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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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HaEcR expression in H. armigera is suppressed by feeding with leaves of transgenic tobacco plants expressing HaEcR dsRNA.
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pone-0038572-g005: HaEcR expression in H. armigera is suppressed by feeding with leaves of transgenic tobacco plants expressing HaEcR dsRNA.

Mentions: We assume that the molting defects in H. armigera larvae resulted from suppression of its HaEcR mRNA level by feeding with leaves of transgenic tobacco plants expressing HaEcR dsRNA. To verify this hypothesis, HaEcR mRNA levels in H. armigera larvae were measured by quantitative real-time PCR (qRT–PCR). Importantly, HaEcR mRNA level significantly decreased in comparison with the control after 24 and 48 hours of feeding, respectively (Figure 5A and B). However, the 20E primary-response gene, HaE75B[35], was only slightly downregulated by 48 hours (data not shown), so we extended the feeding assay for 96 hours. By then, both mRNA levels of HaEcR (Figure 5C) and HaE75B (Figure 5D) were significantly decreased, confirming that the expression of HaE75B requires that of HaEcR[35]. Taken together, we conclude that suppression of HaEcR expression in H. armigera by feeding with transgenic tobacco plants expressing HaEcR dsRNA interrupts the 20E-triggered transcriptional cascade, results in molting defects, and causes larval lethality.


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)

HaEcR expression in H. armigera is suppressed by feeding with leaves of transgenic tobacco plants expressing HaEcR dsRNA.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0038572-g005: HaEcR expression in H. armigera is suppressed by feeding with leaves of transgenic tobacco plants expressing HaEcR dsRNA.
Mentions: We assume that the molting defects in H. armigera larvae resulted from suppression of its HaEcR mRNA level by feeding with leaves of transgenic tobacco plants expressing HaEcR dsRNA. To verify this hypothesis, HaEcR mRNA levels in H. armigera larvae were measured by quantitative real-time PCR (qRT–PCR). Importantly, HaEcR mRNA level significantly decreased in comparison with the control after 24 and 48 hours of feeding, respectively (Figure 5A and B). However, the 20E primary-response gene, HaE75B[35], was only slightly downregulated by 48 hours (data not shown), so we extended the feeding assay for 96 hours. By then, both mRNA levels of HaEcR (Figure 5C) and HaE75B (Figure 5D) were significantly decreased, confirming that the expression of HaE75B requires that of HaEcR[35]. Taken together, we conclude that suppression of HaEcR expression in H. armigera by feeding with transgenic tobacco plants expressing HaEcR dsRNA interrupts the 20E-triggered transcriptional cascade, results in molting defects, and causes larval lethality.

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