The extensive planting of insect resistant crops expressing Bt proteins
contributed to the evolution of resistance in pests as a natural reaction.
The globally destructive pest pink bollworm's resistance to Bt protein
Cry1Ac is linked with mutations in PgCad1 gene, which encodes a cadherin
protein that sticks with Cry1Ac in the larval midgut. In a previous study,
Shenyun Li from Nanjing Agricultural University in
s/download/Facts%20and%20Trends%20-%20China-2017.pdf> China, together with
other scientists, reported a long non-coding RNA (lncRNA) which is linked
with both resistance and susceptibility to Cry1Ac. In their latest study,
they tested the hypothesis that decreasing the expression of the lncRNA also
reduces the transcription of PgCad1 and susceptibility to Cry1Ac. The
results are published in Pesticide Biochemistry and Physiology.
Results of the Quantitative RT-PCR showed that feeding susceptible pink
bollworm neonates with small interfering RNAs (siRNAs) targeting this lncRNA
but not PgCad1 decreased the abundance of transcripts of both the lncRNA and
PgCad1. Furthermore, neonates fed with siRNA showed decreased susceptibility
to Cry1Ac. These findings imply that the lncRNA increases transcription
PgCad1 and susceptibility of pink bollworm to Cry1Ac.