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Improvement of pest resistance in transgenic tobacco plants expressing dsRNA of an insect-associated gene EcR.

Zhu JQ, Liu S, Ma Y, Zhang JQ, Qi HS, Wei ZJ, Yao Q, Zhang WQ, Li S - PLoS ONE (2012)

Bottom Line: The adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades.When H. armigera larvae were fed with the whole transgenic tobacco plants expressing EcR dsRNA, resistance to H. armigera was significantly improved in transgenic plants.Meanwhile, when H. armigera larvae were fed with leaves of transgenic tobacco plants expressing EcR dsRNA, its EcR mRNA level was dramatically decreased causing molting defects and larval lethality.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.

ABSTRACT
The adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades. Recently, transgenic plant expressing double-stranded RNA (dsRNA) targeting pest genes emerges as a promising strategy for improving pest resistance in crops. The steroid hormone, 20-hydroxyecdysone (20E), predominately controls insect molting via its nuclear receptor complex, EcR-USP. Here we report that pest resistance is improved in transgenic tobacco plants expressing dsRNA of EcR from the cotton bollworm, Helicoverpa armigera, a serious lepidopteran pest for a variety of crops. When H. armigera larvae were fed with the whole transgenic tobacco plants expressing EcR dsRNA, resistance to H. armigera was significantly improved in transgenic plants. Meanwhile, when H. armigera larvae were fed with leaves of transgenic tobacco plants expressing EcR dsRNA, its EcR mRNA level was dramatically decreased causing molting defects and larval lethality. In addition, the transgenic tobacco plants expressing H. armigera EcR dsRNA were also resistant to another lepidopteran pest, the beet armyworm, Spodoptera exigua, due to the high similarity in the nucleotide sequences of their EcR genes. This study provides additional evidence that transgenic plant expressing dsRNA targeting insect-associated genes is able to improve pest resistance.

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Related in: MedlinePlus

Ingestion of bacterial-expressed HaEcR dsRNA results in molting defects and lethality in H. armigera larvae.(A) The L4440-HaEcR construct producing HaEcR dsRNA in E. coli HT115. (B) Expression of HaEcR dsRNA was confirmed by electrophoresis on 1% agarose gel. (C) Ingestion of bacterial-expressed HaEcR dsRNA caused up to 60% larval lethality in H. armigera. (D) Some H. armigera larvae died as larval-pupal intermediates.
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pone-0038572-g001: Ingestion of bacterial-expressed HaEcR dsRNA results in molting defects and lethality in H. armigera larvae.(A) The L4440-HaEcR construct producing HaEcR dsRNA in E. coli HT115. (B) Expression of HaEcR dsRNA was confirmed by electrophoresis on 1% agarose gel. (C) Ingestion of bacterial-expressed HaEcR dsRNA caused up to 60% larval lethality in H. armigera. (D) Some H. armigera larvae died as larval-pupal intermediates.

Mentions: Apparently, ddH2O and the host bacteria HT115 caused no effects on larval growth and development in H. armigera. Likewise, the control dsRNA prepared from HT115 containing the empty vector L4440 and L4440-GFP caused less than 5% larval lethality. However, HaEcR dsRNA prepared from HT115 containing L4440-HaEcR resulted in up to 60% larval lethality (Figure 1C). Most larvae that fed on HaEcR dsRNA failed to shed cuticles during larval molting and died with small sizes, or formed larval-pupal intermediates (Figure 1D) with lethal phenotypes similar to EcR RNAi in B. mori[33]. However, HaUSP dsRNA prepared from HT115 containing L4440-HaUSP only caused ∼10% lethality, likely due to a comparatively low efficiency of RNAi knockdown.


Improvement of pest resistance in transgenic tobacco plants expressing dsRNA of an insect-associated gene EcR.

Zhu JQ, Liu S, Ma Y, Zhang JQ, Qi HS, Wei ZJ, Yao Q, Zhang WQ, Li S - PLoS ONE (2012)

Ingestion of bacterial-expressed HaEcR dsRNA results in molting defects and lethality in H. armigera larvae.(A) The L4440-HaEcR construct producing HaEcR dsRNA in E. coli HT115. (B) Expression of HaEcR dsRNA was confirmed by electrophoresis on 1% agarose gel. (C) Ingestion of bacterial-expressed HaEcR dsRNA caused up to 60% larval lethality in H. armigera. (D) Some H. armigera larvae died as larval-pupal intermediates.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369839&req=5

pone-0038572-g001: Ingestion of bacterial-expressed HaEcR dsRNA results in molting defects and lethality in H. armigera larvae.(A) The L4440-HaEcR construct producing HaEcR dsRNA in E. coli HT115. (B) Expression of HaEcR dsRNA was confirmed by electrophoresis on 1% agarose gel. (C) Ingestion of bacterial-expressed HaEcR dsRNA caused up to 60% larval lethality in H. armigera. (D) Some H. armigera larvae died as larval-pupal intermediates.
Mentions: Apparently, ddH2O and the host bacteria HT115 caused no effects on larval growth and development in H. armigera. Likewise, the control dsRNA prepared from HT115 containing the empty vector L4440 and L4440-GFP caused less than 5% larval lethality. However, HaEcR dsRNA prepared from HT115 containing L4440-HaEcR resulted in up to 60% larval lethality (Figure 1C). Most larvae that fed on HaEcR dsRNA failed to shed cuticles during larval molting and died with small sizes, or formed larval-pupal intermediates (Figure 1D) with lethal phenotypes similar to EcR RNAi in B. mori[33]. However, HaUSP dsRNA prepared from HT115 containing L4440-HaUSP only caused ∼10% lethality, likely due to a comparatively low efficiency of RNAi knockdown.

Bottom Line: The adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades.When H. armigera larvae were fed with the whole transgenic tobacco plants expressing EcR dsRNA, resistance to H. armigera was significantly improved in transgenic plants.Meanwhile, when H. armigera larvae were fed with leaves of transgenic tobacco plants expressing EcR dsRNA, its EcR mRNA level was dramatically decreased causing molting defects and larval lethality.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.

ABSTRACT
The adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades. Recently, transgenic plant expressing double-stranded RNA (dsRNA) targeting pest genes emerges as a promising strategy for improving pest resistance in crops. The steroid hormone, 20-hydroxyecdysone (20E), predominately controls insect molting via its nuclear receptor complex, EcR-USP. Here we report that pest resistance is improved in transgenic tobacco plants expressing dsRNA of EcR from the cotton bollworm, Helicoverpa armigera, a serious lepidopteran pest for a variety of crops. When H. armigera larvae were fed with the whole transgenic tobacco plants expressing EcR dsRNA, resistance to H. armigera was significantly improved in transgenic plants. Meanwhile, when H. armigera larvae were fed with leaves of transgenic tobacco plants expressing EcR dsRNA, its EcR mRNA level was dramatically decreased causing molting defects and larval lethality. In addition, the transgenic tobacco plants expressing H. armigera EcR dsRNA were also resistant to another lepidopteran pest, the beet armyworm, Spodoptera exigua, due to the high similarity in the nucleotide sequences of their EcR genes. This study provides additional evidence that transgenic plant expressing dsRNA targeting insect-associated genes is able to improve pest resistance.

Show MeSH
Related in: MedlinePlus