A calmodulin-binding transcription factor links calcium signaling to antiviral RNAi defense in plants.
Cell Host Microbe
; 29(9): 1393-1406.e7, 2021 09 08.
Article
de En
| MEDLINE
| ID: mdl-34352216
ABSTRACT
RNA interference (RNAi) is an across-kingdom gene regulatory and defense mechanism. However, little is known about how organisms sense initial cues to mobilize RNAi. Here, we show that wounding to Nicotiana benthamiana cells during virus intrusion activates RNAi-related gene expression through calcium signaling. A rapid wound-induced elevation in calcium fluxes triggers calmodulin-dependent activation of calmodulin-binding transcription activator-3 (CAMTA3), which activates RNA-dependent RNA polymerase-6 and Bifunctional nuclease-2 (BN2) transcription. BN2 stabilizes mRNAs encoding key components of RNAi machinery, notably AGONAUTE1/2 and DICER-LIKE1, by degrading their cognate microRNAs. Consequently, multiple RNAi genes are primed for combating virus invasion. Calmodulin-, CAMTA3-, or BN2-knockdown/knockout plants show increased susceptibility to geminivirus, cucumovirus, and potyvirus. Notably, Geminivirus V2 protein can disrupt the calmodulin-CAMTA3 interaction to counteract RNAi defense. These findings link Ca2+ signaling to RNAi and reveal versatility of host antiviral defense and viral counter-defense.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Maladies des plantes
/
Nicotiana
/
Calmoduline
/
Signalisation calcique
/
Interférence par ARN
Langue:
En
Journal:
Cell Host Microbe
Sujet du journal:
MICROBIOLOGIA
Année:
2021
Type de document:
Article
Pays d'affiliation:
Chine