Sulcia selectively maintains genes replacing functions of its predecessor for amino-acid biosynthesis and retains genes underlying efficient routes of energy production, including a complete TCA cycle, potentially relaxing the severe energy limitations of the xylem-feeding hosts (amino acid provision, growth regulation).

Portiera has bacterial homologues of fungal carotenoid biosynthesis genes, supporting the hypothesis that endosymbiotic bacteria can provide a source of carotenoids and indicating that related lineages of sap-feeding insects have acquired the ability to synthesize carotenoids by independent mechanisms (chemical biosynthesis/pigmentation alteration).