History of Herbicide-Tolerant Crops, Methods of Development and Current State of the Art – Emphasis on Glyphosate Tolerance

1992 ◽  
Vol 6 (3) ◽  
pp. 626-634 ◽  
Author(s):  
Ganesh M. Kishore ◽  
Stephen R. Padgette ◽  
Robert T. Fraley
Keyword(s):  
Weed Management ◽  
Effective Means ◽  
Shikimate Pathway ◽  
Management Program ◽  
Crop Plants ◽  
Epsp Synthase ◽  
Glyphosate Tolerance ◽  
Specific Expression ◽  
Expression Of Genes ◽  
Wide Range

Weed management is an integral part of agriculture; weeds lower both productivity and quality of agricultural products. A combination of mechanical, chemical, biological, and cultural methods is expected to deliver a sustainable weed management program for the next two decades. While chemical methods offer the most cost effective means of weed management, crop selectivity has hampered the use of the best chemicals for weed management. Recent progress in gene technology has facilitated the introduction and expression of genes to confer a wide range of traits to crop plants. Application of this technology has resulted in the development of crop plant genotypes that are resistant to a specific herbicide. This article describes the progress that has been made by our group toward the introduction of glyphosate tolerance to crop plants. Glyphosate [N-(phosphonomethyl)glycine] kills plants due to inhibition of the biosynthesis of aromatic compounds via the shikimate pathway. Our approach for introduction of glyphosate tolerance is based on insertion and expression in plants of a gene encoding a glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, a key enzyme of the shikimate pathway. The wild type enzyme present in plants is susceptible to inhibition glyphosate; variants of EPSP synthase have been produced that are less susceptible to inhibition by glyphosate. Expression of genes encoding these variants has been shown to confer glyphosate tolerance to plants. The degree of glyphosate tolerance is related to the tolerance characteristics of the EPSP synthase variant, its substrate activity, targeting to the plastid, and the level of expression of the variant gene. The tissue specificity of expression of the variant EPSP synthase has also been shown to be critical since glyphosate is a systemic herbicide and is translocated to many growing points within the plant. Our studies on glyphosate tolerance have substantially enhanced our understanding of the mode-of-action of glyphosate, the shikimate pathway, and protein sorting within plant cells, as well as developmental and tissue specific expression of genes in plants. Commercial use of glyphosate tolerance technology is expected to affect positively, the weed management arsenal available to the farmers, the sustainability of farm land and groundwater, and promote the use of a “soft” herbicide.

Increased Glyphosate Tolerance in ‘Aurora Gold’ Hard Fescue (Festuca longifolia)

2005 ◽  
Vol 19 (3) ◽  
pp. 640-646 ◽  
Author(s):  
Stephen E. Hart ◽  
Jeffrey F. Derr ◽  
Darren W. Lycan ◽  
Crystal Rose-Fricker ◽  
William A. Meyer
Keyword(s):  
New Jersey ◽  
Weed Management ◽  
Recurrent Selection ◽  
Management Program ◽  
Environmental Benefits ◽  
Golf Course ◽  
Glyphosate Tolerance ◽  
Phenotypic Recurrent Selection ◽  
Stand Thinning ◽  
Selection For

Studies were conducted in New Jersey and Virginia to evaluate the response of ‘Aurora Gold’ hard fescue, which had undergone five cycles of phenotypic recurrent selection for increased glyphosate tolerance, to direct applications of glyphosate. ‘Discovery’ hard fescue, which had not undergone recurrent selection, was also included in the study. Glyphosate treatments were initiated in early/mid-May and applied once, twice, or three times at 4- to 5-wk intervals at rates ranging from 0.1 to 1.6 kg ae/ha. Aurora Gold was more tolerant to glyphosate than Discovery in all experiments, indicating that recurrent selection was successful in increasing glyphosate tolerance in hard fescue. Single applications of glyphosate at rates ranging from 0.6 to 0.8 kg/ha could be applied to Aurora Gold with minimal injury or stand thinning (<20%), whereas multiple applications of glyphosate could be applied at rates ranging from 0.4 to 0.6 kg/ha. The use of Aurora Gold in areas planted to hard fescue, such as golf course roughs, vineyards, orchards, and landscapes, would allow the integration of direct glyphosate applications into an overall weed management program providing potential economic and environmental benefits.

scholarly journals ‘JS501’ and ‘Replay’ Perennial Ryegrass Glyphosate Tolerance and Rates Required for Annual Bluegrass (Poa annua L.) Control

HortScience ◽  
2012 ◽  
Vol 47 (7) ◽  
pp. 932-935 ◽  
Author(s):  
Christian M. Baldwin ◽  
A. Douglas Brede ◽  
Jami J. Mayer
Keyword(s):  
Perennial Ryegrass ◽  
Weed Management ◽  
Linear Regression Analysis ◽  
Cost Savings ◽  
Field Trials ◽  
Application Rate ◽  
Management Program ◽  
Poa Annua ◽  
Glyphosate Tolerance ◽  
Annual Bluegrass

Incorporating the use of glyphosate into a weed management program offers turfgrass managers increased flexibility and cost savings when attempting to control troublesome weeds such as annual bluegrass (ABG) (Poa annua L.). Field trials of glyphosate tolerant perennial ryegrass (PRG) (Lolium perenne L.) cultivars, JS501 and Replay, were initiated to determine glyphosate tolerance and rates required for ABG control. In the tolerance trial, glyphosate was applied on 15 Sept. 2010 and 9 Aug. 2011 at rates of 0, 0.29, 0.58, 1.16, 1.74, 2.32, and 3.48 kg·ha−1 a.e. Glufosinate was also applied at 0, 1.68, and 3.37 kg·ha−1 a.i. In the ABG control trial, glyphosate was applied on 17 June followed by 19 Aug. 2009 and 25 June followed by 25 Aug. 2010 at rates of 0, 0.15, 0.29, 0.44, and 0.58 kg·ha−1 a.e. In the tolerance trial, linear regression analysis revealed a glyphosate application rate of 0.81 kg·ha−1 a.e. was required to cause 20% leaf firing. By the end of the trial, the highest rate of glufosinate resulted in nearly complete desiccation of ‘Replay’ PRG. For ABG control, after four glyphosate applications over a 2-year period, a rate of 0.29 kg·ha−1 a.e. or greater resulted in less than 10% ABG. Untreated plots had ≈83% ABG infestation. Discoloration was not noted for either PRG cultivar at any point over the 2-year trial period. Based on the environmental conditions of each trial, results suggest a recommended application rate should be 0.29 kg·ha−1 a.e. during summer months. This rate is sufficient for ABG control and also provides protection in case spray overlap occurs during an application.

The State versus the People

2020 ◽  
Author(s):  
Matthew Rendle
Keyword(s):  
French Revolution ◽  
Effective Means ◽  
State Control ◽  
Scarce Resources ◽  
Soviet State ◽  
The People ◽  
Wide Range ◽  
Complex Picture ◽  
The Military

This book provides the first detailed account of the role of revolutionary justice in the early Soviet state. Law has often been dismissed by historians as either unimportant after the October Revolution amid the violence and chaos of civil war or even, in the absence of written codes and independent judges, little more than another means of violence. This is particularly true of the most revolutionary aspect of the new justice system, revolutionary tribunals—courts inspired by the French Revolution and established to target counter-revolutionary enemies. This book paints a more complex picture. The Bolsheviks invested a great deal of effort and scarce resources into building an extensive system of tribunals that spread across the country, including into the military and the transport network. At their peak, hundreds of tribunals heard hundreds of thousands of cases every year. Not all ended in harsh sentences: some were dismissed through lack of evidence; others given a wide range of sentences; others still suspended sentences; and instances of early release and amnesty were common. This book, therefore, argues that law played a distinct and multifaceted role for the Bolsheviks. Tribunals stood at the intersection between law and violence, offering various advantages to the Bolsheviks, not least strengthening state control, providing a more effective means of educating the population on counter-revolution, and enabling a more flexible approach to the state’s enemies. All of this adds to our understanding of the early Soviet state and, ultimately, of how the Bolsheviks held on to power.

scholarly journals Role of Transposable Elements in Gene Regulation in the Human Genome

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 118
Author(s):  
Arsala Ali ◽  
Kyudong Han ◽  
Ping Liang
Keyword(s):  
Gene Regulation ◽  
Transposable Elements ◽  
Regulatory Sequences ◽  
Rna Sequences ◽  
Expression Of Genes ◽  
Wide Range ◽  
Lineage Specificity ◽  
Regulatory Rnas ◽  
Potential Factors ◽  
Interspersed Repeats

Transposable elements (TEs), also known as mobile elements (MEs), are interspersed repeats that constitute a major fraction of the genomes of higher organisms. As one of their important functional impacts on gene function and genome evolution, TEs participate in regulating the expression of genes nearby and even far away at transcriptional and post-transcriptional levels. There are two known principal ways by which TEs regulate the expression of genes. First, TEs provide cis-regulatory sequences in the genome with their intrinsic regulatory properties for their own expression, making them potential factors for regulating the expression of the host genes. TE-derived cis-regulatory sites are found in promoter and enhancer elements, providing binding sites for a wide range of trans-acting factors. Second, TEs encode for regulatory RNAs with their sequences showed to be present in a substantial fraction of miRNAs and long non-coding RNAs (lncRNAs), indicating the TE origin of these RNAs. Furthermore, TEs sequences were found to be critical for regulatory functions of these RNAs, including binding to the target mRNA. TEs thus provide crucial regulatory roles by being part of cis-regulatory and regulatory RNA sequences. Moreover, both TE-derived cis-regulatory sequences and TE-derived regulatory RNAs have been implicated in providing evolutionary novelty to gene regulation. These TE-derived regulatory mechanisms also tend to function in a tissue-specific fashion. In this review, we aim to comprehensively cover the studies regarding these two aspects of TE-mediated gene regulation, mainly focusing on the mechanisms, contribution of different types of TEs, differential roles among tissue types, and lineage-specificity, based on data mostly in humans.

A method for correcting acoustic finite-difference amplitudes for elastic effects

Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. T243-T255 ◽  
Author(s):  
James W. D. Hobro ◽  
Chris H. Chapman ◽  
Johan O. A. Robertsson
Keyword(s):  
Wave Equation ◽  
Finite Difference ◽  
Effective Means ◽  
Cost Effective ◽  
P Wave ◽  
S Waves ◽  
Velocity Models ◽  
Acoustic Simulation ◽  
Wide Range ◽  
Elastic Simulation

We present a new method for correcting the amplitudes of arrivals in an acoustic finite-difference simulation for elastic effects. In this method, we selectively compute an estimate of the error incurred when the acoustic wave equation is used to approximate the behavior of the elastic wave equation. This error estimate is used to generate an effective source field in a second acoustic simulation. The result of this second simulation is then applied as a correction to the original acoustic simulation. The overall cost is approximately twice that of an acoustic simulation but substantially less than the cost of an elastic simulation. Because both simulations are acoustic, no S-waves are generated, so dispersed converted waves are avoided. We tested the characteristics of the method on a simple synthetic model designed to simulate propagation through a strong acoustic impedance contrast representative of sedimentary geology. It corrected amplitudes to high accuracy for reflected arrivals over a wide range of incidence angles. We also evaluated results from simulations on more complex models that demonstrated that the method was applicable in realistic sedimentary models containing a wide range of seismic contrasts. However, its accuracy was reduced for wide-angle reflections from very high impedance contrasts such as a shallow top-salt interface. We examined the influence of modeling at coarse grid resolutions, in which converted S-waves in the equivalent elastic simulation are dispersed. These results provide some validation for the accuracy of the method when applied using finite-difference grids designed for acoustic modeling. The method appears to offer a cost-effective means of modeling elastic amplitudes for P-wave arrivals in a useful range of velocity models. It has several potential applications in imaging and inversion.

scholarly journals Molecular and physiological characterization of the effects of auxin-enriched rootstock on grafting

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Longmei Zhai ◽  
Xiaomin Wang ◽  
Dan Tang ◽  
Qi Qi ◽  
Huseyin Yer ◽  
...  
Keyword(s):  
Callus Formation ◽  
Ethylene Biosynthesis ◽  
Union Formation ◽  
Biosynthetic Gene ◽  
Graft Union ◽  
Specific Expression ◽  
Physiological Characterization ◽  
Graft Healing ◽  
Expression Of Genes ◽  
Or Gene

AbstractsGrafting is a highly useful technique, and its success largely depends on graft union formation. In this study, we found that root-specific expression of the auxin biosynthetic gene iaaM in tobacco, when used as rootstock, resulted in more rapid callus formation and faster graft healing. However, overexpression of the auxin-inactivating iaaL gene in rootstocks delayed graft healing. We observed increased endogenous auxin levels and auxin-responsive DR5::GUS expression in scions of WT/iaaM grafts compared with those found in WT/WT grafts, which suggested that auxin is transported upward from rootstock to scion tissues. A transcriptome analysis showed that auxin enhanced graft union formation through increases in the expression of genes involved in graft healing in both rootstock and scion tissues. We also observed that the ethylene biosynthetic gene ACS1 and the ethylene-responsive gene ERF5 were upregulated in both scions and rootstocks of the WT/iaaM grafts. Furthermore, exogenous applications of the ethylene precursor ACC to the junction of WT/WT grafts promoted graft union formation, whereas application of the ethylene biosynthesis inhibitor AVG delayed graft healing in WT/WT grafts, and the observed delay was less pronounced in the WT/iaaM grafts. These results demonstrated that elevated auxin levels in the iaaM rootstock in combination with the increased auxin levels in scions caused by upward transport/diffusion enhanced graft union formation and that ethylene was partially responsible for the effects of auxin on grafting. Our findings showed that grafting success can be enhanced by increasing the auxin levels in rootstocks using transgenic or gene-editing techniques.

Pythium intermedium. [Descriptions of Fungi and Bacteria].

1964 ◽  
Author(s):  
G. M. Waterhouse
Keyword(s):  
North America ◽  
South America ◽  
Geographical Distribution ◽  
Root Rot ◽  
Crop Plants ◽  
Foot Rot ◽  
Damping Off ◽  
Wide Range

Abstract A description is provided for Pythium intermedium. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts represented by the following families: Begoniaceae, Bromeliaceae, Chenopodiaceae, Compositae, Coniferae, Cruciferae, Euphorbiaceae, Geraniaceae, Gramineae, Leguminosae, Liliaceae, Linaceae, Moraceae, Onagraceae, Ranunculaceae, Rosaceae, Solanaceae, Ulmaceae, Violaceae; also in the Equisetales and Filicales. DISEASES: Damping-off of seedlings, foot rot and root rot of ornamentals, occasionally of crop plants and trees. GEOGRAPHICAL DISTRIBUTION: Asia (China); Australia & Oceania (Hawaii); Europe (England, Belgium, France, Germany, Holland, Sweden, U.S.S.R.); North America (U.S.A.); South America (Argentina). TRANSMISSION: A common soil inhabitant.

Incorporating Neural Network Material Models Within Finite Element Analysis for Rheological Behavior Prediction

2006 ◽  
Vol 129 (1) ◽  
pp. 58-65 ◽  
Author(s):  
B. Scott Kessler ◽  
A. Sherif El-Gizawy ◽  
Douglas E. Smith
Keyword(s):  
Finite Element ◽  
Effective Means ◽  
Element Model ◽  
Operating Conditions ◽  
Behavior Prediction ◽  
Element Analysis ◽  
Material Models ◽  
Rheological Models ◽  
Wide Range ◽  
Novel Method

The accuracy of a finite element model for design and analysis of a metal forging operation is limited by the incorporated material model’s ability to predict deformation behavior over a wide range of operating conditions. Current rheological models prove deficient in several respects due to the difficulty in establishing complicated relations between many parameters. More recently, artificial neural networks (ANN) have been suggested as an effective means to overcome these difficulties. To this end, a robust ANN with the ability to determine flow stresses based on strain, strain rate, and temperature is developed and linked with finite element code. Comparisons of this novel method with conventional means are carried out to demonstrate the advantages of this approach.

scholarly journals Selenium supplementation: does soil supplementation help and why?

2003 ◽  
Vol 62 (2) ◽  
pp. 393-397 ◽  
Author(s):  
John R. Arthur
Keyword(s):  
Effective Means ◽  
Careful Consideration ◽  
Selenium Supplementation ◽  
Physiological Changes ◽  
Disease Treatment ◽  
Hormone Synthesis ◽  
Metabolic Functions ◽  
Wide Range ◽  
The Uk ◽  
Se Status

There are now concerns that dietary Se intake is inadequate for the population in the UK and parts of Europe. Many different methods can be proposed to deal with this problem. Experience from Finland suggests that the addition of Se to fertiliser is a safe and effective means of increasing the intake of the micronutrient in the human population. However, careful consideration needs to be given to the potential consequences of increasing Se intake. It is important to understand the biochemical and physiological changes that may occur with any increase in Se intake within the UK population. Se is an essential component of at least twenty functional proteins within mammals. These proteins are essential for a range of metabolic functions, including antioxidant activity, thyroid hormone synthesis and immune function. Thus, any increase in Se intake has the potential to influence in a wide range of factors that may impinge on the incidence of chronic disease. Treatment of soil with Se-supplemented fertiliser will certainly increase total Se in food products derived from areas where this treatment is in place. Consumption of such foods will increase Se status in many populations where the existing intake does not meet requirements. If the increases in Se intake are not toxic the overall consequences have the potential to be beneficial.

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