A simple procedure for mounting wrinkle-free sections on formvar-coated slot grids

Rowley, J. Carter; Moran, David T.

doi:10.1016/s0304-3991(75)80018-0

Cited by 205 publications

(65 citation statements)

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“…The thick sections were collected with a gold ring, put on glass slides, stained with toluidine blue (1.0 g toluidine blue, 1.0 g sodium borate, and 100 mL water), filtered in a 0.22 µm cellulose membrane, and permanently mounted in Permalt medium. The thin sections were picked up on gold slot grids and left to dry on Formvar-coated aluminum racks (Rowley & Moran, 1975). The sections were post-stained with uranyl acetate, followed by lead citrate for 3 min each.…”

Section: Methodsmentioning

confidence: 99%

Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

Lucas

Alves

Pereira

et al. 2012

Pesq. agropec. bras.

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-The objective of this work was to evaluate the effects of plant essential oils (EOs) on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings under greenhouse conditions. The effects of citronella, lemongrass, clove, and tea tree EOs, at 0.1%, on X. vesicatoria cells were evaluated by transmission electron microscopy. All EOs showed direct toxic effect on the bacteria at a 10%-concentration in vitro. Under greenhouse conditions, the EOs of clove, citronella, tea tree, and lemongrass reduced disease severity. EOs of clove and tea tree, and streptomycin sulfate promoted loss of electron-dense material and alterations in the cytoplasm, whereas EO of tea tree promoted cytoplasm vacuolation, and those of citronella, lemongrass, clove, and tea tree caused damage to the bacterial cell wall. The EOs at a concentration of 0.1% reduce the severity of the disease.Index terms: alternative control of plant disease, cell ultrastructure, pathogenic bacteria. Atividade antibacteriana de óleos essenciais sobre Xanthomonas vesicatoria e controle da mancha-bacteriana do tomateiroResumo -O objetivo deste trabalho foi avaliar o efeito de óleos essenciais (OEs) no crescimento de Xanthomonas vesicatoria, na morfologia e na ultraestrutura bacteriana, e na severidade da mancha-bacteriana do tomateiro. OEs de citronela, cravo-da-índia, canela, capim-limão, eucalipto, tomilho e árvore-de-chá foram avaliados in vitro nas concentrações de 0,1, 1,0, 10 e 100% em leite em pó a 1,0%. O efeito dos OEs, a 0,1%, na severidade da mancha-bacteriana do tomateiro foram avaliados em plantas de tomateiro em casa de vegetação. Os efeitos dos óleos de citronela, capim-limão, cravo-da-índia e árvore-de-chá, a 0,1%, nas células de X. vesicatoria foram avaliados por meio de microscopia eletrônica de transmissão. Todos os OEs apresentaram efeito tóxico direto sobre as bactérias na concentração de 10% in vitro. Em casa de vegetação, os OEs de cravo-da-índia, citronela, árvore-de-chá e capim-limão reduziram a severidade da doença. Os OEs de cravo-da-índia e árvore-de-chá, e o sulfato de estreptomicina promoveram perda de material eletro-denso e alterações no citoplasma, enquanto o OE de árvore-de-chá promoveu vacuolização do citoplasma, e os de citronela, capim-limão, cravo-da-índia e árvore-de-chá causaram danos à parede celular bacteriana. Os OEs, na concentração de 0,1%, reduzem a severidade da doença.Termos para indexação: controle alternativo de doenças de plantas, ultraestrutura celular, bactéria fitopatogênica.

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Section: Methodsmentioning

confidence: 99%

Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

Lucas

Alves

Pereira

et al. 2012

Pesq. agropec. bras.

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“…Cytological analysis: For all cytological studies, three to five embryonic axes per treatment were excised from the (Rowley and Moran, 1975). Sections were post-stained with uranyl acetate followed by lead citrate (3 min each) and examined using a transmission electron microscope (Zeiss EM 109, Carl Zeiss, Jena, Germany).…”

Section: Scanning Electron Microscopy (Sem)mentioning

confidence: 99%

Physiological and cytological aspects of Inga vera subsp. affinis embryos during storage

Faria

Davide

Silva

et al. 2006

Braz. J. Plant Physiol.

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The remarkably short storability of recalcitrant seeds has prevented their inclusion in programs of ex situ conservation. The causes of their desiccation sensitivity and rapid decline in viability during storage are not fully elucidated yet. In this study the highly recalcitrant, fully viable embryos of the tree species Inga vera subsp. affinis were stored under various conditions and analyzed physiologically and cytologically at intervals, in order to obtain more insights in their loss of viability during storage. Embryos stored fully hydrated at 5 o C fully lost viability in 18 d. Sealed storage of partially dehydrated embryos slightly prolonged their viability, with 95% germination being attained after 14 d of storage. However, after 30 d of storage, viability was completely lost. Storage of hydrated embryos in a solution of polyethylene glycol (PEG) at -1.7 MPa water potential was capable of maintaining high germinability until 30 d of storage. When added to the PEG solution, abscisic acid showed a strong temperature-dependent interaction, with a positive effect on the longevity of embryos stored at 20 o C and a negative effect on embryos stored at 5 o C. In any case, embryo viability could be maintained no longer than 50 d. Embryos from seeds collected from the same trees in the following year showed better storability and still attained 45% germination after 62 d of storage. Analysis of cellular alterations during storage and viability loss of the embryos showed disappearance of starch granules and various damages to the cells, such as cell wall folding and cytoplasm fragmentation. Key-words: abscisic acid, polyethylene glycol, recalcitrant seeds, seed conservationAspectos fisiológicos e citológicos de embriões de Inga vera subsp. affinis durante o armazenamento: A capacidade reduzida de armazenamento apresentada pelas sementes recalcitrantes tem impedido sua inclusão em programas de conservação ex situ. As causas da rápida queda da viabilidade durante o armazenamento ainda não estão totalmente elucidadas. Visando, portanto, a um melhor entendimento desse comportamento, embriões de sementes recalcitrantes de Inga vera subsp. affinis foram armazenados sob várias condições e avaliados periodicamente com relação a aspectos fisiológicos e citológicos. Embriões armazenados sem secagem, a 5 o C, perderam totalmente a viabilidade em 18 dias. Embriões parcialmente desidratados apresentaram 95% de germinação após 14 dias de armazenamento em sacos plásticos selados. Entretanto, após 30 dias de armazenamento, a viabilidade foi totalmente perdida. O armazenamento de embriões sem secagem em solução de polietileno glicol (PEG) a um potencial hídrico de -1,7 MPa foi capaz de manter uma alta capacidade de germinação até 30 dias de armazenamento. Quando adicionado à solução de PEG, o ácido abscísico mostrou uma forte interação com a temperatura de armazenamento, com um efeito positivo na longevidade dos embriões armazenados a 20 o C, porém um efeito negativo nos embriões armazenados a 5 o C. No entanto, em nenhuma condição...

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“…Thin sections (<100 nm) were cut with an MT 6000-XL (RMC Inc., Tucson, A Z ) dtramicrotome and collected on Formvar-coated, gilded copper slot grids (Ted Pella) and placed on Formvar bridges to dry (Rowley and Moran, 1975).…”

Section: Emmentioning

confidence: 99%

Developmental and Tissue-Specific Structural Alterations of the Cell-Wall Polysaccharides of Arabidopsis thaliana Roots

et al. 1996

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The plant cell wall is a dynamic structure that plays important roles i n growth and development and in the interactions of plants with their environment and other organisms. We have used monoclonal antibodies that recognize different carbohydrate epitopes present i n plant cell-wall polysaccharides to locate these epitopes in roots of developing Arabidopsis fhaliana seedlings. An epitope i n the pectic polysaccharide rhamnogalacturonan I is observed in the walls of epidermal and cortical cells in mature parts of the root. This epitope is inserted into the walls i n a developmentally regulated manner. Initially, the epitope is observed in atrichoblasts and later appears in trichoblasts and simultaneously in cortical cells. A terminal a-fucosyl-containing epitope is present i n almost all of the cell walls in the root. An arabinosylated (1 +6)-P-galactan epitope is also found in all of the cell walls of the root with the exception of lateral root-cap cell walls. It is striking that these three polysaccharide epitopes are not uniformly distributed (or accessible) within the walls of a given cell, nor are these epitopes distributed equally across the two walls laid down by adjacent cells. Our results further suggest that the biosynthesis and differentiation of primary cell walls in plants are precisely regulated i n a temporal, spatial, and developmental manner.The understanding of the role(s) of cell walls in plant biology has evolved considerably in recent years. Whereas the function of cell walls was initially viewed as primarily providing form and structure to plant cells, it has now become clear that the wall has a variety of other functions in plant growth and development (Roberts, 1990) and in the interactions of plants with their environment and other organisms (Hahn et al., 1989). It is therefore important to learn where the macromolecular components. are located within the walls of individual cells and within tissues and how the structures of the wall polymers change as a function of plant growth and development and during active defense against disease and environmental stress.Monoclonal antibodies have proven to be valuable tools for studies of the dynamics of cell surface glycoconjugates in animals (Hakomori, 1984; Feizi and Childs, 1987). Studies of the temporal, spatial, and developmental dynamics of plant cell-wall glycoconjugates have lagged behind corresponding animal studies because of the more limited collection of monoclonal antibodies against cell-wall carbohydrate epitopes that is available and because of the difficulty in characterizing the epitopes recognized by the available antibodies. Previous studies of plant cell-wall dynamics have focused on cell surface glycoproteins, since arrays of monoclonal antibodies have been generated against two types of such complex glycoconjugates, the arabinogalactan-proteins (Anderson et al., 1984;

show abstract

A simple procedure for mounting wrinkle-free sections on formvar-coated slot grids

Cited by 205 publications

References 1 publication

Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

Physiological and cytological aspects of Inga vera subsp. affinis embryos during storage

Developmental and Tissue-Specific Structural Alterations of the Cell-Wall Polysaccharides of Arabidopsis thaliana Roots

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