Open AccessPlants use identical inhibitors to protect their cell wall pectin against microbes and insects
Author(s) -
Kirsch Roy,
Vurmaz Esma,
Schaefer Carolin,
Eberl Franziska,
Sporer Theresa,
Haeger Wiebke,
Pauchet Yannick
Publication year - 2020
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.6180
Subject(s) - biology , mutant , insect , cell wall , plant defense against herbivory , arabidopsis thaliana , herbivore , larva , arabidopsis , botany , gene , microbiology and biotechnology , biochemistry
As fundamentally different as phytopathogenic microbes and herbivorous insects are, they enjoy plant‐based diets. Hence, they encounter similar challenges to acquire nutrients. Both microbes and beetles possess polygalacturonases (PGs) that hydrolyze the plant cell wall polysaccharide pectin. Countering these threats, plant proteins inhibit PGs of microbes, thereby lowering their infection rate. Whether PG‐inhibiting proteins (PGIPs) play a role in defense against herbivorous beetles is unknown. To investigate the significance of PGIPs in insect–plant interactions, feeding assays with the leaf beetle Phaedon cochleariae on Arabidopsis thaliana pgip mutants were performed. Fitness was increased when larvae were fed on mutant plants compared to wild‐type plants. Moreover, PG activity was higher, although PG genes were downregulated in larvae fed on PGIP ‐deficient plants, strongly suggesting that PGIPs impair PG activity. As low PG activity resulted in delayed larval growth, our data provide the first in vivo correlative evidence that PGIPs act as defense against insects.