ECCENTRIC GROWTH AND GROWTH STRESS IN INCLINED STEMS OF GNETUM GNEMON

Gnetum gnemon L. (Gnetales) forms hardwood-like secondary xylem in its trunks and branches although it is a gymnosperm. The present study tested the surface growth stress in relation to anatomical and chemical properties of the secondary xylem in inclined and vertical stems of G. gnemon using morphological and chemical composition analyses. Secondary growth was promoted on the upper half of the cross section in an inclined stem; at the same time, tensile growth stress increased on the upper side and decreased on the lower side of the inclined stem. However, formation of reaction wood fibers was not detected on either side. The microfibril angle was associated with differences in tensile growth stress. Thus, we conclude that negative gravitropism in G. gnemon is caused by a synergistic effect of increased tensile growth stress as well as the promotion of secondary growth on the upper side of the inclined stem. Our results are comparable to the negative gravitropism observed in the family Magnoliaceae, which does not form gelatinous fibers in its tension wood.

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Negative gravitropism of Ginkgo biloba: growth stress and reaction wood formation

Holzforschung ◽

10.1515/hf-2015-0005 ◽

2016 ◽

Vol 70 (3) ◽

pp. 267-274 ◽

Cited By ~ 6

Author(s):

Tatsuya Shirai ◽

Hiroyuki Yamamoto ◽

Miyuki Matsuo ◽

Mikuri Inatsugu ◽

Masato Yoshida ◽

...

Keyword(s):

Ginkgo Biloba ◽

Lignin Content ◽

Linear Regression Analysis ◽

Multiple Linear Regression Analysis ◽

Wood Formation ◽

Growth Stress ◽

Reaction Wood ◽

Cellulose Content ◽

S2 Layer ◽

Negative Gravitropism

Abstract Ginkgo (Ginkgo biloba L.) forms thick, lignified secondary xylem in the cylindrical stem as in Pinales (commonly called conifers), although it has more phylogenetic affinity to Cycadales than to conifers. Ginkgo forms compression wood-like (CW-like) reaction wood (RW) in its inclined stem as it is the case in conifers. However, the distribution of growth stress is not yet investigated in the RW of ginkgo, and thus this tissue resulting from negative gravitropism is still waiting for closer consideration. The present study intended to fill this gap. It has been demonstrated that, indeed, ginkgo forms RW tissue on the lower side of the inclined stem, where the compressive growth stress (CGS) was generated. In the RW, the micorofibril angle in the S2 layer, the air-dried density, and the lignin content increased, whereas the cellulose content decreased. These data are quite similar to those of conifer CWs. The multiple linear regression analysis revealed that the CGS is significantly correlated by the changes in the aforementioned parameters. It can be safely concluded that the negative gravitropism of ginkgo is very similar to that of conifers.

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Wood Anatomy of nine Japanese Hardwood species forming reaction wood without gelatinous fibers

IAWA Journal ◽

10.1163/22941932-90000016 ◽

2010 ◽

Vol 31 (2) ◽

pp. 191-202 ◽

Cited By ~ 8

Author(s):

R.S. Sultana ◽

F. Ishiguri ◽

S. Yokota ◽

K. Iizuka ◽

T. Hiraiwa ◽

...

Keyword(s):

Lignin Content ◽

Reaction Wood ◽

Wood Fibers ◽

Acetyl Bromide ◽

Euonymus Alatus ◽

Opposite Wood ◽

Gelatinous Fibers ◽

Hardwood Species ◽

Daphne Odora ◽

Clerodendron Trichotomum

The anatomy of reaction wood was studied in nine naturally growing Japanese hardwood species, all showing eccentric growth on the upper side of their leaning branches. The number of vessels decreased in the xylem of the upper side accompanying the formation of reaction wood. A typical G-layer was not detected in the reaction wood fibers, but an S3 layer was present in all nine species. The cellulose microfibril arrangement with an S helix was similar in the S3 layers of both reaction and opposite wood fibers. A decrease of lignin content occurred in the reaction wood fibers in all nine species. The coniferyl and sinapyl aldehyde units in the lignins were strongly reduced in the S2 layer of reaction wood fibers of four species, i.e., Euscaphis japonica, Rhododendron wadanum, Clerodendron trichotomum, and Daphne odora, and much less so in five other species, i.e., Viburnum dilatatum, Enkianthus subsessilis, Euonymus alatus, Ilex macropoda, and Ilex crenata. The syringyl content was lower in the S2 layer of reaction wood fibers than that in opposite wood of all nine species. On the other hand, chemical analysis of lignin using the acetyl bromide method showed that, among the nine species, lignin content was reduced most strongly in Clerodendron trichotomum. Tension wood-like characteristics are present on the upper side of leaning branches in all nine species, except that G-fibers are absent.

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GROWTH STRAINS AND RELATED WOOD STRUCTURES IN THE LEANING TRUNKS AND BRANCHES OF TROCHODENDRON ARALIOIDES - A VESSEL-LESS DICOTYLEDON

IAWA Journal ◽

10.1163/22941932-90001634 ◽

2007 ◽

Vol 28 (2) ◽

pp. 211-222 ◽

Cited By ~ 6

Author(s):

Ling-Long Kuo-Huang ◽

Shin-Shin Chen ◽

Yan-San Huang ◽

Shiang-Jiuun Chen ◽

Yi-In Hsieh

Keyword(s):

Microfibril Angle ◽

Wall Layer ◽

Growth Stress ◽

Lower Side ◽

Wood Structures ◽

Opposite Wood ◽

Gelatinous Fibers ◽

Percentage Area ◽

Gelatinous Fiber ◽

The Difference

Leaning trunks and branches of Trochodendron aralioides Sieb. & Zucc., a primitive vessel-less dicotyledon, show increased radial growth and gelatinous fibers on the upper side similar to the features found in dicotyledons with vessels. The patterns of peripheral longitudinal growth strain are variable among trees but similar at different heights within the same leaning trunk. Growth strains on the lower side of the trunks are very small but they are relatively large on the lower side of the branches. Growth stress in the branches is partly affected by the gravitational bending stress, which would be exerted mostly on the lower side. Large spring back strains of branches are associated with large surface strains. Both the microfibril angle (MFA) and the percentage area of gelatinous fiber show positive relationships with the measured strains. The MFA of the S2 wall layer in tracheids in the opposite wood is 24.6 ± 2.2°, whereas the MFA of gelatinous layer in the tension wood is only 14.2 ± 2.7°. The difference of MFA between the gelatinous fibers and the opposite wood is one of the factors accounting for the large contracting force for reorientation.

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Structure of the secondary xylem and development of a cambial variant in Serjania mexicana (Sapindaceae)

IAWA Journal ◽

10.1163/22941932-bja10075 ◽

2021 ◽

pp. 1-11

Author(s):

Kishore S. Rajput ◽

Amit D. Gondaliya ◽

Roger Moya

Keyword(s):

Secondary Xylem ◽

Secondary Growth ◽

Stem Anatomy ◽

The Family ◽

Ray Cells ◽

Cambial Variant ◽

Proportional Increase ◽

Plant Families ◽

Ray Parenchyma Cells ◽

Cambial Variants

Abstract The lianas in the family Sapindaceae are known for their unique secondary growth which differs from climbing species in other plant families in terms of their cambial variants. The present study deals with the stem anatomy of self-supporting and lianescent habit, development of phloem wedges, the ontogeny of cambial variants and structure of the secondary xylem in the stems of Serjania mexicana (L.) Willd. Thick stems (15–20 mm) were characterized by the presence of distinct phloem wedges and tangentially wide neo-formed cambial cylinders. As the stem diameter increases, there is a proportional increase in the number of phloem wedges and neo-formed vascular cylinders. The parenchymatous (pericyclic) cells external to phloem wedges that are located on the inner margin of the pericyclic fibres undergo dedifferentiation, become meristematic and form small segments of cambial cylinders. These cambia extend tangentially into wide and large segments of neoformations. Structurally, the secondary xylem and phloem of the neo-formed vascular cylinders remain similar to the derivatives produced by the regular vascular cambium. The secondary xylem is composed of vessels (wide and narrow), fibres, axial and ray parenchyma cells. The occurrence of perforated ray cells is a common feature in both regular and variant xylem.

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Reaction wood anatomy and lignin distribution in Gnetum gnemon branches

Journal of Wood Science ◽

10.1007/s10086-018-1772-2 ◽

2018 ◽

Vol 64 (6) ◽

pp. 872-879 ◽

Cited By ~ 1

Author(s):

Haruna Aiso-Sanada ◽

Futoshi Ishiguri ◽

Denny Irawati ◽

Imam Wahyudi ◽

Shinso Yokota

Keyword(s):

Wood Anatomy ◽

Reaction Wood ◽

Lignin Distribution ◽

Gnetum Gnemon

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ANATOMICAL CHARACTERIZATION OF TENSION WOOD IN Hevea brasiliensis (Willd. ex A. Juss.) Mull. Arg.

Revista Árvore ◽

10.1590/0100-67622016000600016 ◽

2016 ◽

Vol 40 (6) ◽

pp. 1099-1107

Author(s):

Letícia Maria Alves Ramos ◽

João Vicente de Figueiredo Latorraca ◽

Thayanne Caroline Castor Neto ◽

Letícia Souza Martins ◽

Elias Taylor Durgante Severo

Keyword(s):

Hevea Brasiliensis ◽

Fiber Length ◽

Tension Wood ◽

Rubber Tree ◽

Microfibril Angle ◽

Vessel Diameter ◽

Longitudinal Distribution ◽

Axial Parenchyma ◽

Gelatinous Fibers ◽

Gelatinous Fiber

ABSTRACT Tension wood is an important anatomical structure for its participation in the orientation of the trunk and the architecture of the branches as a function of structural reinforcement. However, its presence in large amounts significantly affects the technological properties of wood, just as in the rubber tree. Nevertheless, there is still demand for information about the origin, distribution and structural features in this species. Thus, this study aims to characterize the cellular structures in tension and opposite wood in Hevea brasiliensis (rubber tree), as well as its radial and longitudinal distribution. Discs at the base and the middle of the commercial logs were collected from three trees in a commercial plantation located in Tabapoã - SP. Tangential diameter of vessels, fiber length (gelatinous and non-gelatinous fibers), microfibril angle and proportionality of cellular elements (vessels, axial parenchyma, ray, gelatinous fibers and non-gelatinous fibers) were measured, and influence of gelatinous fiber presence in vessel diameter was observed. Gelatinous fibers were observed in the two types of wood and in the two trunk heights. Both types of wood were distinguished by gelatinous fiber length and the proportion of axial parenchyma. The tension wood in mid-trunk was the most different, with long gelatinous fibers and less abundant, larger vessel diameter and vessel proportion. Moreover, smaller vessel diameter was observed in the regions with a high proportion of gelatinous fibers, suggesting that the plant invests more support than in liquid transport.

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Microfibril angle, crystalline characteristics, and chemical compounds of reaction wood in stem wood of Pinus densiflora

Wood Science and Technology ◽

10.1007/s00226-019-01140-w ◽

2019 ◽

Vol 54 (1) ◽

pp. 123-137

Author(s):

Byantara Darsan Purusatama ◽

Jung Kee Choi ◽

Seung Hwan Lee ◽

Nam Hun Kim

Keyword(s):

Pinus Densiflora ◽

Microfibril Angle ◽

Chemical Compounds ◽

Reaction Wood ◽

Stem Wood

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REACTION TISSUES IN GNETUM GNEMON A PRELIMINARY REPORT

IAWA Journal ◽

10.1163/22941932-90000385 ◽

2001 ◽

Vol 22 (4) ◽

pp. 401-413 ◽

Cited By ~ 8

Author(s):

P. B. Tomlinson

Keyword(s):

Cell Walls ◽

Tension Wood ◽

Secondary Xylem ◽

Secondary Phloem ◽

Outer Cortex ◽

Cortical Cells ◽

Wood Fibres ◽

Developmental Feature ◽

Gnetum Gnemon ◽

Clear Differentiation

Gnetum gnemon exhibits Rouxʼs model of tree architecture, with clear differentiation of orthotropic from plagiotropic axes. All axes have similar anatomy and react to displacement in the same way. Secondary xylem of displaced stems shows little eccentricity of development and no reaction anatomy. In contrast, there is considerable eccentricity in extra-xylary tissue involving both primary and secondary production of apparent tension-wood fibres (gelatinous fibres) of three main kinds. Narrow primary fibres occur concentrically in all axes in the outer cortex as a normal developmental feature. In displaced axes gelatinous fibres are developed abundantly and eccentrically on the topographically upper side, from pre-existing and previously undetermined primary cortical cells. They are wide with lamellate cell walls. In addition narrow secondary phloem fibres are also differentiated abundantly and eccentrically on the upper side of displaced axes. These gelatinous fibres are narrow and without obviously lamellate cell walls. Eccentric gelatinous fibres thus occupy a position that suggests they have the function of tension wood fibres as found in angiosperms. This may be the first report in a gymnosperm of fibres with tension capability. Gnetum gne-mon thus exhibits reaction tissues of unique types, which are neither gymnospermous nor angiospermous. Reaction tissues seem important in maintaining the distinctive architecture of the tree.

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

Polish Botanical Journal ◽

10.1515/pbj-2016-0003 ◽

2016 ◽

Vol 61 (1) ◽

pp. 89-98 ◽

Cited By ~ 2

Author(s):

Kishore S. Rajput

Keyword(s):

Secondary Xylem ◽

Monsoon Season ◽

Secondary Growth ◽

Vascular Bundles ◽

Growth Rings ◽

Successive Cambia ◽

Initial Stage ◽

Ray Cells ◽

Cell Layers ◽

Ray Parenchyma Cells

Abstract 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.

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Branches versus stems in woody plants: control of branch diameter growth and angle

Canadian Journal of Botany ◽

10.1139/b98-156 ◽

1998 ◽

Vol 76 (11) ◽

pp. 1852-1856 ◽

Cited By ~ 1

Author(s):

Brayton F Wilson

Keyword(s):

Acer Rubrum ◽

Growth Stress ◽

Diameter Growth ◽

Reaction Wood ◽

Differential Growth ◽

Lateral Shoot ◽

Branch Diameter ◽

Growth Stresses ◽

Branch Angle ◽

Apical Control

The results of three studies at different stages of branch development demonstrated the importance of apical control of diameter growth in both stem formation and branch angle. Diameter growth is controlled by competition between branches and the stem for branch-produced photosynthate. Apical control of branch angle occurs only in species that can produce differential growth stresses. In those species, upward bending is largely regulated by the amount of branch diameter growth. The first study followed stem formation from current shoots in Kalmia latifolia L., a shrub without terminal buds or apical control of branch angle. When several current or older shoots were competing, the longest, most distal lateral shoot usually became the stem. Shoot angle was poorly correlated with eventual dominance. A more proximal lateral shoot on the underside of a leaning parent became the longest, dominant lateral in 24% of the parent shoots. The second study used stem girdles to test the hypothesis that the subjacent stem competes with the branch for branch-produced photosynthate. Results from Pinus strobus L. supported the hypothesis, but results from Betula lenta L. and Acer rubrum L. did not. The third study removed apical control from branches of six forest-shrub species by cutting off the stem above the branch. Branches of all species increased diameter growth after cutting the stem, but only branches of Ilex verticillata (L.) Gray, Hamamelis virginiana L., and Cornus amomum Mill. developed differential growth stress and bent upward. Treated branches of Gaylusaccia baccata (Wang.) K. Koch, Viburnum cassinoides L., and K. latifolia sagged as much as controls.Key words: apical control, diameter growth, branch angle, growth stress, reaction wood.

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