The Green Gut: chlorophyll degradation in the gut of Spodoptera littoralis


  • A. Badgaa
  • R. Büchler
  • N. Wielsch
  • M. Walde
  • R. Heintzmann
  • Y. Pauchet
  • A. Svatos
  • K. Ploss
  • W. Boland


  • Journal of Chemical Ecology


  • J Chem Ecol 41 (11): 965-974


  • Chlorophylls, the most prominent natural pigments, are part of the daily diet of herbivorous insects. The spectrum of ingested and digested chlorophyll metabolites compares well to the pattern of early chlorophyll-degradation products in senescent plants. Intact chlorophyll is rapidly degraded by proteins in the front- and midgut. Unlike plants, insects convert both chlorophyll a and b into the corresponding catabolites. MALDI-TOF/MS imaging allowed monitoring the distribution of the chlorophyll catabolites along the gut of Spodoptera littoralis larvae. The chlorophyll degradation in the fore- and mid-gut is strongly pH dependent, and requires alkaline conditions. Using LC-MS/MS analysis we identified a lipocalin-type protein in the intestinal fluid of S. littoralis homolog to the chlorophyllide a binding protein from Bombyx mori. Widefield and high-resolution autofluorescence microscopy revealed that the brush border membranes are covered with the chlorophyllide binding protein tightly bound via its GPI-anchor to the gut membrane. A function in defense against gut microbes is discussed.