Recommend Plant Signaling & Behavior (PS&B) to your librarian for 2008. Download form here.

Sign up for Table of Contents Alerts!

PS&B is the official journal of the Society for Plant Neurobiology. Full membership ($60 annually) and student membership ($30 annually) include online access to the journal. Click here to join.

Email this page

Print this page

Article Addendum

Induction as well as suppression: How aphid saliva may exert opposite effects on plant defense

Torsten Will and Aart J.E. van Bel

Purchase article for $19

Subscribe to this journal for $79/year

Aphids ingest from the sieve tubes and by doing so they are confronted with sieve-tube occlusion mechanisms, which are part of the plant defense system. Because aphids are able to feed over longer periods, they must be able to prevent occlusion of the sieve plates induced by stylet penetration. Occlusion probably depends upon Ca²⁺-influx into the sieve element (SE) lumen. Aphid behavior, biochemical tests and in vitro experiments demonstrated that aphid’s watery saliva, injected during initial phase of a stylet penetration into the SE lumen, contains proteins that are able to bind calcium and prevent calcium-induced SE occlusion. In this addendum, we speculate on the consequences of saliva secretion for plant resistance. (a) The release of elicitors (e.g., oligogalacturonides) due to cell wall digestion by gel saliva enzymes may increase the resistance of cortex, phloem parenchyma cells and companion cells (CC) around the puncture site. (b) Ca²⁺-binding by aphid watery saliva may suppress the local defense responses in the SEs. (c) Signaling cascades triggered in CCs may lead to systemic resistance.

Authors

Torsten Will

Plant Cell Biology Research Group; Department of General Botany; Justus Liebig University; Giessen, Germany

Aart J.E. van Bel

Justus-Liebig-University

Purchase article for $19

Subscribe to this journal for $79/year