scholarly journals Use of anatomical root markers for species identification in Catasetum (Orchidaceae) at the Portal da Amazônia region, MT, Brazil

2015 ◽  
Vol 45 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Ivone Vieira da SILVA ◽  
Rubens Maia de OLIVEIRA ◽  
Ana Aparecida Bandini ROSSI ◽  
Angelita Benevenuti da SILVA ◽  
Daiane Maia de OLIVEIRA
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cortical Cell ◽  
Central Area ◽  
Digital Camera ◽  
Root Anatomy ◽  
Wall Thickening ◽  
Vascular Cylinder ◽  
Endodermal Cell ◽  
Mato Grosso

Orchidaceae is one of the largest botanical families, with approximately 780 genera. Among the genera of this family, Catasetum currently comprises 166 species. The aim of this study was to characterize the root anatomy of eight Catasetum species, verifying adaptations related to epiphytic habit and looking for features that could contribute to the vegetative identification of such species. The species studied were collected at the Portal da Amazônia region, Mato Grosso state, Brazil. The roots were fixed in FAA 50, cut freehand, and stained with astra blue/fuchsin. Illustrations were obtained with a digital camera mounted on a photomicroscope. The roots of examined species shared most of the anatomical characteristics observed in other species of the Catasetum genus, and many of them have adaptations to the epiphytic habit, such as presence of secondary thickening in the velamen cell walls, exodermis, cortex, and medulla. Some specific features were recognized as having taxonomic application, such as composition of the thickening of velamen cell walls, ornamentation of absorbent root-hair walls, presence of tilosomes, composition and thickening of the cortical cell walls, presence of mycorrhizae, endodermal cell wall thickening, the number of protoxylem poles, and composition and thickening of the central area of the vascular cylinder. These traits are important anatomical markers to separate the species within the genus and to generate a dichotomous identification key for Catasetum. Thus, providing a useful tool for taxonomists of this group

scholarly journals Domain-specific and cell type-specific localization of two types of cell wall matrix polysaccharides in the clover root tip.

1992 ◽  
Vol 118 (2) ◽  
pp. 467-479 ◽  
Author(s):  
M A Lynch ◽  
L A Staehelin
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cellular Differentiation ◽  
Cortical Cell ◽  
Middle Lamella ◽  
Root Cap ◽  
Root Tip ◽  
Cortical Cells ◽  
Peripheral Cell ◽  
Clover Root

Using immunocytochemical techniques and antibodies that specifically recognize xyloglucan (anti-XG), polygalacturonic acid/rhamnogalacturonan I (anti-PGA/RG-I), and methylesterified pectins (JIM 7), we have shown that these polysaccharides are differentially synthesized and localized during cell development and differentiation in the clover root tip. In cortical cells XG epitopes are present at a threefold greater density in the newly formed cross walls than in the older longitudinal walls, and PGA/RG-I epitopes are detected solely in the expanded middle lamella of cortical cell corners, even after pretreatment of sections with pectinmethylesterase to uncover masked epitopes. These results suggest that in cortical cells XG and PGA/RG-I are differentially localized not only to particular wall domains, but also to particular cell walls. In contrast to their nonoverlapping distribution in cortical cells, XG epitopes and PGA/RG-I epitopes largely colocalize in the epidermal cell walls. The results also demonstrate that the middle lamella of the longitudinal walls shared by epidermal cells and by epidermal and cortical cells constitutes a barrier to the diffusion of cell wall and mucilage molecules. Synthesis of XG and PGA/RG-I epitope-containing polysaccharides also varies during cellular differentiation in the root cap. The differentiation of gravitropic columella cells into mucilage-secreting peripheral cells is marked by a dramatic increase in the synthesis and secretion of molecules containing XG and PGA/RG-I epitopes. In contrast, JIM 7 epitopes are present at abundant levels in columella cell walls, but are not detectable in peripheral cell walls or in secreted mucilage. There were also changes in the cisternal labeling of the Golgi stacks during cellular differentiation in the root tip. Whereas PGA/RG-I epitopes are detected primarily in cis- and medial Golgi cisternae in cortical cells (Moore, P. J., K. M. M. Swords, M. A. Lynch, and L. A. Staehelin. 1991. J. Cell Biol. 112:589-602), they are localized predominantly in the trans-Golgi cisternae and the trans-Golgi network in epidermal and peripheral root cap cells. These observations suggest that during cellular differentiation the plant Golgi apparatus can be both structurally and functionally reorganized.

Loblolly pine seedling root anatomy and iron accumulation as affected by soil waterlogging

1987 ◽  
Vol 17 (10) ◽  
pp. 1257-1264 ◽  
Author(s):  
M. R. McKevlin ◽  
D. D. Hook ◽  
W. H. Mckee Jr. ◽  
S. U. Wallace ◽  
J. R. Woodruff
Keyword(s):  
Loblolly Pine ◽  
Cell Walls ◽  
Cortical Cell ◽  
Root Anatomy ◽  
Intercellular Spaces ◽  
Seedling Root ◽  
Aeration System ◽  
Pine Seedlings ◽  
Epidermal Surface ◽  
Bordered Pits

Loblolly pine seedlings were grown under flooded and drained conditions in a greenhouse pot study. Flooded roots developed aerenchyma tissue within the stele between the xylem poles, extending from the phloem outward to the pericycle. Large intercellular spaces were present in the pericyclic parenchyma within the phellogen of flooded woody roots. Flooded stems exhibited lenticel hypertrophy. Large intercellular spaces in the cortex were continuous with intercellular spaces in the pericyclic parenchyma of the root. Flooding of roots generally resulted in accumulation of Fe on the epidermal surface and in as well as between cortical cell walls inward to the endodermis. Fe accumulated in and between the precursor phloem cells and became more evident in the region of maturation. In roots with secondary thickening, little Fe was visible in the phloem but was present in helical secondary walls of tracheids. Fe also accumulated on and in bordered pits of root tracheids. Results suggest that flooded loblolly pine seedlings possess a limited internal aeration system and that diffusion of oxygen into the root system may be responsible for the presence of oxidized Fe within the stele.

Histological study of syncytia induced in cereals by the Mediterranean cereal cyst nematode Heterodera latipons

Nematology ◽  
2008 ◽  
Vol 10 (2) ◽  
pp. 279-287 ◽  
Author(s):  
Yuji Oka ◽  
Mishael Mor ◽  
Yitzhak Spiegel
Keyword(s):  
Cell Wall ◽  
Histological Study ◽  
Parenchymal Cell ◽  
Cortical Cell ◽  
Syncytium Formation ◽  
Wheat Root ◽  
Heterodera Avenae ◽  
Vascular Cylinder ◽  
Cell Layers ◽  
Heterodera Latipons

AbstractFeeding sites of Heterodera latipons in wheat, barley and Lolium rigidum were studied and compared with those of Heterodera avenae in wheat. Juveniles of H. latipons penetrated mainly differentiated roots and chose a root cortical cell as their initial syncytium cell (ISC) in wheat and barley, whilst H. avenae chose a vascular parenchymal cell as an ISC. The cell associated with females in wheat root underwent hypertrophy, and incorporated endodermis, pericycle and parenchyma cells of the vascular cylinder by cell wall dissolution. Syncytia of H. latipons contained a high number of organelles, including endoplasmic reticulum, mitochondria, plastids and amoeboid nuclei, whilst those of H. avenae were highly vacuolated. The syncytium partly occupied both the cortex and the vascular cylinder in contrast to those of H. avenae, which occupied most of the space within the vascular cylinder near the infection site. The cortical cell associated with H. latipons males did not undergo hypertrophy, but had dense cytoplasm, and incorporation of other cells by cell wall dissolution was rare. A similar syncytium formation process was observed with barley, but a cortical cell, several cell layers away from the endodermis, was chosen for the ISC. In resistant L. rigidum, H. latipons juveniles chose an endodermal cell or its neighbouring cortical cell as an ISC. Partial dissolution of cell wall was observed in neighbouring parenchymal cells, although the nematode did not develop into adults.

scholarly journals Cell-wall thickening in Bacillus subtilis. Comparison of thickened and normal walls

1970 ◽  
Vol 120 (1) ◽  
pp. 159-170 ◽  
Author(s):  
R. C. Hughes ◽  
P. J. Tanner ◽  
Elaine Stokes
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cell Walls ◽  
Teichoic Acid ◽  
Cellular Growth ◽  
Wall Thickening ◽  
Complete Medium ◽  
Bacillus Subtilis 168 ◽  
Normal Wall

1. Incubation of Bacillus subtilis 168 trp in a glucose–amino acids–salts medium lacking tryptophan leads to an inhibition of cellular growth without affecting cell-wall synthesis. The cell walls increased approximately two- to three-fold in thickness and at the same time the amount of mucopeptide in the cells measured chemically increased to about the same extent. 2. Synthesis of mucopeptide and teichoic acid as measured by the extent of incorporation of radioactivity continued linearly for approximately 1h and then stopped. No reason was found for the strictly limited synthesis of the wall polymers. 3. The initial rates of incorporation of [32P]Pi or [3H]alanine into teichoic acid and of 3H-labelled amino acids into mucopeptide were not appreciably inhibited by the addition of chloramphenicol to the glucose–amino acids–salts medium. 4. There was no selective turnover of the mucopeptide synthesized by the cells in a medium lacking tryptophan on resumption of growth in a complete medium. 5. Wall synthesis taking place during the thickening process was similar to normal wall synthesis proceeding in growing cells. Walls of different thicknesses prepared from cells incubated for various times in incomplete medium did not differ qualitatively in composition. The products of autolysis of thickened walls were isolated and the analyses indicated a close similarity in the details of their mucopeptide structure compared with the mucopeptide of cells growing in the exponential phase.

Aerial root cap structure of an orchid, Epidendrum

1981 ◽  
Vol 59 (9) ◽  
pp. 1702-1708 ◽  
Author(s):  
Susan J. Blackman ◽  
Edward C. Yeung
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Cell Walls ◽  
Root Cap ◽  
Wall Material ◽  
Wall Thickening ◽  
Cell Wall Material ◽  
Random Orientation ◽  
Mitotic Figures ◽  
Distal Cell

The root cap of Epidendrum ibaguense has a rounded profile with a root cap junction present between the cap and meristem. A distinct columella region is lacking. Mitotic figures are infrequent in the root cap initial cells. The root cap initials and their immediate derivatives show few dictyosomes, little endoplasmic reticulum, plastids lacking starch, and few vacuoles. As the cells age they increase in size and show increasing vacuolation. Plastids increase by division and accumulate large starch grains. Throughout the root cap, amyloplasts maintain a random orientation in the cell. Endoplasmic reticulum also becomes more abundant as the cells age. In older cells, hypertrophied dictyosomes are evident and cell wall material begins accumulating between the distal cell wall and the plasmalemma. Wall thickening progresses with age though radial walls remain largely unthickened. Vacuolation progresses and is followed by complete senescence leaving only the cell walls.

scholarly journals The reorganization of root anatomy and ultrastructure of syncytial cells in tomato (Lycopersicon esculentum Mill.) infected with potato cyst nematode (Globodera rostochiensis Woll.)

2011 ◽  
Vol 76 (3) ◽  
pp. 181-191 ◽  
Author(s):  
Sylwia Fudali ◽  
Władysław Golinowski
Keyword(s):  
Cell Wall ◽  
Secondary Growth ◽  
Ultrastructural Level ◽  
Immunogold Labelling ◽  
Globodera Rostochiensis ◽  
Root Anatomy ◽  
Vascular Cylinder ◽  
Protein Distribution ◽  
Cell Wall Breakdown ◽  
Local Cell

The sequence of anatomical and ultrastructural events leading to the syncytium development in tomato roots infected with <em>Globodera rostochiensis</em> was examined. The syncytia were preferentially induced in cortical or pericyclic cells in the elongation zone of root. They developed towards the vascular cylinder by incorporation of new cells via local cell wall breakdown. After surrounding primary phloem bundle and reaching xylem tracheary elements syncytia spread along vascular cylinder. Roots in primary state of growth seemed to be the best place for syncytium induction as syncytia formed in the zone of secondary growth were less hypertrophied. At the ultrastructural level syncytial elements were characterized by strong hypertrophy, breakdown of central vacuole, increased volume of cytoplasm, proliferation of organelles, and enlargement of nuclei. On the syncytial wall adjoining vessels the cell wall ingrowths were formed, while the syncytial walls at interface of phloem were considerably thickened. They lacked of functional plasmodesmata and did not form any ingrowths. Using immunofluorescent-labelling and immunogold-labelling methods tomato expansin 5 protein was localized in nematode infected roots. The distribution of LeEXP A5 was restricted only to the walls of syncytia. The protein distribution pattern indicated that LeEXP A5 could mediates cell wall expansion during hypertrophy of syncytial elements.

scholarly journals Arabidopsis XTH4 and XTH9 contribute to wood cell expansion and secondary wall formation

2019 ◽  
Author(s):  
Sunita Kushwah ◽  
Alicja Banasiak ◽  
Nobuyuki Nishikubo ◽  
Marta Derba-Maceluch ◽  
Mateusz Majda ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Expansion ◽  
Cell Walls ◽  
Secondary Wall ◽  
Secondary Xylem ◽  
Cell Wall Integrity ◽  
Wall Thickening ◽  
Xylem Cell ◽  
Secondary Wall Thickening ◽  
Secondary Wall Formation

ABSTRACTIn dicotyledons, xyloglucan is the major hemicellulose of primary walls affecting the load-bearing framework with participation of XTH enzymes. We used loss- and gain-of function approaches to study functions of abundant cambial region expressed XTH4 and XTH9 in secondary growth. In secondarily thickened hypocotyls, these enzymes had positive effects on vessel element expansion and fiber intrusive growth. In addition, they stimulated secondary wall thickening, but reduced secondary xylem production. Cell wall analyses of inflorescence stems revealed changes in lignin, cellulose, and matrix sugar composition, indicating overall increase in secondary versus primary walls in the mutants, indicative of higher xylem production compared to wild type (since secondary walls were thinner). Intriguingly, the number of secondary cell wall layers was increased in xth9 and reduced in xth4, whereas the double mutant xth4x9 displayed intermediate number of layers. These changes correlated with certain Raman signals from the walls, indicating changes in lignin and cellulose. Secondary walls were affected also in the interfascicular fibers where neither XTH4 nor XTH9 were expressed, indicating that these effects were indirect. Transcripts involved in secondary wall biosynthesis and in cell wall integrity sensing, including THE1 and WAK2, were highly induced in the mutants, indicating that deficiency in XTH4 and XTH9 triggers cell wall integrity signaling, which, we propose, stimulates the xylem cell production and modulates secondary wall thickening. Prominent effects of XTH4 and XTH9 on secondary xylem support the hypothesis that altered xyloglucan can affect wood properties both directly and via cell wall integrity sensing.SIGNIFICANCE STATEMENTXyloglucan is a ubiquitous component of primary cell walls in all land plants but has not been so far reported in secondary walls. It is metabolized in muro by cell wall-residing enzymes - xyloglucan endotransglycosylases/hydrolases (XTHs), which are reportedly abundant in vascular tissues, but their role in these tissues is unclear. Here we report that two vascular expressed enzymes in Arabidopsis, XTH4 and XTH9 contribute to the secondary xylem cell radial expansion and intrusive elongation in secondary vascular tissues.Unexpectedly, deficiency in their activities highly affect chemistry and ultrastructure of secondary cell walls by non-cell autonomous mechanisms, including transcriptional induction of secondary wall-related biosynthetic genes and cell wall integrity sensors. These results link xyloglucan metabolism with cell wall integrity pathways, shedding new light on previous reports about prominent effects of xyloglucan metabolism on secondary walls.One sentence summaryXTH4 and XTH9 positively regulate xylem cell expansion and fiber intrusive tip growth, and their deficiency alters secondary wall formation via cell wall integrity sensing mechanisms.

scholarly journals A Transcriptomic Analysis of Xylan Mutants Does Not Support the Existence of A Secondary Cell Wall Integrity System in Arabidopsis

2018 ◽  
Author(s):  
Nuno Faria Blanc ◽  
Jenny C. Mortimer ◽  
Paul Dupree
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Secondary Cell Wall ◽  
Cell Wall Integrity ◽  
Wall Thickening ◽  
Similar System ◽  
Analogous System ◽  
A Cell ◽  
Secondary Cell Wall Thickening ◽  
Signalling Cascade

AbstractYeast have long been known to possess a cell wall integrity (CWI) system, and recently an analogous system has been described for the primary walls of plants (PCWI) that leads to changes in plant growth and cell wall composition. A similar system has been proposed to exist for secondary cell walls (SCWI). However, there is little data to support this. Here, we analysed the stem transcriptome of a set of cell wall biosynthetic mutants in order to investigate whether cell wall damage, in this case caused by aberrant xylan synthesis, activates a signalling cascade or changes in cell wall synthesis gene expression. Our data revealed remarkably few changes to the transcriptome. We hypothesise that this is because cells undergoing secondary cell wall thickening have entered a committed programme leading to cell death, and therefore a SCWI system would have limited impact. The absence of transcriptomic responses to secondary cell wall alterations may facilitate engineering of the secondary cell wall of plants.

scholarly journals Histopathology of Infection and Colonization of Susceptible and Resistant Port-Orford-Cedar by Phytophthora lateralis

2007 ◽  
Vol 97 (6) ◽  
pp. 684-693 ◽  
Author(s):  
Eunsung Oh ◽  
Everett M. Hansen
Keyword(s):  
Cell Walls ◽  
Structural Changes ◽  
Vascular System ◽  
Cortical Cell ◽  
Wall Thickening ◽  
Natural Forests ◽  
Cortical Cells ◽  
Fiber Cells ◽  
Phytophthora Lateralis ◽  
Port Orford Cedar

Port-Orford-cedar (POC) root disease, caused by Phytophthora lateralis, continues to kill POC in landscape plantings and natural forests in western North America. POC trees resistant to P. lateralis have been identified and propagated. Cytological observations of P. lateralis in susceptible and resistant roots and stems were made with light and transmission electron microscopy to identify resistance mechanisms. No differences in infection pathway and initial colonization were observed between susceptible and resistant roots, although there were differences in the rate and extent of development. Germ tubes formed appressoria, and penetration hyphae grew either between or directly through epidermal cell walls; inter- and intracellular hyphae colonized the root cortex. In susceptible roots, hyphae penetrated into the vascular system within 48 h of inoculation. In contrast, hyphae in roots of resistant seedlings grew more slowly in cortical cells and were not observed to penetrate to the vascular tissues. In resistant roots, infection was marked by general thickening of cortical cell walls, wall appositions around penetrating hyphae, collapse of cortical cells, and accumulation of osmophillic granules around hyphae. In susceptible stems, hyphae grew inter- and intracellularly in all cells of the secondary phloem except fiber cells, but were concentrated in sieve and parenchyma cells in the functional phloem. The pattern of penetration and colonization of hyphae was similar in the resistant stems, except that hyphae were found in the fiber cells of the xylem. In resistant stems, there were fewer hyphae in the functional phloem, and cytological changes such as damaged nuclei and disintegrated cytoplasm were evident. Structural changes in resistant stems included collapsed cells, wall thickening, secretory bodies, apposition of electron dense materials, and crystals in cell walls.

scholarly journals Perubahan Morfologi dan Anatomi Kalus Catharanthus roseus dengan Perlakuan Triptofan (The morphological and anatomical changes on tryptophan-treated callus of Catharanthus roseus)

2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Dingse Pandiangan
Keyword(s):  
Cell Wall ◽  
Catharanthus Roseus ◽  
Digital Camera ◽  
Morphological Structure ◽  
Wall Thickening ◽  
Anatomical Changes ◽  
Paraffin Method

AbstrakPenelitian tentang perubahan morfologi dan anatomi kalus Catharanthus roseus dengan pemberian perlakuan triptofan telah dilakukan. Penelitian ini bertujuan untuk melengkapi informasi tentang perubahan yang terjadi pada kalus khususnya struktur anatomi dan morfologi sel kalus Catharanthus roseus setelah diberi perlakuan prekursor triptofan 175 mg/L. Pengamatan anatomi kalus dilakukan dengan metoda Parafin yang didokumentasikan dengan mikroskop Nikon Halogen 100 W perbesaran 10X10 dan difoto dengan camera Nikon DXM 1200F. Penampakan morfologi kalus didokumentasikan dengan camera digital Cannon. Hasil penelitian menunjukkan bahwa pertumbuhan kalus yang diberi perlakuan triptofan lebih lambat pada awalnya, namun bertahan hidup sampai 40 hari kultur. Kalus tanpa triptofan cepat bertumbuh pada awalnya sampai hari ke 18 kultur, setelah itu tidak ada pertumbuhan lagi. Setelah kultur 40 hari kultur, kalus dengan perlakuan triptofan tetap bertumbuh dengan baik sedangkan kontrol sudah rusak atau lisis. Struktur sel kalus perlakuan triptofan setelah 28 kali subkultur menunjukkan adanya penebalan dinding sel, sedangkan sel kalus kontrol mengalami lisis atau kerusakan sel.Kata kunci: anatomi, Catharanthus roseus, kalus, morfologi, triptofanAbstractA research on the morphological and anatomical changes on tryptophan-treated callus of Catharanthus roseus was conducted. This study aimed to complete the information about the changes, particularly on anatomical and morphological structure of Catharanthus roseus callus cells after treatment of 175 mg/L precursor tryptophan. Anatomical observations was conducted using paraffin method, documented using a Nikon microscope with a 10x10 magnification and the photograph was taken using the Nikon DXM 100 W Halogen 1200F camera. The appearance of callus morphology was documented by Cannon digital camera. The results showed that the growth of tryptophan-treated callus was slower at the beginning, but it survived by 40-day culture. Non-tryptophan callus grew rapidly by 18-day culture and did not grow later on. Tryptophan-treated callus for 40 days grew well, whereas control callus was damaged or lysis. The tryptophan-treated callus after 28 times subcultures showed cell wall thickening, whereas the control callus cells are lysis or damaged.Keywords: anatomy, callus, Catharanthus roseus, morphology, tryptophan

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