Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1 -- 1926 2023-12-05 12:31:02 |
2 format Meta information modification 1926 2023-12-06 02:53:12 |

Video Upload Options

Do you have a full video?


Are you sure to Delete?
If you have any further questions, please contact Encyclopedia Editorial Office.
Sorokan, A.; Gabdrakhmanova, V.; Kuramshina, Z.; Khairullin, R.; Maksimov, I. Genetic Engineering Approach for Next-Generation of Bt-Based Agents. Encyclopedia. Available online: (accessed on 24 June 2024).
Sorokan A, Gabdrakhmanova V, Kuramshina Z, Khairullin R, Maksimov I. Genetic Engineering Approach for Next-Generation of Bt-Based Agents. Encyclopedia. Available at: Accessed June 24, 2024.
Sorokan, Antonina, Venera Gabdrakhmanova, Zilya Kuramshina, Ramil Khairullin, Igor Maksimov. "Genetic Engineering Approach for Next-Generation of Bt-Based Agents" Encyclopedia, (accessed June 24, 2024).
Sorokan, A., Gabdrakhmanova, V., Kuramshina, Z., Khairullin, R., & Maksimov, I. (2023, December 05). Genetic Engineering Approach for Next-Generation of Bt-Based Agents. In Encyclopedia.
Sorokan, Antonina, et al. "Genetic Engineering Approach for Next-Generation of Bt-Based Agents." Encyclopedia. Web. 05 December, 2023.
Genetic Engineering Approach for Next-Generation of Bt-Based Agents

Bacillus thuringiensis Berliner (Bt) and B. cereus sensu stricto Frankland and Frankland are closely related species of aerobic, spore-forming bacteria included in the B. cereus sensu lato group. This group is one of the most studied, but it remains also the most mysterious species of bacteria. Despite more than a century of research on the features of these ubiquitous bacteria, there are a lot of questionable issues related to their taxonomy, resistance to external influences, endophytic existence, their place in multidimensional relationships in the ecosystem, and many others.

endophytes insecticide nematicide Cry Vip Bt-crops

1. Introduction

Now, genetic modifications of Bt serve the purpose of dissolving two main problems of Bt-preparations, such as increase in bacteria tolerance to the impact of environmental factors and improving its insecticidal effects against different pests. The strategies of genetic engineering approaches to constructing strains with the required properties are as follows: (1) the up-regulation of the key enzyme gene involved in the target compound biosynthesis; (2) relieving the inhibition and/or repression of the key enzyme; and (3) the interruption of the pathways for synthesizing by-products [1]. The development of next-generation artificially improved Bt strains or strains heterologically producing Bt-toxins involves a broad spectrum of DNA reorganization, such as site-directed mutagenesis (SDM), the suppression and overexpression of genes, including RNA interference (RNAi) [2][3] Initially, RNAi was proposed as a suggestive strategy for the inhibition of viral infection. It is a post-transcriptional gene regulation mechanism characteristic of (possibly) all eukaryotes, including insect pests [4][5][6]. The mechanism is triggered by double-stranded RNA (dsRNA) precursors that are processed into short-interfering RNA (siRNA) duplexes, which then realize the recognition and repression of complementary dsRNAs, such as mRNAs or viral genomic RNAs [7].

2. Improvement of Insecticidal Properties of Bacterial Strains

Currently, genetic engineering approaches make it possible to transfer/supplement/modify genes encoding insectotoxin to other Bt strains or strains of another bacterial species using homologous recombination [8]. Current information on Cry- and non-Cry genes, which were used for the recombination of a broad spectrum of bacterial strains is assumed in [4][9]. An important tool for the recombination of Bt strains is site-specific recombination (SSR), which is useful for engineering strains with original combinations of Cry toxins genes with improved insecticidal activity [2][3][10]. It seems interesting to create endophytic Bt or other bacterial species whose populations in the internal tissues of plants would be safe from the environment and have greater activity against pests. These investigations originated in the last decade of the 20th century when the Bt gene encoding Cry1Aa was expressed in root-associated P. fluorescens [11]. Thus, the introduction of the cry1Ia gene into the endophytic strain B. subtilis 26D does not lead to the loss of the endophytic status of B. subtilis 26DCryChS line and gives impetus to its insecticidal and aphicidal activity in vitro and in planta [12][13]. Endophytic Burkholderia pyrrocinia JKSH007 heterologically expressing the Btcry218 gene showed an effectiveness against Bombyx mori L. [14]. The ability of Pantoea agglomerans 33.1:pJTT expressing cry1Ac7 to inhabit Saccharum officinarum L. tissues was confirmed by re-isolation from the plant’s rhizosphere, roots and shoots. Thus, the introduction of an exogenous gene did not affect the plant–host interaction but increased the mortality of Diatraea saccharalis Fabricius, 1794 fed on inoculated stems [15]. The transfer of “useful” insectotoxin genes from other economically important Bt strains to endophytic bacteria, as well as the maintenance of their consortiums, should contribute to the creation of new-generation biological agents based on them. At the same time, modern technologies for editing microbial genomes based on the CRISPRCas9 platform [7][16] can be proposed to disable the α-exotoxin and β-exotoxin synthesis of Bt.

3. Approaches to the Development of UV-Tolerant Bt

The problem of the UV-irradiation susceptibility of Bt seriously restricts its effective use. The exogenous addition of UV protective agents, such as rhodamine B or methyl green, can protect spores from the light [17]. Subsequently, for the same purpose, latex particles, ethanol, and olive oil have been used to encapsulate Bt in colloidosomes [18][19].
Homologous recombination technology was used for the insertion of the yhfS gene encoding acetyl-CoA acyltransferase in Bt LLP29 R-yhfS. The loss of the yhfS gene in the knockout strain Bt LLP29 Δ-yhfS led to the reduction in antioxidant ability and reduced UV resistance of the mutant [20]. The cell-surface exposure of chitinase Chi9602ΔSP was developed on the basis of Bt BMB171 using two repeat N-terminal regions of autolysin (Mbgn)2 as the anchoring motif. After continuous culturing for 120 h, the line of Bt expressing chitinase Chi9602ΔSP showed narrow pH tolerance and obviously enhanced UV radiation resistance capacity in addition to a high inhibitory effect towards phytopathogenic fungi, F. oxysporum FB012 and Botryosphaeria berengeriana FB016 [21]. CRISPR/Cas9 systems have been used to knock out the homogentisate-1,2-dioxygenase (hmgA) gene and obtain a melanin-producing mutant Bt HD-1-1 hmgA. The anti-UV test shows that melanin arranges protection to both Bt cells and Cry toxin crystals. After UV-irradiation the strain Bt HD-1-1 hmgA still had an 80% insecticidal activity against H. armigera, while the wild line only had about 20% [22].
Cry genes have been expressed in P. fluorescens and Anabaena sp. to increase the damage to crystals from UV light [23][24], as well as in E. coli; B. megaterium [25]; B. subtilis [26]; Clavibacter xyli Davis et al. 1984; Herbaspirillum seropedicae Baldani et al. 1986; R. leguminosarum [9]; Beauveria bassiana (Bals.-Criv.) Vuill., 1912 [27]; etc. The recombinant strain P. fluorescens is the base of biopesticide “CellCapTM” (Mycogen Corp.; Indianapolis, IN, USA), contains encapsulated Cry toxins [28]. The increase in the amount of Bt-plants can be partially attributed to the means of the protection of insectotoxins from UV rays [29].

4. Bt Crops Prospects

Since 1996, genetically engineered Bt crops have been planted in the fields, which led to a “gene revolution” in agricultural production [30][31]. By the early 21th century, Bt-potato, Bt-cotton, Bt-maize, Bt-eggplant, etc. were actively distributed worldwide, which allowed for a significant reduction in the amount of chemical insecticides used in a number of countries [32][33]. However, this approach lead to a fairly rapid spread of resistant pest populations [34][35][36]. To overcome insect resistance, it is possible to introduce Bt crops containing more than two genes encoding insecticidal proteins [35][36]. The Bollgard cotton variety bearing Cry1Ac gene decreased the viability of pink bollworm Pectinophora gossypiella (Saunders, 1844) and corn earworm Helicoverpa zea Boddie, 1850. Plants of the Bollgard II variety, expressing two Bt endotoxins, expand the spectrum of protective features against lepidopteran pests [37]. Bt-cotton with cassettes of protective genes (1Ac/Cry2Ab/Vip3A), (Cry1Ab/Cry2Ac/Vip3Aa19) or (Cry1Ac/Cry1F/Vip3A) was cultivated in the 2016–2017 season on more than 90% of the arable lands of Australia [38].
Currently, the creation of plants containing not only Cry or Vip genes but also containing other gene sequences is of interest in order to increase the effectiveness of biological plant protection against pests. Recently, the US EPA approved a transgenic corn, SmartStaxPRO, expressing the Cry3Bb1 protein, and a dsRNA complementing the RNA of the vacuolar protein DvSnf7 of Diabrotica virgifera LeConte, 1858 [39][40]. A vector containing information about dsRNA targeting the acid methyltransferase gene of the juvenile hormone biosynthesis of H. armigera was inserted into the genome of Bt-cotton and impaired the resistance of pest compared to plants expressing only insectotoxic proteins [41]. The RNAi-mediated knockdown of H. armigera acetylcholinesterase, the ecdysone receptor, and v-ATPase-A genes by producing dsRNAs homologous to genetic targets in potato plants led to mortality and abnormal development in the larva of this insect (recorded ten days post feeding) [3].
Apparently, the application of single Bt genes to modify plant genomes will be gradually replaced by multiple Bt toxin genes or Bt with other nucleotide sequences.

5. Bt as a Means of dsRNAs Deliverance

The important problem of interference methods is dsRNA degradation by nucleases in the gut lumen and tissues of insects. Retaining dsRNA molecules in the gut or hemocoel of pest insects is the key aspect of an effective dsRNA delivery [2]. Thus, dsRNase catalyzing the specific cleavage of dsRNA has been found in the saliva of Lygus lineolaris Palisot de Beauvois, 1818 [42]; pea aphid Acyrthosiphon pisum Harris, 1776 [43]; Schistocerca gregaria Forskal, 1775 [44]; H. armigera [3]; etc. A dsRNA cassette targeting the multiple genes of H. armigera revealed more rapid cleavage in midgut juice compared to the hemolymph [3], and for this reason, the Bt-mediated appearance of pores in digestion membranes, can improve the efficacy of dsRNAs along with dsRNAs targeting dsRNases [45]. The stability of mRNA provided by, for example, the Shine–Dalgarno sequence (GAAAG-GAGG), is a promising factor of the high-level expression of Cry genes in Bt [3][46][47]. The binding of the 30S ribosomal subunit to this sequence might prevent mRNA cleavage by RNAses of pest. The use of a sporulation-dependent promoter of Cry genes of Bt for the transcription of the target dsRNA sequence, leads to the fact that the dsRNA will be spontaneously produced during the sporulation phase [47][48]. It has been demonstrated that the incorporation of plasmid pBtdsSBV-VP1, which carries out dsRNA complemental to the VP1 sequence of the sacbrood virus (SBV) in Bt 4Q7 and the subsequent appliance of exogenous total RNA, leads to a decrease in SVB severance in Apis cerana (Fabricius, 1793) families [48]. Then, the plasmid pBtdsSBV-VP1 was inserted into the Bt NT0423, which expresses Cry1 protein, resulting in SBV replication being repressed in A. cerana bees as well as the viability of the A. cerana parasite Galleria mellonella L. [46]. These results demonstrated that dsRNA-expressing Bt products could be efficiently exploited for the control of both viral diseases and insect pests simultaneously.
And furthermore, it is possible to enhance the toxicity of Cry toxins using dsRNA cassettes. Thus, Bt strains 8010AKi and BMB171AKi expressing the dsRNA of the arginine kinase gene (PxAK) of P. xylostella, flanking two ends with the promoter Pro3α, effectively decreased PxAK expression in ones treated with the composition with wild Cry-producing Bt 8010 and caused a higher lewel of mortality of the pest [49]. Separately, E. coli HT115 dsINT expressing the dsRNA of integrin β1 subunit gene (SeINT) cause a less than 50% mortality rate against Spodoptera exigua Hubner, 1808 larvae, and E. coli expressing Cry1Ca led to a maximal 58% mortality rate of the pest. When S. exigua larvae were treated with the Cry1Ca-expressing bacteria (E. coli or Bt subsp. aizawai from commercial Xentari insecticide) after treatment with E. coli HT115 dsINT, the insecticidal activity of the Cry1Ca was significantly enhanced up to about 80% [47]. The nuclease gene HaREase characteristic for Lepidoptera is up-regulated by dsRNA and affects RNAi in H. armigera. When this gene was knocked out using the CRISPR/Cas9 system, the midgut epithelium structure was not affected in the ΔHaREase mutant, but when larvae were fed an artificial diet with sublethal doses (2.5 or 4 μg/g) of Cry1Ac, the growth rate of the ΔHaREase line was repressed significantly [50]. The insecticidal activity of the Bt-based biopesticide Xentari™ (Valent BioSciences) against larvae of S. littoralis was significantly enhanced by pre-treatment with dsRNA-Bac targeted against the Sl 102 gene, which is responsible for insect cell aggregation and encapsulation to protect against Bt infection [51]. Likewise, the efficacy of biological preparations based on live Bt cells was enhanced when used together with dsRNA-Bac specific to sequences of the P. xylostella Pxf gene [52], which caused insect resistance to Cry1Ac toxin. The RNAi-mediated suppression of the Cat L-like gene encoding the lysosomal cathepsin L-like cysteine protease of Bombyx mori led to an increase in larvae mortality under the influence of Bt subsp. kurstaki strain ABTS-351 (Dipel®, Valent BioSciences, Libertyville, IL, USA) [53]. It is probably that the increase in insect resistance to biocontrol agents based on Bt strains producing toxins and the use of this bacterium as a platform for the expression of dsRNA can help in pest control using the Cry + RNAi strategy [51][52][53].


  1. Xu, J.Z.; Zhang, W.G. Strategies used for genetically modifying bacterial genome: Site-directed mutagenesis, gene inactivation, and gene over-expression. J. Zhejiang Univ. Sci. B. 2016, 17, 83–99.
  2. Scott, J.G.; Michel, K.; Bartholomay, L.C.; Siegfried, B.D.; Hunter, W.B.; Smagghe, G.; Zhu, K.Y.; Douglas, A.E. Toward the elements of successful insect RNAi. J. Insect Physiol. 2013, 59, 1212–1221.
  3. Sharif, M.N.; Iqbal, M.S.; Alam, R.; Awan, M.F.; Tariq, M.; Ali, Q.; Nasir, I.A. Silencing of multiple target genes via ingestion of dsRNA and PMRi affects development and survival in Helicoverpa armigera. Sci. Rep. 2022, 12, 10405.
  4. Azizoglu, U.; Jouzani, G.S.; Yilmaz, N.; Baz, E.; Ozkok, D. Genetically modified entomopathogenic bacteria; recent developments; benefits and impacts: A review. Sci. Total. Environ. 2020, 734, 139169.
  5. Azizoglu, U.; Salehi Jouzani, G.; Sansinenea, E. Biotechnological advances in Bacillus thuringiensis and its toxins: Recent updates. Rev. Environ. Sci. Biotechnol. 2023, 22, 319–348.
  6. Wang, M.; Geng, L.; Jiao, S.; Wang, K.; Xu, W.; Shu, C.; Zhang, J. Bacillus thuringiensis exopolysaccharides induced systemic resistance against Sclerotinia sclerotiorum in Brassica campestris L. Biol. Control 2023, 183, 105267.
  7. Baumann, V.; Lorenzer, C.; Thell, M.; Winkler, A.M.; Winkler, J. RNAi-mediated knockdown of protein expression. Methods Mol. Biol. 2017, 1654, 351–360.
  8. Karabörklü, S.; Azizoglu, U.; Azizoglu, Z.B. Recombinant entomopathogenic agents: A review of biotechnological approaches to pest insect control. World J. Microbiol. Biotechnol. 2018, 34, 14.
  9. Peng, Q.; Yu, Q.; Song, F. Expression of cry genes in Bacillus thuringiensis biotechnology. Appl. Microbiol. Biotechnol. 2019, 103, 1617–1626.
  10. Sansinenea, E.; Vázquez, C.; Ortiz, A. Genetic manipulation in Bacillus thuringiensis for strain improvement. Biotechnol. Lett. 2010, 32, 1549–1557.
  11. Obukowicz, M.G.; Perlak, F.J.; Kusano, K.K.; Mayer, E.J.; Watrud, L.S. Integration of the delta endotoxin gene of Bacillus thuringiensis into the chromosome of root-colonizing pseudomonads using Tn5. Gene 1986, 45, 327–331.
  12. Maksimov, I.V.; Blagova, D.K.; Veselova, S.V.; Sorokan, A.V.; Burkhanova, G.F.; Cherepanova, E.A.; Sarvarova, E.R.; Rumyantsev, S.D.; Alekseev, V.Y.; Khayrullin, R.M. Recombinant Bacillus subtilis 26DCryChS line with gene Btcry1Ia encoding Cry1Ia toxin from Bacillus thuringiensis promotes integrated wheat defense against pathogen Stagonospora nodorum Berk. and greenbug Schizaphis graminum Rond. Biocontrol 2020, 144, 326–338.
  13. Sorokan, A.; Cherepanova, E.; Burkhanova, G.; Veselova, S.; Rumyantsev, S.; Alekseev, V.; Mardanshin, I.; Sarvarova, E.; Khairullin, R.; Benkovskaya, G.; et al. Endophytic Bacillus spp. as a prospective biological tool for control of viral diseases and non-vector Leptinotarsa decemlineata Say. in Solanum tuberosum L. Front. Microbiol. 2020, 11, 569457.
  14. Li, Y.; Wu, C.; Xing, Z.; Gao, B.; Zhang, L. Engineering the bacterial endophyte Burkholderia pyrrocinia JK-SH007 for the control of lepidoptera larvae by introducing the cry218 genes of Bacillus thuringiensis. Biotechnol. Biotechnol. Equip. 2017, 31, 1167–1172.
  15. Quecine, M.C.; Araújo, W.L.; Tsui, S.; Parra, J.R.P.; Azevedo, J.L.; Pizzirani-Kleiner, A.A. Control of Diatraea saccharalis by the endophytic Pantoea agglomerans 33.1 expressing cry1Ac7. Arch. Microbiol. 2014, 196, 227–234.
  16. Soonsanga, S.; Luxananil, P.; Promdonkoy, B. Modulation of Cas9 level for efficient CRISPR-Cas9-mediated chromosomal and plasmid gene deletion in Bacillus thuringiensis. Biotechnol. Lett. 2020, 42, 625–632.
  17. Cohen, E.; Rozen, H.; Joseph, T.; Braun, S.; Margulies, L. Photoprotection of Bacillus thuringiensis kurstaki from ultraviolet irradiation. J. Invertebr. Pathol. 1991, 57, 343–351.
  18. Jallouli, W.; Sellami, S.; Sellami, M.; Tounsi, S. Efficacy of olive mill wastewater for protecting Bacillus thuringiensis formulation from UV radiations. Acta Trop. 2014, 140, 19–25.
  19. Jalali, E.; Maghsoudi, S.; Noroozian, E. Ultraviolet protection of Bacillus thuringiensis through microencapsulation with pickering emulsion method. Sci. Rep. 2020, 10, 20633.
  20. Liu, X.; Zhang, Y.; Du, X.; Luo, X.; Tan, W.; Guan, X.; Zhang, L. Effect of yhfS gene on Bt LLP29 antioxidant and UV rays resistance. Pest Manag. Sci. 2023, 79, 2087–2097.
  21. Tang, M.; Sun, X.; Zhang, S.; Wan, J.; Li, L.; Ni, H. Improved catalytic and antifungal activities of Bacillus thuringiensis cells with surface display of Chi9602ΔSP. J. Appl. Microbiol. 2017, 122, 106–118.
  22. Zhu, L.; Chu, Y.; Zhang, B.; Yuan, X.; Wang, K.; Liu, Z.; Sun, M. Creation of an industrial Bacillus thuringiensis strain with high melanin production and UV tolerance by gene editing. Front. Microbiol. 2022, 13, 913715.
  23. Khasdan, V.; Ben-Dov, E.; Manasherob, R.; Boussiba, S.; Zaritsky, A. Mosquito larvicidal activity of transgenic Anabaena PCC 7120 expressing toxin genes from Bacillus thuringiensis subsp. israelensis. FEMS Microbiol. Lett. 2003, 227, 189–195.
  24. Peng, R.; Xiong, A.; Li, X.; Fuan, H.; Yao, Q. A delta-endotoxin encoded in Pseudomonas fluorescens displays a high degree of insecticidal activity. Appl. Microbiol. Biotechnol. 2003, 63, 300–306.
  25. Sharma, H.C. Biotechnological Approaches for Pest Management and Ecological Sustainability, 1st ed.; CRC Press: Boca Raton, FL, USA, 2009; 526p.
  26. Zhang, N.; Wang, Z.; Shao, J.; Xu, Z.; Liu, Y.; Xun, W.; Miao, Y.; Shen, Q.; Zhang, R. Biocontrol mechanisms of Bacillus: Improving the efficiency of green agriculture. Microb. Biotechnol. 2023. early view.
  27. Deng, S.Q.; Zou, W.H.; Li, D.L.; Chen, J.T.; Huang, Q.; Zhou, L.J.; Tian, X.X.; Chen, Y.J.; Peng, H.J. Expression of Bacillus thuringiensis toxin Cyt2Ba in the entomopathogenic fungus Beauveria bassiana increases its virulence towards Aedes mosquitoes. PLoS Negl. Trop. Dis. 2019, 13, e0007590.
  28. Hernandez-Fernandez, J. Bacillus thuringiensis: A natural tool in insect pest control. Ch. 8. In The Handbook of Microbial Bioresurses; Gupta, V.R., Sharma, G.D., Tuohy, M.G., Gaur, R., Eds.; CAB International: Wallingford, UK, 2016; pp. 121–139. Available online: (accessed on 26 November 2023).
  29. Dubey, A.; Saiyam, D.; Kumar, A.; Hashem, A.; Abd_Allah, E.F.; Khan, M.L. Bacterial root endophytes: Characterization of their competence and plant growth promotion in soybean (Glycine max (L.) Merr.) under drought stress. Int. J. Environ. Res. Public Health 2021, 18, 931.
  30. Carlson, R. Estimating the biotech sector’s contribution to the US economy. Nat. Biotechnol. 2016, 34, 247–255.
  31. Dourado, M.N.; Leite, T.F.; Barroso, P.A.V.; Araujo, W.L. Genetically modified organisms in the tropics: Challenges and perspectives. In Diversity and Benefits of Microorganisms from the Tropics; De Azevedo, J.L., Quecine, M.C., Eds.; Springer International Publishing: New York, NY, USA, 2017; pp. 403–430.
  32. Yele, Y.; Poddar, N. Virus-insect vector interaction and their management. In Adaptive Crop Protection Management Strategies; Prasad, D., Lal, G., Ahmad, I., Eds.; Write and Print Publications: New Delhi, India, 2019; pp. 384–396.
  33. Alam, I.; Salimullah, M. Genetic Engineering of eggplant (Solanum melongena L.): Progress; controversy and potential. Horticulturae 2021, 7, 78.
  34. Hassan, T.U.; Bano, A.; Naz, I.; Hussain, M. Bacillus cereus: A competent plant growth promoting bacterium of saline sodic field. Pak. J. Bot. 2018, 50, 1029–1037.
  35. Chen, W.B.; Lu, G.Q.; Cheng, H.M.; Liu, C.X.; Xiao, Y.T.; Xu, C.; Shen, Z.C.; Soberón, M.; Bravo, A.; Wu, K.M. Transgenic cotton co-expressing chimeric Vip3AcAa and Cry1Ac confers effective protection against Cry1Ac-resistant cotton bollworm. Transgenic Res. 2017, 26, 763–774.
  36. Katta, S.; Talakayala, A.; Reddy, M.K.; Addepally, U.; Garladinne, M. Development of transgenic cotton (Narasimha) using triple gene Cry2Ab-Cry1F-Cry1Ac construct conferring resistance to lepidopteran pest. J. Biosci. 2020, 45, 31.
  37. Jost, P.; Shurley, D.; Culpepper, S.; Roberts, P.; Nichols, R.; Reeves, J.; Anthony, S. Economic comparison of transgenic and nontransgenic cotton production systems in Georgia. Agron. J. 2008, 100, 42–51.
  38. Tabashnik, B.E.; Carrière, Y. Evaluating Cross-resistance between Vip and Cry Toxins of Bacillus thuringiensis. J. Econ. Entomol. 2020, 113, 553–561.
  39. Moar, W.; Khajuria, C.; Pleau, M.; Ilagan, O.; Chen, M.; Jiang, C. Cry3Bb1-resistant western corn rootworm, Diabrotica virgifera virgifera (LeConte) does not exhibit cross-resistance to DvSnf7 dsRNA. PLoS ONE 2017, 12, e0169175.
  40. Reinders, J.D.; Reinders, E.E.; Robinson, E.A.; French, B.W.; Meinke, L.J. Evidence of western corn rootworm (Diabrotica virgifera virgifera LeConte) field-evolved resistance to Cry3Bb1 + Cry34/35Ab1 maize in Nebraska. Pest Manag. Sci. 2022, 78, 1356–1366.
  41. Ni, M.; Ma, W.; Wang, X.; Gao, M.; Dai, Y.; Wei, X. Next-generation transgenic cotton: Pyramiding RNAi and Bt counters insect resistance. Plant Biotechnol. J. 2017, 15, 1204–1213.
  42. Terenius, O.; Papanicolaou, A.; Garbutt, J.S.; Eleftherianos, I.; Huvenne, H.; Kanginakudru, S.; Albrechtsen, M. RNA interference in Lepidoptera: An overview of successful and unsuccessful studies and implications for experimental design. J. Insect Physiol. 2011, 57, 231–245.
  43. Christiaens, O.; Swevers, L.; Smagghe, G. DsRNA degradation in the pea aphid (Acyrthosiphon pisum) associated with lack of response in RNAi feeding and injection assay. Peptides 2014, 53, 307–314.
  44. Wynant, N.; Santos, D.; Verdonck, R.; Spit, J.; Van Wielendaele, P.; Vanden, B.J. Identification, functional characterization and phylogenetic analysis of double stranded RNA degrading enzymes present in the gut of the desert locust; Schistocerca gregaria. Insect Biochem. Mol. Biol. 2014, 46, 1–8.
  45. Huang, X.; Jing, D.; Prabu, S.; Zhang, T.; Wang, Z. RNA interference of phenoloxidases of the fall armyworm, Spodoptera frugiperda, enhance susceptibility to Bacillus thuringiensis protein Vip3Aa19. Insects 2022, 13, 1041.
  46. Park, M.G.; Choi, J.Y.; Park, D.H.; Wang, M.; Kim, H.J.; Je, Y.H. Simultaneous control of sacbrood virus (SBV) and Galleria mellonella using a Bt strain transformed to produce dsRNA targeting the SBV vp1 gene. Entomologia 2021, 41, 233–242.
  47. Kim, E.; Park, Y.; Kim, Y. A transformed bacterium expressing double-stranded RNA specific to integrin beta1 enhances Bt toxin efficacy against a polyphagous insect pest, Spodoptera exigua. PLoS ONE 2015, 10, e0132631.
  48. Park, M.G.; Kim, W.J.; Choi, J.Y.; Kim, J.H.; Park, D.H.; Kim, J.Y. Development of a Bacillus thuringiensis based dsRNA production platform to control sacbrood virus in Apis cerana. Pest Manag. Sci. 2020, 76, 1699–1704.
  49. Jiang, Y.X.; Chen, J.Z.; Li, M.W.; Zha, B.H.; Huang, P.R.; Chu, X.M.; Chen, J.; Yang, G. The Combination of Bacillus thuringiensis and its engineered strain expressing dsRNA increases the toxicity against Plutella xylostella. Int. J. Mol. Sci. 2022, 23, 444.
  50. Guan, R.; Chen, Q.; Li, H.; Hu, S.; Miao, X.; Wang, G.; Yang, B. Knockout of the HaREase gene improves the stability of dsRNA and increases the sensitivity of Helicoverpa armigera to Bacillus thuringiensis toxin. Front. Physiol. 2019, 10, 1368.
  51. Caccia, S.; Astarita, F.; Barra, E.; Di Lelio, I.; Varricchio, P.; Pennacchio, F. Enhancement of Bacillus thuringiensis toxicity by feeding Spodoptera littoralis larvae with bacteria expressing immune suppressive dsRNA. J. Pest Sci. 2020, 93, 303–314.
  52. Kang, S.; Sun, D.; Qin, J.; Guo, L.; Zhu, L.; Bai, Y.; Wu, Q.; Wang, S.; Zhou, X.; Guo, Z.; et al. Fused: A promising molecular target for an RNAi-based strategy to manage Bt resistance in Plutella Xylostella (L.). J. Pest Sci. 2021, 95, 101–114.
  53. Yang, L.; Sun, Y.; Chang, M.; Zhang, Y.; Qiao, H.; Huang, S.; Kan, Y.; Yao, L.; Li, D.; Ayra-Pardo, C. RNA interference-mediated knockdown of Bombyx mori haemocyte-specific cathepsin L (Cat L)-like cysteine protease gene increases Bacillus thuringiensis kurstaki toxicity and reproduction in insect cadavers. Toxins 2022, 14, 394.
Contributors MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to : , , , ,
View Times: 231
Revisions: 2 times (View History)
Update Date: 06 Dec 2023
Video Production Service