Portal de Periódicos da CAPES

Carminic acid dye from the homopteran Dactylopius coccus hemolymph is consumed during treatment with different microbial elicitors

2003; Wiley; Volume: 54; Issue: 1 Linguagem: Inglês

10.1002/arch.10099

1520-6327

Fidel de la Cruz Hernández‐Hernández, Fernando García‐Gil de Muñoz, Alberto Rojas‐Martínez, Salvador Hernández‐Martínez, Humberto Lanz‐Mendoza,

Insect symbiosis and bacterial influences

The activation of Dactylopius coccus (Costa) hemolymph with microbial polysaccharide molecules was studied. Hemolymph incubated in the presence of laminarin, zymosan, and N-acetyl glucosamine produced a dark fibrillar precipitated, and the red pigment (carminic acid) was consumed (measured spectrophotometrically at 495 nm). Lipopolysaccharide (LPS) did not induce any response. The reaction was inhibited with millimolar concentrations of serine and cysteine protease inhibitors, EGTA and phenyl thiourea. It was also diminished by prostaglandin synthesis inhibitors: dexamethasone, acetylsalicylic acid, and indomethacin. However, Mg2+ chelator EDTA did not inhibit hemolymph activation. Hemolymph proteins were depleted from soluble phase during treatment with laminarin, but a group of around 34 kDa remained unmodified. These results showed that D. coccus hemolymph is activated by microbial elicitors, its activation depends on eicosanoids, and suggest participation of a prophenoloxidase (PPO)-like activation system that could consume carminic acid. We are currently dissecting the molecular factors involved in D. coccus hemolymph activation to determine homologies and differences with other arthropods immune response pathways.