title: Rapid hydrolysis of quorum-sensing molecules in the gut of lepidopteran larvae.
abstract: Microorganisms compete for nutrients and living space in the gut of plant-feeding insect larvae, such as Spodoptera spp. Their physiological activities and their organization are generally controlled or synchronised by "autoinducers", such as N-acylhomoserinelactones (AHLs). Due to the strongly alkaline milieu in the insect gut, the lactone ring of AHLs is rapidly and spontaneously opened. Further degradation to the inactive components homoserine and the acyl moiety is then achieved by a microbial N-acylamino acid hydrolase (AAH) and related enzymatic activities in the insect gut. Initialised by the alkaline milieu, such activities might account for the complete absence of AHLs in the intestinal fluid of the studied Spodoptera spp. The AHL-recognition system of E. coli RV308pSB40, but not that of Agrobacterium tumefaciens NT1/pZLR4 and Chromobacterium violaceum CV026, was found to be inhibited by the structurally related N-acylglutamines, which are abundantly present in the gut of many lepidopteran larvae. Our observations suggest an active role of the insect in interfering with the quorum sensing of their gut microbiota by several independent strategies.
authors.affiliation: Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745 Jena, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Funke
authors.forename: Rita
authors.initials: R
authors.lastname: Büchler
authors.forename: Vertica
authors.initials: V
authors.lastname: Mahobia
authors.forename: Alexander
authors.initials: A
authors.lastname: Schneeberg
authors.forename: Michael
authors.initials: M
authors.lastname: Ramm
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Boland
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism; D000581:Amidohydrolases / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D001419:Bacteria / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D004926:Escherichia coli / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005973:Glutamine / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000382:microbiology; D007814:Larva / Q000378:metabolism / Q000382:microbiology; D007915:Lepidoptera / Q000254:growth & development* / Q000378:metabolism* / Q000382:microbiology; D053038:Quorum Sensing / Q000187:drug effects; D013997:Time Factors
chemical_list: D054742:Acyl-Butyrolactones; D005227:Fatty Acids; D005973:Glutamine; D000581:Amidohydrolases; C032846:alpha-N-acylamino acid hydrolase