Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: anatomy of mycorrhizae

1992 ◽  
Vol 22 (12) ◽  
pp. 1901-1916 ◽  
Author(s):  
Carolyn J. McQuattie ◽  
George A. Schier
Keyword(s):  
Root Meristem ◽  
Light And Electron Microscopy ◽  
Mycorrhizal Fungus ◽  
Solution Ph ◽  
Root Cortex ◽  
Anatomical Changes ◽  
Fungal Hyphae ◽  
Pitch Pine ◽  
Growth Chambers ◽  
Cellular Alterations

Newly germinated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, or 50 mg/L aluminum (Al) in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Anatomical changes in roots stressed by ozone and Al, singly and in combination, were determined by light and electron microscopy. All ozone concentrations reduced the percentage of mycorrhizal colonization. In contrast, Al increased the percentage of colonization at low concentration, reducing it only at the highest level. Aluminum caused more overall deterioration of root cortex than ozone, though both treatments adversely affected the mycorrhizal fungus. Increased vacuolation in the root meristem was caused by both ozone and Al. Additional effects of ozone on cells in the meristem were the swelling of the nuclear membrane and invaginations in the plasmalemma. Intracellular fungal hyphae were observed at the highest level of ozone and (or) Al. The combined effect of ozone and Al on the anatomy of mycorrhizae was greater (possibly synergistic) than the effect of each pollutant alone. Similar cellular alterations have also been observed in forests damaged by pollution.

Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: needle ultrastructure

1993 ◽  
Vol 23 (7) ◽  
pp. 1375-1387 ◽  
Author(s):  
Carolyn J. McQuattie ◽  
George A. Schier
Keyword(s):  
Light And Electron Microscopy ◽  
Mycorrhizal Fungus ◽  
Membrane System ◽  
High Concentration ◽  
Solution Ph ◽  
Pitch Pine ◽  
Cytological Changes ◽  
Growth Chambers ◽  
Starch Formation ◽  
Cell Collapse

Newly germinated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, or 50 mg/L aluminum in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Cytological changes in needles of seedlings stressed by ozone and aluminum, singly and in combination, were determined by light and electron microscopy. The most pronounced changes in needles exposed to ozone occurred in the outer mesophyll, whereas major changes in the presence of aluminum occurred in the stele and inner mesophyll. At lower levels of either ozone or aluminum, the cytoplasm became more densely stained. Accumulation of dense materials appeared at intermediate treatment concentrations, and at high concentration localized cell collapse and deterioration became evident. Ozone or aluminum caused similar changes in the chloroplasts, for example, increase in number of plastoglobuli, accumulation of starch, formation of electron-dense stroma, and swelling or disruption of thylakoid membrane system. Ozone and aluminum in combination generally caused histological and cytological damage in needles to occur at lower concentrations than either aluminum or ozone alone.

Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: growth and nutrient relations

1990 ◽  
Vol 20 (11) ◽  
pp. 1714-1719 ◽  
Author(s):  
George A. Schier ◽  
Carolyn J. McQuattie ◽  
Keith F. Jensen
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Mycorrhizal Fungus ◽  
Mineral Elements ◽  
Growth Effect ◽  
Solution Ph ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Pitch Pine ◽  
Nutrient Relations

Newly germimated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, 50, or 100 mg/L of aluminum (Al) in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Increasing the concentration of ozone or Al caused increasing reductions in needle length, seedling height, and biomass of needles, stems, and roots. Significant ozone × Al interactions indicated that ozone and Al were interacting synergistically in reducing growth. Effect of treatments on the root/shoot ratio demonstrated that shoot growth was more sensitive to Al than root growth, whereas root growth was more sensitive to ozone. The concentration of most mineral elements (P, K, Ca, Mg, Mn, Cu, Zn) in needles was reduced by ozone or Al. Iron was the only element that increased with increasing concentrations of ozone or Al.

scholarly journals Tolerance of Eugenia dysenterica to Aluminum: Germination and Plant Growth

Plants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 317 ◽  
Author(s):  
Arthur Almeida Rodrigues ◽  
Sebastião Carvalho Vasconcelos Filho ◽  
Caroline Müller ◽  
Douglas Almeida Rodrigues ◽  
Juliana de Fátima Sales ◽  
...  
Keyword(s):  
Plant Cells ◽  
Low Ph ◽  
High Availability ◽  
Hydroponic System ◽  
Anatomical Changes ◽  
Al Content ◽  
Starch Grain ◽  
Growth Chambers ◽  
Hydroponic Systems ◽  
Eugenia Dysenterica

Native Cerrado plants are exposed to soils with low pH and high availability of Al. In this study, we measured the Al content in adult plants, and investigated the effects of various Al doses on germination and early development of Eugenia dysenterica plants. For germination tests, the seeds were soaked in Al solution and evaluated for twenty days in growth chambers. In a second experiment, young plants were cultivated in hydroponic systems with various Al concentrations to evaluate the morphological, anatomical and physiological characteristics of E. dysenterica. Anatomical changes and low germinative vigor were observed in seeds germinated in 600 and 800 μmol Al3+ L−1. In the hydroponic system, 200 μmol Al3+ L−1 stimulated root growth in young plants. The activity of antioxidant enzymes and the accumulation of phenolic compounds were greatest at the highest Al doses, preventing changes in gas exchange and chlorophyll a fluorescence. Starch grain accumulation was noted in plant cells exposed to 200 and 400 μmol Al3+ L−1. Adult E. dysenterica trees also accumulated Al in leaves, bark and seeds. These data suggest that E. dysenterica is tolerant to Al.

scholarly journals Developmental Anatomy of Lesions on `Sunburst' Mandarin Leaves Initiated by Citrus Rust Mite Feeding

1991 ◽  
Vol 116 (4) ◽  
pp. 663-668 ◽  
Author(s):  
D.S. Achor ◽  
L.G. Albrigo ◽  
C.W. McCoy
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Citrus Reticulata ◽  
Developmental Anatomy ◽  
Anatomical Changes ◽  
Fungal Invasion ◽  
Mite Feeding ◽  
Phyllocoptruta Oleivora ◽  
Citrus Rust Mite

Upper surface leaf lesions on `Sunburst' mandarin [(Citrus reticulata Blanco × (C. paradisi Macf. × C. reticulate)] associated with feeding by the citrus rust mite [Phyllocoptruta oleivora (Ashm.)] are more severe than those on other citrus cultivars. Development of leaf lesions on `Sunburst' mandarin and two other cultivars were examined by light and electron microscopy. Damaged leaves treated with a fungicide confirmed that the anatomical changes on `Sunburst' are an enhanced wound periderm response to feeding injury by rust mite and not the result of fungal invasion.

scholarly journals Spatial differences in stoichiometry of EGR phosphatase and Microtubule-Associated Stress Protein 1 control root meristem activity during drought stress.

2021 ◽  
Author(s):  
Toshisagba Longkumer ◽  
Chih-Yun Chen ◽  
Marco Biancucci ◽  
Bhaskara Govinal Badiger ◽  
Paul E. Verslues
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Cell Expansion ◽  
Growth Regulation ◽  
Root Meristem ◽  
Stress Protein ◽  
Root Cell ◽  
Root Cortex ◽  
Meristem Cell ◽  
Meristem Size

During moderate severity drought and low water potential (Ψw) stress, poorly understood signaling mechanisms restrict both meristem cell division and subsequent cell expansion. We found that the Clade E Growth-Regulating 2 (EGR2) protein phosphatase and Microtubule Associated Stress Protein 1 (MASP1) differed in their stoichiometry of expression across the root meristem and had opposing effects on root meristem activity at low Ψw. Ectopic MASP1 or EGR expression increased or decreased, respectively, root meristem size and root elongation during low Ψw stress. This, along with the ability of phosphomimic MASP1 to overcome EGR suppression of root meristem size and observation that ectopic EGR expression had no effect on unstressed plants, indicated that during low Ψw EGR activation and attenuation of MASP1 phosphorylation in their overlapping zone of expression determines root meristem size and activity. Ectopic EGR expression also decreased root cell size at low Ψw. Conversely, both the egr1-1egr2-1 and egr1-1egr2-1masp1-1 mutants had similarly increased root cell size; but, only egr1-1egr2-1 had increased cell division. These observations demonstrated that EGRs affect meristem activity via MASP1 but affect cell expansion via other mechanisms. Interestingly, EGR2 was highly expressed in the root cortex, a cell type important for growth regulation and environmental response.

scholarly journals Structure and development of root gall induced by Meloidogyne javanica in Glycine max L.

2019 ◽  
Vol 40 (3) ◽  
pp. 1033
Author(s):  
Roberta Mendes Isaac Ferreira Vilela ◽  
Vitor Campana Martini ◽  
Letícia de Almeida Gonçalves ◽  
Vinícius Coelho Kuster ◽  
Denis Coelho de Oliveira
Keyword(s):  
Glycine Max ◽  
Host Plant ◽  
Light And Electron Microscopy ◽  
Meloidogyne Javanica ◽  
Giant Cells ◽  
Infection Process ◽  
Site Formation ◽  
Thick Wall ◽  
Vascular Cylinder ◽  
Root Cortex

Galls formed by root-knot nematodes have been studied in several cultivated species focusing on understanding the intimate relationship between parasite and the host plant. Species of Meloidogyne induce the development of a feeding site in the cortex or vascular cylinder of the host plant and are totally dependent on this site formation to complete their life cycle. Therefore, we focused on anatomical, cytological and histochemical changes during the establishment and development of galls and giant cells induced by Meloidogyne javanica in the roots of Glycine max. Seeds of soybean (susceptible cultivar M8372 IPRO) were sown in trays with coconut fibre substrate and the seedlings were removed ten days after the seeds emerged for nematode inoculation. The roots from inoculated and non-inoculated (control) were sampled at different stages of development until 55 days after inoculation. Histological, cytological, histochemical analysis were performed in light and electron microscopy in non-galled tissue and galls induced by M. javanica. The galls showed different shapes and abundance in the roots inoculated by M. javanica. The induction of galls occurs by hypertrophy of the root cortex shortly after the initial infection process. Giant cells were formed 18 days after nematode inoculation. These giant or nourishing cells are multinucleated, and have a dense cytoplasm, a thick wall with invaginations, many mitochondria and small vacuoles. The anatomical sections indicated a disorganisation of the cells of the cortex and vascular cylinder in relation to the control root.

Cell shape, chromosome orientation and the position of the plane of division in Vicia faba root cortex cells

1992 ◽  
Vol 103 (3) ◽  
pp. 847-855 ◽  
Author(s):  
J.L. Oud ◽  
N. Nanninga
Keyword(s):  
Vicia Faba ◽  
Cell Shape ◽  
Root Meristem ◽  
Three Dimensional ◽  
Progressive Increase ◽  
Root Cortex ◽  
Division Plane ◽  
Daughter Cells ◽  
Spindle Axis ◽  
Original Cell

Three-dimensional chromosome orientation was studied in thick sections of Vicia faba root meristem, using confocal microscopy and digital image analysis techniques. In the proliferative part of the root meristem, where the cells are organized in longitudinal files, it was expected to find dividing cells with a spindle axis parallel to the file axis and, occasionally, perpendicular to the file axis (resulting in a local file bifurcation). However, we observed a large number of oblique spindle axes. From metaphase to telophase there was a progressive increase in the rotation of the spindle axis. A 90° turn of the metaphase equator plane was never observed. Three-dimensional measurements of both the space occupied by the ana- and telophase chromosome configurations, and the size of the corresponding cortex cells, showed that most cells were too flat for an orientation of the spindle parallel to the file axis. Apparently, cell size limitations forced the spindle to rotate during mitosis. Consequently, the nuclei in the daughter cells were positioned diagonally in opposite directions, instead of on top of each other. In the majority of these cells, a transverse plane of division would intersect the nuclei. Therefore, the new cell wall was sigmoid shaped or oblique. Most daughter cells remained within the original cell file but, occasionally, in extremely flat cells the position of the daughter nuclei forced the cell to set a plane of division parallel to the file axis. This resulted in file bifurcation. It has been concluded that cell shape, the extent of spindle rotation and the position of the division plane are related.

A note on the feeding of the nematode, Anguillulina macrura

1943 ◽  
Vol 21 (1) ◽  
pp. 17-19 ◽  
Author(s):  
T. Goodey
Keyword(s):  
Close Association ◽  
Agrostis Stolonifera ◽  
Root Cortex ◽  
Nematode Genus ◽  
Fungal Hyphae ◽  
Root Tissues

Certain species of the nematode genus Anguillulina which commonly occur in close association with the roots of grasses are known to invade the root cortex and to reproduce therein. Thus Anguillulina pratensis, A. obtusa and A. erythrinae all occur in the roots of Agrostis stolonifera L. in pastures at this Institute. The writer has on a few occasions, also found one or two specimens of the small tapering-tailed species, A. agricola and A. costata, within the root cortex of the same kind of grass but further observations are needed before we can say definitely whether these two species actually parasitize roots and reproduce within the tissues. An occasional specimen of A. intermedia has also been found by the writer once or twice inside root tissues but never in what could be regarded as fresh, sound roots, and in view of Linford's (1937) observations on the ability of this species to feed upon fungal hyphae, it is probably safest to regard it as not a true parasite. The examples found may have entered partly decayed roots in search of fungal hyphae.

Fungal calcium oxalate in mycorrhizae of Monotropa uniflora

1990 ◽  
Vol 68 (3) ◽  
pp. 533-543 ◽  
Author(s):  
Karen M. Snetselaar ◽  
Kenneth D. Whitney
Keyword(s):  
Calcium Oxalate ◽  
Cell Walls ◽  
Mycorrhizal Fungus ◽  
Late Summer ◽  
Mineral Nutrients ◽  
Metabolic Process ◽  
Precipitation Event ◽  
Nutrient Transfer ◽  
Calcium Oxalate Crystals ◽  
Fungal Hyphae

Monotropa uniflora is an achlorophyllous angiosperm that is obligately mycotrophic. The "monotropoid" mycorrhizae it forms resemble ectomycorrhizae but are distinguished by elaborations of the epidermal cell walls that surround intruding fungal hyphae. Monotropoid mycorrhizae collected from blooming plants in late summer contained calcium oxalate crystals between mantle hyphae. The crystals appeared to form in association with hyphal walls and grew into a matrix outside the hyphae. Production of calcium oxalate by M. uniflora's mycobiont seems to be a coordinated metabolic process rather than a random precipitation event. The significance of calcium translocation and isolation as calcium oxalate to this mycorrhizal fungus is unclear, but the presence of extensive crystal deposits during and after flowering of the host plant suggests a possible link with the nutrient transfer occurring at that time. Mycorrhizal regulation of calcium may affect the availability of mineral nutrients to the associated Monotropa plants. Key words: Monotropa uniflora, mycorrhiza, calcium oxalate, ectomycorrhiza.

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