Juvenile Hormone Synthesis Pathway Gene SfIPPI Regulates Sogatella furcifera Reproduction

Abstract

The juvenile hormone (JH) is crucial for insect reproduction, and isopentenyl pyrophosphate isomerase (IPPI) is a key enzyme in the JH synthesis pathway. However, few studies have investigated how IPPI regulates insect reproduction. This study identifies and characterizes the IPPI gene (SfIPPI) from the important agricultural pest Sogatella furcifera. A phylogenetic analysis reveals a high homology of SfIPPI with the IPPI amino acid sequences of Laodelphax striatellus and Nilaparvata lugens (Stål). Furthermore, SfIPPI is expressed at various developmental stages and in various tissues of S. furcifera, and is significantly higher on the 5th day of adult emergence and in integument tissue, while lower levels are found on the 3rd day of adult emergence and in fat body and gut tissue. After silencing SfIPPI using RNA interference, the ovarian development is significantly inhibited and the fecundity is significantly reduced when compared with the control group. Additionally, SfIPPI silencing significantly decreases the expression levels of downstream JH signal transduction pathway genes (SfJHAMT, SfFAMeT, and SfKr-h1) and SfVg. Our findings are helpful in elucidating the molecular mechanism underlying the regulation of insect reproduction through genes in the JH synthesis pathway, and they provide a theoretical basis for the development of pest control treatments targeting SfIPPI.

Identification and functional analysis of isopentenyl pyrophosphate isomerase genes in the whiteflies Bemisia tabaci (Hemiptera: Aleyrodidae)

“…It has been demonstrated that AaIPPI plays a critical role in the synthesis of JH in A. aegypti , and changing the AaIPPI mRNA levels inhibits JH biosynthesis ( Diaz et al 2012 ). The SfIPPI protein is involved in female reproduction, and silencing SfIPPI had a negative effect on ovarian development and egg production in Sogatella furcifera ( Gong et al 2022a ). The above studies have shown that IPPI plays a certain role in female reproduction.…”

“…In Caenorhabditis elegans , IPPI is critical for viability, the mutation of isopentenyl-diphosphate isomerase Idi-1 blocked larval growth and development ( Yochem et al 2005 ). In Sogatella furcifera (Horvath) (Hemiptera, Delphacidae), the IPPI gene is involved in the female reproduction process, and knockdown of the SfIPPI significantly blocks ovarian development and egg production ( Gong et al 2022b ). In addition, IPPI is involved in the JH synthesis process in Aedes aegypti ( Diaz et al 2012 ).…”

Effect of four chitinase genes on the female fecundity in Sogatella furcifera (Horváth)

“…28 Additionally, research has shown that silencing SfVg and SfVgR significantly reduces the number of laid eggs and the hatching rates. 29 Furthermore, knocking down genes related to JH biosynthesis (i.e., SfHMGR, SfJHAMT, SfIPPI and SfFAMeT) and JH signal transduction (SfMet and SfKr-h1) significantly inhibits ovarian development and the number of laid eggs in S. furcifera, [30][31][32][33][34] indicating that genes related to JH signaling pathways are also involved in reproductive regulation. Additionally, it has been found that the TOR signaling pathway also participates in regulating the reproduction of S. furcifera.…”