Journal Article

Glucosylation prevents plant defense activation in phloem-feeding insects

Malka, Osnat, Götz, Monika, Gershenzon, Jonathan, Reichelt, Michael, Morin, Shai, Colvin, John, Vassão, Daniel G., Stanišić, Aleksa, Juravel, Ksenia, Mondaca, Lilach L., Paetz, Christian, Stein, Beate, Winter, Stephan, Easson, Michael L. A. E., Luck, Katrin, Santos-Garcia, Diego, Springate, Simon

2020

Overview

The metabolic adaptations by which phloem-feeding insects counteract plant defense compounds are poorly known. Two-component plant defenses, such as glucosinolates, consist of a glucosylated protoxin that is activated by a glycoside hydrolase upon plant damage. Phloem-feeding herbivores are not generally believed to be negatively impacted by two-component defenses due to their slender piercing-sucking mouthparts, which minimize plant damage. However, here we document that glucosinolates are indeed activated during feeding by the whitefly Bemisia tabaci . This phloem feeder was also found to detoxify the majority of the glucosinolates it ingests by the stereoselective addition of glucose moieties, which prevents hydrolytic activation of these defense compounds. Glucosylation of glucosinolates in B. tabaci was accomplished via a transglucosidation mechanism, and two glycoside hydrolase family 13 (GH13) enzymes were shown to catalyze these reactions. This detoxification reaction was also found in a range of other phloem-feeding herbivores. The whitefly Bemisia tabaci defends against plant glucosinolate toxins by serial addition of glucose moieties catalyzed by a pair of glycoside hydrolases, preventing toxin activation during feeding on the plant tissue.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: 631/92/221 / 631/92/349 / 631/92/604 / 631/92/607 / Adaptation / Animals / Arabidopsis - immunology / Arabidopsis - metabolism / Arabidopsis - parasitology / Bemisia tabaci / Biochemical Engineering / Biochemistry / Bioorganic Chemistry / Cell Biology / Chemical reactions / Chemistry / Chemistry and Materials Science / Chemistry/Food Science / Defense mechanisms / Detoxification / Feeding / Feeding Behavior - physiology / Gene Expression / Glucose / Glucosinolates / Glucosinolates - chemistry / Glucosinolates - metabolism / Glycosidases / Glycoside hydrolase / Glycoside Hydrolases - classification / Glycoside Hydrolases - genetics / Glycoside Hydrolases - metabolism / Glycosides / Glycosylation / Hemiptera - classification / Hemiptera - enzymology / Hemiptera - genetics / Herbivores / Host-Parasite Interactions - immunology / Hydrolase / Impact damage / Insect Proteins - classification / Insect Proteins - genetics / Insect Proteins - metabolism / Insects / Mouthparts / Phloem / Phloem - immunology / Phloem - metabolism / Phloem - parasitology / Phylogeny / Plant Immunity / Plant tissues / Stereoselectivity / Toxins