Dietary and phylogenetic correlates of digestive trypsin activity in insect pests
Abstract:
Because food proteins are crucial for insect survival, growth, and
fecundity, enzymes involved in their digestion have attracted the
attention of fundamental entomologists studying the mechanisms and
patterns of dietary specialization, and applied entomologists searching
for more efficient modes of pest control. Most insects digest proteins
using trypsin, an endopeptidase that cleaves polypeptide chains on the
carboxyl side of arginine and lysine, two basic amino acids. As the most
ancestral proteinase, trypsin is wide-spread in the digestive tract of
insects from various orders and with various feeding habits. The present
review focuses on biochemical and molecular characteristics, mechanisms
of regulation, and adaptive/non-adaptive changes of trypsin activity in
response to heterogeneous food environments in a phylogenetic context.
Within- and among-species variations in trypsin structure and regulation
that contribute to better matching with specific food types are
emphasized. We also discuss the relevance of these data for choosing an
appropriate strategy for control of insect pests. Pest control
strategies to reduce trypsin activity by interfering with substrate
binding or trypsin synthesis and secretion have been suggested.
Successful application of these procedures requires a multi-disciplinary
approach and knowledge about digestive physiology of the pest, as well
as the structural characteristics of trypsins that determine their
interaction with proteinaceous inhibitors and other food compounds,
about patterns of developmental changes in trypsin gene expression,
adaptive responses of insects to food composition, and various
environmental effects on trypsin activity.
Keywords:
trypsin structure; multigene families; regulation; feeding habit; Adaptive responses; insect pest controlSource:
Entomologia Experimentalis Et Applicata, 2015, 157, 2, 123-151
DOI: 10.1111/eea.12349
ISSN: 1570-7458