Understanding Genetic Control of Freezing Resistance Using Potato Species as a Model System

1997 ◽  
pp. 67-75
Author(s):  
Jiwan P. Palta ◽  
John B. Bamberg ◽  
Yu-Kuang Chen ◽  
Sandra E. Vega ◽  
Laurie S. Weiss ◽  
...  
2018 ◽  
Vol 3 (3) ◽  
pp. 86 ◽  
Author(s):  
Damilare Famakinde

Schistosomiasis remains the most important tropical snail-borne trematodiasis that threatens many millions of human lives. In achieving schistosomiasis elimination targets, sustainable control of the snail vectors represents a logical approach. Nonetheless, the ineffectiveness of the present snail control interventions emphasizes the need to develop new complementary strategies to ensure more effective control outcomes. Accordingly, the use of genetic techniques aimed at driving resistance traits into natural vector populations has been put forward as a promising tool for integrated snail control. Leveraging the Biomphalaria-Schistosoma model system, studies unraveling the complexities of the vector biology and those exploring the molecular basis of snail resistance to schistosome infection have been expanding in various breadths, generating many significant discoveries, and raising the hope for future breakthroughs. This review provides a compendium of relevant findings, and without neglecting the current existing gaps and potential future challenges, discusses how a transgenic snail approach may be adapted and harnessed to control human schistosomiasis.


2019 ◽  
Vol 99 (6) ◽  
pp. 873-884 ◽  
Author(s):  
Qiaoyu Wu ◽  
Tianjiu He ◽  
Hui Liu ◽  
Xiaobo Luo ◽  
Wang Yin ◽  
...  

Potato cultivars are sensitive to frost; thus, freezing damage often results in heavy loss of potato yield. In this study, two wild potato species, Solanum acaule W3, which is frost-resistant and has cold-acclimation ability, and Solanum cardiophyllum Cph12, which is frost-sensitive and cannot be cold-acclimated, were used to research the cell structure and physiological changes that occur during cold acclimation. The results showed that the frost resistance of W3 was enhanced by cold acclimation, while the frost resistance of Cph12 did not change. The subcellular characteristics related to the enhancement of freezing resistance mainly include a decrease in the proportion of the vacuole to total cell volume, integrity of the biomembrane, and orderly arrangement of grana lamellae. At the physiological level, the W3 damage index was correlated with membrane lipid peroxidation system indices (including chlorophyll, malondialdehyde, and the difference between relative conductivity before and after freezing treatment in W3), the activity of the antioxidant enzymes superoxide dismutase and catalase, the contents of the osmotic regulators proline and soluble protein, and the contents of the endogenous hormones salicylic acid (SA), indole acetic acid/abscisic acid (IAA/ABA), and SA/ABA, which indicated that cold acclimation enhanced the freezing resistance of wild potato species W3 by enhancing its original cold-tolerance characteristics. The results could be useful to clarify the cold resistance mechanism of plants, and to provide a theoretical basis for cold-resistance breeding.


2007 ◽  
Vol 76 (6) ◽  
pp. 1072-1078 ◽  
Author(s):  
NIJOLE JASINSKIENE ◽  
AURORA ASHIKYAN ◽  
OSVALDO MARINOTTI ◽  
MICHAEL SALAMPESSY ◽  
JUDY COLEMAN ◽  
...  

2018 ◽  
Vol 8 (1) ◽  
pp. 324-334
Author(s):  
A. Ad. Podhaietskyi ◽  
N. V. Kravchenko ◽  
L. V. Kriuchko ◽  
S. M. Gorbas ◽  
A. An. Podhaietskyi

<p>The article presents the theoretical substantiation and experimental data, confirming the natural evolution of potato species from the standpoint of the stability and effectiveness of genetic control of resistance to late blight. Resistant samples of wild potato species which were differ in the appearance of the trait were used as the initial material for research. Artificial infection of seedlings obtained from self-pollination of potato samples with the race of phytophthora (<em>Phytophtora infestans </em>(Mont.) De Bary) 1-11X, Y, Z (25-30 conidia in the view of the microscope, 120 x), which made it possible to identify various types of resistance to fungus. The evolutionary changes of the species, relating their response to the changing of phytopathological situation in their areas have been experimentally proven. The intraspecific variety of <em>S. demissum </em>Lindl and <em>S. stoloniferum </em>Schlechtd. samples by resistance to phytophthora, which manifested both among I1 and among I2, has been identified. Depending on the evolution of the samples, differences in the genetic control of resistance to the pathogen were found, which was manifested in the frequency of appearance of offspring with high resistance, hypersensitivity, high, medium and low field resistance, as well as complete damage of seedlings. In the species of <em>S. demissum</em> the sample was found, in its progeny the seedlings with extremely high resistance to the pathogen were not isolated, but in the case of the UK sample No 27-19 the part of such material was 94.2%. The lower level of genetic control in this species was characterized by the type of supersensitive resistance. Variation in the offspring samples by this type of resistance was observed in the range of 0-78.4%, and the splitting of seedlings with high field stability was even smaller and was within 0-45%. Similar data were obtained for the species of <em>S. stoloniferum</em>. A similar type of conjugate evolution of phytophthora resistance in the testing species has been experimentally proved. There were no differences in the manifestation of hypersensitive resistance or they were very insignificant. The maximum differences between species were 4% in the class with the offspring frequency of 81-100%. Based on the results of the phytophthora resistance evaluation of various samples of potato species in I2, it was assumed that under epiphytotic conditions in the area of species growth, samples with effective genetic control of the trait, i.e., with an extremely high degree of resistance, will be evolutionally promising. </p>


Author(s):  
D. C. Williams ◽  
D. E. Outka

Many studies have shown that the Golgi apparatus is involved in a variety of synthetic activities, and probably no Golgi product is more elaborate than the scales produced by various kinds of phytoflagellates. The formation of calcified scales (coccoliths, Fig. 1,2) of the coccolithophorid phytoflagellates provides a particularly interesting model system for the study of biological mineralization, and the sequential formation of Golgi products.The coccoliths of Hymenomonas carterae consist of a scale-like base (Fig. 2 and 4, b) with a highly structured calcified (CaCO3) rim composed of two distinct elements which alternate about the base periphery (Fig. 1 and 3, A, B). Each element is enveloped by a sheath-like organic matrix (Fig. 3; Fig. 4, m).


Author(s):  
Masako Osumi ◽  
Misuzu Nagano ◽  
Hiroko Kazama

We have found that microbodies appeared profusely together with a remarkable increase in catalase activity in normal alkane-grown cells of hydrocarbon-utilizing Candida yeasts, and that the microbodies multiplied by division in these cells. These features of Candida yeasts seem to provide a useful model system for studies on the biogenesis of the microbody. Subsequently, we have succeeded in isolation of Candida microbodies in an apparently native state, as judged biochemically and morphologically. The presence of DNA in the purified microbody fraction thus obtained was proved by the diphenylamine method. DNA molecule of about 15 urn in contour length was released from an isolated microbody. The physicochemical analyses of the microbody DNA revealed that its buoyant density differed from nuclear and mitochondrial DNAs. All these results lead us to the possibility that there is a novel type of DNA in microbodies.


Author(s):  
M.J. Witcomb ◽  
U. Dahmen ◽  
K.H. Westmacott

Cu-Cr age-hardening alloys are of interest as a model system for the investigation of fcc/bcc interface structures. Several past studies have investigated the morphology and interface structure of Cr precipitates in a Cu matrix (1-3) and good success has been achieved in understanding the crystallography and strain contrast of small needle-shaped precipitates. The present study investigates the effect of small amounts of phosphorous on the precipitation behavior of Cu-Cr alloys.The same Cu-0.3% Cr alloy as was used in earlier work was rolled to a thickness of 150 μm, solution treated in vacuum at 1050°C for 1h followed by quenching and annealing for various times at 820 and 863°C.Two laths and their corresponding diffraction patterns in an alloy aged 2h at 820°C are shown in correct relative orientation in Fig. 1. To within the limit of accuracy of the diffraction patterns the orientation relationship was that of Kurdjumov-Sachs (KS), i.e. parallel close-packed planes and directions.


Author(s):  
V.J. Montpetit ◽  
S. Dancea ◽  
L. Tryphonas ◽  
D.F. Clapin

Very large doses of pyridoxine (vitamin B6) are neurotoxic in humans, selectively affecting the peripheral sensory nerves. We have undertaken a study of the morphological and biochemical aspects of pyridoxine neurotoxicity in an animal model system. Early morphological changes in dorsal root ganglia (DRG) associated with pyridoxine megadoses include proliferation of neurofilaments, ribosomes, rough endoplasmic reticulum, and Golgi complexes. We present in this report evidence of the formation of unique aggregates of microtubules and membranes in the proximal processes of DRG which are induced by high levels of pyridoxine.


Author(s):  
J. T. Ellzey ◽  
D. Borunda ◽  
B. P. Stewart

Genetically alcohol deficient deer mice (ADHN/ADHN) (obtained from the Peromyscus Genetic Stock Center, Univ. of South Carolina) lack hepatic cytosolic alcohol dehydrogenase. In order to determine if these deer mice would provide a model system for an ultrastructural study of the effects of ethanol on hepatocyte organelles, 75 micrographs of ADH+ adult male deer mice (n=5) were compared with 75 micrographs of ADH− adult male deer mice (n=5). A morphometric analysis of mitochondrial and peroxisomal parameters was undertaken.The livers were perfused with 0.1M HEPES buffer followed by 0.25% glutaraldehyde and 2% sucrose in 0.1M HEPES buffer (4C), removed, weighed and fixed by immersion in 2.5% glutaraldehyde in 0.1M HEPES buffer, pH 7.4, followed by a 3,3’ diaminobenzidine (DAB) incubation, postfixation with 2% OsO4, en bloc staining with 1% uranyl acetate in 0.025M maleate-NaOH buffer, dehydrated, embedded in Poly/Bed 812-BDMA epon resin, sectioned and poststained with uranyl acetate and lead citrate. Photographs were taken on a Zeiss EM-10 transmission electron microscope, scanned with a Howtek personal color scanner, analyzed with OPTIMAS 4.02 software on a Gateway2000 4DX2-66V personal computer and stored in Excel 4.0.


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