TITLE:
Impact of the Glucosinolate Sinigrin on Bacterial Communities in Pieris rapae
AUTHORS:
Leslie M. McKinnon, Courtney J. Robinson
KEYWORDS:
Microbiota, Glucosinolates, Plant Secondary Metabolites
JOURNAL NAME:
Advances in Microbiology,
Vol.6 No.8,
July
28,
2016
ABSTRACT: Dynamics in animal-associated microbiota can be
difficult to study due to community complexity. Previous work showed that
microbial communities in the midguts of Pieris
rapae larvae contain relatively few members. In this study, we used P. rapae to test hypotheses related to
how diet impacts gastrointestinal microbiota. More specifically, we
investigated how the concentration of sinigrin, a glucosinolate in the natural
diet of this insect, alters microbial community structure. Larvae were fed
either sterile wheat germ diet alone or amended with 3.0 mg/ml, 6.0 mg/ml, or
9.0 mg/ml of sinigrin. In order to determine shifts in the gut microbial
community, 16S rRNA genes from midguts were subjected to pyrosequencing and
analyzed. Sinigrin had a significant impact on microbial communities in fourth
instar P. rapae larvae, but this was
dependent on concentration. The predominant phyla in all treatment groups were
Proteobacteria and Firmicutes. Significant difference in beta diversity was
typically observed when sinigrin 6 mg/ml and the control treatment groups were
compared. The impact of sinigrin on the structure of the midgut microbiota is
dependent on concentration, but not in a linear fashion. This may indicate that
types and concentrations of glucosinolates have varied impact on midgut
microbial community.