An In Vitro Inhibition Test That Predicts Toxicity of Bacterial Pathogen Combinations in the Colorado Potato Beetle

2002 ◽  
Vol 12 (5) ◽  
pp. 643-647 ◽  
Author(s):  
Phyllis A. W. Martin
Keyword(s):  
Colorado Potato Beetle ◽  
Bacterial Pathogen ◽  
Inhibition Test ◽  
Potato Beetle ◽  
In Vitro Inhibition ◽  
Pathogen Combinations

scholarly journals Transcriptome Profiling of the Potato Exposed to French Marigold Essential Oil with a Special Emphasis on Leaf Starch Metabolism and Defense against Colorado Potato Beetle

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 172
Author(s):  
Sofija Stupar ◽  
Milan Dragićević ◽  
Vele Tešević ◽  
Jovana Stanković-Jeremić ◽  
Vuk Maksimović ◽  
...  
Keyword(s):  
Essential Oil ◽  
Colorado Potato Beetle ◽  
Molecular Mechanisms ◽  
Induced Defense ◽  
Gas Chromatography Mass Spectrometry ◽  
Transcriptional Level ◽  
Starch Metabolism ◽  
Transcriptional Responses ◽  
Potato Beetle

Flower strips of French Marigold are commonly used pest repellents in potato fields. However, the effect of French Marigold volatiles on potato metabolism, physiology and induced defense is unknown. Thus, a microarray transcriptome analysis was performed to study the effects of French Marigold essential oil (EO) on laboratory-grown potato. After 8 h of exposure to EO, with gas chromatography/mass spectrometry (GC/MS)-detected terpinolene and limonene as dominant compounds, 2796 transcripts were differentially expressed with fold change >2 compared to expression in controls. A slightly higher number of transcripts had suppressed expression (1493 down- vs. 1303 up-regulated). Since transcripts, annotated to different photosynthesis-related processes, were mostly down-regulated, we selected a set of 10 genes involved in the leaf starch metabolism pathway, and validated microarray patterns using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Except for decreased synthesis and induced decomposition of starch granule in leaves, 8 h long EO exposure slightly elevated the accumulation of sucrose compared to glucose and fructose in subjected potato plants. An in vitro feeding bioassay with Colorado potato beetle showed that EO-induced alternations on transcriptional level and in the sugars’ metabolism caused the enhancement of feeding behavior and overall development of the tested larvae. Results of comprehensive analysis of transcriptional responses in potato exposed to French Marigold EO provide a basis for further elucidation of molecular mechanisms underlying eco-physiological interactions in companion planting cropping systems.

scholarly journals Validating the potential of double-stranded RNA targeting Colorado potato beetle mesh gene in laboratory and field trials

2020 ◽  
Author(s):  
Marko Petek ◽  
Anna Coll ◽  
Rok Ferenc ◽  
Jaka Razinger ◽  
Kristina Gruden
Keyword(s):  
Colorado Potato Beetle ◽  
Field Trial ◽  
Larval Growth ◽  
Field Trials ◽  
Larval Survival ◽  
Innovative Technology ◽  
Feeding Experiments ◽  
Potato Beetle

ABSTRACTColorado potato beetle (CPB) is an agricultural pest of solanaceous crops, notorious for its rapid resistance development to chemical pesticides. Foliar spraying of dsRNA formulations is a promising innovative technology providing highly specific and environmentally acceptable option for CPB management.We designed dsRNA to silence CPB mesh gene (dsMESH) and performed laboratory feeding trials to assess impacts on beetle survival and development. We compared the effectiveness of in-vivo and in-vitro produced dsRNA in a series of laboratory experiments. We additionally performed a field trial in which the efficacy of dsRNA sprayed onto potato foliage was compared to a spinosad-based insecticide.We showed that dsMESH ingestion consistently and significantly impaired larval growth and decreased larval survival in laboratory feeding experiments. In-vivo produced dsRNA performed similarly as in-vitro synthesised dsRNA in laboratory settings. In the field trial, dsMESH was as effective in controlling CPB larvae as a commercial spinosad insecticide, its activity was however slower. We discuss limitations and benefits of a potential dsMESH-based CPB management strategy and list some important RNAi based CPB research topics, which will have to be addressed in future.

scholarly journals Potential of Proteinase Inhibitors for Insect Pest Control: The Case of the Colorado Potato Beetle

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 767D-767
Author(s):  
S. Overney ◽  
V.Q. Le ◽  
S. Visal ◽  
S. Yelle
Keyword(s):  
Colorado Potato Beetle ◽  
Proteinase Inhibitors ◽  
Insect Pest ◽  
Cysteine Proteases ◽  
Crop Damage ◽  
Cysteine Protease Inhibitor ◽  
In Vitro Assays ◽  
Potato Plants ◽  
Potato Beetle

Bioengineering economically important plants with proteinase inhibitors (PIs) is a promising method for the control of insect pests. In the case of the Colorado potato beetle (CPB; Leptinotarsa decemlineata Say), the major insect pest of potato fields, 80% of the digestive proteases are of cysteine type. We showed that 60% of these cysteine proteases are inhibited by oryzacystatins (OCs). The use of these cysteine protease inhibitor genes therefore appears of great interest for the production of Coleoptera-resistant transgenic plants of potato. Complementary studies of biochemical in vitro assays showed an apparent absence of direct interference between OCs and potato proteases. The high regeneration efficiency of the genetically transformed plants with OC gene and the “normal” phenotypical growth of the resulting transgenic potato plants suggested that these foreign genes do not interact with important physiological processes in the potato plants. In vivo assays of PIs against CPB at various developmental stages suggest the significant potential of OCs as an effective way to control CPB populations and crop damage.

scholarly journals Length-dependent accumulation of double-stranded RNAs in plastids affects RNA interference efficiency in the Colorado potato beetle

2020 ◽  
Vol 71 (9) ◽  
pp. 2670-2677 ◽  
Author(s):  
Wanwan He ◽  
Wenbo Xu ◽  
Letian Xu ◽  
Kaiyun Fu ◽  
Wenchao Guo ◽  
...  
Keyword(s):  
Rna Interference ◽  
Colorado Potato Beetle ◽  
Plant Protection ◽  
Larval Growth ◽  
High Accumulation ◽  
Potato Plants ◽  
Potato Beetle ◽  
Rnai Response ◽  
Rnai Effect

Abstract Transplastomic potato plants expressing double-stranded RNA (dsRNA) targeted against essential genes of the Colorado potato beetle (CPB) can be lethal to larvae by triggering an RNA interference (RNAi) response. High accumulation levels of dsRNAs in plastids are crucial to confer an efficient RNAi response in the insects. However, whether length and sequence of the dsRNA determine the efficacy of RNAi and/or influence the level of dsRNA accumulation in plastids is not known. We compared the RNAi efficacy of different lengths of dsRNA targeted against the CPB β-Actin gene (ACT) by feeding in vitro-synthesized dsRNAs to larvae. We showed that, while the 60 bp dsRNA induced only a relatively low RNAi response in CPB, dsRNAs of 200 bp and longer caused high mortality and similar larval growth retardation. When the dsRNAs were expressed from the plastid (chloroplast) genome of potato plants, we found that their accumulation were negatively correlated with length. The level of dsRNA accumulation was positively associated with the observed mortality, suppression of larval growth, and suppression of target gene expression. Importantly, transplastomic potato plants expressing the 200 bp dsRNA were better protected from CPB than plants expressing the 297 bp dsRNA, the best-performing line in our previous study. Our results suggest that the length of dsRNAs is an important factor that influences their accumulation in plastids and thus determines the strength of the insecticidal RNAi effect. Our findings will aid the design of optimized dsRNA expression constructs for plant protection by plastid-mediated RNAi.

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