Acid rain effects on foliar histology of Artemisia tilesii

1984 ◽  
Vol 62 (3) ◽  
pp. 463-474 ◽  
Author(s):  
C. M. Adams ◽  
N. G. Dengler ◽  
T. C. Hutchinson
Keyword(s):  
Acid Rain ◽  
Fungal Pathogens ◽  
Leaf Tissue ◽  
Epidermal Cells ◽  
Simulated Acid Rain ◽  
Scanning Electron Micrographs ◽  
Mesophyll Cells ◽  
Spongy Mesophyll ◽  
Abnormal Cell ◽  
Naturally Occurring

The present study describes the effects of simulated acid rain (pH 2.5–5.6) on foliar histology of an arctic herb, Artemisia tilesii Ledeb., which is remarkably tolerant to naturally occurring atmospheric acidity at Smoking Hills, N.W.T. Plants were exposed to simulated acid rain twice weekly for 4 weeks in exposure chambers in the greenhouse. Droplets as acidic as pH 2.5 caused limited macroscopic foliar damage. However, much greater damage was observed when sectioned leaf tissue was examined microscopically. On leaves having no injury visible to the unaided eye, small lesions consisting of one to three collapsed epidermal cells were observed in scanning electron micrographs and in cleared leaves after exposure to rain of pH 3.0 and 3.5. Stomata remained open in damaged areas of acid-sprayed leaves. Lesions most commonly developed from an initial collapse of a few adaxial epidermal cells, followed by progressive injury of underlying tissues. Palisade and spongy mesophyll cells underwent hypertrophic (abnormal cell enlargement) and hyperplastic (abnormal cell division) responses in the region adjacent to severely collapsed tissue, causing reduced intercellular spaces. These effects isolated the injured areas from adjacent healthy tissues, and resembled wound periderm responses to fungal pathogens and to mechanical irritation. This response may be one mechanism of limiting acid rain damage.

scholarly journals Effects of simulated acid rain on leaf anatomy and micromorphology of Genipa americana L. (Rubiaceae)

2006 ◽  
Vol 49 (2) ◽  
pp. 313-321 ◽  
Author(s):  
Bruno Francisco Sant'Anna-Santos ◽  
Luzimar Campos da Silva ◽  
Aristéa Alves Azevedo ◽  
Rosane Aguiar
Keyword(s):  
Acid Rain ◽  
Leaf Blade ◽  
Leaf Tissue ◽  
Guard Cells ◽  
Simulated Acid Rain ◽  
Spongy Parenchyma ◽  
Mesophyll Cells ◽  
Parenchyma Cells ◽  
Water Ph ◽  
Micromorphological Analysis

Experiments were conducted in order to characterize the injuries on leaf structure and micromorphology of G. americana and evaluate the degree of susceptibility of this species to simulated acid rain. Plants were exposed to acid rain (pH 3.0) for ten consecutive days. Control plants were submitted only to distilled water (pH 6.0). Leaf tissue was sampled and fixed for light and scanning electron microscopy. Necrotic interveinal spots on the leaf blade occurred. Epidermis and mesophyll cells collapse, hypertrophy of spongy parenchyma cells, accumulation of phenolic compounds and starch grains were observed in leaves exposed to acid rain. The micromorphological analysis showed, in necrotic areas, plasmolized guard cells and cuticle rupture. Epidermal and mesophyll cells alterations occurred before symptoms were visualized in the leaves. These results showed the importance of anatomical data for precocious diagnosis injury and to determine the sensitivity of G. americana to acid rain.

scholarly journals Salinity tolerance in chickpea is associated with the ability to ‘exclude’ Na from leaf mesophyll cells

2019 ◽  
Vol 70 (18) ◽  
pp. 4991-5002 ◽  
Author(s):  
Lukasz Kotula ◽  
Peta L Clode ◽  
Juan De La Cruz Jimenez ◽  
Timothy D Colmer
Keyword(s):  
Salinity Tolerance ◽  
Structural Damage ◽  
Leaf Tissue ◽  
Cell Types ◽  
Epidermal Cells ◽  
Salinity Treatment ◽  
Mesophyll Cells ◽  
X Ray ◽  
Leaf Mesophyll ◽  
Excessive Accumulation

Abstract Salinity tolerance is associated with Na ‘exclusion’ from, or ‘tissue tolerance’ in, leaves. We investigated whether two contrasting chickpea genotypes, salt-tolerant Genesis836 and salt-sensitive Rupali, differ in leaf tissue tolerance to NaCl. We used X-ray microanalysis to evaluate cellular Na, Cl, and K concentrations in various cell types within leaflets and also in secretory trichomes of the two chickpea genotypes in relation to photosynthesis in control and saline conditions. TEM was used to assess the effects of salinity on the ultrastructure of chloroplasts. Genesis836 maintained net photosynthetic rates (A) for the 21 d of salinity treatment (60 mM NaCl), whereas A in Rupali substantially decreased after 11 d. Leaflet tissue [Na] was low in Genesis836 but had increased markedly in Rupali. In Genesis836, Na was accumulated in epidermal cells but was low in mesophyll cells, whereas in Rupali cellular [Na] was high in both cell types. The excessive accumulation of Na in mesophyll cells of Rupali corresponded to structural damage to the chloroplasts. Maintenance of photosynthesis and thus salinity tolerance in Genesis836 was associated with an ability to ‘exclude’ Na from leaflets and in particular from the photosynthetically active mesophyll cells, and to compartmentalize Na in epidermal cells.

scholarly journals Changes in the Cellular Concentrations of Elements in Tobacco Leaf Tissues during Growth and Senescence

1989 ◽  
Vol 14 (5) ◽  
pp. 297-312
Author(s):  
P Echlin
Keyword(s):  
Leaf Tissue ◽  
Mesophyll Cells ◽  
Spongy Mesophyll ◽  
X Ray ◽  
Positive Correlation ◽  
Stages Of Growth ◽  
Sodium Magnesium ◽  
Leaf Tissues ◽  
Phosphorus And Potassium ◽  
Late Stages

AbstractQuantitative X-ray microanalysis for nine elements has been carried out on frozen, fully hydrated fracture faces of upper and lower epidermis, palisade and spongy mesophyll cells in leaf tissue of Nicotianatabacum L. cv. Coker 319 taken from plants at five different stages of growth. Although concentrations of aluminium, silicon and chlorine generally fell below the minimum-detection limit, the values for sodium, magnesium, phosphorus, sulphur, potassium and calcium were consistently higher and showed differences among tissue types and stages of growth. The general trend was for elemental concentrations to increase up to the mature and ripe stages of growth and then to decrease as the leaf ages further. The sodium values were highest at the beginning and end of the five stages of growth, with higher amounts in the epidermal tissues. As the leaves age, the levels of magnesium fell in the photosynthetic tissues but increased in the epidermal tissues. Such changes could be correlated with higher concentrations of potassium at the early stages of growth and with much lower values at the late stages. The sulphur levels showed only small differences between tissue types at all stages of growth. The calcium levels increased with age and there were consistently higher concentrations in the photosynthetic tissues than in the two epidermal layers. The levels of phosphorus were low in all tissue types and decreased with age. There is an increasing positive correlation between phosphorus and magnesium and a decreasing positive correlation between phosphorus and potassium during growth and senescence.

An analysis of the effects of gibberellic acid on the leaflet structure of dwarf cultivars of pea (Pisum sativum)

1979 ◽  
Vol 57 (10) ◽  
pp. 1089-1092 ◽  
Author(s):  
G. F. Israelstam ◽  
Erica Davis
Keyword(s):  
Pisum Sativum ◽  
Gibberellic Acid ◽  
Surface Area ◽  
Epidermal Cells ◽  
Mesophyll Cells ◽  
Spongy Mesophyll ◽  
Number Of Layers ◽  
Dwarf Cultivar ◽  
Palisade Cells ◽  
Degree Of Differentiation

The effects of gibberellic acid (GA3) on the penultimate leaflets of dwarf and normal cultivars of pea were investigated. In control plants, the leaflets of the dwarf were heavier, thicker, and had a smaller surface area than the normal. Epidermal and palisade cells of the dwarf were longer than those of the normal cultivar and the dwarf had longer spongy mesophyll cells and more layers of spongy mesophyll than the normal, with fewer intercellular spaces.Application of GA3 to dwarf plants increased leaflet surface area and length of epidermal cells, while leaflet weight and thickness and the number of layers of spongy mesophyll cells decreased. No significant changes in the leaflet of the normal cultivar were induced by GA3.The overall effect of GA3 application to the dwarf cultivar was to induce a degree of differentiation in the penultimate leaflets such that they tended to resemble more closely those of the normal cultivar.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

Effect of Simulated Acid Rain on Gas Exchanges of Three Compositae Invasive Plants

2013 ◽  
Vol 48 (2) ◽  
pp. 160-167
Author(s):  
Song Liying ◽  
Ke Zhanhong ◽  
Sun Lanlan ◽  
Peng Changlian
Keyword(s):  
Acid Rain ◽  
Invasive Plants ◽  
Simulated Acid Rain ◽  
Gas Exchanges
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