scholarly journals Discovery of a naturally-occurring allele of eIF4E1.S in Nicotiana tabacum and development of a co-dominant marker

Euphytica ◽  
2021 ◽  
Vol 217 (7) ◽  
Author(s):  
Shifeng Lin ◽  
Ralph E. Dewey ◽  
Rengang Wang ◽  
Jing Yu ◽  
Mingjin Long ◽  
...  
Phytomedicine ◽  
2007 ◽  
Vol 14 (5) ◽  
pp. 344-352 ◽  
Author(s):  
Ezra R. Lowe ◽  
Andrew C. Everett ◽  
Miranda Lau ◽  
Anwar Y. Dunbar ◽  
David Michener ◽  
...  

2020 ◽  
Author(s):  
Shifeng Lin ◽  
Ralph E. Dewey ◽  
Rengang Wang ◽  
Jing Yu ◽  
Mingjin Long ◽  
...  

Abstract Background: The Potato Virus Y (PVY) resistance tobacco mutant VAM, which was produced by X-ray irradiation, and its derived mutant va were previously shown to contain large chromosomal deletions. Among the genes deleted in lines containing these loci is a specific eukaryotic translation initiation factor 4E (eIF4E) gene, designated eIF4E1.S, whose protein product has been shown to facilitate infection by certain potyviruses, the most important of which from an agronomic perspective is PVY. Because the extent of the deletions and the exact nature of their specific breakpoints have not been precisely established for VAM or va, it has not been possible to develop co-dominant markers for these loci. Results: Here, we identified a PVY-resistant tobacco landrace Fuquanliuye with a deletion in the 3' region of the eIF4E1.S gene. The approximate position of the 5' deletion breakpoint was defined by segmented amplification, cloning and sequencing. Using information from this analysis, a chromosome walk was initiated and the nucleotide sequence of the deletion junction was obtained. Through comparison with the tobacco reference genome, it was found that an approximately 27 kb sequence including the 3' region of the eIF4E1.S gene was deleted from the Fuquanliuye genome and nine extra nucleotides of unknown origin were inserted at the breakpoint. Based on the information above, a PCR-based co-dominant molecular marker for the identification of the eIF4E1.S mutant allele was developed. Using this co-dominant marker, we genotyped F2 plants segregating for the eIF4E1.S mutant allele and confirmed good consistency between the genotype and the phenotype to PVY virus. Conclusions: We report a novel naturally-occurring mutant allele of eIF4E1.S from the PVY-resistant tobacco landrace Fuquanliuye, designated eIF4E1.Fu, and a PCR-based co-dominant marker specific for eIF4E1.Fu. This may provide a valuable genetic resource and a basis for marker-assisted selection to improve the PVY resistance of breeding cultivars/lines.


Author(s):  
A. W. Fetter ◽  
C. C. Capen

Atrophic rhinitis in swine is a disease of uncertain etiology in which infectious agents, hereditary predisposition, and metabolic disturbances have been reported to be of primary etiologic importance. It shares many similarities, both clinically and pathologically, with ozena in man. The disease is characterized by deformity and reduction in volume of the nasal turbinates. The fundamental cause for the localized lesion of bone in the nasal turbinates has not been established. Reduced osteogenesis, increased resorption related to inflammation of the nasal mucous membrane, and excessive resorption due to osteocytic osteolysis stimulated by hyperparathyroidism have been suggested as possible pathogenetic mechanisms.The objectives of this investigation were to evaluate ultrastructurally bone cells in the nasal turbinates of pigs with experimentally induced atrophic rhinitis, and to compare these findings to those in control pigs of the same age and pigs with the naturally occurring disease, in order to define the fundamental lesion responsible for the progressive reduction in volume of the osseous core.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


Author(s):  
G. M. Hutchins ◽  
J. S. Gardner

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.


Author(s):  
Egbert W. Henry

Tobacco mosaic virus (TMV) infection has been studied in several investigations of Nicotiana tabacum leaf tissue. Earlier studies have suggested that TMV infection does not have precise infective selectivity vs. specific types of tissues. Also, such tissue conditions as vein banding, vein clearing, liquification and suberization may result from causes other than direct TMV infection. At the present time, it is thought that the plasmodesmata, ectodesmata and perhaps the plasmodesmata of the basal septum may represent the actual or more precise sites of TMV infection.TMV infection has been implicated in elevated levels of oxidative metabolism; also, TMV infection may have a major role in host resistance vs. concentration levels of phenolic-type enzymes. Therefore, enzymes such as polyphenol oxidase, peroxidase and phenylalamine ammonia-lyase may show an increase in activity in response to TMV infection. It has been reported that TMV infection may cause a decrease in o-dihydric phenols (chlorogenic acid) in some tissues.


Author(s):  
David R. Veblen

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.


2020 ◽  
Vol 134 (12) ◽  
pp. 1403-1432 ◽  
Author(s):  
Manal Muin Fardoun ◽  
Dina Maaliki ◽  
Nabil Halabi ◽  
Rabah Iratni ◽  
Alessandra Bitto ◽  
...  

Abstract Flavonoids are polyphenolic compounds naturally occurring in fruits and vegetables, in addition to beverages such as tea and coffee. Flavonoids are emerging as potent therapeutic agents for cardiovascular as well as metabolic diseases. Several studies corroborated an inverse relationship between flavonoid consumption and cardiovascular disease (CVD) or adipose tissue inflammation (ATI). Flavonoids exert their anti-atherogenic effects by increasing nitric oxide (NO), reducing reactive oxygen species (ROS), and decreasing pro-inflammatory cytokines. In addition, flavonoids alleviate ATI by decreasing triglyceride and cholesterol levels, as well as by attenuating inflammatory mediators. Furthermore, flavonoids inhibit synthesis of fatty acids and promote their oxidation. In this review, we discuss the effect of the main classes of flavonoids, namely flavones, flavonols, flavanols, flavanones, anthocyanins, and isoflavones, on atherosclerosis and ATI. In addition, we dissect the underlying molecular and cellular mechanisms of action for these flavonoids. We conclude by supporting the potential benefit for flavonoids in the management or treatment of CVD; yet, we call for more robust clinical studies for safety and pharmacokinetic values.


2008 ◽  
Vol 78 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Fan ◽  
Jiang ◽  
Zhang ◽  
Bai

In efforts to identify naturally occurring compounds that act as protective agents, resveratrol, a phytoalexin existing in wine, has attracted much interest because of its diverse pharmacological characteristics. Considering that apoptosis induction is the most potent defense approach for cancer treatment, we have tried to summarize our present understanding of apoptosis induction by resveratrol based on the two major apoptosis pathways.


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