RNAi-Mediated Suppression of Laccase2 Impairs Cuticle Tanning and Molting in the Cotton Boll Weevil (Anthonomus grandis)

Firmino, Alexandre Augusto Pereira; Pinheiro, Daniele H.; Pinto, Clidia Eduarda Moreira; Antonino, José Dijair; Macedo, Leonardo Lima Pepino; Martins-de-Sa, Diogo; Arraes, Fabrício Barbosa Monteiro; Coelho, Roberta Ramos; Fonseca, Fernando Campos de Assis; Silva, Maria Cristina Mattar; Engler, Janice de Almeida; Silva, Marília Santos; Lourenço-Tessutti, Isabela Tristan; Terra, Walter R.; Grossi-de-Sá, Maria Fátima

doi:10.3389/fphys.2020.591569

Cited by 9 publications

(3 citation statements)

References 78 publications

(116 reference statements)

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“… 32 Decrease in hatchability and increased mortality have been reported by Rolim in cotton boll weevil. 49 It can be attributed to the fact that the insect cuticle is composed of intertwined chitin chains embedded in a protein matrix, where the absence of chitin may result in mechanical weakness and death of the embryo. 50 Similar to other chitin biosynthesis inhibitors, lufenuron acts by impairing cuticle deposition, as reported with boll weevils.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of chemosterility effect of different insect growth regulators on Bactrocera zonata population

et al. 2023

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The indiscriminate application of synthetic pesticides on horticultural plants for the management of Bactrocera zonata has both economic and environmental implications due to the biomagnification of harmful residues in humans via the food chain. This necessitates the use of some eco-friendly control measures such as insect growth regulators (IGRs) as an alternative. A laboratory experiment was laid out to determine the potential chemosterilant effect of five IGRs including pyriproxyfen, novaluron, lufenuron, buprofezin, and flubendiamide at six different concentrations on B. zonata after treating adult diet. Using the oral bioassay, B. zonata were fed on IGRs impregnated diet (50–300 ppm/5 mL diet) which was replaced with the normal diet after 24 h of feeding. Ten pairs of B. zonata were placed in a separate plastic cage accommodating an ovipositor attractant guava for eggs collection and calculation. An analysis of the result revealed that fecundity and hatchability were higher at a low dose and vice versa. Lufenuron at 300 ppm/5 mL of diet significantly decreased the fecundity rate (31.1%) as compared to pyriproxyfen, novaluron, buprofezin and flubendiamide, which had 39.3%, 39.3%, 43.8%, and 47.5%, respectively. The lowest hatchability (19.9%) was noted in lufenuron treated diet followed by pyriproxyfen, novaluron, buprofezin, and flubendiamide, which had 22.1%, 25.0%, 30.9%, and 31.6%, respectively. Furthermore, in a population of crosses between the lufenuron treated male and female, a significant decrease in fecundity (45.5%) and hatchability (51.7%) was noted as compared to other IGRs. Overall, this study identified the chemosterilant potential of lufenuron on the population of B. zonata which can be integrated for its management strategy.

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Section: Discussionmentioning

confidence: 99%

Evaluation of chemosterility effect of different insect growth regulators on Bactrocera zonata population

et al. 2023

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“…While a moderate RNAi response is observed following the injection of small amounts of dsRNA in the CBW ( Macedo et al, 2017 ; Firmino et al, 2020 ; Moreira-Pinto et al, 2021 ), large amounts of dsRNA are required to produce strong and persistent gene silencing that culminates in clear phenotypic effects when the dsRNA is delivered through feeding ( Garcia et al, 2017 ). Therefore, the relatively weak RNAi response of CBW upon dsRNA treatment hampers the functional analysis of genes through the RNAi approach and the selection of potential target genes that could be used in the development of RNAi-mediated control methods.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous silencing of juvenile hormone metabolism genes through RNAi interrupts metamorphosis in the cotton boll weevil

Vasquez

Pinheiro²,

Teixeira³

et al. 2023

Front. Mol. Biosci.

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The cotton boll weevil (CBW) (Anthonomus grandis) is one of the major insect pests of cotton in Brazil. Currently, CBW control is mainly achieved by insecticide application, which is costly and insufficient to ensure effective crop protection. RNA interference (RNAi) has been used in gene function analysis and the development of insect control methods. However, some insect species respond poorly to RNAi, limiting the widespread application of this approach. Therefore, nanoparticles have been explored as an option to increase RNAi efficiency in recalcitrant insects. Herein, we investigated the potential of chitosan–tripolyphosphate (CS-TPP) and polyethylenimine (PEI) nanoparticles as a dsRNA carrier system to improve RNAi efficiency in the CBW. Different formulations of the nanoparticles with dsRNAs targeting genes associated with juvenile hormone metabolism, such as juvenile hormone diol kinase (JHDK), juvenile hormone epoxide hydrolase (JHEH), and methyl farnesoate hydrolase (MFE), were tested. The formulations were delivered to CBW larvae through injection (0.05–2 µg), and the expression of the target genes was evaluated using RT-qPCR. PEI nanoparticles increased targeted gene silencing compared with naked dsRNAs (up to 80%), whereas CS-TPP-dsRNA nanoparticles decreased gene silencing (0%–20%) or led to the same level of gene silencing as the naked dsRNAs (up to 50%). We next evaluated the effects of targeting a single gene or simultaneously targeting two genes via the injection of naked dsRNAs or dsRNAs complexed with PEI (500 ng) on CBW survival and phenotypes. Overall, the gene expression analysis showed that the treatments with PEI targeting either a single gene or multiple genes induced greater gene silencing than naked dsRNA (∼60%). In addition, the injection of dsJHEH/JHDK, either naked or complexed with PEI, significantly affected CBW survival (18% for PEI nanoparticles and 47% for naked dsRNA) and metamorphosis. Phenotypic alterations, such as uncompleted pupation or malformed pupae, suggested that JHEH and JHDK are involved in developmental regulation. Moreover, CBW larvae treated with dsJHEH/JHDK + PEI (1,000 ng/g) exhibited significantly lower survival rate (55%) than those that were fed the same combination of naked dsRNAs (30%). Our findings demonstrated that PEI nanoparticles can be used as an effective tool for evaluating the biological role of target genes in the CBW as they increase the RNAi response.

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“…Remarkable advances have been made by different groups in developing transgenic and non-transgenic approaches to improve plant resistance to a range of pests [ 17 , 18 , 19 , 20 , 21 ]. Some of the contributions worth highlighting are the discovery and validation of potential target genes to design RNAi molecules to control the CBW [ 22 , 23 , 24 , 25 ], the improvement of the understanding of basic mechanisms of RNAi in insects [ 11 ], and the design of novel approaches to improve RNAi efficacy [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

Stabilized Double-Stranded RNA Strategy Improves Cotton Resistance to CBW (Anthonomus grandis)

Ribeiro

Vasquez

Macedo

et al. 2022

IJMS

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Cotton is the most important crop for fiber production worldwide. However, the cotton boll weevil (CBW) is an insect pest that causes significant economic losses in infested areas. Current control methods are costly, inefficient, and environmentally hazardous. Herein, we generated transgenic cotton lines expressing double-stranded RNA (dsRNA) molecules to trigger RNA interference-mediated gene silencing in CBW. Thus, we targeted three essential genes coding for chitin synthase 2, vitellogenin, and ecdysis-triggering hormone receptor. The stability of expressed dsRNAs was improved by designing a structured RNA based on a viroid genome architecture. We transformed cotton embryos by inserting a promoter-driven expression cassette that overexpressed the dsRNA into flower buds. The transgenic cotton plants were characterized, and positive PCR transformed events were detected with an average heritability of 80%. Expression of dsRNAs was confirmed in floral buds by RT-qPCR, and the T1 cotton plant generation was challenged with fertilized CBW females. After 30 days, data showed high mortality (around 70%) in oviposited yolks. In adult insects fed on transgenic lines, chitin synthase II and vitellogenin showed reduced expression in larvae and adults, respectively. Developmental delays and abnormalities were also observed in these individuals. Our data remark on the potential of transgenic cotton based on a viroid-structured dsRNA to control CBW.

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RNAi-Mediated Suppression of Laccase2 Impairs Cuticle Tanning and Molting in the Cotton Boll Weevil (Anthonomus grandis)

Cited by 9 publications

References 78 publications

Evaluation of chemosterility effect of different insect growth regulators on Bactrocera zonata population

Evaluation of chemosterility effect of different insect growth regulators on Bactrocera zonata population

Simultaneous silencing of juvenile hormone metabolism genes through RNAi interrupts metamorphosis in the cotton boll weevil

Stabilized Double-Stranded RNA Strategy Improves Cotton Resistance to CBW (Anthonomus grandis)

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