Angiotensin-converting enzymes modulate aphid-plant interactions.

Wei Wang,Hong Lu,Shaoliang Chen,Lan Luo,Le Kang,Feng Cui

doi:10.1038/srep08885

Wei Wang, Hong Lu + Show 4 more

Open Access

https://doi.org/10.1038/srep08885

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Abstract

Angiotensin-converting enzymes (ACEs) are key components of the renin–angiotensin system in mammals. However, the function of ACE homologs in insect saliva is unclear. Aphids presumably deliver effector proteins via saliva into plant cells to maintain a compatible insect–plant interaction. In this study, we showed that ACE modulates aphid–plant interactions by affecting feeding behavior and survival of aphids on host plants. Three ACE genes were identified from the pea aphid Acyrthosiphon pisum genome. ACE1 and ACE2 were highly expressed in the salivary glands and are predicted to function as secretory proteins. The ACE2 transcript level decreased in aphids fed on artificial diet compared with aphids fed on Vicia faba. The knockdown of the expression of each ACE by RNAi failed to affect aphid survival. When ACE1 and ACE2 were simultaneously knocked down, aphid feeding was enhanced. Aphids required less time to find the phloem sap and showed longer passive ingestion. However, the simultaneous knockdown of ACE1 and ACE2 resulted in a higher mortality rate than the control group when aphids were fed on plants. These results indicated that ACE1 and ACE2 function together to modulate A. pisum feeding and survival on plants.

Highlights

Angiotensin-converting enzymes (ACEs) are key components of the renin–angiotensin system in mammals
When the sequence of ACE highly expressed in aphid salivary glands[18], which is referred in the present study as ACE1 (XM_001951605 in NCBI and ACYPI000733 in aphidbase), was used to perform BLAST against the A. pisum genome, two other ACE homolog genes, namely, ACE2 (XM_001943123 in NCBI and ACYPI007204 in aphidbase) and ACE3 (XM_001949361 in NCBI and ACYPI005682 in aphidbase) were detected
The three ACE genes are located in different scaffolds of the aphid genome, scaffolds EQ116294 (ACE1), EQ116276 (ACE2), and EQ113364 (ACE3)

Summary

Introduction

Angiotensin-converting enzymes (ACEs) are key components of the renin–angiotensin system in mammals. Aphids presumably deliver effector proteins via saliva into plant cells to maintain a compatible insect–plant interaction. We showed that ACE modulates aphid–plant interactions by affecting feeding behavior and survival of aphids on host plants. The simultaneous knockdown of ACE1 and ACE2 resulted in a higher mortality rate than the control group when aphids were fed on plants. These results indicated that ACE1 and ACE2 function together to modulate A. pisum feeding and survival on plants. Based on the enriched ACE expression in aphid salivary glands and the presence of ACE in aphid saliva, ACEs presumably enter the plant phloem and possibly other tissues during feeding. We aimed to determine whether ACE putatively functions as an effector protein to modulate aphid–plant interactions

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