Pyruvate Kinase Is Required for Sex Pheromone Biosynthesis in Helicoverpa armigera

Abstract

Pyruvate kinase (PYK) is a speed-limited enzyme of glycolysis that catalyzes the formation of pyruvate, and plays an important role in acetyl-CoA synthesis. The acetyl-CoA is the precursor of sex pheromone biosynthesis in Helicoverpa armigera. However, the role of PYK in sex pheromone biosynthesis remains elusive. Here, PYK in H. armigera (HaPYK) was found to be highly expressed in the pheromone glands (PGs). The developmental expression profile of HaPYK was consistent with the fluctuation of sex pheromone release. Function analysis revealed that the knockdown of HaPYK led to a decrease in the levels of pyruvic acid and acetyl-CoA in PGs, which in turn caused a significant decrease in cis-11-hexadecenal (Z11-16: Ald) production, female capability to attract males, and mating frequency. Further study demonstrated that sugar feeding (5% sugar) increased the transcription and enzyme activity of HaPYK, thereby facilitating sex pheromone biosynthesis. Moreover, pheromone biosynthesis activating neuropeptide (PBAN) upregulated HaPYK activity through protein kinase C (PKC), as shown by PKC-specific inhibitor analysis. Altogether, our results revealed that PBAN activated HaPYK by Ca2+/PKC, thereby regulating the synthesis of pyruvate and subsequent acetyl-CoA, ensuring the supply of sex pheromone precursor, and finally facilitating sex pheromone biosynthesis and mating behavior.

Trehalase is required for sex pheromone biosynthesis in Helicoverpa armigera

“…Thus, sugar feeding markedly increases the concentrations of trehalose and acyl‐CoA in PG, and ultimately facilitating sex pheromone biosynthesis is easy to understand. These views were also confirmed in H. armigera , in which, the knockdown of HaPYK , a rate‐limiting enzyme in glycolysis, reduces acetyl‐CoA contents, and consequently, decreases sex pheromone production (Yao et al, 2021). Acetyl‐CoA is known to be produced via glycolysis and tricarboxylic acid cycle by using glucose as a material (Foster & Anderson, 2015).…”

“…These findings clearly indicate the importance of sugar supplements in female adults. Furthermore, data from H. virescens , M. separata , and H. armigera demonstrated that sugar feeding increases trehalose content and sex pheromone production, demonstrating the importance of supplemental nutrition in sex pheromone biosynthesis (Foster, 2009; Foster & Anderson, 2015; Yao et al, 2021; Y. Zhang et al, 2020). Acetyl‐CoA acts as the precursor in sex pheromone biosynthesis.…”

“…Zhang et al, 2020). In H. armigera, sugar feeding promotes the biosynthesis of sex pheromones in PGs (Yao et al, 2021). These studies have clearly described the role of trehalose…”

“…In Mythimna separata , sugar‐feeding female moths produce more sex pheromones by increasing trehalose content in PGs (Y. Zhang et al, 2020). In H. armigera , sugar feeding promotes the biosynthesis of sex pheromones in PGs (Yao et al, 2021). These studies have clearly described the role of trehalose in sex pheromone biosynthesis.…”