Phosphofructokinase downregulation disturbed termite social behaviors and immunity against fungal infections.

Social behaviors and immunity can help termites defend against pathogenic infections, which require the consumption of plenty of energy. Phosphofructokinase (PFK) is a key rate-limiting enzyme in glycolysis (a carbohydrate metabolic pathway) that generates energy. However, how PFK-mediated energy metabolism influences social behaviors and immunity against pathogens in termites is unknown. Here, we investigated the impacts of the pfk gene and entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) on social behaviors (locomotion and allogrooming) and immunity in the termite Reticulitermes chinensis Snyder. Our results showed that pfk gene silencing and fungal infection decreased the production of energy (ATP and NADH), impaired locomotion, weakened immunity (decreased immune gene expression and reduced antifungal activity) and reduced survival at the individual level in termites. Silencing of the pfk gene in nestmates caused lower allogrooming frequencies toward fungus-exposed termites. Downregulation of pfk significantly disrupted locomotion and decreased the survival of fungus-exposed termites placed with pfk-silenced nestmates compared to fungus-treated termites placed with gfp-silenced nestmates. Our findings illustrated that pfk-mediated dysfunctional energy metabolism disturbed social behaviors and immunity to defend against fungal infections in termites, which provides new insights into understanding the mechanisms of social behaviors and immunity in social insects. [ABSTRACT FROM AUTHOR]