Role of the Genetic Background in Resistance to Plant Viruses

In view of major economic problems caused by viruses, the development of genetically resistant crops is critical for breeders but remains limited by the evolution of resistance-breaking virus mutants. During the plant breeding process, the introgression of traits from Crop Wild Relatives results in a dramatic change of the genetic background that can alter the resistance efficiency or durability. Here, we conducted a meta-analysis on 19 Quantitative Trait Locus (QTL) studies of resistance to viruses in plants. Frequent epistatic effects between resistance genes indicate that a large part of the resistance phenotype, conferred by a given QTL, depends on the genetic background. We next reviewed the different resistance mechanisms in plants to survey at which stage the genetic background could impact resistance or durability. We propose that the genetic background may impair effector-triggered dominant resistances at several stages by tinkering the NB-LRR (Nucleotide Binding-Leucine-Rich Repeats) response pathway. In contrast, effects on recessive resistances by loss-of-susceptibility—such as eIF4E-based resistances—are more likely to rely on gene redundancy among the multigene family of host susceptibility factors. Finally, we show how the genetic background is likely to shape the evolution of resistance-breaking isolates and propose how to take this into account in order to breed plants with increased resistance durability to viruses.

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Stories and the Self

Journal of Media Psychology Theories Methods and Applications ◽

10.1027/1864-1105/a000255 ◽

2020 ◽

Vol 32 (2) ◽

pp. 47-58 ◽

Cited By ~ 1

Author(s):

Stefan Krause ◽

Markus Appel

Keyword(s):

Meta Analysis ◽

The Self ◽

The Other ◽

Lower Degree ◽

Contrast Effects ◽

Self Perception ◽

Self Perceptions ◽

Other Hand ◽

The One ◽

Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

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Resistance mechanisms of epidermal growth factor receptor tyrosine kinase inhibitors in non‐small cell lung cancer patients: A meta‐analysis

Thoracic Cancer ◽

10.1111/1759-7714.13878 ◽

2021 ◽

Author(s):

Nobuaki Kobayashi ◽

Seigo Katakura ◽

Chisato Kamimaki ◽

Kohei Somekawa ◽

Nobuhiko Fukuda ◽

...

Keyword(s):

Receptor Tyrosine Kinase ◽

Kinase Inhibitors ◽

Meta Analysis ◽

Growth Factor Receptor ◽

Resistance Mechanisms ◽

Small Cell ◽

Small Cell Lung ◽

Lung Cancer Patients ◽

Epidermal Growth ◽

Receptor Tyrosine Kinase Inhibitors

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Global patterns in genomic diversity underpinning the evolution of insecticide resistance in the aphid crop pest Myzus persicae

Communications Biology ◽

10.1038/s42003-021-02373-x ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Kumar Saurabh Singh ◽

Erick M. G. Cordeiro ◽

Bartlomiej J. Troczka ◽

Adam Pym ◽

Joanna Mackisack ◽

...

Keyword(s):

Host Plant ◽

Myzus Persicae ◽

Resistance Mechanisms ◽

Genomic Diversity ◽

Resistance Mutations ◽

Host Plant Adaptation ◽

Repeated Evolution ◽

Evolution Of Resistance ◽

Selective Forces ◽

Clonal Lines

AbstractThe aphid Myzus persicae is a destructive agricultural pest that displays an exceptional ability to develop resistance to both natural and synthetic insecticides. To investigate the evolution of resistance in this species we generated a chromosome-scale genome assembly and living panel of >110 fully sequenced globally sampled clonal lines. Our analyses reveal a remarkable diversity of resistance mutations segregating in global populations of M. persicae. We show that the emergence and spread of these mechanisms is influenced by host–plant associations, uncovering the widespread co‐option of a host-plant adaptation that also offers resistance against synthetic insecticides. We identify both the repeated evolution of independent resistance mutations at the same locus, and multiple instances of the evolution of novel resistance mechanisms against key insecticides. Our findings provide fundamental insights into the genomic responses of global insect populations to strong selective forces, and hold practical relevance for the control of pests and parasites.

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Aggregation of Argulus coregoni (Crustacea: Branchiura) on rainbow trout (Oncorhynchus mykiss): a consequence of host susceptibility or exposure?

Parasitology ◽

10.1017/s0031182004006407 ◽

2004 ◽

Vol 130 (2) ◽

pp. 169-176 ◽

Cited By ~ 25

Author(s):

M. BANDILLA ◽

T. HAKALAHTI ◽

P. J. HUDSON ◽

E. T. VALTONEN

Keyword(s):

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Acquired Resistance ◽

Infection Intensity ◽

Similar Rate ◽

Resistance Mechanisms ◽

Host Population ◽

Host Susceptibility ◽

Relative Significance ◽

Argulus Coregoni

By sampling individual rainbow trout, Oncorhynchus mykiss, at a fish farm we showed that Argulus coregoni were aggregated within their host population. The relative significance of susceptibility and exposure generating the observed pattern was tested using experimental infections. We examined, whether rainbow trout developed protective resistance mechanisms against the louse following a challenge infection and if there was variation between individual trout in their susceptibility to A. coregoni metanauplii. Fish were exposed to 20 A. coregoni for 5, 25, 50, 85 or 120 min and the numbers attaching recorded. Three weeks later, developing argulids were removed and the experiment repeated with a standardized exposure of 20 metanauplii. Prior exposure of fish with A. coregoni did not reduce the total infection intensity compared to naïve fish, but fish gained infection more rapidly. We suggest that there is no protective acquired resistance of pre-exposed rainbow trout to subsequent Argulus exposure. The possibility that an immunosuppressive mechanism by argulids was acting enabling the higher attachment rate could be refuted since control individuals, not previously exposed to lice, gained the infection at a similar rate as the fish challenged twice. Our results do not indicate clear differences in susceptibility among individual fish but the transmission of metanauplii on fish seemed to be opportunistic and non-selective. Our results support the view that variation in exposure time, rather than differences in susceptibility of individual hosts, might be the key factor in generating the aggregated distribution of Argulus on their hosts.

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Bacillus thuringiensis and Its Pesticidal Crystal Proteins

Microbiology and Molecular Biology Reviews ◽

10.1128/mmbr.62.3.775-806.1998 ◽

1998 ◽

Vol 62 (3) ◽

pp. 775-806 ◽

Cited By ~ 1847

Author(s):

E. Schnepf ◽

N. Crickmore ◽

J. Van Rie ◽

D. Lereclus ◽

J. Baum ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Integrated Management ◽

Management Strategies ◽

Resistance Mechanisms ◽

Maximum Efficiency ◽

Crystal Proteins ◽

Evolution Of Resistance ◽

Complex Relationships ◽

Bacterium Bacillus ◽

Natural Settings

SUMMARY During the past decade the pesticidal bacterium Bacillus thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the complex relationships between the structure, mechanism of action, and genetics of the organism’s pesticidal crystal proteins, and a coherent picture of these relationships is beginning to emerge. Other studies have focused on the ecological role of the B. thuringiensis crystal proteins, their performance in agricultural and other natural settings, and the evolution of resistance mechanisms in target pests. Armed with this knowledge base and with the tools of modern biotechnology, researchers are now reporting promising results in engineering more-useful toxins and formulations, in creating transgenic plants that express pesticidal activity, and in constructing integrated management strategies to insure that these products are utilized with maximum efficiency and benefit.

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Characterization of the Contribution of Genetic Background and Gender to Disease Progression in the SOD1 G93A Mouse Model of Amyotrophic Lateral Sclerosis: A Meta-Analysis

Journal of Neuromuscular Diseases ◽

10.3233/jnd-140068 ◽

2015 ◽

Vol 2 (2) ◽

pp. 137-150 ◽

Cited By ~ 40

Author(s):

Stephen R. Pfohl ◽

Martin T. Halicek ◽

Cassie S. Mitchell

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Mouse Model ◽

Disease Progression ◽

Genetic Background ◽

Meta Analysis ◽

And Gender ◽

Lateral Sclerosis ◽

Sod1 G93a Mouse

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Evolution of the Insecticide Target Rdl in African Anopheles Is Driven by Interspecific and Interkaryotypic Introgression

Molecular Biology and Evolution ◽

10.1093/molbev/msaa128 ◽

2020 ◽

Vol 37 (10) ◽

pp. 2900-2917 ◽

Cited By ~ 4

Author(s):

Xavier Grau-Bové ◽

Sean Tomlinson ◽

Andrias O O’Reilly ◽

Nicholas J Harding ◽

Alistair Miles ◽

...

Keyword(s):

Large Scale ◽

Sequence Data ◽

Management Strategies ◽

Natural Populations ◽

Resistance Mechanisms ◽

Health Concern ◽

Malaria Vectors ◽

Resistance Mutations ◽

Development Of Resistance ◽

Evolution Of Resistance

Abstract The evolution of insecticide resistance mechanisms in natural populations of Anopheles malaria vectors is a major public health concern across Africa. Using genome sequence data, we study the evolution of resistance mutations in the resistance to dieldrin locus (Rdl), a GABA receptor targeted by several insecticides, but most notably by the long-discontinued cyclodiene, dieldrin. The two Rdl resistance mutations (296G and 296S) spread across West and Central African Anopheles via two independent hard selective sweeps that included likely compensatory nearby mutations, and were followed by a rare combination of introgression across species (from A. gambiae and A. arabiensis to A. coluzzii) and across nonconcordant karyotypes of the 2La chromosomal inversion. Rdl resistance evolved in the 1950s as the first known adaptation to a large-scale insecticide-based intervention, but the evolutionary lessons from this system highlight contemporary and future dangers for management strategies designed to combat development of resistance in malaria vectors.

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The character or the variation: the genetic analysis of the insecticide-resistance phenotype

Bulletin of Entomological Research ◽

10.1017/s000748530000002x ◽

2000 ◽

Vol 90 (1) ◽

pp. 3-7 ◽

Cited By ~ 25

Author(s):

J.A. McKenzie

Keyword(s):

Genetic Analysis ◽

Insecticide Resistance ◽

Integrated Pest Management ◽

Pest Management ◽

Genetic Basis ◽

Genotypic Variation ◽

Resistance Mechanisms ◽

Beneficial Insects ◽

Rare Mutations ◽

Evolution Of Resistance

AbstractIn this critique it is argued that the genetic basis of the evolution of resistance is dependent on how the phenotypic, and underlying genotypic, variation is channelled during a selective response. A polygenic response is preferentially favoured if selection acts within the phenotypic distribution of susceptibles; a monogenic response is predicted if selection screens rare mutations with phenotypes outside that susceptible distribution. The relevance of this model to the method of genetic analysis, the prediction of resistance mechanisms to novel insecticides, the generation of resistant beneficial insects and the development of the most effective resistance and integrated pest management programmes is discussed.

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