Biotech Updates

Silencing of Midgut-Expressed Genes in Lepidopterans through Ingestion of RNAi Expressing Plants

November 15, 2017

Plant-mediated RNAi (PMRi) silencing of insect genes definitely has great potential for crop protection. The team of Spoorthi Poreddy, together with researchers from the Max-Planck-Institute for Chemical Ecology evaluated the effectiveness of this approach under field conditions.

The team transformed wild tobacco (Nicotiana attenuate) and cultivated tobacco (N. tabacum) to express a stranded RNA (dsRNA) that targets the insects' midgut-expressed genes, the nicotine-ingestion induced cytochrome P450 monooxygenase and the lyciumoside-IV-ingestion induced β-glucosidase1. These larval genes are important for the larvae's response to ingested toxins.

When Manduca sexta and Manduca quinquemaculata larvae attacked the transgenic N. attenuata plants, their midgut genes were found to be strongly silenced. Further analysis revealed that the transcripts of the targeted genes were reduced by up to 90%, without reducing the transcripts of the larvae's most similar, potential off-target genes.

These results conclude that PMRi specifically silence genes in insects. With careful selection of targets, this approach might protect crops from attacks from insect pests.

For more information, read the article in BMC Plant Biology.