LAUSR

BACKGROUND The cosmopolitan pest, Aphis gossypii Glover, globally causes considerable economic losses on various crops by its feeding damage and disease transmission. Transgenic plants that produce double-stranded RNA (dsRNA) targeted to insect genes are being developed as a pest control strategy. In this study, we evaluated the effect of transgenic cotton-mediated RNAi on the growth and detoxification ability of A. gossypii, after the transgenic cotton lines expressing dsAgCYP6CY3-P1 (the TG cotton lines) was obtained on the basis of exploring the functions of CYP6CY3 in our previous research. RESULTS The developmental time of 3rd and 4th instar nymphs which fed on the TG cotton lines were significantly prolonged. Life table parameters showed that the fitness of cotton aphids from the TG cotton lines declined. Additionally, the relative expression level of CYP6CY3 in cotton aphids which fed on the TG cotton lines was significantly reduced by 47.3% at 48h compared with that from the non-transgenic cotton (the NT cotton). Bioassay showed that silencing of CYP6CY3 increased mortality of the nymphs to imidacloprid by 28.49 % (at 24 h) and to acetamiprid by 73.77 % (at 48 h), respectively. CONCLUSION These results indicated that the TG cotton lines delayed the growth and development of A. gossypii, but also decreased population density and increased its sensitivity to imidacloprid and acetamiprid, respectively. The results provide further support for the development and application of plant-mediated RNAi. This article is protected by copyright. All rights reserved.