a stimulant and hunting aid. In light of the psychopharmacological complexity of harmala alkaloids, and ethnographic evidence for a wide range of B. caapi uses,future research should reconsider B. caapi's cultural heritage and psychopharmacological potential as a stimulant and antidepressant-like substance.

  9. Lenticels as indicators of atmospheric smoke pollution

    Energy Technology Data Exchange (ETDEWEB)

    Pesek, F.

    1960-01-01

    The invasion of smoke pollution gets from the atmosphere into the plants only by lenticels and stomata. The most toxic smoke constituents penetrating into the stele are SO/sub 2/, H/sub 2/SiF/sub 6/, H/sub 3/AsO/sub 4/, HCl and C/sub 6/H/sub 5/OH. Lenticels are bark stomata filled with merenchym tissue, which hinders the entrance of mechanical smoke particles into the interior tissues of the stele. In autumn, the lenticels are packed by cork slabs formed by the cork cambium. In spring, this cork slab is broken by a new mechanical tissue. Sambucus nigra L. has a merenchym sensitive to the presence of smoke pollution, and the lenticels may serve, therefore, as indicators of smoke pollution in the atmosphere. The intensity of damage caused by smoke constituents penetrating into the plants through lenticels depends upon a series of exterior and interior factors. They are the number of lenticels per area unit of bark surface in the whole circumference, the pH of the biocomplex near the lenticel in the interior tissues of stele, and the concentration of smoke pollution in the atmosphere. The most effective way of preventing smoke damage is to install pollution control equipment in the industrial works.

  10. The Regulatory Mechanism of MLT/MT1 Signaling on the Growth of Antler Mesenchymal Cells

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    Feifei Yang

    2017-10-01

    Full Text Available Melatonin (MLT plays an important role in regulating the physiological cycle of seasonal breeding animals. Melatonin receptor I (MT1 is effectively expressed in the cambium layer of deer antler. However, the function and metabolic mechanism of MLT/MT1 signaling in the mesenchymal cells of sika deer remain to be further elucidated. In this work, we detected the effects of MLT/MT1 signaling on mesenchymal cells proliferation and the interaction between MLT/MT1 and IGF1/IGF1-R signaling. The results show that (1 deer antler mesenchymal cells actually express MT1; (2 exogenous melatonin significantly promotes mesenchymal cells proliferation, while MT1 knock-down significantly impairs the positive effects of melatonin; and (3 melatonin significantly enhanced IGF1/IGF1-R signaling, as both the expression of IGF1 and IGF-1R increased, while MT1 knock-down significantly decreased IGF1-R expression and IGF1 synthesis. In summary, these data verified that MLT/MT1 signaling plays a crucial role in antler mesenchymal proliferation, which may be mediated by IGF1/IGF1-R.

  11. A biomechanical perspective on the role of large stem volume and high water content in baobab trees (Adansonia spp.; Bombacaceae).

    Science.gov (United States)

    Chapotin, Saharah Moon; Razanameharizaka, Juvet H; Holbrook, N Michele

    2006-09-01

    The stems of large trees serve in transport, storage, and support; however, the degree to which these roles are reflected in their morphology is not always apparent. The large, water-filled stems of baobab trees (Adansonia spp.) are generally assumed to serve a water storage function, yet recent studies indicate limited use of stored water. Through an analysis of wood structure and composition, we examined whether baobab morphology reflects biomechanical constraints rather than water storage capacity in the six Madagascar baobab species. Baobab wood has a high water content (up to 79%), low wood density (0.09-0.17 g · cm(-3)), high parenchyma content (69-88%), and living cells beyond 35 cm into the xylem from the cambium. Volumetric construction cost of the wood is several times lower than in more typical trees, and the elastic modulus approaches that of parenchyma tissue. Safety factors calculated from estimated elastic buckling heights were low, indicating that baobabs are not more overbuilt than other temperate and tropical trees, yet the energy investment in stem material is comparable to that in temperate deciduous trees. Furthermore, the elastic modulus of the wood decreases with water content, such that excessive water withdrawal from the stem could affect mechanical stability.

  12. Production of basement membrane laminin and type IV collagen by tumors of striated muscle: an immunohistochemical study of rhabdomyosarcomas of different histologic types and a benign vaginal rhabdomyoma.

    Science.gov (United States)

    Autio-Harmainen, H; Apaja-Sarkkinen, M; Martikainen, J; Taipale, A; Rapola, J

    1986-12-01

    Immunohistochemical methods were used to demonstrate the distribution of basement membrane laminin and type IV collagen in eight tumors derived from striated muscle (three botryoid, two alveolar, and two adult-type rhabdomyosarcomas; one benign vaginal rhabdomyoma). All of the tumors produced significant amounts of both basement membrane components. Stainings clearly revealed the alveolar nature of the rhabdomyosarcomas, with the alveolar spaces surrounded by distinct basement membranes. Different stages of cellular development were identified in the botryoid sarcomas, with the most immature cells of the cambium layer devoid of external basement membrane around the tumor cells, although the stroma contained finely dispersed basement membrane material and some cells contained intracytoplasmic laminin or type IV collagen, indicative of the synthesis of these proteins. The more mature cells, which had abundant granular cytoplasm, were enveloped by distinct basement membranes and seemed to have coalesced, forming structures resembling myotubes. The adult-type rhabdomyosarcomas were composed of large pleomorphic cells that were surrounded by basement membranes, either individually or in small groups. Some giant cells contained intracytoplasmic laminin. The vaginal rhabdomyoma was composed of round rhabdoblastic cells or elongated strap cells with cross-striations. Cells of both of these types were surrounded by thin but distinct basement membranes. The results suggest that demonstration of basement membranes would be helpful in the diagnosis of tumors derived from striated muscle. The findings concerning different stages of maturation of tumor cells are in accordance with previous in vitro observations of myoblastic cells.

  13. Cosuppression of Eukaryotic Release Factor 1-1 in Arabidopsis Affects Cell Elongation and Radial Cell Division

    Science.gov (United States)

    Petsch, Katherine Anne; Mylne, Joshua; Botella, José Ramón

    2005-01-01

    The role of the eukaryotic release factor 1 (eRF1) in translation termination has previously been established in yeast; however, only limited characterization has been performed on any plant homologs. Here, we demonstrate that cosuppression of eRF1-1 in Arabidopsis (Arabidopsis thaliana) has a profound effect on plant morphology, resulting in what we term the broomhead phenotype. These plants primarily exhibit a reduction in internode elongation causing the formation of a broomhead-like cluster of malformed siliques at the top of the inflorescence stem. Histological analysis of broomhead stems revealed that cells are reduced in height and display ectopic lignification of the phloem cap cells, some phloem sieve cells, and regions of the fascicular cambium, as well as enhanced lignification of the interfascicular fibers. We also show that cell division in the fascicular cambial regions is altered, with the majority of vascular bundles containing cambial cells that are disorganized and possess enlarged nuclei. This is the first attempt at functional characterization of a release factor in vivo in plants and demonstrates the importance of eRF1-1 function in Arabidopsis. PMID:16113224

  14. Size correlations among cambial initials and their derivatives in Polyalthia longifolia Thw.

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    D. D. Sharma

    2015-01-01

    Full Text Available The length and breadth of the cambial initials and their derivatives have been examined in Polyalthia longifolia, a tropical tree possessing non-storied cambium. Taking the average size of the initials and the elements originating from them, most of the sieve-tube elements have been found to be slightly shorter in length than the fusiform initials. On the other hand, a few of these are still shorter - almost half of the fusiform initials, due to transverse or somewhat oblique divisions in the sieve element mother cells. The vessel elements are slightly shorter but 5-6 times wider than the fusiform initials. The parenchyma strands, in phloem comprising cells storing starch or tannin (pps, in xylem accumulating starch only (ssps, are more or less equal to fusiform initials indicating that the xylem and phloem mother cells forming parenchyma cells have not undergone any major change except for transverse divisions. The individual vessel-associated parenchyma cells (v.a.p. cells are wider but much shorter in length as compared to the starch-storing parenchyma cells (s.s.p. cells indicating that more transverse divisions have occured in the strands of the former than those of the latter. Among all the cambial derivatives, the fibers exhibit maximum increase in length, due to intrusive growth. The ray parenchyma cells are slightly longer than the ray initials possibly due to the elongation of these initials during their transformation into vascular ray cells.

  15. Spatial tissue distribution of polyacetylenes in carrot root.

    Science.gov (United States)

    Baranska, Malgorzata; Schulz, Hartwig

    2005-06-01

    The presented results show the usefulness of Raman spectroscopy in the investigation of polyacetylenes in carrot root. The components are measured directly in the plant tissue without any preliminary sample preparation. Compared with the strong polyacetylene signals the spectral impact of the surrounding biological matrix is weak, except for carotenoids, and therefore it does not contribute significantly to the obtained results. Three different Raman mapping techniques applied here have revealed essential information about the investigated compounds. Using point acquisition several spectra have been measured to demonstrate the complex composition of the polyacetylene fraction in carrot root. The molecular structures of falcarinol, falcarindiol and falcarindiol 3-acetate are similar but their Raman spectra exhibit differences demonstrated by the shift of their -C triple bond C- mode. Line mapping performed along the diameter of transversely cut carrot roots has been used to investigate the relative concentration of polyacetylenes and carotenoids. An area map provides detailed information regarding the distribution of both components. It has been found that high accumulation of polyacetylenes is located in the outer section of the root, namely the pericyclic parenchyma, and in the phloem part close to the secondary cambium. The highest concentration of carotenes is seen in the immediate vicinity to polyacetylene conglomerates.

  16. Atypical origin, structure and arrangement of secondary tracheary elements in the stem of the monocotyledonous dragon tree, Dracaena draco.

    Science.gov (United States)

    Jura-Morawiec, Joanna

    2017-01-01

    Tracheary elements within the secondary body of a dragon tree shared features characteristic of fibres. Their considerable intrusive growth resulted in a rigid network with a braid-like arrangement which contributes towards the tree-like form of the plant. Monocot cambium gives rise to xylem and phloem which become organized into vascular bundles. The xylem consists entirely of tracheids, and these undergo considerable intrusive elongation during their development, unlike the tracheids of conifers and those of vesselless dicotyledons. Monocot tracheids have not been fully investigated, and our understanding of their structure is incomplete. Therefore, in this study the degree of variation in the structure and arrangement of secondary tracheary elements of monocots were determined, based on the Dracaena draco stem. In addition, its mechanical and physiological implications were discussed. Analysis of series of thin serial sections and macerations of the immature and fully developed tracheids showed that the course of intrusive elongation of tracheids was determined by the spatial relationship that exists between the growing tracheid and surrounding cells, and was not usually parallel to the stem axis. It influenced the shape of tracheids, as well the cross-sectional shape of vascular bundles. Tracheids become twisted or even interwoven and so, their ends do not join with the ends of other tracheids. The complexity of the tracheid network, that functions both in transport and mechanical support, seems to have a major impact on the tree-like growth habit of D. draco.

  17. Bio-ecological Peculiarities of Genus Pinus L. Species Under Conditions of Eastern Georgia

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    Tamar Nadiradze

    2014-06-01

    Full Text Available The article discusses bio-ecological peculiarities of the following species of genus Pinus L. spread in eastern Georgia: Pinus eldarica Medw., P. griffithii McCleland., P. cembra L., P. pallasiana Lamb., P. pinea L., P. sabiniana Dougl., P. sylvestris L., P. sosnowskyi Nakai, P. strobus L., the perspectives of their usage in Green Building and contemporary problems. We have studied the periods of bud opening, vegetation ending, starting and finishing of cambium action, sprout woodening process, time and rate of growing in height, and regularities of accumulation-transformation of storage carbohydrates. The studies revealed that the annual development cycle of all these species includes all morphological -physiological periods: sprout growth, latent growth, organic and forced rest. They are characterized by the good growth-development; almost all of them are perspective for eastern Georgia, particularly, for all regions of inner Kakheti. However, in recent years, massive drying up of pine forests groves takes place in eastern Georgia. That is why it is necessary to conduct the fitopatologic research, identify the pest causing the damage and plan the measures against it.

  18. Oxidase activity in lignifying xylem of a taxonomically diverse range of trees: identification of a conifer laccase.

    Science.gov (United States)

    Richardson, A; Duncan, J; McDougall, G J

    2000-09-01

    In a diverse taxonomic range of tree species, including representative species of ancient families of angiosperms (Magnolia x soulangiana Soul.-Bod.) and gymnosperms (Ginkgo biloba L.), oxidase activity was associated with cell walls of developing xylem and was enriched in extracts of cell wall-associated glycoproteins. In all species where oxidase activity was detected histochemically, it was expressed in cell walls of lignifying, differentiating xylem cells and was absent from old wood, cambium and phloem, suggesting that oxidases have a conservative role in lignification of tree xylem. An oxidase from the developing xylem of Picea sitchensis (Bong) Carr. (Sitka spruce) was partially purified by a combination of lectin affinity and immobilized metal ion affinity chromatography. A portion of the total oxidase activity had high affinity for immobilized zinc ions and this feature allowed it to be separated from the bulk of oxidase activity. Two polypeptides that could have been responsible for the bound oxidase activity were enriched by this procedure. The smaller polypeptide of Mr approximately 73 kDa yielded an N-terminal amino-acid sequence that was homologous to laccase-like polyphenol oxidases (E.C. 1.10.3.2) from loblolly pine (Pinus taeda L.), poplar (Populus euramericana (Dode) Guinier) and Arabidopsis. The larger polypeptide (Mr approximately 77 kDa) yielded an N-terminal amino-acid sequence that was homologous with a range of plant subtilisin-like serine proteinases. The roles of oxidase and proteinase activities in developing xylem are discussed.

  19. Anatomical structure of african violet (Saintpaulia ionantha L. vitro- and exvitroplantlets

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    Adriana PETRUŞ-VANCEA

    2010-11-01

    Full Text Available In this article we study the histo-anatomical structure of vegetative organs of African violet (Saintpaulia ionantha L. vitro- and exvitroplantlets in comparison with similar aspects at the same organs of the greenhouse plants (control lot. The phytoinoculs vitroculture period was 120 days, the ex vitro acclimatization for the exvitroplantlets needed 30 days, and the greenhouse cultivar was 2 years old. Finally, we found that only rootlets of the vitroplantlets had a primary structure because at stemlets level has been identified the cambium presence still the vitroculture period. The cortical parenchyma cells at vitro- and exvitroplantlets was larger and less compact in comparison with those of control lot. Also, in the vitroplantlet rootles and stemlets the report cortex:central cylinder was much higher and vascular bundle was very poorly represented that at exvitroplantlets, but especially in comparison with these aspects in the plants grown in natural conditions. The spongy parenchyma at leaflets from in vitro culture was composed of fewer cell layers which was larger and less compact in comparison with those of exvitroplantlet leaf homologous layers and with the same layers from the leaf of greenhouse plants. At in vitro leaflets the peryphloemic protective mechanical tissue was at an early forming stage. However, we consider these differences as being due to the plants normal ontogenetic development.

  20. DESARROLLO DE LA VARIANTE CAMBIAL EN SERJANIA MERIDIONALIS (SAPINDACEAE, PAULLINIEAE

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    M. Lucía Borniego

    2014-01-01

    Full Text Available La familia Sapindaceae representa uno de los grupos de plantas trepadoras más importante del Neo - trópico y presenta diversas variantes cambiales, algunas exclusivas. En esta contribución se describe el desarrollo del leño de Serjania meridionalis , la especie más austral del género, estudiado mediante técnicas anatómicas convencionales sobre la base de material proveniente de Isla Martín García (Buenos Aires, Argentina. El sistema vascular primario es eustélico. El crecimiento secundario se inicia con un cambium típico; sin embargo, con posterioridad, se desdiferencian meristemas de engrosamiento secun - dario supernumerarios. Estos meristemas producen nuevos cilindros vasculares (xilema y floema secun - darios en la periferia del cilindro vascular original. La presencia de cilindros vasculares cordados en los tallos añosos de S. meridionalis es novedad para la especie y plantea la necesidad de rever la dicotomía presencia-ausencia de variantes cambiales en muchas claves de identificación.

  1. Proper gibberellin localization in vascular tissue is required to regulate adventitious root development in tobacco

    Science.gov (United States)

    Chen, Xiaoyang; Li, Wei

    2013-01-01

    Bioactive gibberellins (GAs) are involved in many developmental aspects of the life cycle of plants, acting either directly or through interaction with other hormones. Accumulating evidence suggests that GAs have an important effect on root growth; however, there is currently little information on the specific regulatory mechanism of GAs during adventitious root development. A study was conducted on tobacco (Nicotiana tabacum) plants for altered rates of biosynthesis, catabolism, and GA signalling constitutively or in specific tissues using a transgenic approach. In the present study, PtGA20ox, PtGA2ox1, and PtGAI were overexpressed under the control of the 35S promoter, vascular cambium-specific promoter (LMX5), or root meristem-specific promoter (TobRB7), respectively. Evidence is provided that the precise localization of bioactive GA in the stem but not in the roots is required to regulate adventitious root development in tobacco. High levels of GA negatively regulate the early initiation step of root formation through interactions with auxin, while a proper and mobile GA signal is required for the emergence and subsequent long-term elongation of established primordia. The results demonstrated that GAs have an inhibitory effect on adventitious root formation but a stimulatory effect on root elongation. PMID:23918971

  2. Mini-incubators improve the adventitious rooting performance of Corymbia and Eucalyptus microcuttings according to the environment in which they are conditioned.

    Science.gov (United States)

    Brondani, Gilvano E; Oliveira, Leandro S DE; Konzen, Enéas R; Silva, André L L DA; Costa, Jefferson L

    2017-10-16

    We addressed a major challenge in the in vitro clonal propagation of Corymbia citriodora, Eucalyptus urophylla and E. benthamii by using an ex vitro adventitious rooting strategy in a mini-incubator. Mini-incubators were placed in four environments for rooting. A shade house with no fogging system and a greenhouse with no ventilation but with a fogging environment had the best performance in terms of rooting, root growth and survival of microcuttings. Daily recording of the temperature within each mini-incubator in each environment allowed the verification of negative correlations between the maximum average temperature and the survival, adventitious rooting and root growth. The ideal maximum air temperature for the efficient production of clonal plants was 28.4°C (± 5.5°C), and the minimum was 20.3°C (± 6.2°C). E. benthamii was more sensitive to higher temperatures than C. citriodora and E. urophylla. Nevertheless, placing mini-incubators in the shade house with no fogging system resulted in a stable and uniform performance among the three species, with 100.0% survival and 81.4% rooting. Histological sections of the adventitious roots revealed connection with the stem vascular cambium. Therefore, our experimental system demonstrated the potential of mini-incubators coupled with the proper environment to optimize the adventitious rooting performance of microcuttings.

  3. Mini-incubators improve the adventitious rooting performance of Corymbia and Eucalyptus microcuttings according to the environment in which they are conditioned

    Directory of Open Access Journals (Sweden)

    GILVANO E. BRONDANI

    2017-10-01

    Full Text Available ABSTRACT We addressed a major challenge in the in vitro clonal propagation of Corymbia citriodora, Eucalyptus urophylla and E. benthamii by using an ex vitro adventitious rooting strategy in a mini-incubator. Mini-incubators were placed in four environments for rooting. A shade house with no fogging system and a greenhouse with no ventilation but with a fogging environment had the best performance in terms of rooting, root growth and survival of microcuttings. Daily recording of the temperature within each mini-incubator in each environment allowed the verification of negative correlations between the maximum average temperature and the survival, adventitious rooting and root growth. The ideal maximum air temperature for the efficient production of clonal plants was 28.4°C (± 5.5°C, and the minimum was 20.3°C (± 6.2°C. E. benthamii was more sensitive to higher temperatures than C. citriodora and E. urophylla. Nevertheless, placing mini-incubators in the shade house with no fogging system resulted in a stable and uniform performance among the three species, with 100.0% survival and 81.4% rooting. Histological sections of the adventitious roots revealed connection with the stem vascular cambium. Therefore, our experimental system demonstrated the potential of mini-incubators coupled with the proper environment to optimize the adventitious rooting performance of microcuttings.

  4. Intelligence, Cognition, and Language of Green Plants.

    Science.gov (United States)

    Trewavas, Anthony

    2016-01-01

    A summary definition of some 70 descriptions of intelligence provides a definition for all other organisms including plants that stresses fitness. Barbara McClintock, a plant biologist, posed the notion of the 'thoughtful cell' in her Nobel prize address. The systems structure necessary for a thoughtful cell is revealed by comparison of the interactome and connectome. The plant root cap, a group of some 200 cells that act holistically in responding to numerous signals, likely possesses a similar systems structure agreeing with Darwin's description of acting like the brain of a lower organism. Intelligent behavior requires assessment of different choices and taking the beneficial one. Decisions are constantly required to optimize the plant phenotype to a dynamic environment and the cambium is the assessing tissue diverting more or removing resources from different shoot and root branches through manipulation of vascular elements. Environmental awareness likely indicates consciousness. Spontaneity in plant behavior, ability to count to five and error correction indicate intention. Volatile organic compounds are used as signals in plant interactions and being complex in composition may be the equivalent of language accounting for self and alien recognition by individual plants. Game theory describes competitive interactions. Interactive and intelligent outcomes emerge from application of various games between plants themselves and interactions with microbes. Behavior profiting from experience, another simple definition of intelligence, requires both learning and memory and is indicated in the priming of herbivory, disease and abiotic stresses.

  5. Biomechanics and functional morphology of a climbing monocot

    Science.gov (United States)

    Hesse, Linnea; Wagner, Sarah T.; Neinhuis, Christoph

    2016-01-01

    Plants with a climbing growth habit possess unique biomechanical properties arising from adaptations to changing loading conditions connected with close attachment to mechanical supports. In monocot climbers, mechanical adaptation is restricted by the absence of a bifacial vascular cambium. Flagellaria indica was used to investigate the mechanical properties and adaptations of a monocot climber that, uniquely, attaches to the surrounding vegetation via leaf tendrils. Biomechanical methods such as three-point bending and torsion tests were used together with anatomical studies on tissue development, modification and distribution. In general, the torsional modulus was lower than the bending modulus; hence, torsional stiffness was less than flexural stiffness. Basal parts of mature stems showed the greatest stiffness while that of more apical stem segments levelled off. Mechanical properties were modulated via tissue maturation processes mainly affecting the peripheral region of the stem. Peripheral vascular bundles showed a reduction in the amount of conducting tissue while the proportion and density of the bundle sheath increased. Furthermore, adjacent bundle sheaths merged resulting in a dense ring of fibrous tissue. Although F. indica lacks secondary cambial growth, the climbing habit is facilitated by a complex interaction of tissue maturation and attachment. PMID:26819259

  6. Effects of the pollution by petroleum on the tracheids along the stem of Podocarpus lambertii Klotzsch ex Endl., Podocarpaceae

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    LT. Maranho

    Full Text Available Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae is native and a member of the Pinophyta (Gymnosperm of southern Brazil, locally known as "pinheiro-bravo". The present work aims to investigate the effects of petroleum on the tracheids dimensions. Wood samples from twenty individuals were studied along the stem, ten being exposed to pollution and ten used as a control set. The wood samples were collected from incisions at three levels: at the ground level, and one and two metres above the ground level. From these samples, sub-samples were selected at the border of the growth layers in the vascular cambium-medulla direction. The methodology followed that traditionally recommended for plant anatomy studies, with analyses done by light microscopy (OLYMPUS - BX41 assisted by the software Image Pro-plus for measurements. Comparison of the individuals exposed to petroleum with the control set, showed that the length, diameter and cell wall width of the tracheids of the former were smaller, a trend which was statistically significant according to the Student's t-test. These traits were observed mainly on the tracheids of the last growth layer, corresponding to the year in which the individuals were exposed to petroleum.

  7. Effects of the pollution by petroleum on the tracheids along the stem of Podocarpus lambertii Klotzsch ex Endl., Podocarpaceae

    Energy Technology Data Exchange (ETDEWEB)

    Maranho, L.T.; Dziedzic, M. [Universidade Positivo (UP), Curitiba, PR (Brazil). Curso de Mestrado em Gestao Ambiental], email: maranho@unicenp.edu.br; Muniz, G.I.B.; Kuniyoshi, Y.S.; Galvao, F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Ciencias Florestais

    2009-07-01

    Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae) is native and a member of the Pinophyta (Gymnosperm) of southern Brazil, locally known as 'pinheiro-bravo'. The present work aims to investigate the effects of petroleum on the tracheids dimensions. Wood samples from twenty individuals were studied along the stem, ten being exposed to pollution and ten used as a control set. The wood samples were collected from incisions at three levels: at the ground level, and one and two metres above the ground level. From these samples, sub-samples were selected at the border of the growth layers in the vascular cambium-medulla direction. The methodology followed that traditionally recommended for plant anatomy studies, with analyses done by light microscopy (Olympus - BX41) assisted by the software Image Pro-plus for measurements. Comparison of the individuals exposed to petroleum with the control set, showed that the length, diameter and cell wall width of the tracheids of the former were smaller, a trend which was statistically significant according to the Student's t-test. These traits were observed mainly on the tracheids of the last growth layer, corresponding to the year in which the individuals were exposed to petroleum. (author)

  8. A simple shoot multiplication procedure using internode explants, and its application for particle bombardment and Agrobacterium-mediated transformation in watercress.

    Science.gov (United States)

    Ogita, Shinjiro; Usui, Miki; Shibutani, Nanae; Kato, Yasuo

    2009-07-01

    A shoot multiplication system derived from internode explants was investigated with the aim of improving genetic characteristics of watercress (Nasturtium officinale R. Br.). Internodes of ca. 1 cm excised from in vitro stock shoot culture were placed on half-strength Murashige and Skoog (MS) medium supplemented with 3 muM 2,4-dichlorophenoxyacetic acid as a pre-treatment. Laser scanning microscopy indicated clearly that the first sign of meristematic cell division could be seen after 1-2 days of pre-culture, and meristematic tissues multiplied along the vascular cambium of the internode segment during 7 days of culture. Multiple shoots could be obtained from more than 90% of the pre-treated explants when they were subsequently transferred to MS medium supplemented with 1 muM thidiazuron for 3 weeks. These findings indicate that pre-treatment of the internodes for 7 days promoted their capacity for organogenesis. Using this pre-treatment, frequent generation of transgenic watercress plants was achieved by adapting particle bombardment and Agrobacterium-mediated transformation techniques with a construct expressing a synthetic green florescent protein gene.

  9. STUDI LINGKAR TUMBUH POHON DI KAWASAN HUTAN TAMAN NASIONAL SIBERUT KEPULAUAN MENTAWAI

    Directory of Open Access Journals (Sweden)

    . Mansyurdin

    2016-03-01

    Full Text Available Growth ring trees are formed by activity of the cambium which is influenced by the changing seasons.   In the tropical are not all of  trees species produce  the growth ring, because the season of  tropics is more uniform throughout the year and does not show sharp distinction between the periods of high rainfall and period of low rainfall. This study has concentred on several tree forest areas in Siberut National Park, Mentawai Islands. Samples were ollected by using borer on the main stem on the height of 130 cm. To see or not to see growing circle with to be checked macroscopically and microscopically. The macroscopic examination was done polished core by several grades of sandpaper in the transverse surface Tree species which have growth ring continued to microscopic observation with making slice anatomy. Based on 46 species of trees were examined, and  6 species were with found a growth ring in the number of cell mixture early wood and late wood from these species.

  10. Using pheromones to protect heat-injured lodgepole pine from mountain pine beetle infestation. Forest Service research note

    Energy Technology Data Exchange (ETDEWEB)

    Amman, G.D.; Ryan, K.C.

    1994-01-01

    The bark beetle antiaggregative pheromones, verbenone and ipsdienol, were tested in protecting heat-injured lodgepole pine (Pinus contorta Dougl. ex Loud.) from mountain pine beetle (Dendroctonus ponderosae) infestation in the Sawtooth National Recreation Area in central Idaho. Peat moss was placed around 70 percent of the basal circumference of lodgepole pines. When the peat moss was ignited, it simulated the smoldering of natural duff, generating temperatures that killed the cambium. The four treatments tested were uninjured tree, heat-injured tree, heat-injured tree treated with verbenone, and heat-injured tree treated with verbenone plus ipsdienol. Treatments were replicated 20 times. Mountain pine beetles were attracted into treatment blocks by placing mountain pine beetle tree baits on metal posts 3 to 5 meters from treated trees. Fisher's Extract Test showed that treatment and beetle infestation were not independent (P < 0.015). Check treatments contained more unattacked and mass-attacked trees, whereas pheromone treatments contained more unsuccessfully attacked trees.

  11. Effect of auxin on xylem tracheids differentiation in decapitated stems of Pinus silvestris L. and its interaction with some vitamins and growth regulators

    Directory of Open Access Journals (Sweden)

    T. J. Wodzicki

    2015-01-01

    Full Text Available The effects of several vitamins and substances known as important agents in regulation of cell metabolism upon secondary xylem differentiation were studied in interaction with auxin (IAA as applied in lanoline to decapitated stems of 5-year-old Pinus silvestris trees in early and late-summer. Tested substances were: gibberellic acid, kinetin, nicotinic acid, thiamine, pyridoxine, calcium panthotenate, choline chloride, riboflavin, inositol, ascorbic acid, vitamin, A (alcohol, vitamin A (ester, saponin. None of the effects of these substances appeared significant enough to indicate the involvement in the seasonal variation of the response of cambium or differentiating tracheids to auxin. However, several effects, especially those of inositol, vitamin A and pyridoxine upon cambial xylem production and further stages of tracheid differentiation were observed. Auxin (IAA affected cambial activity and subsequent differentiation of tracheids during the earliest stages of cell ontogenesis. At these stages auxin treatment induced quantitative expression of the developmental processes involving radial growth and secondary wall formation by tracheids. In this respect, auxin did not affect cells advanced in differentiation, however, it proved to be an essential factor in the completion of the full cycle of tracheid ontogenesis.

  12. The acropetal effects of indole-3-acetic acid in isolated shoot segments of Acer pseudoplatanus L. II. Possible regulation by a vectorial fieid of auxin waves

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    Jacek A. Adamczyk

    2014-01-01

    Full Text Available The acropetal effects of auxin on elongation of axillary buds and on modulation of the wave-like pattern of basipetal efflux of natural auxin to agar from Acer pseudoplatanus L. shoots were studied. When synthetic IAA was applied to cut surfaces of one of two branches the elongation growth of buds situated on the opposite branch was retarded, suggesting regulation independent of the direct action of the molecules of the applied IAA. Oscillations in basipetal transport of natural auxin along the stem segments were observed corroborating the results of other authors using different tree species. Apical application of synthetic IAA for 1 hour to the lateral branch caused a phase shift of the wave-like pattern of basipetal efflux of natural auxin, when the stem segment above the treated branch was sectioned. The same effect was observed evoked by the laterally growing branch which is interpreted as an effect of natural auxin produced by the actively growing shoot. These modulations could be propagated acropetally at a rate excluding direct action of auxin molecules at the sites of measurement. The results seem to corroborate the hypothesis suggesting that auxin is involved in acropetal regulation of shoot apex growth through its effect upon modulation of the vectorial field which arises when the auxin-waves translocate in cambium.

  13. Estudios evolutivos-del desarrollo en tallos fósiles de Corystospermaceae (Corystospermales, Spermatopsida Evolutionary developmental studies in fossil stems of Corystospermaceae

    Directory of Open Access Journals (Sweden)

    Josefina Bodnar

    2012-06-01

    in gondwanic Triassic paleofloras. This group accounts for an excellent case study because their stems are preserved permineralized, showing cellular and histological details, and it is possible to examine their whole ontogeny in a single individual since the cells of the secondary xylem and phloem are produced in successive layers retaining permanently their position. In the ontogenetic studies of pteridosperms, regulating mechanisms of development must be discerned comparing with ontogenies of comparable living plants. This extrapolation is possible since it is known that regulating processes of secondary growth are homologous in all lygnophytes. Most of corystosperm axes present a dissected secondary vascular cylinder, and tissues with unusual development and position, which is caused by four classes of cambial deviations: 1- differential activity throughout the stem circumference; 2- remnant activity; 3- inverse or centripetal cambium; and 4 - successive inverse and/or normal cambia (poyxyly. The origin of these cambium deviations is intimately linked to heterotopic events, including neoheterotopy and homeosis. By comparison with living plant studies, it is theorized that homeotic genes implied with these events could be those related to the beginning of cambial activity, cell differentiation, and vascular bundle arrangement.

  14. Resprouting from roots in four Brazilian tree species

    Directory of Open Access Journals (Sweden)

    Adriana Hissae Hayashi

    2009-09-01

    Full Text Available Previous studies pointed out that species richness and high density values within the Leguminosae in Brazilian forest fragments affected by fire could be due, at least partially, to the high incidence of root sprouting in this family. However, there are few studies of the factors that induce root sprouting in woody plants after disturbance. We investigated the bud formation on root cuttings, and considered a man-made disturbance that isolates the root from the shoot apical dominance of three Leguminosae (Bauhinia forficata Link., Centrolobium tomentosum Guill. ex Benth, and Inga laurina (Sw. Willd and one Rutaceae (Esenbeckia febrifuga (St. Hil. Juss. ex Mart.. All these species resprout frequently after fire. We also attempted to induce bud formation on root systems by removing the main trunk, girdling or sectioning the shallow lateral roots from forest tree species Esenbeckia febrifuga and Hymenaea courbaril L. We identified the origin of shoot primordia and their early development by fixing the samples in Karnovsky solution, dehydrating in ethyl alcohol series and embedding in plastic resin. Serial sections were cut on a rotary microtome and stained with toluidine blue O. Permanent slides were mounted in synthetic resin. We observed different modes of bud origin on root cuttings: close to the vascular cambium (C. tomentosum, from the callus (B. forficata and E. febrifuga and from the phloematic parenchyma proliferation (I. laurina. Fragments of B. forficata root bark were also capable of forming reparative buds from healing phellogen formed in callus in the bark’s inner side. In the attempt of bud induction on root systems, Hymenaea courbaril did not respond to any of the induction tests, probably because of plant age. However, Esenbeckia febrifuga roots formed suckers when the main trunk was removed or their roots were sectioned and isolated from the original plant. We experimentally demonstrated the ability of four tree species to

  15. Engineering biomimetic periosteum with β-TCP scaffolds to promote bone formation in calvarial defects of rats.

    Science.gov (United States)

    Zhang, Dan; Gao, Peng; Li, Qin; Li, Jinda; Li, Xiaojuan; Liu, Xiaoning; Kang, Yunqing; Ren, Liling

    2017-06-05

    There is a critical need for the management of large bone defects. The purpose of this study was to engineer a biomimetic periosteum and to combine this with a macroporous β-tricalcium phosphate (β-TCP) scaffold for bone tissue regeneration. Rat bone marrow-derived mesenchymal stem cells (rBMSCs) were harvested and cultured in different culture media to form undifferentiated rBMSC sheets (undifferentiated medium (UM)) and osteogenic cell sheets (osteogenic medium (OM)). Simultaneously, rBMSCs were differentiated to induced endothelial-like cells (iECs), and the iECs were further cultured on a UM to form a vascularized cell sheet. At the same time, flow cytometry was used to detect the conversion rates of rBMSCs to iECs. The pre-vascularized cell sheet (iECs/UM) and the osteogenic cell sheet (OM) were stacked together to form a biomimetic periosteum with two distinct layers, which mimicked the fibrous layer and cambium layer of native periosteum. The biomimetic periostea were wrapped onto porous β-TCP scaffolds (BP/β-TCP) and implanted in the calvarial bone defects of rats. As controls, autologous periostea with β-TCP (AP/β-TCP) and β-TCP alone were implanted in the calvarial defects of rats, with a no implantation group as another control. At 2, 4, and 8 weeks post-surgery, implants were retrieved and X-ray, microcomputed tomography (micro-CT), histology, and immunohistochemistry staining analyses were performed. Flow cytometry results showed that rBMSCs were partially differentiated into iECs with a 35.1% conversion rate in terms of CD31. There were still 20.97% rBMSCs expressing CD90. Scanning electron microscopy (SEM) results indicated that cells from the wrapped cell sheet on the β-TCP scaffold apparently migrated into the pores of the β-TCP scaffold. The histology and immunohistochemistry staining results from in vivo implantation indicated that the BP/β-TCP and AP/β-TCP groups promoted the formation of blood vessels and new bone tissues in the bone

  16. Proteomics of plasma membranes from poplar trees reveals tissue distribution of transporters, receptors, and proteins in cell wall formation.

    Science.gov (United States)

    Nilsson, Robert; Bernfur, Katja; Gustavsson, Niklas; Bygdell, Joakim; Wingsle, Gunnar; Larsson, Christer

    2010-02-01

    By exploiting the abundant tissues available from Populus trees, 3-4 m high, we have been able to isolate plasma membranes of high purity from leaves, xylem, and cambium/phloem at a time (4 weeks after bud break) when photosynthesis in the leaves and wood formation in the xylem should have reached a steady state. More than 40% of the 956 proteins identified were found in the plasma membranes of all three tissues and may be classified as "housekeeping" proteins, a typical example being P-type H(+)-ATPases. Among the 213 proteins predicted to be integral membrane proteins, transporters constitute the largest class (41%) followed by receptors (14%) and proteins involved in cell wall and carbohydrate metabolism (8%) and membrane trafficking (8%). ATP-binding cassette transporters (all members of subfamilies B, C, and G) and receptor-like kinases (four subfamilies) were two of the largest protein families found, and the members of these two families showed pronounced tissue distribution. Leaf plasma membranes were characterized by a very high proportion of transporters, constituting almost half of the integral proteins. Proteins involved in cell wall synthesis (such as cellulose and sucrose synthases) and membrane trafficking were most abundant in xylem plasma membranes in agreement with the role of the xylem in wood formation. Twenty-five integral proteins and 83 soluble proteins were exclusively found in xylem plasma membranes, which identifies new candidates associated with cell wall synthesis and wood formation. Among the proteins uniquely found in xylem plasma membranes were most of the enzymes involved in lignin biosynthesis, which suggests that they may exist as a complex linked to the plasma membrane.

  17. Cassava C-repeat binding factor 1 gene responds to low temperature and enhances cold tolerance when overexpressed in Arabidopsis and cassava.

    Science.gov (United States)

    An, Dong; Ma, Qiuxiang; Wang, Hongxia; Yang, Jun; Zhou, Wenzhi; Zhang, Peng

    2017-05-01

    Cassava MeCBF1 is a typical CBF transcription factor mediating cold responses but its low expression in apical buds along with a retarded response cause inefficient upregulation of downstream cold-related genes, rendering cassava chilling-sensitive. Low temperature is a major abiotic stress factor affecting survival, productivity and geographic distribution of important crops worldwide. The C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB) are important regulators of abiotic stress response in plants. In this study, MeCBF1, a CBF-like gene, was identified in the tropical root crop cassava (Manihot esculenta Crantz). The MeCBF1 encodes a protein that shares strong homology with DREB1As/CBFs from Arabidopsis as well as other species. The MeCBF1 was localized to the nucleus and is mainly expressed in stem and mature leaves, but not in apical buds or stem cambium. MeCBF1 expression was not only highly responsive to cold, but also significantly induced by salt, PEG and ABA treatment. Several stress-associated cis-elements were found in its promoter region, e.g., ABRE-related, MYC recognition sites, and MYB responsive element. Compared with AtCBF1, the MeCBF1 expression induced by cold in cassava was retarded and upregulated only after 4 h, which was also confirmed by its promoter activity. Overexpression of MeCBF1 in transgenic Arabidopsis and cassava plants conferred enhanced crytolerance. The CBF regulon was smaller and not entirely co-regulated with MeCBF1 expression in overexpressed cassava. The retarded MeCBF1 expression in response to cold and attenuated CBF-regulon might lead cassava to chilling sensitivity.

  18. Auxin-responsive DR5 promoter coupled with transport assays suggest separate but linked routes of auxin transport during woody stem development in Populus.

    Directory of Open Access Journals (Sweden)

    Rachel Spicer

    -organized vascular cambium.

  19. The poplar basic helix-loop-helix transcription factor BEE3 – Like gene affects biomass production by enhancing proliferation of xylem cells in poplar

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Seol Ah, E-mail: s6022029@korea.ac.kr; Choi, Young-Im, E-mail: yichoi99@forest.go.kr; Cho, Jin-Seong, E-mail: jinsung3932@gmail.com; Lee, Hyoshin, E-mail: hslee@forest.go.kr

    2015-06-19

    Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems. - Highlights: • We identify the BEE3-like gene form hybrid poplar (Populus alba × Populus glandulosa). • We examine effects of overexpression of PagBEE3L on growth in poplar. • We found that 35S:BEE3L transgenic plants showed more rapid growth than wild-type plants. • BEE3L protein plays an important role in the development of plant stem.

  20. Auxin-responsive DR5 promoter coupled with transport assays suggest separate but linked routes of auxin transport during woody stem development in Populus.

    Science.gov (United States)

    Spicer, Rachel; Tisdale-Orr, Tracy; Talavera, Christian

    2013-01-01

    Polar auxin transport (PAT) is a major determinant of plant morphology and internal anatomy with important roles in vascular patterning, tropic growth responses, apical dominance and phyllotactic arrangement. Woody plants present a highly complex system of vascular development in which isolated bundles of xylem and phloem gradually unite to form concentric rings of conductive tissue. We generated several transgenic lines of hybrid poplar (Populus tremula x alba) with the auxin-responsive DR5 promoter driving GUS expression in order to visualize an auxin response during the establishment of secondary growth. Distinct GUS expression in the cambial zone and developing xylem-side derivatives supports the current view of this tissue as a major stream of basipetal PAT. However, we also found novel sites of GUS expression in the primary xylem parenchyma lining the outer perimeter of the pith. Strands of primary xylem parenchyma depart the stem as a leaf trace, and showed GUS expression as long as the leaves to which they were connected remained attached (i.e., until just prior to leaf abscission). Tissue composed of primary xylem parenchyma strands contained measurable levels of free indole-3-acetic acid (IAA) and showed basipetal transport of radiolabeled auxin ((3)H-IAA) that was both significantly faster than diffusion and highly sensitive to the PAT inhibitor NPA. Radiolabeled auxin was also able to move between the primary xylem parenchyma in the interior of the stem and the basipetal stream in the cambial zone, an exchange that was likely mediated by ray parenchyma cells. Our results suggest that (a) channeling of leaf-derived IAA first delineates isolated strands of pre-procambial tissue but then later shifts to include basipetal transport through the rapidly expanding xylem elements, and (b) the transition from primary to secondary vascular development is gradual, with an auxin response preceding the appearance of a unified and radially-organized vascular cambium.

  1. Association of allelic variation in PtoXET16A with growth and wood properties in Populus tomentosa.

    Science.gov (United States)

    Wang, Bowen; Zhang, Deqiang

    2014-09-23

    Xyloglucan endo-transglycosylases (XETs) modify the xyloglucan-cellulose framework of plant cell walls and, thus, affect cell wall expansion and strength. Dissecting the mechanism by which natural variation in XETs affects wood properties can inform breeding efforts to improve wood quality and yield traits. To this end, we isolated a full-length PtoXET16A cDNA clone from Populus tomentosa. Real-time PCR analysis showed that PtoXET16A was maximally expressed in the root, followed by phloem, cambium, and developing xylem, suggesting that PtoXET16A plays important roles in the development of vascular tissues. Nucleotide diversity and linkage disequilibrium analysis revealed that PtoXET16A has high single nucleotide polymorphism (SNP) diversity (π = 0.01266 and θ(w) = 0.01392) and low linkage disequilibrium (r² ≥ 0.1, within 900 bp). SNP- and haplotype-based association analyses of 426 individuals from a natural population indicated that nine SNPs (including two non-synonymous markers and one splicing variant) (p ≤ 0.05, false discovery rate Q ≤ 0.01), and nine haplotypes (p ≤ 0.05) were significantly associated with growth and wood properties, each explaining from 3.40%-10.95% of phenotypic variance. This work shows that examination of allelic variation and linkage disequilibrium by a candidate-gene-based approach can help to decipher the genetic basis of wood formation. Moreover, the SNP markers identified in this study can potentially be applied for marker-assisted selection to improve growth and wood-property traits in Populus.

  2. Single nucleotide polymorphisms in a cellulose synthase gene (PtoCesA3) are associated with growth and wood properties in Populus tomentosa.

    Science.gov (United States)

    Xu, Baohua; Tian, Jiaxing; Du, Qingzhang; Gong, Chenrui; Pan, Wei; Zhang, Deqiang

    2014-12-01

    In plants, the composition and organization of the cell wall determine cell shape, enable cell expansion, and affect the properties of woody tissues. Cellulose synthase (CesA) genes encode the enzymes involved in the synthesis of cellulose which is the major component of plant primary and secondary cell walls. Here, we isolated a full-length PtoCesA3 cDNA from the stem cambium tissue of Populus tomentosa. Tissue-specific expression profiling showed that PtoCesA3 is highly expressed during primary cell wall formation. Estimation of single nucleotide polymorphism (SNP) diversity and linkage disequilibrium (LD) revealed that PtoCesA3 harbors high SNP diversity (π(T) = 0.00995 and θ(w) = 0.0102) and low LD (r(2) ≥ 0.1, within 1,280 bp). Association analysis in a P. tomentosa association population (460 individuals) showed that seven SNPs (false discovery rate Q wood properties, explaining 4.09-7.02% of the phenotypic variance. All significant marker-trait associations were validated in at least one of the three smaller subsets (climatic regions) while five associations were repeated in the linkage population. Variation in RNA transcript abundance among genotypic classes of significant loci was also confirmed in the association or linkage populations. Identification of PtoCesA3 and examining its allelic polymorphisms using association studies open an avenue to understand the mechanism of cellulose synthesis in the primary cell wall and its effects on the properties of woody tissues.

  3. Pretreatment of periosteum with TGF-beta1 in situ enhances the quality of osteochondral tissue regenerated from transplanted periosteal grafts in adult rabbits.

    Science.gov (United States)

    Olivos-Meza, A; Fitzsimmons, J S; Casper, M E; Chen, Q; An, K-N; Ruesink, T J; O'Driscoll, S W; Reinholz, G G

    2010-09-01

    To compare the efficacy of in situ transforming growth factor-beta1 (TGF-beta1)-pretreated periosteum to untreated periosteum for regeneration of osteochondral tissue in rabbits. In the pretreatment group, 12 month-old New Zealand white rabbits received subperiosteal injections of 200 ng of TGF-beta1 percutaneously in the medial side of the proximal tibia, 7 days prior to surgery. Control rabbits received no treatment prior surgery. Osteochondral transverse defects measuring 5mm proximal to distal and spanning the entire width of the patellar groove were created and repaired with untreated or TGF-beta1-pretreated periosteal grafts. Post-operatively the rabbits resumed normal cage activity for 6 weeks. Complete filling of the defects with regenerated tissue was observed in both the TGF-beta1-pretreated and control groups with reformation of the original contours of the patellar groove. The total histological score (modified O'Driscoll) in the TGF-beta1-pretreated group, 20 (95% Confidence Interval (CI), 19-21), was significantly higher (P=0.0001) than the control group, 18 (16-19). The most notable improvements were in structural integrity and subchondral bone regeneration. No significant differences in glycosaminoglycan or type II collagen content, or equilibrium modulus were found between the surgical groups. The cambium of the periosteum regenerated at the graft harvest site was significantly thicker (P=0.0065) in the TGF-beta1-pretreated rabbits, 121 microm (94-149), compared to controls, 74 microm (52-96), after 6 weeks. This study demonstrates that in situ pretreatment of periosteum with TGF-beta1 improves osteochondral tissue regeneration at 6-weeks post-op compared to untreated periosteum in 12 month-old rabbits. Copyright 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  4. Intrusive growth of primary and secondary phloem fibres in hemp stem determines fibre-bundle formation and structure.

    Science.gov (United States)

    Snegireva, Anastasia; Chernova, Tatyana; Ageeva, Marina; Lev-Yadun, Simcha; Gorshkova, Tatyana

    2015-05-27

    Plant fibres-cells with important mechanical functions and a widely used raw material-are usually identified in microscopic sections only after reaching a significant length or after developing a thickened cell wall. We characterized the early developmental stages of hemp (Cannabis sativa) stem phloem fibres, both primary (originating from the procambium) and secondary (originating in the cambium), when they still had only a primary cell wall. We gave a major emphasis to the role of intrusive elongation, the specific type of plant cell growth by which fibres commonly attain large cell length. We could identify primary phloem fibres at a distance of only 1.2-1.5 mm from the shoot apical meristem when they grew symplastically with the surrounding tissues. Half a millimeter further downwards along the stem, fibres began their intrusive elongation, which led to a sharp increase in fibre numbers visible within the stem cross-sections. The intrusive elongation of primary phloem fibres was completed within the several distal centimetres of the growing stem, before the onset of their secondary cell wall formation. The formation of secondary phloem fibres started long after the beginning of secondary xylem formation. Our data indicate that only a small portion of the fusiform cambial initials (fibres. The key determinant of final bundle structure, both for primary and secondary phloem fibres, is intrusive growth. Through bi-directional elongation, fibres join other fibres initiated individually in other stem levels, thus forming the bundles. Our results provide the specific developmental basis for further biochemical and molecular-genetic studies of phloem fibre development in hemp, but may be applied to many other species. Published by Oxford University Press on behalf of the Annals of Botany Company.

  5. Imago feeding preference of the black fir sawyer Monochamus urussovi Fisch. (Coleoptera: Cerambycidae

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    Grodnitsky Dmitry

    2017-03-01

    Full Text Available Mass outbreaks of the black fir sawyer M. urussovi regularly occur in forest stands dominated by Siberian fir Abies sibirica; outbreaks have been observed only on fir and exclusively in Siberia, although the beetle is also found in the vast territory including Finland, Poland, Ukraine, Kazakhstan, China, Russian Far East and Japan. A closely related common species M. sutor has never produced outbreaks; its larvae have been registered only in Scots pine. Feeding preferences of the two species were compared under experimental conditions; total numbers of tested specimens were 132 (M. urussovi and 40 (M. sutor. M. sutor beetles were caught in nature, M. urussovi pupas and young adults were collected from fir trunks; pupas were reared to beetles. Each beetle was placed into a covered plastic enclosure for 24 hours and offered cut shoots of fir, spruce, Siberian pine, Scots pine, larch, birch and willow; all cuts were of the same length and diameter, needles and leaves had been previously removed. Beetles of the two species showed different feeding preference. M. sutor imagoes completely ignored fir shoots, definitely preferring Scots pine. M. urussovi feeding behavior was different: beetles did consume bark, bast and cambium of fir. However, they were mainly fed on Scots pine shoots. Feeding preference given to Scots pine by beetles grown in fir trunks can be explained by the hypothesis that this species originated on pine. Mass outbreaks of M. urussovi in Siberian fir-dominated forest ecosystems occur, because these plant communities are historically young (evidently much less than 10 000 years and yet unbalanced, transitional sort of ecosystems, so fir did not have enough evolutionary time to get adapted to injure by the sawyer and Ophiostoma fungi carried by beetles.

  6. In vitro rhizogenesis: histoanatomy of Cedrela odorata (Meliaceae microcuttings

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    Liliana Millán-Orozco

    2011-03-01

    Full Text Available Cedrela odorata (Meliaceae is considered as one of the most valuable forest tree in the tropics. Clonal propagation of this species provide an alternative method to propagate superior genotypes, being the production of good quality adventitious roots one of the most important steps in micropropagation techniques. The sequence of anatomical changes that takes place during the formation of adventitious roots in shoots of Cedrela odorata cultured in vitro is described in this study. Eigth-week-old shoots, from multiplication cultures, were rooted in Murashige and Skoog´s medium (1962 with half- strength macronutrients and with 0 or 1mg/l indole-3-butyric acid (IBA. Between 12 and 24h after the start of rooting, some cambium, phloem and interfascicular parenchyma cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed, especially in shoots treated with auxin (dedifferentiation phase. After 3-4 days, the number of dedifferentiated cells and mitotic divisions increased considerably, and the formation of groups of some 30-40 meristematic cells (meristemoids was observed (induction phase. The first primordial roots developed from the 4th-5th day. The vascular tissues of these primordia connected to those of the explant, and roots began to emerge from the base by day 6. Development of the primordial roots was similar in the control shoots and shoots treated with 1mg/l IBA, although there were more roots per explant in the latter. Rev. Biol. Trop. 59 (1: 447-453. Epub 2011 March 01.

  7. Transcriptome analysis of immature xylem in the Chinese fir at different developmental phases

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    Yunxing Zhang

    2016-06-01

    Full Text Available Background.Chinese fir [Cunninghamia lanceolata (Lamb. Hook.] is one of the most important native tree species for timber production in southern China. An understanding of overall fast growing stage, stem growth stage and senescence stage cambium transcriptome variation is lacking. We used transcriptome sequencing to identify the repertoire of genes expressed during development of xylem tissue in Chinese fir, aiming to delineate the molecular mechanisms of wood formation. Results. We carried out transcriptome sequencing at three different cultivation ages (7Y, 15Y and 21Y generating 68.71 million reads (13.88 Gbp. A total of 140,486 unigenes with a mean size of 568.64 base pairs (bp were obtained via de novo assembly. Of these, 27,427 unigenes (19.52% were further annotated by comparison to public protein databases. A total of 5,331 (3.79% unigenes were mapped into 118 pathways by searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG. Differentially expressed genes (DEG analysis identified 3, 16 and 5,899 DEGs from the comparison of 7Y vs. 15Y, 7Y vs. 21Y and 15Y vs. 21Y, respectively, in the immature xylem tissues, including 2,638 significantly up-regulated and 3,280 significantly down-regulated genes. Besides, five NAC transcription factors, 190 MYB transcription factors, and 34 WRKY transcription factors were identified respectively from Chinese fir transcriptome. Conclusion. Our results revealed the active transcriptional pathways and identified the DEGs at different cultivation phases of Chinese fir wood formation. This transcriptome dataset will aid in understanding and carrying out future studies on the molecular basis of Chinese fir wood formation and contribute to future artificial production and applications.

  8. Radial patterns of sap flow in woody stems of dominant and understory species: scaling errors associated with positioning of sensors.

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    Nadezhdina, Nadezhda; Cermák, Jan; Ceulemans, Reinhart

    2002-09-01

    We studied sap flow in dominant coniferous (Pinus sylvestris L.) and broadleaf (Populus canescens L.) species and in understory species (Prunus serotina Ehrh. and Rhododendron ponticum L.) by the heat field deformation (HFD) method. We attempted to identify possible errors arising during flow integration and scaling from single-point measurements to whole trees. Large systematic errors of -90 to 300% were found when it was assumed that sap flow was uniform over the sapwood depth. Therefore, we recommend that the radial sap flow pattern should be determined first using sensors with multiple measuring points along a stem radius followed by single-point measurements with sensors placed at a predetermined depth. Other significant errors occurred in the scaling procedure even when the sap flow radial pattern was known. These included errors associated with uncertainties in the positioning of sensors beneath the cambium (up to 15% per 1 mm error in estimated xylem depth), and differences in environmental conditions when the radial profile applied for integration was determined over the short term (up to 47% error). High temporal variation in the point-to-area correction factor along the xylem radius used for flow integration is also problematic. Compared with midday measurements, measurements of radial variation of sap flow in the morning and evening of sunny days minimized the influence of temporal variations on the point-to-area correction factor, which was especially pronounced in trees with a highly asymmetric sap flow radial pattern because of differences in functioning of the sapwood xylem layers. Positioning a single-point sensor at a depth with maximum sap flow is advantageous because of the high sensitivity of maximum sap flow to water stress conditions and changes in micro-climate, and because of the lower random errors associated with the positioning of a single-point sensor along the xylem radius.

  9. Structure-function relationships in highly modified shoots of cactaceae.

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    Mauseth, James D

    2006-11-01

    Cacti are extremely diverse structurally and ecologically, and so modified as to be intimidating to many biologists. Yet all have the same organization as most dicots, none differs fundamentally from Arabidopsis or other model plants. This review explains cactus shoot structure, discusses relationships between structure, ecology, development and evolution, and indicates areas where research on cacti is necessary to test general theories of morphogenesis. Cactus leaves are diverse; all cacti have foliage leaves; many intermediate stages in evolutionary reduction of leaves are still present; floral shoots often have large, complex leaves whereas vegetative shoots have microscopic leaves. Spines are modified bud scales, some secrete sugar as extra-floral nectaries. Many cacti have juvenile/adult phases in which the flowering adult phase (a cephalium) differs greatly from the juvenile; in some, one side of a shoot becomes adult, all other sides continue to grow as the juvenile phase. Flowers are inverted: the exterior of a cactus 'flower' is a hollow vegetative shoot with internodes, nodes, leaves and spines, whereas floral organs occur inside, with petals physically above stamens. Many cacti have cortical bundles vascularizing the cortex, however broad it evolves to be, thus keeping surface tissues alive. Great width results in great weight of weak parenchymatous shoots, correlated with reduced branching. Reduced numbers of shoot apices is compensated by great increases in number of meristematic cells within individual SAMs. Ribs and tubercles allow shoots to swell without tearing during wet seasons. Shoot epidermis and cortex cells live and function for decades then convert to cork cambium. Many modifications permit water storage within cactus wood itself, adjacent to vessels.

  10. Cellular machinery of wood production: differentiation of secondary xylem in Pinus contorta var. latifolia.

    Science.gov (United States)

    Samuels, A L; Rensing, K H; Douglas, C J; Mansfield, S D; Dharmawardhana, D P; Ellis, B E

    2002-11-01

    The objectives of this study were to define cell structure during pine secondary xylem development and to integrate this information with current knowledge of the biochemistry and physiology of secondary cell wall biosynthesis in gymnosperms. Lodgepole pine (Pinus contorta var. latifolia Englem.) cambium and secondary xylem were cryofixed using high pressure freezing and freeze-substitution which allowed excellent preservation of the cell structure of developing secondary xylem and enabled high-resolution transmission electron microscopic viewing of these cells for the first time. In contrast to their precursors in the adjacent cambial zone, developing tracheids were active in secondary wall deposition, with abundant cortical microtubules and developing bordered pits. These cells were also characterized by unusual Golgi structures: the trans-Golgi network was highly developed and the associated vesicles were large and darkly stained. These unusual Golgi structures persisted throughout the period of xylem maturation until programmed cell death occurred. Immuno-cytochemistry and enzyme-gold probes were used to investigate the distribution of key secretory products (mannans) and a lignification-associated enzyme (coniferin beta-glucosidase) during xylogenesis. Mannans were localized to the secondary cell wall, the trans-Golgi cisternae and trans-Golgi network vesicles of developing xylem. Coniferin beta-glucosidase was found only in the secondary cell wall. The cell wall localization of coniferin beta-glucosidase, the enzyme responsible for cleaving glucose from coniferin to generate free coniferyl alcohol, provides a mechanism to de-glucosylate monolignols in muro. A two-step model of lignification of conifer tracheids is proposed. First, Golgi-mediated secretion deposits monolignols into the cell wall, where they polymerize in cell corners and middle lamella. Secondly, cell lysis releases stored, vacuolar monolignol glucosides into the wall where they are

  11. Structural changes in the vascular bundles of light-exposed and shaded spruce needles suffering from Mg deficiency and ozone pollution.

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    Boxler-Baldoma, Carmen; Lütz, Cornelius; Heumann, Hans-Günther; Siefermann-Harms, Dorothea

    2006-02-01

    The correlation between structural changes of the vascular bundles and needle yellowing was examined for needles of damaged spruce (Picea abies (L.) Karst.) growing at a Mg-deficient and ozone polluted mountain site in the Central Black Forest (840m a.s.l.). In the previous year's sun-exposed needles, the following sequence of events was observed: (1) rapid needle yellowing, (2) hypertrophy and anomalous divisions of cambium cells, (3) phloem collapse, and, (4) production of atypical xylem tracheids. Under defined shade (reduction of the photosynthetically active photon flux density of the ambient light by 85-90%), the needles remained green, while the phloem collapsed completely within the first 6 weeks of shading; subsequently, a reversal of the collapse was observed. Under both light conditions, the content of Mg not bound to chlorophyll (Mg(free)) was in the range of 0.1 mg g(-1) needle dry matter, and hardly changed throughout the investigation period. After Mg fertilization, the Mg(free) level of the previous year's needles increased to 0.2 mg g(-1) dry matter, the light-exposed needles remained green, and the vascular bundles developed no anomalies. The data show that the rapid needle yellowing of ozone-exposed Mg-deficient needles did not depend on the collapse of the phloem. Mg deficiency played a key role in the development of anomalous vascular bundles under light, and also appears to explain the transient changes in sieve cell structure under shade. The role of Mg deficiency, rather than ozone pollution, in the damage of the sieve cells was confirmed in a long-term ozone exposure experiment with young clonal spruce growing under defined conditions.

  12. Identification of cyst nematode B-type CLE peptides and modulation of the vascular stem cell pathway for feeding cell formation.

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    Xiaoli Guo

    2017-02-01

    Full Text Available Stem cell pools in the SAM (shoot apical meristem, RAM (root apical meristem and vascular procambium/cambium are regulated by CLE-receptor kinase-WOX signaling modules. Previous data showed that cyst nematode CLE-like effector proteins delivered into host cells through a stylet, act as ligand mimics of plant A-type CLE peptides and are pivotal for successful parasitism. Here we report the identification of a new class of CLE peptides from cyst nematodes with functional similarity to the B-type CLE peptide TDIF (tracheary element differentiation inhibitory factor encoded by the CLE41 and CLE44 genes in Arabidopsis. We further demonstrate that the TDIF-TDR (TDIF receptor-WOX4 pathway, which promotes procambial meristem cell proliferation, is involved in beet cyst nematode Heterodera schachtii parasitism. We observed activation of the TDIF pathway in developing feeding sites, reduced nematode infection in cle41 and tdr-1 wox4-1 mutants, and compromised syncytium size in cle41, tdr-1, wox4-1 and tdr-1 wox4-1 mutants. By qRT-PCR and promoter:GUS analyses, we showed that the expression of WOX4 is decreased in a clv1-101 clv2-101 rpk2-5 mutant, suggesting that WOX4 is a potential downstream target of nematode CLEs. Exogenous treatment with both nematode A-type and B-type CLE peptides induced massive cell proliferation in wild type roots, suggesting that the two types of CLEs may regulate cell proliferation during feeding site formation. These findings highlight an important role of the procambial cell proliferation pathway in cyst nematode feeding site formation.

  13. The impact of an increasing elephant population on the woody vegetation in southern Sabi Sand Wildtuin, South Africa

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    Kay Hiscocks

    1999-02-01

    Full Text Available In 1961, a fence was erected between privately owned Sabi Sand Wildtuin (SSW and the Kruger National Park (KNP, which largely prevented elephants entering the SSW. In 1993, the fence was removed. This lead to a rapid influx of elephants into the SSW during the winter months, most of which move back into the KNP during the wet summer season. In 1993, the SSW elephant population was 1/1045 ha but increased to 1/305.8 ha in 1996. It more than doubled to 1/146 ha in 1998. This study was undertaken on the property Kingston, in southern SSW, to assess the impact of elephants on woody vegetation and determine why they show seasonal dietary preferences for specific tree parts. Vegetation utilisation was recorded on a five kilometer transect of vehicle track in 1996 and repeated in 1998. From the transect, species density was calculated for those trees impacted on. Trees that had been newly bark stripped were recorded in 1996 and 1998. Cambium samples were collected in summer and winter from eight tree species. Field observations of elephants impacting on woody vegetation augmented the data base. Transect analysis showed a strong correlation between tree utilisation and density. The most visual damage was of Combretum apiculatum, Acacia burkei, Pterocarpus rotundifolius and Grewia species. Tree damage increased by 73 from 1996 to 1998. Significantly higher levels of nitrogen, sodium and magnesium were found in the species most regularly bark stripped. Bull elephants were responsible for 94 of the trees seen uprooted. The results suggested that SSW can sustain the present elephant population, but further influx at the present rate of increase, will have a negative impact on the reserve.

  14. The effect of slope exposition on the growth dynamics of Larix gmelinii in permafrost conditions of Central Siberia. I. Differences in tree radial dynamics growth in the north- and south-facing slopes

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    А. V. Benkova

    2015-08-01

    Full Text Available This paper is devoted to revealing the distinctive characteristics of radial growth of larch trees (Larix gmelinii (Rupr. Rupr. growing in permafrost contrast conditions of the north and south facing slopes (Central Siberia, 64°19´23˝ N, 100°13´28˝ E. Even-aged larch stems regenerated after strong fire in 1899 in opposite north and south facing slopes of the hills situated on the banks of Kulingdakan stream were under study. Two sample sites at the middle part of the slopes were established. 23 model trees in the north facing slope and 13 ones in the south-facing slope were selected for dendrochronological analysis. From each tree, disks at 1.3 m height of the stems were taken. Tree ring widths were measured, comparative analysis of dynamics of radial growth in the slopes was made. In order to separate time intervals, characterized by distinctive climate impact on radial increment, sliding response functions were calculated and analyzed. Daily solar radiation for both sample sites was calculated. The results showed that solar radiation in the north-facing slope is 20 % less than that in south-facing slope. Solar radiation regime promotes intensive thickening of moss-lichen cover, so that its thickness to 2009 was nearly two times thicker than in south-facing slope. Both factors affected the worth thermal soil growth conditions in the north facing slope. The latter was responsible for narrower ring widths formation in the stems and governed higher sensitivity of the trees to air temperature in the periods of cambium reactivation, start and intensive growth.

  15. Formation and spread of callus tissue and tangential rows of resin ducts in Larix decidua and Picea abies following rockfall impacts.

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    Schneuwly, Dominique M; Stoffel, Markus; Bollschweiler, Michelle

    2009-02-01

    After mechanical wounding, callus tissue and tangential rows of traumatic resin ducts (TRDs) are formed in many conifer species. This reaction can be used to date past events of geomorphic processes such as rockfall, debris flow and snow avalanches. However, only few points are known about the tangential spread or the timing of callus tissue and TRD formation after wounding. We analyzed 19 Larix decidua Mill. (European larch) and eight Picea abies (L.) Karst. (Norway spruce) trees that were severely damaged by rockfall activity, resulting in a total of 111 injuries. Callus tissue appeared sparsely on the cross sections and was detected on only 4.2% of the L. decidua samples and 3.6% of the P. abies samples. In contrast, TRDs were present on all cross sections following wounding and were visible on more than one-third (34% in L. decidua and 36.4% in P. abies) of the circumference where the cambium was not destroyed by the rockfall impact. We observe different reactions in the trees depending on the seasonal timing of wounding. The tangential spread of callus tissue and TRDs was more important if the injury occurred during the growth period than during the dormant season, with the difference between seasons being more pronounced for callus tissue formation than for TRD formation. We observed an intra-annual radial migration of TRDs with increasing tangential distance from the wound in 73.2% of the L. decidua samples and 96.6% of the P. abies samples. The persistence of TRD formation in the years following wounding showed that only L. decidua trees produced TRDs 2 years after wounding (10.5%), whereas P. abies trees produced TRDs 5 years after wounding (> 50%).

  16. Pharmacognostical and phytochemical studies on roots of Bombax ceiba Linn.

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    Pankaj H. Chaudhary

    2014-12-01

    Full Text Available Context: Bombax ceiba Linn. (Bombacaceae is a well-known plant for its antihypertensive, antioxidant, antidiabetic, aphrodisiac and uterine tonicity properties. Aims: To study pharmacognostical, physicochemical and phytochemically the roots of this plant. Methods: Pharmacognostical study included the macroscopic characters like size, color, surface characteristics, texture, fracture characteristics and odor of the roots. The intact root as well as powdered drug were studied under a microscope to analyze the cellular characteristics of the drug. Physicochemical parameter like extractive values, loss on drying (LOD, total ash, water-soluble and acid insoluble ash, foaming index and hemolytic index of Bombax ceiba root powder were determined as per WHO guidelines. Preliminary phytochemical screening and qualitative chemical examination studies have been carried out for the various phytoconstituents. HPTLC have also carried out using cyclohexane: diethyl ether: ethyl acetate as mobile phase. Results: Chemical evaluation and TLC studies shown presence of alkaloids, glycosides, flavonoids, steroids, saponins and tannins. The microscopic characters have shown presence of cork, cambium, xylem vessels, stone cells, starch grains, calcium oxalate crystals and phloem fibers. Microscopy analysis of the powder included the cork cells, fibers, calcium oxalate crystals and vessel. The presence of steroids was confirmed in HPTLC fingerprinting studies. Conclusions: Pharmacognostical and preliminary phytochemical screening of Bombax ceiba roots will be useful in order to authenticate, standardize and avoid any adulteration in the raw material. The diagnostic microscopic characters and physicochemical data will be helpful in the development of a monograph. The chromatographic fingerprinting profile can be used to standardize extracts and formulations containing Bombax ceiba roots.

  17. Plant physiology at the institute for philosophy in Brno in Mendel’s teacher F. Diebl textbook from 1835

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    Jiří Šebánek

    2012-01-01

    Full Text Available Gregor Mendel attended lectures of F. Diebl, professor of natural history and agricultural science at the Institute of Philosophy in Brno. Diebl published his lectures in a textbook “Abhandlungen über die allgemeine und besondere Naturgeschichte, Brünn 1835.” From the textbook the level of scientific knowledge in plant biology is obvious, with which the later founder of a new field of biology – genetics got acquainted. Diebl considered germination to be a specific method of fermentation transforming seed starch into a sugary matter which nourishes the germinating plant. In the physiology of nutrition he distinguished nutrition from the soil via roots from nutrition from the air via leaves. The former is based primarily on the humus theory of A. Thaer (1809 because not until 5 years after the publication of Diebl’s textbook J. Liebig initiated the mineral theory. Diebl’s presentation of photosynthesis was based on information available at that time about the release of oxygen by green plants under conditions of light and the uptake of CO2, but he had no knowledge about the passage of CO2 into the leaves through stomata. Remarkable is Diebl’s discovery that respiration increases during flowering. Electricity is considered to be a force significantly supporting the life processes of plants. Diebl also noticed the difference between diurnal and night evaporation of water from the leaves. In his textbook growth is connected with nutrition only, as it was the entire 19th century. Stem thickening from the cambium is described very simply. Bud and root regeneration is given the term reproduction which today is commonly used in relation to sexual reproduction. Diebl considered nyctinastic movements (bending or unbending of the leaves and closing of the flowers at night to be “sleep”. He described fertilisation in a primitive way, because it was not until 1848 that the first exact description came out.

  18. Resprouting from roots in four Brazilian tree species.

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    Hayashi, Adriana Hissae; Appezzato-da-Glória, Beatriz

    2009-09-01

    Previous studies pointed out that species richness and high density values within the Leguminosae in Brazilian forest fragments affected by fire could be due, at least partially, to the high incidence of root sprouting in this family. However, there are few studies of the factors that induce root sprouting in woody plants after disturbance. We investigated the bud formation on root cuttings, and considered a man-made disturbance that isolates the root from the shoot apical dominance of three Leguminosae (Bauhinia forficata Link., Centrolobium tomentosum Guill. ex Benth, and Inga laurina (Sw.) Willd) and one Rutaceae (Esenbeckia febrifuga (St. Hil.) Juss. ex Mart.). All these species resprout frequently after fire. We also attempted to induce bud formation on root systems by removing the main trunk, girdling or sectioning the shallow lateral roots from forest tree species Esenbeckia febrifuga and Hymenaea courbaril L. We identified the origin of shoot primordia and their early development by fixing the samples in Karnovsky solution, dehydrating in ethyl alcohol series and embedding in plastic resin. Serial sections were cut on a rotary microtome and stained with toluidine blue O. Permanent slides were mounted in synthetic resin. We observed different modes of bud origin on root cuttings: close to the vascular cambium (C. tomentosum), from the callus (B. forficata and E. febrifuga) and from the phloematic parenchyma proliferation (I. laurina). Fragments of B. forficata root bark were also capable of forming reparative buds from healing phellogen formed in callus in the bark's inner side. In the attempt of bud induction on root systems, Hymenaea courbaril did not respond to any of the induction tests, probably because of plant age. However, Esenbeckia febrifuga roots formed suckers when the main trunk was removed or their roots were sectioned and isolated from the original plant. We experimentally demonstrated the ability of four tree species to resprout from roots

  19. Engineering vascularized bone grafts by integrating a biomimetic periosteum and β-TCP scaffold.

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    Kang, Yunqing; Ren, Liling; Yang, Yunzhi

    2014-06-25

    Treatment of large bone defects using synthetic scaffolds remain a challenge mainly due to insufficient vascularization. This study is to engineer a vascularized bone graft by integrating a vascularized biomimetic cell-sheet-engineered periosteum (CSEP) and a biodegradable macroporous beta-tricalcium phosphate (β-TCP) scaffold. We first cultured human mesenchymal stem cells (hMSCs) to form cell sheet and human umbilical vascular endothelial cells (HUVECs) were then seeded on the undifferentiated hMSCs sheet to form vascularized cell sheet for mimicking the fibrous layer of native periosteum. A mineralized hMSCs sheet was cultured to mimic the cambium layer of native periosteum. This mineralized hMSCs sheet was first wrapped onto a cylindrical β-TCP scaffold followed by wrapping the vascularized HUVEC/hMSC sheet, thus generating a biomimetic CSEP on the β-TCP scaffold. A nonperiosteum structural cell sheets-covered β-TCP and plain β-TCP were used as controls. In vitro studies indicate that the undifferentiated hMSCs sheet facilitated HUVECs to form rich capillary-like networks. In vivo studies indicate that the biomimetic CSEP enhanced angiogenesis and functional anastomosis between the in vitro preformed human capillary networks and the mouse host vasculature. MicroCT analysis and osteocalcin staining show that the biomimetic CSEP/β-TCP graft formed more bone matrix compared to the other groups. These results suggest that the CSEP that mimics the cellular components and spatial configuration of periosteum plays a critical role in vascularization and osteogenesis. Our studies suggest that a biomimetic periosteum-covered β-TCP graft is a promising approach for bone regeneration.

  20. Stereo and scanning electron microscopy of in-shell Brazil nut (Bertholletia excelsa H.B.K.): part two-surface sound nut fungi spoilage susceptibility.

    Science.gov (United States)

    Scussel, Vildes M; Manfio, Daniel; Savi, Geovana D; Moecke, Elisa H S

    2014-11-01

    This work reports the in-shell Brazil nut spoilage susceptible morpho-histological characteristics and fungi infection (shell, edible part, and brown skin) through stereo and scanning electron microscopies (SEM). The following characteristics related to shell (a) morphology-that allow fungi and insects' entrance to inner nut, and (b) histology-that allow humidity absorption, improving environment conditions for living organisms development, were identified. (a.1) locule in testae-the nut navel, which is a cavity formed during nut detaching from pods (located at 1.0 to 2.0/4th of the shell B&C nut faces linkage). It allows the nut brown skin (between shell and edible part) first contact to the external environment, through the (a.2) nut channel-the locule prolongation path, which has the water/nutrients cambium function for their transport and distribution to the inner seed (while still on the tree/pod). Both, locule followed by the channel, are the main natural entrance of living organisms (fungi and insects), including moisture to the inner seed structures. In addition, the (a.3) nut shell surface-which has a crinkled and uneven surface morphology-allows water absorption, thus adding to the deterioration processes too. The main shell histological characteristic, which also allows water absorption (thus improving environment conditions for fungi proliferation), is the (b.1) cell wall porosity-the multilayered wall and porous rich cells that compose the shell faces double tissue layers and the (b.2) soft tissue-the mix of tissues 2 faces corner/linkage. This work also shows in details the SEM nut spoilage susceptible features highly fungi infected with hyphae and reproductive structures distribution. © 2014 Institute of Food Technologists®

  1. Spatio-temporal relief from hypoxia and production of reactive oxygen species during bud burst in grapevine (Vitis vinifera).

    Science.gov (United States)

    Meitha, Karlia; Konnerup, Dennis; Colmer, Timothy D; Considine, John A; Foyer, Christine H; Considine, Michael J

    2015-09-01

    Plants regulate cellular oxygen partial pressures (pO2), together with reduction/oxidation (redox) state in order to manage rapid developmental transitions such as bud burst after a period of quiescence. However, our understanding of pO2 regulation in complex meristematic organs such as buds is incomplete and, in particular, lacks spatial resolution. The gradients in pO2 from the outer scales to the primary meristem complex were measured in grapevine (Vitis vinifera) buds, together with respiratory CO2 production rates and the accumulation of superoxide and hydrogen peroxide, from ecodormancy through the first 72 h preceding bud burst, triggered by the transition from low to ambient temperatures. Steep internal pO2 gradients were measured in dormant buds with values as low as 2·5 kPa found in the core of the bud prior to bud burst. Respiratory CO2 production rates increased soon after the transition from low to ambient temperatures and the bud tissues gradually became oxygenated in a patterned process. Within 3 h of the transition to ambient temperatures, superoxide accumulation was observed in the cambial meristem, co-localizing with lignified cellulose associated with pro-vascular tissues. Thereafter, superoxide accumulated in other areas subtending the apical meristem complex, in the absence of significant hydrogen peroxide accumulation, except in the cambial meristem. By 72 h, the internal pO2 gradient showed a biphasic profile, where the minimum pO2 was external to the core of the bud complex. Spatial and temporal control of the tissue oxygen environment occurs within quiescent buds, and the transition from quiescence to bud burst is accompanied by a regulated relaxation of the hypoxic state and accumulation of reactive oxygen species within the developing cambium and vascular tissues of the heterotrophic grapevine buds. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company.

  2. IMPACTS, PATTERNS, INFLUENCING FACTORS AND POLICIES OF FUELWOOD EXTRACTION IN WAY KAMBAS NATIONAL PARK, INDONESIA

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    Ari Rakatama

    2016-04-01

    Full Text Available Uncontrolled fuelwood extraction from conservation forest of Way Kambas National Park (WKNP could threaten the existing forest. This paper studies the way to tackle the forest degradation in WKNP, with less negative impacts to the local people. Study was conducted by analysing existing data and maps of WKNP in terms of forest degradation, forest inventories, current policies, survey on how fuelwood is extracted, observation on fuelwood gatherers, fuelwood demand, and identification of further policy options. Results show that the most significant factors influencing the fuelwood extraction activity in WKNP are land ownership, followed by the distance to forest area, income level, the number of household members and age of household head. In the field, the fuelwood utilization is allowed by WKNP Authority, although it is formally forbidden.It was stated that fuelwood extraction in the area should be less than 2.89 ton/ha/year to maintain its sustainability, based on the mean WNKP forest tree annual increment. The fact shows that fuelwood extraction in WKNP reduces of forest biomass stock (1.06 tons/ha/year and decreases species diversity index (from 3.05 to 2.45, species evenness index (from 1.06 to 0.91 and old-young tree ratio (from 1.29 to 1. Ecosystem quality reduction is mainly caused by destructive techniques in extracting fuelwood such as slashing, scratching cambium, and cutting trees. Therefore, recommended policy includes legalizing fuelwood extraction with restrictions, providing alternative fuelwood and other biomass energy resources outside WKNP, conducting preventive (establishing checkpoints and increasing patrols and pre-emptive (educating and campaigning efforts, collaborating with other stakeholders, and empowering local economy.

  3. Cell longevity and sustained primary growth in palm stems.

    Science.gov (United States)

    Tomlinson, P Barry; Huggett, Brett A

    2012-12-01

    Longevity, or organismal life span, is determined largely by the period over which constituent cells can function metabolically. Plants, with modular organization (the ability continually to develop new organs and tissues) differ from animals, with unitary organization (a fixed body plan), and this difference is reflected in their respective life spans, potentially much longer in plants than animals. We draw attention to the observation that palm trees, as a group of monocotyledons without secondary growth comparable to that of lignophytes (plants with secondary growth from a bifacial cambium), retain by means of sustained primary growth living cells in their trunks throughout their organismal life span. Does this make palms the longest-lived trees because they can grow as individuals for several centuries? No conventional lignophyte retains living metabolically active differentiated cell types in its trunk for this length of time, even though the tree as a whole can exist for millennia. Does this contrast also imply that the long-lived cells in a palm trunk have exceptional properties, which allows this seeming immortality? We document the long-life of many tall palm species and their inherent long-lived stem cell properties, comparing such plants to conventional trees. We provide a summary of aspects of cell age and life span in animals and plants. Cell replacement is a feature of animal function, whereas conventional trees rely on active growth centers (meristems) to sustain organismal development. However, the long persistence of living cells in palm trunks is seen not as evidence for unique metabolic processes that sustain longevity, but is a consequence of unique constructional features. This conclusion suggests that the life span of plant cells is not necessarily genetically determined.

  4. How does climate influence xylem morphogenesis over the growing season? Insights from long-term intra-ring anatomy in Picea abies.

    Science.gov (United States)

    Castagneri, Daniele; Fonti, Patrick; von Arx, Georg; Carrer, Marco

    2017-04-01

    During the growing season, the cambium of conifer trees produces successive rows of xylem cells, the tracheids, that sequentially pass through the phases of enlargement and secondary wall thickening before dying and becoming functional. Climate variability can strongly influence the kinetics of morphogenetic processes, eventually affecting tracheid shape and size. This study investigates xylem anatomical structure in the stem of Picea abies to retrospectively infer how, in the long term, climate affects the processes of cell enlargement and wall thickening. Tracheid anatomical traits related to the phases of enlargement (diameter) and wall thickening (wall thickness) were innovatively inspected at the intra-ring level on 87-year-long tree-ring series in Picea abies trees along a 900 m elevation gradient in the Italian Alps. Anatomical traits in ten successive tree-ring sectors were related to daily temperature and precipitation data using running correlations. Close to the altitudinal tree limit, low early-summer temperature negatively affected cell enlargement. At lower elevation, water availability in early summer was positively related to cell diameter. The timing of these relationships shifted forward by about 20 (high elevation) to 40 (low elevation) d from the first to the last tracheids in the ring. Cell wall thickening was affected by climate in a different period in the season. In particular, wall thickness of late-formed tracheids was strongly positively related to August-September temperature at high elevation. Morphogenesis of tracheids sequentially formed in the growing season is influenced by climate conditions in successive periods. The distinct climate impacts on cell enlargement and wall thickening indicate that different morphogenetic mechanisms are responsible for different tracheid traits. Our approach of long-term and high-resolution analysis of xylem anatomy can support and extend short-term xylogenesis observations, and increase our

  5. Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

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    Jorge Reyes-Rivera

    Full Text Available In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35% of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.

  6. Seasonal Variation of Carbon Metabolism in the Cambial Zone of Eucalyptus grandis.

    Science.gov (United States)

    Budzinski, Ilara G F; Moon, David H; Lindén, Pernilla; Moritz, Thomas; Labate, Carlos A

    2016-01-01

    Eucalyptus species are the most widely hardwood planted in the world. It is one of the successful examples of commercial forestry plantation in Brazil and other tropical and subtropical countries. The tree is valued for its rapid growth, adaptability and wood quality. Wood formation is the result of cumulative annual activity of the vascular cambium. This cambial activity is generally related to the alternation of cold and warm, and/or dry and rainy seasons. Efforts have focused on analysis of cambial zone in response to seasonal variations in trees from temperate zones. However, little is known about the molecular changes triggered by seasonal variations in trees from tropical countries. In this work we attempted to establish a global view of seasonal alterations in the cambial zone of Eucalyptus grandis Hill ex Maiden, emphasizing changes occurring in the carbon metabolism. Using transcripts, proteomics and metabolomics we analyzed the tissues harvested in summer-wet and winter-dry seasons. Based on proteomics analysis, 70 proteins that changed in abundance were successfully identified. Transcripts for some of these proteins were analyzed and similar expression patterns were observed. We identified 19 metabolites differentially abundant. Our results suggest a differential reconfiguration of carbon partioning in E. grandis cambial zone. During summer, pyruvate is primarily metabolized via ethanolic fermentation, possibly to regenerate NAD(+) for glycolytic ATP production and cellular maintenance. However, in winter there seems to be a metabolic change and we found that some sugars were highly abundant. Our results revealed a dynamic change in E. grandis cambial zone due to seasonality and highlight the importance of glycolysis and ethanolic fermentation for energy generation and maintenance in Eucalyptus, a fast growing tree.

  7. Accumulation of plant small heat-stress proteins in storage organs.

    Science.gov (United States)

    Lubaretz, Olga; Zur Nieden, Uta

    2002-06-01

    Plant small heat-stress proteins (sHSPs) have been shown to be expressed not only after exposure to elevated temperatures, but also at particular developmental stages such as embryogenesis, microsporogenesis, and fruit maturation. This paper presents new data on the occurrence of sHSPs in vegetative tissues, their tissue-specific distribution, and cellular localization. We have found sHSPs in 1-year-old twigs of Acer platanoides L. and Sambucus nigra L. and in the liana Aristolochia macrophylla Lamk. exclusively in the winter months. In tendrils of Aristolochia, sHSPs were localized in vascular cambium cells. After budding, in spring, these proteins were no longer present. Furthermore, accumulation of sHSPs was demonstrated in tubers and bulbs of Allium cepa L., Amaryllis ( Hippeastrum hybridum hort.), Crocus albiflorus L., Hyacinthus orientalis L., Narcissus pseudonarcissus L., Tulipa gesneriana L., and Solanum tuberosum L. (potato). In potato tubers and bulb scales of Narcissus the stress proteins were localized in the central vacuoles of storage parenchyma cells. In order to obtain more information on a possible functional correlation between storage proteins and sHSPs, the accumulation of both types of protein in tobacco seeds during seed ripening and germination was monitored. The expression of sHSPs and globulins started simultaneously at about the 17th day after anthesis. During seed germination the sHSPs disappeared in parallel with the storage proteins. Furthermore, in embryos of transgenic tobacco plants, which do not contain any protein bodies or storage proteins, no sHSPs were found. Thus, the occurrence of sHSPs in perennial plant storage organs seems to be associated with the presence of storage proteins.

  8. Missing Rings in Pinus halepensis – The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events

    Science.gov (United States)

    Novak, Klemen; de Luis, Martin; Saz, Miguel A.; Longares, Luis A.; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B. K.; Papadopoulos, Andreas; Smith, Kevin T.

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  9. Missing Rings in Pinus halepensis - The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events.

    Science.gov (United States)

    Novak, Klemen; de Luis, Martin; Saz, Miguel A; Longares, Luis A; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B K; Papadopoulos, Andreas; Smith, Kevin T

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  10. Hypoxia and hypercarbia in endophagous insects: Larval position in the plant gas exchange network is key.

    Science.gov (United States)

    Pincebourde, Sylvain; Casas, Jérôme

    2016-01-01

    Gas composition is an important component of any micro-environment. Insects, as the vast majority of living organisms, depend on O2 and CO2 concentrations in the air they breathe. Low O2 (hypoxia), and high CO2 (hypercarbia) levels can have a dramatic effect. For phytophagous insects that live within plant tissues (endophagous lifestyle), gas is exchanged between ambient air and the atmosphere within the insect habitat. The insect larva contributes to the modification of this environment by expiring CO2. Yet, knowledge on the gas exchange network in endophagous insects remains sparse. Our study identified mechanisms that modulate gas composition in the habitat of endophagous insects. Our aim was to show that the mere position of the insect larva within plant tissues could be used as a proxy for estimating risk of occurrence of hypoxia and hypercarbia, despite the widely diverse life history traits of these organisms. We developed a conceptual framework for a gas diffusion network determining gas composition in endophagous insect habitats. We applied this framework to mines, galls and insect tunnels (borers) by integrating the numerous obstacles along O2 and CO2 pathways. The nature and the direction of gas transfers depended on the physical structure of the insect habitat, the photosynthesis activity as well as stomatal behavior in plant tissues. We identified the insect larva position within the gas diffusion network as a predictor of risk exposure to hypoxia and hypercarbia. We ranked endophagous insect habitats in terms of risk of exposure to hypoxia and/or hypercarbia, from the more to the less risky as cambium mines>borer tunnels≫galls>bark mines>mines in aquatic plants>upper and lower surface mines. Furthermore, we showed that the photosynthetically active tissues likely assimilate larval CO2 produced. In addition, temperature of the microhabitat and atmospheric CO2 alter gas composition in the insect habitat. We predict that (i) hypoxia indirectly favors

  11. Transcriptional transitions in Nicotiana benthamiana leaves upon induction of oil synthesis by WRINKLED1 homologs from diverse species and tissues.

    Science.gov (United States)

    Grimberg, Åsa; Carlsson, Anders S; Marttila, Salla; Bhalerao, Rishikesh; Hofvander, Per

    2015-08-08

    Carbon accumulation and remobilization are essential mechanisms in plants to ensure energy transfer between plant tissues with different functions or metabolic needs and to support new generations. Knowledge about the regulation of carbon allocation into oil (triacylglycerol) in plant storage tissue can be of great economic and environmental importance for developing new high-yielding oil crops. Here, the effect on global gene expression as well as on physiological changes in leaves transiently expressing five homologs of the transcription factor WRINKLED1 (WRI1) originating from diverse species and tissues; Arabidopsis thaliana and potato (Solanum tuberosum) seed embryo, poplar (Populus trichocarpa) stem cambium, oat (Avena sativa) grain endosperm, and nutsedge (Cyperus esculentus) tuber parenchyma, were studied by agroinfiltration in Nicotiana benthamiana. All WRI1 homologs induced oil accumulation when expressed in leaf tissue. Transcriptome sequencing revealed that all homologs induced the same general patterns with a drastic shift in gene expression profiles of leaves from that of a typical source tissue to a source-limited sink-like tissue: Transcripts encoding enzymes for plastid uptake and metabolism of phosphoenolpyruvate, fatty acid and oil biosynthesis were up-regulated, as were also transcripts encoding starch degradation. Transcripts encoding enzymes in photosynthesis and starch synthesis were instead down-regulated. Moreover, transcripts representing fatty acid degradation were up-regulated indicating that fatty acids might be degraded to feed the increased need to channel carbons into fatty acid synthesis creating a futile cycle. RT-qPCR analysis of leaves expressing Arabidopsis WRI1 showed the temporal trends of transcripts selected as 'markers' for key metabolic pathways one to five days after agroinfiltration. Chlorophyll fluorescence measurements of leaves expressing Arabidopsis WRI1 showed a significant decrease in photosynthesis, even though

  12. Silver birch (Betula pendula) plants with aux and rol genes show consistent changes in morphology, xylem structure and chemistry.

    Science.gov (United States)

    Piispanen, Riikka; Aronen, Tuija; Chen, Xiwen; Saranpää, Pekka; Häggman, Hely

    2003-08-01

    The effects of Agrobacterium pRiA4 rol and aux genes, controlled by their endogenous promoters, on tree growth and wood anatomy and chemistry were studied in 5- and 7-year-old silver birch (Betula pendula Roth) plants. Southern hybridization confirmed the following rol and aux gene combinations: control plants (no genes transferred); plants with rolC and rolD genes; plants with rolA, rolB, rolC and rolD genes; and plants with rolA, rolB, rolC, rolD, aux1 and aux2 genes. Transgene mRNA was most abundant in phloem/cambium samples and in the developing xylem, whereas no expression was detected in leaves. Plants with rolC and rolD genes or with all the rol genes were significantly shorter and had smaller leaves and a more bushy growth habit than control plants or plants with both aux and rol genes. Morphological observations and wood chemistry analyses revealed that plants with rol genes produced less xylem and broke bud later than control plants or plants with both aux and rol genes. Tension wood was detected in both control and transgenic plants irrespective of their gene combination, probably as a result of greenhouse cultivation. Xylem fibers were shorter in transgenic plants than in control plants, and plants with all the rol genes were characterized by shorter vessels compared with the control plants and a smaller proportional area of vessels compared with the other groups. In addition, silver birch plants with all the rol genes had approximately a 3.3% lower concentration of total acid soluble carbohydrates than control plants. We conclude that the rolC and rolD genes induced the typical "rol-phenotype," and that this was emphasized by concomitant expression of the rolA and rolB genes and alleviated by the presence of aux1 and aux2 genes. We observed consistent phenotypic effects of rol and aux genes on the morphology, anatomy and cell wall chemistry of the plants.

  13. Gene family structure, expression and functional analysis of HD-Zip III genes in angiosperm and gymnosperm forest trees.

    Science.gov (United States)

    Côté, Caroline L; Boileau, Francis; Roy, Vicky; Ouellet, Mario; Levasseur, Caroline; Morency, Marie-Josée; Cooke, Janice E K; Séguin, Armand; MacKay, John J

    2010-12-11

    Class III Homeodomain Leucine Zipper (HD-Zip III) proteins have been implicated in the regulation of cambium identity, as well as primary and secondary vascular differentiation and patterning in herbaceous plants. They have been proposed to regulate wood formation but relatively little evidence is available to validate such a role. We characterised and compared HD-Zip III gene family in an angiosperm tree, Populus spp. (poplar), and the gymnosperm Picea glauca (white spruce), representing two highly evolutionarily divergent groups. Full-length cDNA sequences were isolated from poplar and white spruce. Phylogenetic reconstruction indicated that some of the gymnosperm sequences were derived from lineages that diverged earlier than angiosperm sequences, and seem to have been lost in angiosperm lineages. Transcript accumulation profiles were assessed by RT-qPCR on tissue panels from both species and in poplar trees in response to an inhibitor of polar auxin transport. The overall transcript profiles HD-Zip III complexes in white spruce and poplar exhibited substantial differences, reflecting their evolutionary history. Furthermore, two poplar sequences homologous to HD-Zip III genes involved in xylem development in Arabidopsis and Zinnia were over-expressed in poplar plants. PtaHB1 over-expression produced noticeable effects on petiole and primary shoot fibre development, suggesting that PtaHB1 is involved in primary xylem development. We also obtained evidence indicating that expression of PtaHB1 affected the transcriptome by altering the accumulation of 48 distinct transcripts, many of which are predicted to be involved in growth and cell wall synthesis. Most of them were down-regulated, as was the case for several of the poplar HD-Zip III sequences. No visible physiological effect of over-expression was observed on PtaHB7 transgenic trees, suggesting that PtaHB1 and PtaHB7 likely have distinct roles in tree development, which is in agreement with the functions that

  14. Gene family structure, expression and functional analysis of HD-Zip III genes in angiosperm and gymnosperm forest trees

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    Cooke Janice EK

    2010-12-01

    Full Text Available Abstract Background Class III Homeodomain Leucine Zipper (HD-Zip III proteins have been implicated in the regulation of cambium identity, as well as primary and secondary vascular differentiation and patterning in herbaceous plants. They have been proposed to regulate wood formation but relatively little evidence is available to validate such a role. We characterised and compared HD-Zip III gene family in an angiosperm tree, Populus spp. (poplar, and the gymnosperm Picea glauca (white spruce, representing two highly evolutionarily divergent groups. Results Full-length cDNA sequences were isolated from poplar and white spruce. Phylogenetic reconstruction indicated that some of the gymnosperm sequences were derived from lineages that diverged earlier than angiosperm sequences, and seem to have been lost in angiosperm lineages. Transcript accumulation profiles were assessed by RT-qPCR on tissue panels from both species and in poplar trees in response to an inhibitor of polar auxin transport. The overall transcript profiles HD-Zip III complexes in white spruce and poplar exhibited substantial differences, reflecting their evolutionary history. Furthermore, two poplar sequences homologous to HD-Zip III genes involved in xylem development in Arabidopsis and Zinnia were over-expressed in poplar plants. PtaHB1 over-expression produced noticeable effects on petiole and primary shoot fibre development, suggesting that PtaHB1 is involved in primary xylem development. We also obtained evidence indicating that expression of PtaHB1 affected the transcriptome by altering the accumulation of 48 distinct transcripts, many of which are predicted to be involved in growth and cell wall synthesis. Most of them were down-regulated, as was the case for several of the poplar HD-Zip III sequences. No visible physiological effect of over-expression was observed on PtaHB7 transgenic trees, suggesting that PtaHB1 and PtaHB7 likely have distinct roles in tree development

  15. Missing rings in Pinus halepensis – the missing link to relate the tree-ring record to extreme climatic events

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    Klemen eNovak

    2016-05-01

    Full Text Available Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE. These conditions are associated with decreased growth of trees and their increased vulnerability to pests and diseases. The anatomy of tree rings is responsive to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, cambial cell division may occur throughout almost the entire year. Alternatively, cell division may stop during relatively cool and dry winters, only to resume in the same year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR, which can link tree-ring anatomy to the occurrence of extreme events. A dendrochronological network of Pinus halepensis, a widespread tree species in the Mediterranean basin, was used to determine the relationship of MR to ECE. The network consisted of 113 sites throughout its distribution range. Binomial logistic regression analysis of 2595 MR series determined that MR increased in frequency with increased cambial age. Spatial analysis indicated that the geographic areas of southeastern Spain and northern Algeria contained the greatest frequency of MR. Further regression analysis indicated that the relationship of MR to total monthly precipitation and mean temperature was non-linear. In this first determination of climatic influences on MR, the formation of MR was most strongly associated with the combination of monthly mean temperature above 10°C from previous October till current February and total precipitation below 50 mm from previous September till current May. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a

  16. Sintomatologia da murcha de Ceratocystis fimbriata em eucalipto Symptomatology of Ceratocystis wilt in eucalyptus

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    Francisco Alves Ferreira

    2006-04-01

    Full Text Available Descreveram-se o histórico da murcha de Ceratocystis fimbriata em eucalipto no Brasil e em outros países e a sintomatologia da doença, em plantações clonais com 4 meses a 5 anos de idade, em brotações de tocos, em estacas em enraizamento e em mudas clonais em viveiro, de quatro estados brasileiros. O patógeno evoluía-se da extremidade da raiz, atingindo o colo e tronco acima via parênquima medular, de onde, em diversas alturas, surgiam estrias escuras, que progrediam, via parênquima radial, matando uma porção de câmbio vascular, de floema e de feloderme. Dessa progressão sistêmica do patógeno, ascendente e radialmente, resultava uma lesão longitudinal externamente no tronco, contínua ou descontínua, marrom-avermelhada, coriácea, que passava a sulcada e, posteriormente, a cancro longitudinal, com seus calos longilíneos nas duas laterais. Por esse contexto sintomatológico, pode-se considerar essa enfermidade como um modelo de doença sistêmica em essência florestal, pelo menos na subárea da patologia florestal brasileira. Em brotações novas, em estacas em enraizamento e em mudas clonais as lesões eram longitudinais, contínuas ou descontínuas, negras a arroxeadas. A inativação de xilema em raízes, colo e em diferentes alturas do tronco, ou galho, dava-se pelo adensamento das estrias radiais escuras no lenho.The symptomatology of Ceratocystis fimbriata wilt in eucalyptus was described based on observations of 4-month to 5-year-old clonal plantations, in stump sprouts, rooting cuttings, and rooted seedlings in nurseries. The disease was characterized as a model of systemic disease in woody plants, which starts in roots and progresses upward to the collar and trunk through the medullar parenchyma, where dark stripes irradiate and lead a portion of the vascular cambium, phloem and phelloderm to death. As the pathogen spread upward and radially, a longitudinal reddish-brown, continuous or non-continuous corky lesion

  17. Apical control of xylem formation in the pine stem. I. Auxin effects and distribution of assimilates

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    Tomasz J. Wodzicki

    2014-01-01

    spring and reducing it later in the summer. Prevention of the contact with roots via phloem and cambium in spring (by ring-barking the stem at tree base decreased decapitation-induced downward transport of assimilates. Application of auxin to the decapitated uppermost segment of the main stem resulted in a significant increase of assimilate translocation into the stem. At least two mechanisms of auxin involvement in regulation of the rate of secondary wall deposition in pine stem tracheids can be considered: (a induction (or activation of the cell wall metabolic potential which seems to occur during meristematic or early radial enlargement phases of tracheid differentiation, and (b regulation of substrate availability during the phase of tracheid maturation.

  18. Ontogênese de caneluras em pedúnculo de flores de laranjeira doce infectados pelo vírus da tristeza dos citros estirpe "Capão Bonito"

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    Francisco André Ossamu Tanaka

    2009-12-01

    interrupted by the invading abnormal phloem proliferation, which produces undifferentiated cells with thin cell wall. The irregular activity of the vascular cambium continues followed by the complete degeneration of the xylem complemented by the appearance of dense phenolic deposits. Finally, there is the complete collapse of the xylem in the invaded region, and the corresponding space is occupied by the phloem mass which correspond to the stem pitting.

  19. Analysis of 4,664 high-quality sequence-finished poplar full-length cDNA clones and their utility for the discovery of genes responding to insect feeding

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    Douglas Carl J

    2008-01-01

    Full Text Available Abstract Background The genus Populus includes poplars, aspens and cottonwoods, which will be collectively referred to as poplars hereafter unless otherwise specified. Poplars are the dominant tree species in many forest ecosystems in the Northern Hemisphere and are of substantial economic value in plantation forestry. Poplar has been established as a model system for genomics studies of growth, development, and adaptation of woody perennial plants including secondary xylem formation, dormancy, adaptation to local environments, and biotic interactions. Results As part of the poplar genome sequencing project and the development of genomic resources for poplar, we have generated a full-length (FL-cDNA collection using the biotinylated CAP trapper method. We constructed four FLcDNA libraries using RNA from xylem, phloem and cambium, and green shoot tips and leaves from the P. trichocarpa Nisqually-1 genotype, as well as insect-attacked leaves of the P. trichocarpa × P. deltoides hybrid. Following careful selection of candidate cDNA clones, we used a combined strategy of paired end reads and primer walking to generate a set of 4,664 high-accuracy, sequence-verified FLcDNAs, which clustered into 3,990 putative unique genes. Mapping FLcDNAs to the poplar genome sequence combined with BLAST comparisons to previously predicted protein coding sequences in the poplar genome identified 39 FLcDNAs that likely localize to gaps in the current genome sequence assembly. Another 173 FLcDNAs mapped to the genome sequence but were not included among the previously predicted genes in the poplar genome. Comparative sequence analysis against Arabidopsis thaliana and other species in the non-redundant database of GenBank revealed that 11.5% of the poplar FLcDNAs display no significant sequence similarity to other plant proteins. By mapping the poplar FLcDNAs against transcriptome data previously obtained with a 15.5 K cDNA microarray, we identified 153 FLcDNA clones

  20. Anatomia e desenvolvimento ontogenético de Coffea arabica L. var. typica Cramer Anatomy and ontogenetical development of Coffea arabica L. var. typica Cramer

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    D. M. Dedecca

    1957-01-01

    secondary growth, formed from a vascular cambium which makes its first appearance in a region localized approximately 5 cm from the root apex. Phellogen arises first in the pericycle and later in phloem and gives origin to a relatively thin periderm; this protective layer replaces the epidermis that is gradually killed and sloughs away. Lateral roots originate from pericyclic cells situated at the protoxylem outer edges. The origin of all stem tissues, as well as those of the leaves, can be traced back to a dome-shaped shoot apex, which measure 220-360 microns in diameter and 48-120 microns in its major height; this shoot apex interpreted under the terms of Schmidt's theory shows to possess a tunica composed of two or three cell layers, and a corpus, represented by a central core of irregularly arranged cells. Differentiation of meristematic tissue initiates at the distance of 800-900 microns from the shoot apex, but the complete primary tissue differentiation is only achieved in a region situated 2.5 cm from the shoot apex. Stem cross sections at this level exhibit the following tissue zones: epidermis, angular collenchyma, cortical parenchyma, pericycle, primary phloem, primary xylem and pith. No distinct endodermis is visible. The vascular cambium, firstly visible in a region distant 2.5 cm from the shoot apex, originates from procambial cells localized between the xylem and phloem, being at the beginning only fascicular; the cells of the primary rays undergo cambiform meristematic activity, and interfascicular cambium is thereby formed between the vascular bundles. Following a centripetal differentiation the cambial derivatives give rise to a continuous band of secondary xylem and secondary phloem. Older stem cross sections present a periderm which is about 70 microns thick. Cork cambium arises from the innermost cells of cortex and produces cork externally and phelloderm internally. Petiole presents a tricyclic structure, exhibiting three vascular bundles, the major

  1. Enraizamento de estacas de Ginkgo biloba tratadas com ácido indolbutírico e ácido bórico Rooting of Ginkgo biloba cuttings treated with indolbutyric and boric acids

    Directory of Open Access Journals (Sweden)

    Janice Valmorbida

    2008-04-01

    Full Text Available Objetivou-se neste trabalho estudar o efeito do ácido indolbutírico (AIB e do ácido bórico (B no enraizamento de estacas de Ginkgo biloba. Em estacas com duas folhas, medindo 15 cm de comprimento foram provocadas duas lesões na base de aproximadamente 2 cm, expondo o câmbio e procedeu-se à imersão por 10 segundos no tratamento correspondente, AIB (0, 1000, 2000 e 3000 mg L-1 na ausência ou presença de B (0 e 150 mg L-1. Em seguida foram colocadas para enraizar em bandejas de polipropileno contendo areia lavada. O delineamento foi em blocos casualizados num fatorial 4X2, com seis repetições. Foram avaliadas porcentagem de estacas enraizadas, estacas não enraizadas e mortas, diâmetro e comprimento das raízes, aos 70 dias do tratamento. Os dados foram submetidos à análise de variância sendo previamente testados para normalidade pelo Teste de Shapiro-Wilk. As médias foram comparadas pelo Teste de Tukey. Os tratamentos com 2000 mg L-1 de AIB foram superiores à ausência de AIB (80,55% vs. 55,56%, respectivamente, não diferindo dos demais tratamentos. A utilização de B não afetou a taxa de enraizamento, de estacas não enraizadas e mortas, não havendo interação entre a concentração de AIB e a utilização ou não de B. O diâmetro e o comprimento das raízes não foram afetados pela utilização de AIB e B.The aim of the work was to study the effect of indolbutyric (IBA and boric (B acids to root Ginkgo biloba cuttings. At the base of cuttings, with two leaves and 15 cm of length, were made two lesions with 2 cm to expose the cambium. Cuttings were treated for a period of 10 seconds with four concentrations of IBA (0, 1000, 2000 and 3000 mg L-1 combined with two concentration of B (0 and 150 mg L-1. After that, cuttings were taken in polypropylene trays filled with washed sand. The experimental design was of randomized blocks in the factorial arrangement (4x2, with six replications. After 70 days, evaluations were done

  2. The role of phytochrome A and gibberellins in growth under long and short day conditions: Studies in hybrid aspen

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, M.E. [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Forest Genetics and Plant Physiology

    2000-07-01

    apical meristem and cambium, respectively. Also, these plants have altered wood properties showing more numerous (71 %) and longer (8%) fibres as compared to the control plants. GA levels were modulated by altering the expression of the multifunctional enzyme GA 20-oxidase. This enzyme was shown by the over-expression studies to be a limiting factor in the biosynthesis of GAs. This enzyme was also shown to be regulated at the transcriptional level, both by photoperiod and active GA{sub 4}. Our studies indicate that GA 20-oxidase is very likely to be one of the most important factors in the GA-regulation of growth and growth cessation. In conclusion, these studies have shed light on the early stages of growth cessation in deciduous trees, especially with respect to the role of phyA and GAs. It has also given new information on the importance of GAs in growth as such, with important implications for wood production.

  3. Analysis of 4,664 high-quality sequence-finished poplar full-length

    Energy Technology Data Exchange (ETDEWEB)

    Ralph, S. [University of British Columbia, Vancouver; Gunter, Lee E [ORNL; Tuskan, Gerald A [ORNL; Douglas, Carl [University of British Columbia, Vancouver; Holt, Robert A. [Genome Sciences Centre, Vancouver, BC, Canada; Jones, Steven [Genome Sciences Centre, Vancouver, BC, Canada; Marra, Marco [Genome Sciences Centre, Vancouver, BC, Canada; Bohlmann, J. [University of British Columbia, Vancouver

    2008-01-01

    The genus Populus includes poplars, aspens and cottonwoods, which will be collectively referred to as poplars hereafter unless otherwise specified. Poplars are the dominant tree species in many forest ecosystems in the Northern Hemisphere and are of substantial economic value in plantation forestry. Poplar has been established as a model system for genomics studies of growth, development, and adaptation of woody perennial plants including secondary xylem formation, dormancy, adaptation to local environments, and biotic interactions. As part of the poplar genome sequencing project and the development of genomic resources for poplar, we have generated a full-length (FL)-cDNA collection using the biotinylated CAP trapper method. We constructed four FLcDNA libraries using RNA from xylem, phloem and cambium, and green shoot tips and leaves from the P. trichocarpa Nisqually-1 genotype, as well as insect-attacked leaves of the P. trichocarpa x P. deltoides hybrid. Following careful selection of candidate cDNA clones, we used a combined strategy of paired end reads and primer walking to generate a set of 4,664 high-accuracy, sequence-verified FLcDNAs, which clustered into 3,990 putative unique genes. Mapping FLcDNAs to the poplar genome sequence combined with BLAST comparisons to previously predicted protein coding sequences in the poplar genome identified 39 FLcDNAs that likely localize to gaps in the current genome sequence assembly. Another 173 FLcDNAs mapped to the genome sequence but were not included among the previously predicted genes in the poplar genome. Comparative sequence analysis against Arabidopsis thaliana and other species in the non-redundant database of GenBank revealed that 11.5% of the poplar FLcDNAs display no significant sequence similarity to other plant proteins. By mapping the poplar FLcDNAs against transcriptome data previously obtained with a 15.5 K cDNA microarray, we identified 153 FLcDNA clones for genes that were differentially expressed in

  4. Anatomia do lenho de oito espécies de lianas da família Leguminosae ocorrentes na Floresta Atlântica Wood anatomy of eight liana species of Leguminosae family from Atlantic Rain Forest

    Directory of Open Access Journals (Sweden)

    Arno Fritz das Neves Brandes

    2008-06-01

    common features with the liana habit, as: wide vessels, vessel dimorphism, and high proportion of parenchyma when compared with fibers. Four species of Senegalia genus showed cambial variants made by a single cambium, normal in products but abnormal in conformation. The studied species have similar wood anatomy, many of which are because they belong to the same family and share the same habit. Nevertheless, the eight species studied could be distinguished. The species with cambial variants and Dalbergia frutescens are easy distinguished from the others. However Senegalia tenuifolia, Piptadenia micracantha and Piptadenia adiantoides require much wariness examination to identify the species exclusively by wood anatomical features.

  5. Enraizamento de estacas, crescimento e respostas anatômicas de mudas clonais de cacaueiro ao ácido indol-3-butírico Stem cutting rooting, growth and anatomical responses of cacao tree clonal changes to the indole-3-butyric acid

    Directory of Open Access Journals (Sweden)

    Alberto José dos Santos Júnior

    2008-12-01

    -53, PS-1319 and CA-1.4 were evaluated. The IBA was applied in the base of stem cuttings, as an inert talc, in mixture concentrations of 2, 4, 6 and 8 g kg-1 together with the control, without IBA. The evaluation of the growth of roots, stem and leaves of the four clones were accomplished by 160 days after the cutting (DAC for all the IBA concentrations. However, the anatomical studies of the several plant organs were also made to the 160 DAC, but only for the concentration of 4g kg-1 IBA and the control. The clone CA-1.4 presented increment in the root dry biomass (RDB with the increase of the IBA concentrations, while for the other clones there were decreases of RDB starting from the 4 g kg-1 IBA. The same fact was observed for the stem and leaf dry biomass, except for CCN-10 that did not answer to the increment of the concentrations of IBA. There was an increase of the total leaf area for the clones CP-53 e PS-1319 with the increment of the IBA (concentration up to 4 g kg-1, while the leaves number only increased for the clones CA-1.4 and CP-53, concentrations up to 8 and 4 g kg-1 IBA, respectively. There was a decrease in the number of dead cuttings for the clones CA-1.4 and CCN-10 (up 8 g kg-1 of IBA and for the CP-53 (up to 4 g kg-1 of IBA. The best IBA concentrations for the branch cutting rooting of the cacao clones CP-53, PS-1319 and CCN-10 were of 4, 4 and 6 g kg-1 respectively, while for the clone CA-1.4 was the one of 8 g kg-1; the increase of the IBA concentration promoted anatomical changes in the plant organs of all the clones, influencing the activity of the vascular cambium in the stem and inducing the formation of a larger number of adventitious roots in the stem cuttings.

  6. Estudo histológico sobre a formação de raízes adventícias em estacas caulinares de oliveira (Olea europaea L.: A histological evaluation Adventitious rooting in olive (Olea europaea L. cuttings

    Directory of Open Access Journals (Sweden)

    A. Peixe

    2007-01-01

    cultivares, por este método de propagação vegetativa.Even when stimulated by application of exogenous growth regulators, the ability for adventitious root formation in olive remains highly genotype dependent. When semi-hardwood cuttings are used as propagation material, it’s possible to find cultivars like ‘Cobrançosa’, where it is easy to achieve 70% of adventitious root formation, and cultivars like ‘Galega vulgar’, where 10% of rooting it is very difficult to exceed. Preliminary results of a comparative histological study between the above-mentioned Olea europaea cultivars, looking for differences, both in the stem anatomy and in tissues involved in adventitious root ontogenesis, are now presented. Concerning stem anatomy, the results achieved so far, allow to conclude that no significant differences were observed between the cultivars, both presenting a sclerenchymal ring, that may act as a mechanical barrier to the adventitious root development. The observations made of the ontogenically active regions, showed that in ‘Cobrançosa’ the new roots emerge in the vascular cambium or in the adjacent tissues, whereas in ‘Galega vulgar’ the parenchyma cells of the callus are the ones involved in the appearing of roots morphogenic fields. This significant difference observed between the kind of tissues that are involved in the process of cell des-differentiation and reacquisition of a primary meristematic condition, which is crucial to allow the formation of new root meristems, it’s probably correlated with the great differences observed in the rooting ability of semi-hardwood cutting of this olive cultivars.

  7. Estudio anatómico preliminar de raíz y brote del anón Amazónico (rollinia mucosa (jacq. Baill.

    Directory of Open Access Journals (Sweden)

    Quevedo Enrique

    1994-12-01

    ";,";serif";; font-size: 8.5pt;">y abundante parénquima de almacenamiento, proto y metaxilema, médula (poco común en las Dícotyledoneae y carece de parénquima cortical. El tallo posee tejidos protectores formados central, compuesto por floema (líber y xilema (leño y, entre estos tejidos, el cambium vascular. La hoja conformada por la cutícula cerosa, la epidermis adaxial con células secretoras y la epidermis adaxial con pelos glandulares, el mesofilo constituido por los parénquimas esponjoso y en empalizada y el sistema vascular, formado por las nervaduras, que están constituidas por haces fibrovasculares con floema y xilema rodeados de parénquima. La flor es completa, pues posee los cuatro verticilos con sus órganos dispuestos en espiral, los pétalos son carnosos, con una zona de tricomas y poseen tejido de almacenamiento. El fruto es un sincarpio.