Tracheid Walls Research Articles

Transcriptome profiling of radiata pine branches reveals new insights into reaction wood formation with implications in plant gravitropism.

BackgroundFormation of compression (CW) and opposite wood (OW) in branches and bent trunks is an adaptive feature of conifer trees in response to various displacement forces, such as gravity, wind, snow and artificial bending. Several previous studies have characterized tracheids, wood and gene transcription in artificially or naturally bent conifer trunks. These studies have provided molecular basis of reaction wood formation in response to bending forces and gravity stimulus. However, little is known about reaction wood formation and gene transcription in conifer branches under gravity stress. In this study SilviScan® technology was used to characterize tracheid and wood traits in radiate pine (Pinus radiata D. Don) branches and genes differentially transcribed in CW and OW were investigated using cDNA microarrays.ResultsCW drastically differed from OW in tracheids and wood traits with increased growth, thicker tracheid walls, larger microfibril angle (MFA), higher density and lower stiffness. However, CW and OW tracheids had similar diameters in either radial or tangential direction. Thus, gravity stress largely influenced wood growth, secondary wall deposition, cellulose microfibril orientation and wood properties, but had little impact on primary wall expansion. Microarray gene transcription revealed about 29% of the xylem transcriptomes were significantly altered in CW and OW sampled in both spring and autumn, providing molecular evidence for the drastic variation in tracheid and wood traits. Genes involved in cell division, cellulose biosynthesis, lignin deposition, and microtubules were mostly up-regulated in CW, conferring its greater growth, thicker tracheid walls, higher density, larger MFA and lower stiffness. However, genes with roles in cell expansion and primary wall formation were differentially transcribed in CW and OW, respectively, implicating their similar diameters of tracheid walls and different tracheid lengths. Interestingly, many genes related to hormone and calcium signalling as well as various environmental stresses were exclusively up-regulated in CW, providing important clues for earlier molecular signatures of reaction wood formation under gravity stimulus.ConclusionsThe first comprehensive investigation of tracheid characteristics, wood properties and gene transcription in branches of a conifer species revealed more accurate and new insights into reaction wood formation in response to gravity stress. The identified differentially transcribed genes with diverse functions conferred or implicated drastic CW and OW variation observed in radiata pine branches. These genes are excellent candidates for further researches on the molecular mechanisms of reaction wood formation with a view to plant gravitropism.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-14-768) contains supplementary material, which is available to authorized users.

106年生カラマツ造林木における仮道管S<sub>2</sub>層ミクロフィブリル傾角の年輪内及び樹幹内半径方向変動

106年生カラマツ造林木における仮道管S<sub>2</sub>層ミクロフィブリル傾角の年輪内及び樹幹内半径方向変動

Immunolocalization of 8-5′ and 8-8′ linked structures of lignin in cell walls of Chamaecyparis obtusa using monoclonal antibodies

Mouse monoclonal antibodies were generated against dehydrodiconiferyl alcohol- or pinoresinol-p-aminohippuric acid (pAHA)-bovine serum albumin (BSA) conjugate as probes that specifically react with 8-5' or 8-8' linked structure of lignin in plant cell walls. Hybridoma clones were selected that produced antibodies that positively reacted with dehydrodiconiferyl alcohol- or pinoresinol-pAHA-BSA and negatively reacted with pAHA-BSA and guaiacylglycerol-beta-guaiacyl ether-pAHA-BSA conjugates containing 8-O-4' linkage. Eight clones were established for each antigen and one of each clone that positively reacted with wood sections was selected. The specificity of these antibodies was examined by competitive ELISA tests using various lignin dimers with different linkages. The anti-dehydrodiconiferyl alcohol antibody reacted specifically with dehydrodiconiferyl alcohol and did not react with other model compounds containing 8-O-4', 8-8', or 5-5' linkages. The anti-pinoresinol antibody reacted specifically with pinoresinol and syringaresinol and did not react with the other model compounds containing 8-O-4', 8-5', or 5-5' linkages. The antibodies also did not react with dehydrodiconiferyl alcohol acetate or pinoresinol acetate, indicating that the presence of free phenolic or aliphatic hydroxyl group was an important factor in their reactivity. In sections of Japanese cypress (Chamaecyparis obtusa), labeling by the anti-dehydrodiconiferyl alcohol antibody was found in the secondary walls of phloem fibers and in the compound middle lamellae, and secondary walls of tracheids. Weak labeling by the anti-pinoresinol antibody was found in secondary walls of phloem fibers and secondary walls and compound middle lamellae of developed tracheids. These labelings show the localization of 8-5' and 8-8' linked structure of lignin in the cell walls.

A Middle Devonian Callixylon (Archaeopteridales) from Ronquières, Belgium

A permineralized Callixylon trunk is reported from Ronquières, a mid to late Givetian (Middle Devonian) locality from Belgium. The specimen consists of an 80cm long trunk adpression whose central area is preserved as a pyrite permineralization. The pyritized area is composed of a eustele surrounded by secondary xylem. Tracheids show radially aligned groups of pits separated by unpitted regions on the radial walls of tracheids. The specimen belongs to a group of species characterized by a predominance of uniseriate rays and the lack of ray tracheids. This Callixylon specimen is one of the earliest representatives of the genus. It coexists at the locality with large cladoxylopsids and provides direct evidence that the tree habit had evolved in the archaeopteridalean progymnosperms by the Givetian.

Arthropod interactions with bennettitalean roots in a Triassic permineralized peat from Hopen, Svalbard Archipelago (Arctic)

Multiple thin-sections of a Late Triassic (Carnian) siliceous permineralized peat block likely derived from the De Geerdalen Formation on Hopen Island, Svalbard Archipelago, show a dense mass of roots preserving fine anatomical details of various stages of primary and secondary vascular tissue development. The presence of moderately defined rings with few latewood cells in the secondary xylem attests to growth in a seasonal environment. The presence of mucilage bodies and nests of sclerotic cells in the cortical tissues of the roots and pith of subaerial stem fragments, together with scalariform pitting on radial tracheid walls and 2–12 simple pits per cross-field favor bennettitalean affinities for the roots. Evidence of a rich fauna of detritivores inhabiting the peat profile is represented in the form of extensive damage to cortical tissues of dead roots and abundant coprolites preserved both within chambers excavated in the plant tissues and in the peat matrix. Less common gall-like structures within the roots indicate the presence of parasitic organisms in the palaeo-peat ecosystem.

Pontamine fast scarlet 4B: a new fluorescent dye for visualising cell wall organisation in radiata pine tracheids

Using confocal microscopy, tracheid wall organisation was investigated with pontamine fast scarlet 4B (P4B), a cellulose-specific stain that fluoresced red following green excitation. P4B fluorescence was present throughout unlignified walls (cambium, ray cells, resin canals and parenchyma cells) and in two concentric bands around opposite and compression wood tracheids. Scanning electron micrographs demonstrated these bands as the S1 and S3 layers of normal wood, and the S1 and inner S2 layers of compression wood. Fluorescence was also strongly dependent on the polarisation of the excitation light, a phenomenon referred to as bifluorescence. Compared to two other cell wall stains, Congo red and calcofluor white, P4B showed a higher specificity for the S1 and S3 layers and increased bifluorescence. These results suggest that P4B is an ideal tool with which to investigate the orientation of cellulose microfibrils in the S1 and S3 layers of the tracheid wall.

Cellulose microfibril angles and cell-wall polymers in different wood types of Pinus radiata

Four corewood types were examined from sapling trees of two clones of Pinus radiata grown in a glasshouse. Trees were grown either straight to produce normal corewood, tilted at 45° from the vertical to produce opposite corewood and compression corewood, or rocked to produce flexure corewood. Mean cellulose microfibril angle of tracheid walls was estimated by X-ray diffraction and longitudinal swelling measured between an oven dry and moisture saturated state. Lignin and acetyl contents of the woods were measured and the monosaccharide compositions of the cell-wall polysaccharides determined. Finely milled wood was analysed using solution-state 2D NMR spectroscopy of gels from finely milled wood in DMSO-d6/pyridine-d5. Although there was no significant difference in cellulose microfibril angle among the corewood types, compression corewood had the highest longitudinal swelling. A lignin content >32 % and a galactosyl residue content >6 % clearly divided severe compression corewood from the other corewood types. Relationships could be drawn between lignin content and longitudinal swelling, and between galactosyl residue content and longitudinal swelling. The 2D NMR spectra showed that the presence of H-units in lignin was exclusive to compression corewood, which also had a higher (1 → 4)-β-d-galactan content, defining a unique composition for that corewood type.

Correlative light and scanning electron microscopy of the same sections gives new insights into the effects of pectin lyase on bordered pit membranes in Pinus radiata wood

Bordered pits are structures in the cell walls of softwood tracheids which permit the movement of water between adjacent cells. These structures contain a central pit membrane composed of an outer porous ring (margo) and an inner dense and pectin-rich disc (torus). The membrane is overarched on each side by pit borders. Pits may be aspirated, a condition where the torus seals against the pit border, effectively blocking the pathway between cells. In living trees this maintains overall continuity of water conduction in xylem by sealing off tracheids containing air. Drying of timber results in further pit aspiration, which reduces wood permeability to liquid treatment agents such as antifungal chemicals. One possible way to increase permeability is by treating wood with pectin lyase to modify or remove the torus. The effectiveness of this treatment was initially evaluated using light microscopy (LM) of toluidine blue stained wood. Pectic material is coloured pink-magenta with this stain, and loss of this colour after treatment has been interpreted as indicating destruction of the torus. However, correlative light (LM) and scanning electron (SEM) microscopic observations of identical areas of toluidine blue stained sections revealed that many unstained pits had intact but modified tori when viewed with SEM. These observations indicate that LM alone is not sufficient to evaluate the effects of pectin lyase on pit membranes in wood. Combining LM and SEM gives more complete information

Quantitative Tracheid Anatomy Reveals a Complex Environmental Control of Wood Structure in Continental Mediterranean Climate

A detailed understanding of how the climate models the hydraulic system of trees is still lacking, in spite of the need to understand tree response to the ongoing process of climatic change. A systematic correlation of tracheid anatomical features with climate has not been implemented in Mediterranean ecosystems, where climatic change is expected to be particularly intense. We measured ring width and cell number—in addition to intraring position, lumen size, and wall thickness of tracheids—in 10 Juniperus thurifera individuals from north-central Spain. We used this information to perform an exploratory analysis of how these parameters correlated with climatic variables in 1965–2004. Cell number and ring width shared a relatively similar climatic signal, whereas the anatomical variables provided differentiated and diverse signals about climatic conditions during their formation. Earlywood and latewood tracheids differed in controlling factors, with earlywood tracheid size and wall thickness being positively related to rainfall during early summer and latewood tracheid size being positively related to August temperature. Tracheid anatomical variables improved our understanding of climate effects on tree growth and wood formation under harsh environmental conditions, as those experienced in continental Mediterranean climates, where limiting factors show multiple shifts across the year.

Microfibril angle and density of hinoki (Chamaecyparis obtusa) trees in 15 half-sib families in a progeny test stand in Kyushu, Japan

It was previously believed in Japan that the wood qualities of hinoki (Chamaecyparis obtusa) were superior to sugi (Cryptomeria japonica). However, few studies of wood properties such as MFA (microfibril angle of S2 layer in secondary wall of tracheid) have been completed for hinoki. Some reports have found that hinoki plus tree families have similar mechanical properties to sugi. Here we report the characteristics of MFA and density of hinoki half-sib families in a progeny test stand. There were significant differences in MFA and density between families. The wood properties of two families, Nakatsu 3 and Kanzaki 5, are stable in radial pattern and suitable for structural use. Early selection of hinoki families by MFA and density may be difficult. Effects of MFA and density on E d (dynamic modulus of elasticity) of logs differed between families. The effects of growth rate on MFA and density differed between families and also between juvenile and mature wood. The faster growth rate in Nakatsu 3 appeared to improve wood properties and increase E d of logs, although in many other families, faster growth rate had negative effects on desirable wood properties for structural use.

Tracheid wall thickness and lumen diameter in different axial and radial locations in cultivated Larix sibirica trunks

In Larix trunks the properties of wood differ clearly radially, but the axial differences are smaller as well as being less studied. Wood anatomy is in particular poorly studied, even though all other wood properties derive from cell and tissue structure. The aim of this study was to chart variation in tracheid size (double wall thickness (2CWT), diameter of lumen (RD)) within fast grown cultivated Siberian larch (Larix sibirica Ledeb.) trunks. The differences in 2CWT and RD were clear between earlywood (EW) and latewood (LW), 2CWT increasing clearly less in EW than in LW towards the bark, while RD stayed quite stable in LW but in EW increased markedly towards the bark. The difference in 2CWT between EW and LW increased towards the upper trunk. In conclusion, the radial variation in RD and 2CWT was different between the butt and other studied heights. As the difference in 2CWT between EW and LW was smaller at the butt than the upper portion of the trunk, the wood was the most homogenous at the butt.

Localization of Cell Wall Polysaccharides in Normal and Compression Wood of Radiata Pine: Relationships with Lignification and Microfibril Orientation

The distribution of noncellulosic polysaccharides in cell walls of tracheids and xylem parenchyma cells in normal and compression wood of Pinus radiata, was examined to determine the relationships with lignification and cellulose microfibril orientation. Using fluorescence microscopy combined with immunocytochemistry, monoclonal antibodies were used to detect xyloglucan (LM15), β(1,4)-galactan (LM5), heteroxylan (LM10 and LM11), and galactoglucomannan (LM21 and LM22). Lignin and crystalline cellulose were localized on the same sections used for immunocytochemistry by autofluorescence and polarized light microscopy, respectively. Changes in the distribution of noncellulosic polysaccharides between normal and compression wood were associated with changes in lignin distribution. Increased lignification of compression wood secondary walls was associated with novel deposition of β(1,4)-galactan and with reduced amounts of xylan and mannan in the outer S2 (S2L) region of tracheids. Xylan and mannan were detected in all lignified xylem cell types (tracheids, ray tracheids, and thick-walled ray parenchyma) but were not detected in unlignified cell types (thin-walled ray parenchyma and resin canal parenchyma). Mannan was absent from the highly lignified compound middle lamella, but xylan occurred throughout the cell walls of tracheids. Using colocalization measurements, we confirmed that polysaccharides containing galactose, mannose, and xylose have consistent correlations with lignification. Low or unsubstituted xylans were localized in cell wall layers characterized by transverse cellulose microfibril orientation in both normal and compression wood tracheids. Our results support the theory that the assembly of wood cell walls, including lignification and microfibril orientation, may be mediated by changes in the amount and distribution of noncellulosic polysaccharides.

Vertical and radial profiles in tracheid characteristics along the trunk of Douglas-fir trees with implications for water transport

The main stems of three young Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirbel) Franco) trees were dissected to obtain samples of secondary xylem from internodes axially along the trunk and radially within each internode. From these samples, measurements were obtained of tracheid diameter, length, the number of inter-tracheid pits per tracheid, and the diameter of the pit membranes. In addition, samples were obtained along the trunks of three old growth trees and also a small sample of roots for measurement of tracheid diameter. A gradient was apparent in all measured anatomical characters vertically along a sequence among the outer growth rings. These gradients arose not because of a gradient vertically along the internodes, but because of the strong gradients present at each internode among growth rings out from the pith. Tracheid characteristics were correlated: wider and longer tracheids had more numerous pits and wider pits, such that total pit area was about 6% of tracheid wall area independent of tracheid size. A stem model combining growth rings in parallel and internodes in series allowed for estimates of whole trunk conductance as a function of tree age. Conductance of the stem (xylem area specific conductivity) declined during the early growth of the trees, but appeared to approach a stable value as the trees aged.

Equisetum Xylem: SEM Studies and their Implications

Abstract Scanning electron microscope (SEM) studies of xylem of three species of Equisetum reveal numerous details not previously reported on the basis of light microscopy. SEM images of thick (ca. 1 mm) sections reveal pit shapes, cell contexts, and microstructure of pit membranes. Pit shapes are remarkably diverse in comparison to those of ferns or conifers. Nodal tracheary elements are isodiametric to fusiform in shape, and have crowded circular (mostly) to elongate prominently bordered pits and uniformly thick secondary walls. Internodal tracheary elements, by contrast, have relatively large circular pits with inconspicuous borders. Secondary walls of internodal tracheids are thin, with thickenings that are annular, looplike, or of some intermediate form. Metaxylem internodal tracheary elements line the inner surface of carinal canals ( = proxylem lacunae), and many of the large circular (often crateriform) pits facing the canals may lack pit membranes, especially in E. giganteum and E. myriochaetum....

Cycad Wood from the Lopingian (Late Permian) of Southern China:Shuichengoxylon tianiigen. et sp. nov.

AbstractAnatomically preserved wood collected from coal seam no. 1 of the Naluozhai coal mine in the Lopingian (Late Permian) Wangjiazhai Formation in western Guizhou Province, China, is documented and interpreted. The wood belonged to a trunk with an inferred diameter of 25 cm or more and consists of axial tracheids and horizontal rays. Tracheids vary greatly in size, and small ones are usually irregularly arranged. Tracheid walls are 5–10 μm thick and usually bilayered. There are usually biseriate araucarioides-type bordered pits on the radial tracheid walls. Two to five oval bordered pits are in each cross-field. Ray cells are thin walled, although thick-walled cells exist in some rays. Rays are quite variable in width and height. Uni- and partly biseriate rays are usually 2–20 cells high, while bi- and partly tri- to tetraseriate ones are 5–79 cells high. The cell size of rays is also quite variable and is usually larger than that of tracheids in the tangential direction. There are numerous leaf trace...

Inter-Tracheid and Cross-Field Pitting in Compression Wood and Opposite Wood of Norway Spruce (Picea abies L.)

Inter-tracheid and cross-filed pit specifications in compression wood and opposite wood of Norway spruce (Picea abies) were determined. Fewer pits of a smaller size and a smaller aperture diameter were observed in compression wood. In contrast to the uniseriate arrangement of bordered pit pairs in compression wood, both uniseriate and biseriate pits were observed in opposite wood. In contrast to the circular view of the pit aperture in opposite wood, a slit-like pit aperture was often observed in compression wood. SEM images showed a number of helical fissures on the tracheid walls and bordered pits of compression wood along the microfibril angle in the S2 layer. The cross-field pits in compression wood were dominantly piceoid but sometimes cupressoid and occasionally taxodioid, whereas they were mostly piceoid and occasionally cupressoid in opposite wood. Overall, some significant differences in the inter-tracheid and cross-field pitting between the compression wood and opposite wood can give some explanations for their different air permeability and drying kinetics found in the previous studies.

Effects of Loblolly Pine Wood and Pulp Properties on Sheet Characteristics

The effects of wood properties on the strength of bleachable and linerboard grade kraft pulps from 13-year-old loblolly pine (Pinus taeda) trees were investigated. Eighteen trees were selected based on breast height wood cores to represent specified ranges of specific gravity and lignin content. Air-dry density and stiffness (modulus of elasticity [MOE]), tracheid coarseness, radial diameter, tangential diameter, specific surface area, wall thickness, and microfibril angle (MFA) were estimated using SilviScan wood analysis technology and near infrared reflectance (NIR) spectroscopy. NIR spectra collected in 10 mm sections from the surface radial strips correlated very well with air-dry density, MFA, MOE, and tracheid wall thickness and were used to develop whole tree predictions. In addition, chemical composition, fiber properties, and handsheet strength were measured for both pulp grades. Statistical analysis indicated that wood density, wood fiber coarseness, and pulp fiber length had the greatest effects on sheet properties.

A unique gymnosperm from the latest Permian of China, and its ecophysiological implications

A unique coniferous woody stem Shenoxylon mirabile gen. nov. et sp. nov. is described from the very late Late Permian Changhsingian (Lopingian) Sunjiagou Formation of the Shitanjing coalfield, northern China. The silicified decorticated stem is characterized by a complex pith in the broad (7 mm) eustelic vascular system, thick secondary xylem cylinder and helically arranged leaf traces. The heterogeneous pith consists of a densely arranged sclerified intramedullary sheath that separates the loosely arranged central parenchyma and peripheral sclerified cells into three prominent zones. The primary xylem strands show endarch maturation, the tracheids from the protoxylem to metaxylem showing annular to scalariform/reticulate thickenings. The secondary xylem is pycnoxylic; uniseriate bordered pits are continuous or individually spaced on the radial walls of tracheids, with partially biseriate, alternate or occasionally opposite; the cross-fields show one or two cupressoid pits; ray cells are parenchymatous with smooth walls; axial parenchyma is developed. Growth-rings are present and false rings are frequently developed throughout the secondary xylem; resin canals are absent. The leaf traces are composed of monarch vascular bundles and of circular to longitudinally elongate shape in cross section; they originate from the periphery of the pith and pass through the whole xylem cylinder nearly horizontally. The frequent occurrences of false rings are interpreted as ecophysiological responses of the plant to the environmental turbulences during the latest Permian terrestrial ecosystem.

소나무재선충 감염 소나무의 목재해부학적 특성

소나무재선충병은 우리나라의 대표 수종인 소나무를 괴사시키는 주요 산림병의 하나로 재선충의 침입과 수체내에서의 이동 경로 파악은 이들의 서식 형태를 구명하는데 매우 중요하다. 따라서 본 연구에서는 감염목 내에서의 재선충 주요 서식 부위와 이동 경로를 명확히 구명하기 위해 재선충 피해목에 대한 현미경적 조사를 수행하였다. 그 결과 피해목의 특징으로는 횡단면, 방사단면, 접선단면 모두에서 주로 방사조직이 감염을 통해 진하게 착색된 것으로 드러났으며 수지구에서도 집중적인 피해가 관찰되었다. 또한 형성층과 가까운 변재 부위에서는 연륜을 따라 접선방향으로 연속 배열된 상해수지구로 보이는 특징이 관찰되었다. 재선충은 방사가도관보다는 방사유세포에서 그리고 수평수지구를 지니지 않는 단열방사조직보다는 수평수지구를 지니는 방추형방사조직에서 훨씬 더 많은 재선충이 발견되었으며 방사조직에서 가도관으로 이동하는 선충도 관찰되었다. 방사조직에서 가도관으로의 이동 시 가도관의 벽을 천공한 다음 이동하거나 크기가 작은 개구부인 측벽의 유연벽공을 통해 이동하기보다는 크기가 큰 개구부인 창상 직교분야벽공을 이동 통로로 삼는 것으로 사료되었다. The pine wilt disease is one of the most serious forest diseases that kill the pine trees, and the study on the invasion and movement of the pine wood nematode within the tree is very important for understanding the inhabitation of pine wood nematode. In this relation, the microscopic observation was carried out to study the place of inhabitation and movement of pine wood nematode within the infested wood. In result, the rays were mainly infested by pine wood nematode and showed dark discoloration due to their necrosis in cross, radial and tangential surface. Also, the intensive damage was found in the resin canals. On the other hand, some traumatic resin canals in tangential band were identified in the sapwood near the cambium. In the ray, the pine wood nematode occurred more commonly in the ray parenchyma cell and fusiform ray with horizontal resin canal than in the ray tracheid and uniseriate ray without horizontal resin canal, respectively. The pine wood nematode was thought to move from ray to tracheid through the large natural opening, window-like pit, in the cross-field, neither through the small natural opening, bordered pit, in the tracheid nor through the tracheid wall by creating a bore hole.

Microfibril organization modes in plant cell walls of variable curvature: a model system for two dimensional anisotropic soft matter

We present a mechanical model of the plant cell wall viewed as anisotropic two dimensional soft matter, where a dilute dispersion of cellulose fibrils of variable orientations is uniformly distributed on a curved deformable viscoelastic matrix membrane. The plant cell wall model integrates the elastic energy of the curved membrane, the nematic Landau–de Gennes fiber orientation energy, and competing curvophilic and curvophobic interactions mediated by the membrane geometry and the fibrils' orientation. The selected membrane geometry is a straight cylinder of variable cross-section, whose shape varies from a circle to a sharp super-ellipse as in many cell specimens, and whose size increases as in plant cell wall growth. Model predictions indicate that due to curvature–orientation couplings, the fiber orientation displays three modes: (i) line (along the cylindrical axis), (ii) helical (oblique to the axis), and (iii) ring (normal to the axis), where the former arises under large curvature and the latter under small one. In addition to aligning the fibers in the line mode, high curvature also promotes the order of the fibrils. The predicted fiber structure is validated with fiber structures in the cell wall of tracheids. The structure–property relations for super-elliptical membranes with gradient curvature are established and its role in cell growth shape is predicted. The principal mechanisms are the role of fiber orientation and order on bending stiffness: (a) orientation along the axis has no stiffening effect, (b) orientation along the azimuthal direction produces maximal stiffening, and (c) fiber randomization softens the membrane. The largest fiber stiffening effect is found when the membrane length scale (radius of curvature) and fiber length scale (curvophobic/curvophilic energy ratio) are equal. It is found that super-elliptical shape invariant growth and expansion is preferred for cells with sharp/soft corners and straight/stiff sides. Otherwise growth promotes shape changes. Lastly, master plots that categorize fiber structures by the number of multimodal regimes (line/helix, line/helix/ring) that arise in super-ellipses are used to relate shape and size to domain structures that affect toughness and modulus.