Functional analysis of AgJHAMT gene related to developmental period in Aphis gossypii Glover.

Aphis gossypii is one of the most economically important agricultural pests that cause serious crop losses worldwide, and the indiscriminate chemical application causes resistance development in A. gossypii, a major obstacle to successful control. In this study, we selected the up-regulated expression gene AgJHAMT, which was enriched into juvenile hormone pathway though transcriptome sequencing analysis of the cotton aphids that fed on transgenic cotton lines expressing dsAgCYP6CY3 (the TG cotton). The AgJHAMT gene was overexpressed in cotton aphids which fed on the TG cotton, and its expression profile during the nymphs was clarified. Then, silencing AgJHAMT could advance the developmental period of cotton aphids by 0.5 days compared with control groups. The T and t values of cotton aphids in the dsJHAMT treatment group (6.88 ± 0.15, 1.65 ± 0.06) were significantly shorter than that of the sprayed H₂O control group (7.6 ± 0.14, 1.97 ± 0.09) (P < 0.05), respectively. The fast growth caused by AgJHAMT silencing was rescued by applying the JH analogue, methoprene. Overall, these findings clarified the function of AgJHAMT in the developmental period of A. gossypii. This study contributes to further clarify the molecular mechanisms of delaying the growth and development of cotton aphids by the transgenic cotton lines expressing dsAgCYP6CY3.