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 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

The Ultrastructure and Ontogeny of Pollen in Helleborus Foetidus L

1968 ◽  
Vol 3 (2) ◽  
pp. 161-174
Author(s):  
P. ECHLIN ◽  
H. GODWIN
Keyword(s):  
Cell Wall ◽  
Tapetal Cell ◽  
Pollen Grains ◽  
Ultrastructural Level ◽  
Low Molecular Weight ◽  
Cell Organelles ◽  
Helleborus Foetidus ◽  
Ubisch Bodies ◽  
Ubisch Body ◽  
Development Proceeds

The ontogeny of the tapetum and Ubisch bodies in Helleborus foetidus L. has been examined at the ultrastructural level, and their development has been closely linked with that of the sporogenous cell and pollen grains. During development the tapetum passes through successive phases of synthesis, maturity and senescence, ending in complete dissolution. During the anabolic phase of growth, precursors of the Ubisch bodies are formed as spheroidal vesicles of medium electron density within the tapetal cytoplasm; they are associated with a zone of radiating ribosomes, which, as development proceeds, can clearly be seen to be situated on strands of endoplasmic reticulum. The callose special wall round the microspores and the tapetal cell wall now disintegrate and the pro-Ubisch bodies are extruded through the cell membrance of the tapetal cells, where they remain on the surface of the anther cavity and soon become irregularly coated with sporopollenin. Deposition of sporopollenin continues on the Ubisch bodies at the same time as upon the exines of the developing pollen grains. In both cases, the later stages of sporopollenin deposition are associated with electron-transparent layers of unit-membrane dimensions appearing in section as white lines of uniform thickness. Continuing deposition of sporopollenin leads to the formation of compound or aggregate Ubisch bodies. It is conjectured that the sporopollenin is synthesized from the compounds of low molecular weight released into the anther loculus by the breakdown of the callose special wall and the tapetal cell wall. The final stages of tapetal autolysis involve the disappearance of all the cell organelles. An attempt is made to relate the findings to those described in other recent studies on Ubisch body formation and to combine them in a common ontogenetic pattern.

Enzymology of Plant Cell Wall Breakdown: An Update

2010 ◽  
pp. 73-96 ◽  
Author(s):  
Leonora R. S. Moreira ◽  
Natália vG. Milanezi ◽  
Edivaldo X. F. Filho
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cell Wall Breakdown

CELL WALL BREAKDOWN AND GROWTH IN PEA SEEDLING STEMS

1962 ◽  
Vol 49 (4) ◽  
pp. 311-319 ◽  
Author(s):  
William H. Matchett ◽  
James F. Nance
Keyword(s):  
Cell Wall ◽  
Cell Wall Breakdown ◽  
Pea Seedling

scholarly journals Is size an issue of time? Relationship between the duration of xylem development and cell traits

2019 ◽  
Vol 123 (7) ◽  
pp. 1257-1265 ◽  
Author(s):  
Valentina Buttò ◽  
Sergio Rossi ◽  
Annie Deslauriers ◽  
Hubert Morin
Keyword(s):  
Cell Wall ◽  
Cell Differentiation ◽  
Tree Ring ◽  
Wall Thickness ◽  
Secondary Wall ◽  
Temporal Dynamics ◽  
Secondary Growth ◽  
Growth Equation ◽  
Wall Deposition ◽  
Secondary Wall Deposition

Abstract Background and Aims Secondary growth is a process related to the formation of new cells that increase in size and wall thickness during xylogenesis. Temporal dynamics of wood formation influence cell traits, in turn affecting cell patterns across the tree ring. We verified the hypothesis that cell diameter and cell wall thickness are positively correlated with the duration of their differentiation phases. Methods Histological sections were produced by microcores to assess the periods of cell differentiation in black spruce [Picea mariana (Mill.) B.S.P.]. Samples were collected weekly between 2002 and 2016 from a total of 50 trees in five sites along a latitudinal gradient in Quebec (Canada). The intra-annual temporal dynamics of cell differentiation were estimated at a daily scale, and the relationships between cell traits and duration of differentiation were fitted using a modified von Bertalanffy growth equation. Key Results At all sites, larger cell diameters and cell wall thicknesses were observed in cells that experienced a longer period of differentiation. The relationship was a non-linear, decreasing trend that occasionally resulted in a clear asymptote. Overall, secondary wall deposition lasted longer than cell enlargement. Earlywood cells underwent an enlargement phase that lasted for 12 d on average, while secondary wall thickness lasted 15 d. Enlargement in latewood cells averaged 7 d and secondary wall deposition occurred over an average of 27 d. Conclusions Cell size across the tree ring is closely connected to the temporal dynamics of cell formation. Similar relationships were observed among the five study sites, indicating shared xylem formation dynamics across the entire latitudinal distribution of the species.The duration of cell differentiation is a key factor involved in cell growth and wall thickening of xylem, thereby determining the spatial variation of cell traits across the tree ring.

scholarly journals Rhizome and root anatomy of 14 species of Bromeliaceae

Rodriguésia ◽  
2008 ◽  
Vol 59 (1) ◽  
pp. 113-128 ◽  
Author(s):  
Suzana Lúcia Proença ◽  
Maria das Graças Sajo
Keyword(s):  
Water Absorption ◽  
Root Anatomy ◽  
Vascular Cylinder ◽  
Anatomical Features ◽  
Cerrado Biome ◽  
The Family ◽  
And Storage

ABSTRACT The anatomy of rhizomes and roots of 14 species of Bromeliaceae that occur in the cerrado biome were studied with the aim of pointing out particular anatomical features of the family and possible adaptations related to the environment. All the rhizomes are similar although some have root regions growing inside the cortex. In some species the vascular cylinder of the rhizome is clearly limited from the cortex. The roots are also very similar, although the coating tissue differs in roots growing inside the rhizome or externally to it and the cortex has a variable organization according to the region. The studied species present anatomical features that are associated to water absorption and storage, showing that they are adapted to the cerrado environment.

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