RESUMEN
Geminiviruses are DNA viruses that cause severe diseases in diverse species of plants, resulting in considerable agricultural losses worldwide. C4 proteins are a major symptom determinant in several geminiviruses, including Beet severe curly top virus (BSCTV). Here, we uncovered a novel mechanism by which danger peptide signaling enhances the internalization of BSCTV C4 in plant cells. Previous studies showed that this signaling is important for activation of bacterium- and fungus-triggered immune responses, but its function in plant-virus interactions was previously unknown. Pep1 RECEPTOR1 (PEPR1) and PEPR2 are receptor kinases recognized by Peps (plant elicitor peptides) in the danger peptide pathway. We found that BSCTV C4 up-regulated and interacted with PEPR2 but not PEPR1. The Pep1-PEPR2 complex stimulated the internalization of C4 in both Arabidopsis and Nicotiana benthamiana cells. Furthermore, C4 induced callus formation in Arabidopsis, which was suppressed by PEPR2 overexpression but enhanced in the pepr2 mutants. In the presence of Pep1, overexpression of PEPR2 suppressed BSCTV infection in N. benthamiana. Exogenous Pep1 also reduced BSCTV infection in Arabidopsis in a PEPR2-dependent manner. Thus, PEPR2 recognizes the symptom determinant C4 and enhances its internalization mediated by danger peptides, suppressing BSCTV infection.
Asunto(s)
Proteínas de Arabidopsis , Geminiviridae , Proteínas de Arabidopsis/genética , Péptidos , Células Vegetales , Internalización del VirusRESUMEN
Geminiviruses, such as beet severe curly top virus (BSCTV), are a group of DNA viruses that cause severe plant diseases and agricultural losses. The C4 protein is a major symptom determinant in several geminiviruses; however, its regulatory mechanism and molecular function in plant cells remain unclear. Here, we show that BSCTV C4 is S-acylated in planta, and that this post-translational lipid modification is necessary for its membrane localization and functions, especially its regulation of shoot development of host plants. Furthermore, the S-acylated form of C4 interacts with CLAVATA 1 (CLV1), an important receptor kinase in meristem maintenance, and consequentially affects the expression of WUSCHEL, a major target of CLV1. The abnormal development of siliques in Arabidopsis thaliana infected with BSCTV is also dependent on the S-acylation of C4, implying a potential role of CLAVATA signaling in this process. Collectively, our results show that S-acylation is essential for BSCTV C4 function, including the regulation of the CLAVATA pathway, during geminivirus infection.
Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Geminiviridae/fisiología , Proteínas de Homeodominio/genética , Enfermedades de las Plantas/virología , Proteínas Serina-Treonina Quinasas/genética , Proteínas Virales/metabolismo , Acilación , Arabidopsis/metabolismo , Arabidopsis/virología , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/virología , Proteínas Serina-Treonina Quinasas/metabolismoRESUMEN
Geminivirus infection results in systemic symptoms in plants, but the mechanism by which the virus affects cell-to-cell signalling involved in development and resistance remains unclear. Based on recent evidence, we suggest a potential mechanism that geminivirus C4 proteins interfere with intercellular signals by interacting with receptor-like kinases on the plasma membrane.