scholarly journals Low Mismatch Rate between Double-Stranded RNA and Target mRNA Does Not Affect RNA Interference Efficiency in Colorado Potato Beetle

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 449
Author(s):  
Wanwan He ◽  
Wenbo Xu ◽  
Kaiyun Fu ◽  
Wenchao Guo ◽  
Jiang Zhang
Keyword(s):  
Rna Interference ◽  
Colorado Potato Beetle ◽  
Target Gene ◽  
Insect Pest ◽  
Larval Growth ◽  
Underlying Mechanism ◽  
Site Directed Mutagenesis ◽  
Potato Beetle ◽  
Effective Sirnas ◽  
Mismatch Rate

RNA interference (RNAi)-based technology has been proven as a novel approach for insect pest control. However, whether insects could evolve resistance to RNAi and the underlying mechanism is largely unknown. The target gene mutations were thought to be one of the potential ways to develop the resistance. Here we predicted the effective siRNA candidates that could be derived from dsRNA against the Colorado potato beetle (CPB) β-Actin gene (dsACT). By site-directed mutagenesis, we synthesized the dsRNAs with the defect in generation of effective siRNAs (and thus were supposed to have comparable low RNAi efficacy). We showed that, with mismatches to the target gene, all the dsRNA variants caused similar levels of silencing of target gene, mortality and larval growth retardation of CPB. Our results suggest that when the mismatch rate of dsACT and target β-Actin mRNA is less than 3%, the RNAi efficiency is not impaired in CPB, which might imply the low possibility of RNAi resistance evolving through the sequence mismatches between dsRNA and the target gene.

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.

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

2019 ◽  
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

AbstractTransplastomic 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. Here 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 show 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 levels were correlated with length. dsRNA accumulation levels were 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 levels 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.

scholarly journals Conjugated linoleic acid as a novel insecticide targeting the agricultural pest Leptinotarsa decemlineata

2019 ◽  
Author(s):  
Justin Clements ◽  
Russell L. Groves ◽  
JoAnn Cava ◽  
Caroline Barry ◽  
Scott Chapman ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Larval Mortality ◽  
Larval Growth ◽  
The United States ◽  
Feeding Preference ◽  
Agricultural Pest ◽  
Potato Beetle

AbstractThe Colorado Potato Beetle, Leptinotarsa decemlineata, is a major agricultural pest of solanaceous crops in the United States. Historically, a multitude of insecticides have been used to control problematic populations. Due to increasing resistance to insecticides, novel compounds and methodologies are warranted for the control of beetle populations. Mixed-isomer conjugated linoleic acid has been studied in-depth for its beneficial properties to mammalian systems. At the same time, studies have demonstrated that conjugated linoleic acid can manipulate fatty acid composition in non-mammalian systems, resulting in embryo mortality. Consequently, experiments were conducted to assess the effects of foliar-applied conjugated linoleic acid on larval growth, embryogenesis, and feeding preference in Colorado potato beetle. Both maternal and deterrent effects of dietary conjugated linoleic acid were assessed. Conjugated linoleic acid demonstrated desirable insecticidal properties, including increased larval mortality, slowed larval development, antifeedant effects, and decreased egg viability after maternal ingestion.

scholarly journals RNA interference in the Colorado potato beetle, Leptinotarsa decemlineata: Identification of key contributors

2016 ◽  
Vol 78 ◽  
pp. 78-88 ◽  
Author(s):  
June-Sun Yoon ◽  
Jayendra Nath Shukla ◽  
Zhong Jun Gong ◽  
Kanakachari Mogilicherla ◽  
Subba Reddy Palli
Keyword(s):  
Rna Interference ◽  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Potato Beetle

scholarly journals 633 Field Performance of “Transgenic” Potato, with Resistance to Colorado Potato Beetle and Viruses

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 556E-557 ◽  
Author(s):  
David R. Duncan ◽  
David Hammond ◽  
Jim Zalewski ◽  
John Cudnohufsky ◽  
Wojciech Kaniewski ◽  
...  
Keyword(s):  
Colorado Potato Beetle ◽  
Environmental Protection Agency ◽  
Insect Pest ◽  
Resistance Management ◽  
Field Performance ◽  
Transgenic Potato ◽  
Nutritional Composition ◽  
Management Program ◽  
Russet Burbank ◽  
Potato Beetle

After more than 10 years of research, Monsanto scientists have developed improved seed potatoes that are protected from serious pests, including insects and disease. The first commercial products resulting from this effort were NewLeaf ® potatoes derived from `Russet Burbank' and `Atlantic' parents. The NewLeaf® product was commercialized in 1995 and contains a gene from Bacillus thuringiensis (variety tenebrionis) (B.t.t.). for the production of the Cry3A protein. Potatoes expressing this gene are completely protected from the Colorado potato beetle (CPB) and need no additional chemical protection for this insect pest. The U.S. Food and Drug Administration (FDA), U.S. Dept. of Agriculture (USDA), and U.S. Environmental Protection Agency (EPA) have all determined that these potatoes are the same in safety and nutritional composition as any other `Russet Burbank' and `Atlantic' potatoes. These potatoes have also been approved by Health Canada, Agri-Food Canada and Agriculture Canada and by Japan and Mexico for food use. Commercial growers across North America have experienced outstanding performance while growing NewLeaf® potatoes 3 years in a row. This level of performance is the result of stable, nonsignificant differences in expression of the Cry3A gene. The stable performance, also, is a result of an effective insect resistance management program based on maintaining CPB refuges near NewLeaf ® fields, reducing CPB populations, and monitoring for CPB surviving exposure to NewLeaf® potatoes. In 1998 NewLeaf Y®), conferring resistance to both CPB and potato virus Y, and NewLeaf Plus®, conferring resistance to CPB and potato leafroll virus will be commercially released.

scholarly journals Development of Bt-cry5 Insect-resistant Potato Lines 'Spunta-G2' and 'Spunta-G3'

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1103-1107 ◽  
Author(s):  
D.S. Douches ◽  
W. Li ◽  
K. Zarka ◽  
J. Coombs ◽  
W. Pett ◽  
...  
Keyword(s):  
Potato Tuber ◽  
Colorado Potato Beetle ◽  
Insect Pest ◽  
Transgenic Potato ◽  
Potato Production ◽  
The United States ◽  
Field Trials ◽  
Potato Tuber Moth ◽  
Detached Leaf ◽  
Potato Beetle

The potato tuber moth (Phthorimaea operculella Zeller) is the primary insect pest of cultivated potato (Solanum tuberosum L.) in tropical and subtropical regions, causing both foliar and tuber damage. In contrast, the Colorado potato beetle (Leptinotarsa decemlineata Say) is the most important insect pest in the northern potato production latitudes. The codon-modified Bacillus thuringiensis Bt-cry5 gene (revised nomenclature cry1IaI), specifically toxic to Lepidoptera and Coleoptera, was transformed into cultivar Spunta using an Agrobacterium vector to provide resistance to both potato tuber moth and Colorado potato beetle. The Bt-cry5 gene was placed downstream from the constitutive CaMV35S promoter. Two transgenic 'Spunta' clones, G2 and G3, produced high levels of mortality in first instars of potato tuber moth in detached-leaf bioassays (80% to 83% mortality), laboratory tuber tests (100% mortality), and field trials in Egypt (99% to 100% undamaged tubers). Reduced feeding by Colorado potato beetle first instars was also observed in detached-leaf bioassays (80% to 90% reduction). Field trials in the United States demonstrated that the horticultural performance of the two transgenic lines was comparable to 'Spunta'. These Bt-cry5 transgenic potato plants with high potato tuber moth resistance have value in integrated pest management programs.

Inhibitor of apoptosis is an effective target gene for RNAi‐mediated control of Colorado potato beetle, Leptinotarsa decemlineata

2020 ◽  
Vol 104 (4) ◽  
Author(s):  
Wesley P. F. Máximo ◽  
Jeffrey L. Howell ◽  
Kanakachari Mogilicherla ◽  
Moslem Basij ◽  
Shankar C. R. R. Chereddy ◽  
...  
Keyword(s):  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Target Gene ◽  
Inhibitor Of Apoptosis ◽  
Potato Beetle

scholarly journals Transcriptomics-Based Approach Identifies Spinosad-Associated Targets in the Colorado Potato Beetle, Leptinotarsa decemlineata

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 820
Author(s):  
Pierre Bastarache ◽  
Gabriel Wajnberg ◽  
Pascal Dumas ◽  
Simi Chacko ◽  
Jacynthe Lacroix ◽  
...  
Keyword(s):  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Insect Pest ◽  
Molecular Targets ◽  
Primary Method ◽  
Juvenile Hormone Esterase ◽  
Potato Plants ◽  
Potato Beetle ◽  
Potato Crops ◽  
Generation Sequencing

The Colorado potato beetle Leptinotarsa decemlineata is an insect pest that threatens potato crops globally. The primary method to control its damage on potato plants is the use of insecticides, including imidacloprid, chlorantraniliprole and spinosad. However, insecticide resistance has been frequently observed in Colorado potato beetles. The molecular targets and the basis of resistance to imidacloprid and chlorantraniliprole have both been previously quantified. This work was undertaken with the overarching goal of better characterizing the molecular changes associated with spinosad exposure in this insect pest. Next-generation sequencing was conducted to identify transcripts that were differentially expressed between Colorado potato beetles exposed to spinosad versus control insects. Results showed several transcripts that exhibit different expression levels between the two conditions, including ones coding for venom carboxylesterase-6, chitinase 10, juvenile hormone esterase and multidrug resistance-associated protein 4. In addition, several microRNAs, such as miR-12-3p and miR-750-3p, were also modulated in the investigated conditions. Overall, this work reveals a molecular footprint underlying spinosad response in Colorado potato beetles and provides novel leads that could be targeted as part of RNAi-based approaches to control this insect pest.

Effects of a Prototype Pneumatic Machine to Control the Colorado Potato Beetle on Potato Plant Growth and Tuber Yield

2021 ◽  
Vol 64 (6) ◽  
pp. 2035-2044
Author(s):  
Saad Almady ◽  
Mohamed Khelifi
Keyword(s):  
Plant Growth ◽  
Colorado Potato Beetle ◽  
Tuber Yield ◽  
Control Method ◽  
Insect Pest ◽  
Pneumatic Control ◽  
Potato Plants ◽  
Potato Beetle ◽  
Biological Insecticide ◽  
Leptinotarsa Decemlineata Say

HighlightsA prototype pneumatic machine used to control the Colorado potato beetle (CPB) had no effect on potato plant growth.Yields in pneumatic treatment plots were comparable to those of control plots treated with a biological insecticide.Pneumatic control of the CPB could be an alternative to reduce reliance on chemical insecticides in potato fields.Abstract. The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the major insect pest of potato plants. Currently, the most effective method for controlling the CPB is to apply chemical insecticides throughout its lifecycle. However, the CPB has the ability to resist most chemical insecticides. Control of this insect pest has therefore become extremely difficult, prompting researchers to explore effective alternatives. The use of pneumatic methods to control the CPB is a promising alternative to chemical means. The objective of this study was to develop an effective pneumatic control method for the CPB to reduce the reliance on chemical insecticides in potato fields. In this context, a prototype pneumatic machine was designed and built. The prototype uses positive air pressure to dislodge CPBs from potato foliage, deposit them on the ground between the rows, and crush them. The effects of three airflow velocities (45, 50, and 55 m s-1) and two tractor travel speeds (5 and 6 km h-1) on CPB control, plant growth, and tuber yield were investigated in potato plots. Overall, the results showed no significant differences in yield between treatments (p = 0.3268), indicating that the yield of potato plants treated with the prototype was comparable to that of plants treated with a biological insecticide (Entrust). In addition, the prototype did not have any negative effects on plant growth. This suggests that the prototype could be safely and efficiently used in potato fields to control the CPB. The success of this innovative control method could greatly contribute to reducing the use of chemical insecticides to control the CPB. Keywords: Airflow velocity, Leptinotarsa decemlineata (Say), Pneumatic control, Potato, Travel speed.

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