Functional analysis of <i>AgJHAMT</i> gene related to developmental period in <i>Aphis gossypii</i> Glover

<i>Aphis gossypii</i> is one of the most economically important agricultural pests that cause serious crop losses worldwide, and the indiscriminate chemical application causes resistance development in <i>A. gossypii,</i> a major obstacle to successful control. In this study, we selected the up-regulated expression gene <i>AgJHAMT</i>, which was enriched into juvenile hormone pathway though transcriptome sequencing analysis of the cotton aphids that fed on transgenic cotton lines expressing ds<i>AgCYP6CY3</i> (the TG cotton). The <i>AgJHAMT</i> gene was overexpressed in cotton aphids which fed on the TG cotton, and its expression profile during the nymphs was clarified. Then, silencing <i>AgJHAMT</i> could advance the developmental period of cotton aphids by 0.5 days compared with control groups. The <i>T</i> and <i>t</i> 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) (<i>P</i> < 0.05), respectively. The fast growth caused by <i>AgJHAMT</i> silencing was rescued by applying the JH analogue, methoprene. Overall, these findings clarified the function of <i>AgJHAMT</i> in the developmental period of <i>A. gossypii</i>. This study contributes to further clarify the molecular mechanisms of delaying the growth and development of cotton aphids by the transgenic cotton lines expressing ds<i>AgCYP6CY3</i>.