About

Marce Lorenzen is a professor in the Department of Entomology and Plant Pathology at North Carolina State University. Her laboratory is part of the Genetic Pest Management (GPM) program, where her research focuses on elucidating the molecular mechanisms underlying a novel class of selfish-genetic elements found exclusively in Tribolium flour beetles. These elements, known as Medea, exhibit selfish behavior and have potential applications as gene 'drivers' to influence pest populations, such as pushing pesticide susceptibility into insect pests or reducing vector competence in disease vectors like mosquitoes. Dr. Lorenzen's educational background includes a B.S. from the University of Rhode Island and a Ph.D. from Kansas State University. Her work involves advanced genetic and genomic techniques, including genome editing and RNA interference, to develop sustainable strategies for pest control and to understand insect-virus interactions. She has contributed to research on genome editing of various insect species, development of transgenic systems, and the functional characterization of insect proteins related to vector competence and pest management. Her projects are supported by grants from agencies such as USDA-NIFA and DARPA, emphasizing her role in advancing innovative, biologically-based pest control methods and sustainable agricultural practices.

Research topics

• Genetics
• Biology
• Computer Science
• Botany
• Ecology
• Molecular biology
• Computational biology
• Mathematics
• Zoology
• Telecommunications

Selected publications

• Identification and screening of potential <scp>RNAi</scp> targets in the bean bug <scp> <i>Riptortus pedestris</i> </scp> via virus‐induced gene silencing and root soaking

  Pest Management Science · 2025-10-16 · 2 citations

  article

  BACKGROUND: RNA interference (RNAi) is a promising approach for the development of reliable and sustainable techniques for the control of insect pest of agricultural importance. However, gene selection and efficient double-stranded RNA (dsRNA) delivery remain major challenges in the application of RNAi technology for pest management. RESULTS: In this study, five potential target genes (RpAbd-A, RpAbd-B, RpDicer, RpEcR, and RpLRPPRC) were identified from the genome of Riptortus pedestris. When all target genes were individually silenced using tobacco rattle virus-induced gene silencing (TRV-VIGS) system in Nicotiana tabacum, the expression levels of messenger RNA (mRNA) transcripts in nymphs were significantly reduced by 63.5-96.8% associated with 1.8- to 4.3-fold increases in mortality rates. However, silencing Ecdysone receptor (EcR) gene caused the highest nymph mortality rate (76.7%) compared to other RNAi treatments. Subsequently, EcR gene in R. pedestris nymphs was silenced via root soaking in soybean seedlings, resulting in a 65.8% decrease of EcR expression and a 3.8-fold increase in mortality rate. CONCLUSION: Two dsRNA delivery approaches, TRV-VIGS system and root soaking, were developed in R. pedestris, and gene EcR was considered as the best performing RNAi target. Our findings are of great importance to the future development of effective RNAi-based approaches to control sap-sucking pests. © 2025 Society of Chemical Industry.

  PublisherDOI

• Evaluation of Peregrinus maidis transformer-2 as a target for CRISPR-based control

  PLoS ONE · 2024-04-18 · 3 citations

  articleOpen accessSenior authorCorresponding

  The corn planthopper, Peregrinus maidis, is an economically important pest of corn and sorghum. Here we report the initial steps towards developing a CRISPR-based control method, precision guided sterile insect technique (pgSIT), for this hemipteran pest. Specifically, we evaluated the potential of transformer-2 (tra-2) as a target for sterilizing insects. First, we identified tra-2 transcripts within our P. maidis transcriptome database and performed RNA interference (RNAi) to confirm functional conservation. RNAi-mediated knockdown of Pmtra-2 in nymphs transformed females into pseudomales with deformed ovipositors resembling male claspers. While males showed no overt difference in appearance, they were indeed sterile. Importantly, the results were similar to those observed in another planthopper, Nilaparvata lugens. We also used CRISPR/Cas9 genome editing to assess the impact of tra-2 knockout in injectees. CRISPR-mediated knockout of Pmtra-2 had lethal effects on embryos, and hence not many injectees reached adulthood. However, mosaic knockout of Pmtra-2 did impact female and male fertility, which supports the use of tra-2 as a target for pgSIT in this hemipteran species.

  PublisherOA PDFDOI

• Evaluation of <i>Peregrinus maidis transformer-2</i> as a target for CRISPR-based control

  bioRxiv (Cold Spring Harbor Laboratory) · 2024-03-03 · 1 citations

  preprintOpen accessSenior authorCorresponding

  ABSTRACT The corn planthopper, Peregrinus maidis , is an economically important pest of corn and sorghum. Here we report the initial steps towards developing a CRISPR-based control method, precision guided sterile insect technique (pgSIT), for this hemipteran pest. Specifically, we evaluated the potential of transformer-2 ( tra-2 ) as a target for sterilizing insects. First, we identified tra-2 transcripts within our P. maidis transcriptome database and performed RNA interference (RNAi) to confirm functional conservation. RNAi-mediated knockdown of Pmtra-2 in nymphs transformed females into pseudomales with deformed ovipositors resembling male claspers. While males showed no overt difference in appearance, they were indeed sterile. Importantly, the results were similar to those observed in another planthopper, Nilaparvata lugens . We also used CRISPR/Cas9 genome editing to assess the impact of tra-2 knockout in injectees. CRISPR-mediated knockout of Pmtra-2 had lethal effects on embryos, and hence not many injectees reached adulthood. However, mosaic knockout of Pmtra-2 did impact female and male fertility, which supports the use of tra-2 as a target for pgSIT in this hemipteran species.

  PublisherOA PDFDOI

• Development of an agroinfiltration-based transient hairpin RNA expression system in pak choi leaves (Brassica rapa ssp. chinensis) for RNA interference against Liriomyza sativae

  Pesticide Biochemistry and Physiology · 2024-08-19 · 2 citations

  article
  PublisherDOI

• <scp>CRISPR</scp> /Cas9‐mediated genome editing of <i>Frankliniella occidentalis</i> , the western flower thrips, via embryonic microinjection

  Insect Molecular Biology · 2024-04-27 · 9 citations

  articleOpen accessSenior authorCorresponding

  Abstract The western flower thrips, Frankliniella occidentalis , poses a significant challenge in global agriculture as a notorious pest and a vector of economically significant orthotospoviruses. However, the limited availability of genetic tools for F. occidentalis hampers the advancement of functional genomics and the development of innovative pest control strategies. In this study, we present a robust methodology for generating heritable mutations in F. occidentalis using the CRISPR/Cas9 genome editing system. Two eye‐colour genes, white ( Fo‐w ) and cinnabar ( Fo‐cn ), frequently used to assess Cas9 function in insects were identified in the F. occidentalis genome and targeted for knockout through embryonic microinjection of Cas9 complexed with Fo‐w or Fo‐cn specific guide RNAs. Homozygous Fo‐w and Fo‐cn knockout lines were established by crossing mutant females and males. The Fo‐w knockout line revealed an age‐dependent modification of eye‐colour phenotype. Specifically, while young larvae exhibit orange‐coloured eyes, the colour transitions to bright red as they age. Unexpectedly, loss of Fo‐w function also altered body colour, with Fo‐w mutants having a lighter coloured body than wild type, suggesting a dual role for Fo‐w in thrips. In contrast, individuals from the Fo‐cn knockout line consistently displayed bright red eyes throughout all life stages. Molecular analyses validated precise editing of both target genes. This study offers a powerful tool to investigate thrips gene function and paves the way for the development of genetic technologies for population suppression and/or population replacement as a means of mitigating virus transmission by this vector.

  PublisherOA PDFDOI

• The Genome of Arsenophonus sp. and Its Potential Contribution in the Corn Planthopper, Peregrinus maidis

  Insects · 2024-02-05 · 6 citations

  articleOpen accessSenior authorCorresponding

  The co-evolution between symbionts and their insect hosts has led to intricate functional interdependencies. Advances in DNA-sequencing technologies have not only reduced the cost of sequencing but, with the advent of highly accurate long-read methods, have also enabled facile genome assembly even using mixed genomic input, thereby allowing us to more easily assess the contribution of symbionts to their insect hosts. In this study, genomic data recently generated from Peregrinus maidis was used to assemble the genome of a bacterial symbiont, Pm Arsenophonus sp. This ~4.9-Mb assembly is one of the largest Arsenophonus genomes reported to date. The Benchmarking Universal Single-Copy Orthologs (BUSCO) result indicates that this Pm Arsenophonus assembly has a high degree of completeness, with 96% of the single-copy Enterobacterales orthologs found. The identity of the Pm Arsenophonus sp. was further confirmed by phylogenetic analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicates a major contribution by Pm Arsenophonus sp. to the biosynthesis of B vitamins and essential amino acids in P. maidis, where threonine and lysine production is carried out solely by Pm Arsenophonus sp. This study not only provides deeper insights into the evolutionary relationships between symbionts and their insect hosts, but also adds to our understanding of insect biology, potentially guiding the development of novel pest control methods.

  PublisherOA PDFDOI

• CRISPR/Cas9-mediated genome editing of <i>Frankliniella occidentalis,</i> the western flower thrips, via embryonic microinjection

  bioRxiv (Cold Spring Harbor Laboratory) · 2023-12-01

  preprintOpen accessSenior authorCorresponding

  Abstract The western flower thrips, Frankliniella occidentalis , poses a significant challenge in global agriculture as a notorious pest and a vector of economically significant orthotospoviruses. However, the limited availability of genetic tools for F. occidentalis hampers the advancement of functional genomics and the development of innovative pest control strategies. In this study, we present a robust methodology for generating heritable mutations in F. occidentalis using the CRISPR/Cas9 genome editing system. Two eye-color genes, white ( Fo-w ) and cinnabar ( Fo-cn ), frequently used to assess Cas9 function in insects were identified in the F. occidentalis genome and targeted for knockout through embryonic microinjection of Cas9 complexed with Fo-w or Fo-cn specific guide RNAs. Homozygous Fo-w and Fo-cn knockout lines were established by crossing mutant females and males. The Fo-w knockout line revealed an age-dependent modification of eye-color phenotype. Specifically, while young larvae exhibit ivory-colored eyes, the color transitions to bright red as they age. Unexpectedly, loss of Fo-w function also altered body color, with Fo-w mutants having a lighter colored body than wild type, suggesting a dual role for Fo-w in thrips. In contrast, individuals from the Fo-cn knockout line consistently displayed bright red eyes throughout all life stages. Molecular analyses validated precise editing of both target genes. This study offers a powerful tool to investigate thrips gene functions and paves the way for the development of genetic technologies for population suppression and/or population replacement as a means of mitigating virus transmission by this vector.

  PublisherOA PDFDOI

• A draft Diabrotica virgifera virgifera genome: insights into control and host plant adaption by a major maize pest insect

  BMC Genomics · 2023-01-13 · 19 citations

  articleOpen access

  BACKGROUND: Adaptations by arthropod pests to host plant defenses of crops determine their impacts on agricultural production. The larval host range of western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is restricted to maize and a few grasses. Resistance of D. v. virgifera to crop rotation practices and multiple insecticides contributes to its status as the most damaging pest of cultivated maize in North America and Europe. The extent to which adaptations by this pest contributes to host plant specialization remains unknown. RESULTS: A 2.42 Gb draft D. v. virgifera genome, Dvir_v2.0, was assembled from short shotgun reads and scaffolded using long-insert mate-pair, transcriptome and linked read data. K-mer analysis predicted a repeat content of ≥ 61.5%. Ortholog assignments for Dvir_2.0 RefSeq models predict a greater number of species-specific gene duplications, including expansions in ATP binding cassette transporter and chemosensory gene families, than in other Coleoptera. A majority of annotated D. v. virgifera cytochrome P450s belong to CYP4, 6, and 9 clades. A total of 5,404 transcripts were differentially-expressed between D. v. virgifera larvae fed maize roots compared to alternative host (Miscanthus), a marginal host (Panicum virgatum), a poor host (Sorghum bicolor) and starvation treatments; Among differentially-expressed transcripts, 1,908 were shared across treatments and the least number were between Miscanthus compared to maize. Differentially-expressed transcripts were enriched for putative spliceosome, proteosome, and intracellular transport functions. General stress pathway functions were unique and enriched among up-regulated transcripts in marginal host, poor host, and starvation responses compared to responses on primary (maize) and alternate hosts. CONCLUSIONS: Manual annotation of D. v. virgifera Dvir_2.0 RefSeq models predicted expansion of paralogs with gene families putatively involved in insecticide resistance and chemosensory perception. Our study also suggests that adaptations of D. v. virgifera larvae to feeding on an alternate host plant invoke fewer transcriptional changes compared to marginal or poor hosts. The shared up-regulation of stress response pathways between marginal host and poor host, and starvation treatments may reflect nutrient deprivation. This study provides insight into transcriptomic responses of larval feeding on different host plants and resources for genomic research on this economically significant pest of maize.

  PublisherOA PDFDOI

• Structural and functional insights into the <scp>ATP</scp> ‐binding cassette transporter family in the corn planthopper, <i>Peregrinus maidis</i>

  Insect Molecular Biology · 2023-03-13 · 9 citations

  articleOpen accessSenior authorCorresponding

  The corn planthopper, Peregrinus maidis, is an economically important pest of maize and sorghum. Its feeding behaviour and the viruses it transmits can significantly reduce crop yield. The control of P. maidis and its associated viruses relies heavily on insecticides. However, control has proven difficult due to limited direct exposure of P. maidis to insecticides and rapid development of resistance. As such, alternative control methods are needed. In the absence of a genome assembly for this species, we first developed transcriptomic resources. Then, with the goal of finding targets for RNAi-based control, we identified members of the ATP-binding cassette transporter family and targeted specific members via RNAi. PmABCB_160306_3, PmABCE_118332_5 and PmABCF_24241_1, whose orthologs in other insects have proven important in development, were selected for knockdown. We found that RNAi-mediated silencing of PmABCB_160306_3 impeded ovary development; disruption of PmABCE_118332_5 resulted in localized melanization; and knockdown of PmABCE_118332_5 or PmABCF_24241_1 each led to high mortality within five days. Each phenotype is similar to that found when targeting the orthologous gene in other species and it demonstrates their potential for use in RNAi-based P. maidis control. The transcriptomic data and RNAi results presented here will no doubt assist with the development of new control methods for this pest.

  PublisherOA PDFDOI

• Genome and Genetic Engineering of the House Cricket (Acheta domesticus): A Resource for Sustainable Agriculture

  Biomolecules · 2023-03-24 · 37 citations

  articleOpen access

  Background: The house cricket, Acheta domesticus, is one of the most farmed insects worldwide and the foundation of an emerging industry using insects as a sustainable food source. Edible insects present a promising alternative for protein production amid a plethora of reports on climate change and biodiversity loss largely driven by agriculture. As with other crops, genetic resources are needed to improve crickets for food and other applications. Methods: We present the first high quality annotated genome assembly of A. domesticus from long read data and scaffolded to chromosome level, providing information needed for genetic manipulation. Results: Gene groups related to immunity were annotated and will be useful for improving value to insect farmers. Metagenome scaffolds in the A. domesticus assembly, including Invertebrate Iridescent Virus 6 (IIV6), were submitted as host-associated sequences. We demonstrate both CRISPR/Cas9-mediated knock-in and knock-out of A. domesticus and discuss implications for the food, pharmaceutical, and other industries. RNAi was demonstrated to disrupt the function of the vermilion eye-color gene producing a useful white-eye biomarker phenotype. Conclusions: We are utilizing these data to develop technologies for downstream commercial applications, including more nutritious and disease-resistant crickets, as well as lines producing valuable bioproducts, such as vaccines and antibiotics.

  PublisherOA PDFDOI

Recent grants

• Uncovering the Molecular Mechanisms of Selfish Genetic Elements

  NSF · $695k · 2013–2018

Frequent coauthors

• Brenda Oppert

  Center for Grain and Animal Health Research

  40 shared

• Richard W. Beeman

  40 shared

• Jeffrey A. Fabrick

  U.S. Arid Land Agricultural Research Center

  27 shared

• Cris Oppert

  University of Tennessee at Knoxville

  21 shared

• Juan Luís Jurat-Fuentes

  University of Tennessee at Knoxville

  20 shared

• Konstantin S. Vinokurov

  Institute of Plant Molecular Biology

  20 shared

• Susan J. Brown

  20 shared

• Kaley Morris

  Kansas State University

  19 shared

Labs

• Structural Pest Management Training & Research FacilityPI

Education

• PhD, Biology

  Kansas State University

  2000

Awards & honors

• Tissue-specific transcriptomes (2023)