Herbicides: History, Classification and Genetic Manipulation of Plants for Herbicide Resistance

2014 ◽  
pp. 153-192 ◽  
Author(s):  
Sharad Vats
Keyword(s):  
Herbicide Resistance ◽  
Genetic Manipulation

scholarly journals Virus-mediated transient expression techniques enable genetic modification of Alopecurus myosuroides

2020 ◽  
Author(s):  
Macarena Mellado-Sánchez ◽  
Faye McDiarmid ◽  
Victor Cardoso ◽  
Kostya Kanyuka ◽  
Dana R. MacGregor
Keyword(s):  
Transient Expression ◽  
Herbicide Resistance ◽  
Management Practices ◽  
Fluorescent Protein ◽  
Genetic Manipulation ◽  
Lethal Dose ◽  
Integrated Weed Management ◽  
Gain Of Function ◽  
Winter Cereal ◽  
Alopecurus Myosuroides

AbstractEven though considerable progress has been made in weed ecology, weed molecular biology has been hindered by an inability to genetically manipulate weeds. Genetic manipulation is essential to demonstrate a causative relationship between genotype and phenotype. Herein we demonstrate that virus-mediated transient expression techniques developed for other monocots can be used in black-grass (Alopecurus myosuroides) for loss- and gain-of-function studies. We not only use virus induced gene silencing (VIGS) to create the black-grass exhibiting reduced PHYTOENE DESATURASE expression and virus-mediated overexpression (VOX) to drive GREEN FLUORESCENT PROTEIN, we demonstrate these techniques are applicable to testing hypotheses related to herbicide resistance in black-grass. We use VIGS to demonstrate that AmGSTF1 is necessary for the resistant biotype Peldon to survive fenoxaprop application and show the heterologous expression of the bialaphos resistance gene with VOX is sufficient to confer resistance to an otherwise lethal dose of glufosinate. Black-grass is the most problematic weed for winter-cereal farmers in the UK and Western Europe as it has rapidly evolved adaptions that allow it to effectively avoid current integrated weed management practices. Black-grass also reduces yields and therefore directly threatens food security and productivity. Novel disruptive technologies which mitigate resistance evolution and enable better control over this pernicious weed are therefore required. These virus-mediated protocols offer a step change in our ability to alter genes of interest under controlled laboratory conditions and therefore to gain a molecular-level understanding of how black-grass can survive in the agri-environment.One Sentence SummaryVirus-mediated transient expression techniques create loss- and gain-of-function mutations in black-grass and show causation between specific genotypes and measurable changes in herbicide resistance.

Metabolic engineering of CHO cells to prepare glycoproteins

2018 ◽  
Vol 2 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Qiong Wang ◽  
Michael J. Betenbaugh
Keyword(s):  
Metabolic Engineering ◽  
Cho Cells ◽  
Genetic Manipulation ◽  
Chinese Hamster ◽  
Post Translational Modification ◽  
Effector Functions ◽  
Recombinant Glycoproteins ◽  
Production Platform ◽  
Chemical Inhibitors ◽  
Amino Acid Mutations

As a complex and common post-translational modification, N-linked glycosylation affects a recombinant glycoprotein's biological activity and efficacy. For example, the α1,6-fucosylation significantly affects antibody-dependent cellular cytotoxicity and α2,6-sialylation is critical for antibody anti-inflammatory activity. Terminal sialylation is important for a glycoprotein's circulatory half-life. Chinese hamster ovary (CHO) cells are currently the predominant recombinant protein production platform, and, in this review, the characteristics of CHO glycosylation are summarized. Moreover, recent and current metabolic engineering strategies for tailoring glycoprotein fucosylation and sialylation in CHO cells, intensely investigated in the past decades, are described. One approach for reducing α1,6-fucosylation is through inhibiting fucosyltransferase (FUT8) expression by knockdown and knockout methods. Another approach to modulate fucosylation is through inhibition of multiple genes in the fucosylation biosynthesis pathway or through chemical inhibitors. To modulate antibody sialylation of the fragment crystallizable region, expressions of sialyltransferase and galactotransferase individually or together with amino acid mutations can affect antibody glycoforms and further influence antibody effector functions. The inhibition of sialidase expression and chemical supplementations are also effective and complementary approaches to improve the sialylation levels on recombinant glycoproteins. The engineering of CHO cells or protein sequence to control glycoforms to produce more homogenous glycans is an emerging topic. For modulating the glycosylation metabolic pathways, the interplay of multiple glyco-gene knockouts and knockins and the combination of multiple approaches, including genetic manipulation, protein engineering and chemical supplementation, are detailed in order to achieve specific glycan profiles on recombinant glycoproteins for superior biological function and effectiveness.

Drug-Induced Agranulocytosis: A Mini Review

2016 ◽  
Vol 2 (1) ◽  
pp. 57-59
Author(s):  
Pavithra D ◽  
Praveen D ◽  
Vijey Aanandhi M
Keyword(s):  
Bone Marrow ◽  
Complete Blood Count ◽  
Genetic Manipulation ◽  
White Blood Cells ◽  
Deep Infection ◽  
Morbidity Rate ◽  
Drug Induced ◽  
Serious Adverse Event ◽  
Mortality And Morbidity ◽  
The Individual

Agranulocytosis is also known to be granulopenia, causing neutropenia in circulating blood streams .The destruction of white blood cells takes place which leads to increase in the infection rate in an individual where immune system of the individual is suppressed. The symptoms includes fever, sore throat, mouth ulcers. These are commonly seen as adverse effects of a particular drug and are prescribed for the common diagnostic test for regular monitoring of complete blood count in an admitted patient. Drug-induced agranulocytosis remains a serious adverse event due to occurrence of severe sepsis with deep infection leading to pneumonia, septicaemia, and septic shock in two/third of the patient. Antibiotics seem to be the major causative weapon for this disorder. Certain drugs mainly anti-thyroid drugs, ticlopidine hydrochloride, spironolactone, clozapine, antileptic drugs (clozapine), non-steroidal anti-inflammatory agents, dipyrone are the potential causes. Bone marrow insufficiency followed by destruction or limited proliferative bone marrow destruction takes place. Chemotherapy is rarely seen as a causative agent for this disorder. Genetic manipulation may also include as one of the reason. Agranulocytosis can be recovered within two weeks but the mortality and morbidity rate during the acute phase seems to be high, appropriate adjuvant treatment with broad-spectrum antibiotics are prerequisites for the management of complicated neutropenia. Drugs that are treated for this are expected to change as a resistant drug to the patient. The pathogenesis of agranulocytosis is not yet known. A comprehensive literature search has been carried out in PubMed, Google Scholar and articles pertaining to drug-induced agranulocytosis were selected for review.

Improvement of effectiveness in maize breeding

2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó
Keyword(s):  
Recurrent Selection ◽  
Genetic Manipulation ◽  
Field Testing ◽  
Tissue Cultures ◽  
Maize Breeding ◽  
Breeding Programmes ◽  
Speed Up ◽  
Selection For

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.

New Technologies to Combat Herbicide Resistance

2020 ◽  
Vol 31 (2) ◽  
pp. 90-92
Author(s):  
Rob Edwards
Keyword(s):  
Winter Wheat ◽  
Herbicide Resistance ◽  
Cover Crops ◽  
New Technologies ◽  
Green Revolution ◽  
Arable Land ◽  
Limited Range ◽  
Cultural Control ◽  
Arable Farming ◽  
The Uk

Herbicide resistance in problem weeds is now a major threat to global food production, being particularly widespread in wild grasses affecting cereal crops. In the UK, black-grass (Alopecurus myosuroides) holds the title of number one agronomic problem in winter wheat, with the loss of production associated with herbicide resistance now estimated to cost the farming sector at least £0.5 billion p.a. Black-grass presents us with many of the characteristic traits of a problem weed; being highly competitive, genetically diverse and obligately out-crossing, with a growth habit that matches winter wheat. With the UK’s limited arable crop rotations and the reliance on the repeated use of a very limited range of selective herbicides we have been continuously performing a classic Darwinian selection for resistance traits in weeds that possess great genetic diversity and plasticity in their growth habits. The result has been inevitable; the steady rise of herbicide resistance across the UK, which now affects over 2.1 million hectares of some of our best arable land. Once the resistance genie is out of the bottle, it has proven difficult to prevent its establishment and spread. With the selective herbicide option being no longer effective, the options are to revert to cultural control; changing rotations and cover crops, manual rogueing of weeds, deep ploughing and chemical mulching with total herbicides such as glyphosate. While new precision weeding technologies are being developed, their cost and scalability in arable farming remains unproven. As an agricultural scientist who has spent a working lifetime researching selective weed control, we seem to be giving up on a technology that has been a foundation stone of the green revolution. For me it begs the question, are we really unable to use modern chemical and biological technology to counter resistance? I would argue the answer to that question is most patently no; solutions are around the corner if we choose to develop them.

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