DsRNA-mediated Vital Genes Silencing of Fruit Fly, Bactrocera dorsalis (Hendel) for Producing RNAi Plants| Chapter 7 | New Visions in Biological Science Vol.10

 The oriental fruit fly, Bactrocera dorsalis (Hendel), is the world's most destructive pest, infesting 30 to 100 percent of key fruits and vegetables. It is particularly difficult to regulate due to its polyphagous, multivoltine nature, and unexposed growth stages. There has been no report of fruit fly resistant guava germplasm anywhere in the world thus far. The use of an RNAi method to control fruit flies in fruit crops, particularly guava, could be a viable option.

The goal of this work is to see if important genes like ecr (ecdysone receptor) and rpl19 (a ribosomal protein L19) can be used in dsRNA-based RNAi experiments by feeding bacteria producing appropriate dsRNA to fruit flies. Further, the ecr-RNAi construct was transformed into guava to produce RNAi plants.

Main Body: The dsRNA expression technique based on Escherichia coli was investigated for its potential in controlling B. dorsalis by targeting its two key genes, ecr and rpl19. Treatment of B. dorsalis larvae, emerging pupae, and adults with E. coli, HT115 (DE3) expressing dsRNA of Bdecr and Bdrpl19 with artificial food resulted in severe mortality and abnormalities. Total mortality (including deformity) of maggots, pupae, and adult fruit flies was 86.3 percent, 87.9%, and was highest in 700 l (200x of 3.5x108 cells) dsRNAs of Bdecr and Bdrpl19 bacterial treatments, compared to 350 and 200 l bacterial treatments, respectively. Severe developmental defects, including melanisation and deformities of maggots and pupae, lack of wings, underdeveloped abdomen/absence of complete abdomen, absence of legs, severely curled wings, malformed legs, and incomplete eclosion, were observed in emerged adults, as well as suppression of these target gene expression. An RNAi construct was generated employing the same ECR gene of B. dorsalis and standardised in planta (floral drop) transformation of Allahabad safeda guava cultivar to mobilise the RNAi cassette. Using genomic DNA-PCR with gene and vector specific primer combinations, eight RNAi guava plants (T1) grew from seeds of altered fruits (T0).

Short Conclusion: The study shows that it is possible to mute two potential genes by feeding bacteria producing dsRNA to B. dorsalis at all embryonic stages, paving the way for RNAi-based fruit fly control in a variety of fruit crops, including guava in this case.

 

Author(s) Details:

Prashant Mohanpuria,
School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, 141004 India.

Gurupkar Singh Sidhu,
School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, 141004 India.

Sandeep Singh,
Department of Fruit Science, Punjab Agricultural University, Ludhiana, 141004 India.

Please see the link here:  https://stm.bookpi.org/NVBS-V10/article/view/5986