Plant Immune System Activation Upon Citrus Leprosis Virus C Infection Is Mimicked by the Ectopic Expression of the P61 Viral Protein

Autor(es)

Arena, Gabriella D. ^{[1, 2, 3]} ; Ramos-Gonzalez, Pedro Luis ^[3] ; Falk, Bryce W. ^[4] ; Casteel, Clare L. ^[5] ; Freitas-Astua, Juliana ^{[3, 6]} ; Machado, Marcos A. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Agron Campinas, Ctr Citricultura Sylvio Moreira, Lab Biotecnol, Cordeiropolis - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz ESALQ, Piracicaba - Brazil

^[3] Inst Biol, Lab Biol Mol Aplicada, Sao Paulo - Brazil

^[4] Univ Calif Davis, Dept Plant Pathol, Davis, CA 95616 - USA

^[5] Cornell Univ, Sch Integrat Plant Sci, Ithaca, NY - USA

^[6] Embrapa Mandioca & Fruticultura, Lab Virol Vegetal, Cruz Das Almas - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN PLANT SCIENCE; v. 11, AUG 7 2020.
• Citações Web of Science: 0

Resumo

Citrus leprosis virus C (CiLV-C, genusCilevirus, familyKitaviridae) is an atypical virus that does not spread systemically in its plant hosts. Upon its inoculation byBrevipalpusmites, only localized lesions occur, and the infection remains limited to cells around mite feeding sites. Here, we aimed to gain insights into the putative causes of viral unfitness in plants by expanding the limited knowledge of the molecular mechanisms underlying plant/kitavirid interactions. Firstly, we quantified the CiLV-C viral RNAs during the infection inArabidopsis thalianaplants using RT-qPCR and systematized it by defining three stages of distinguishing subgenomic and genomic RNA accumulation: i) 0-24 h after infestation, ii) 2-4 days after infestation (dai), and iii) 6-10 dai. Accordingly, the global plant response to CiLV-C infection was assessed by RNA-Seq at each period. Results indicated a progressive reprogramming of the plant transcriptome in parallel to the increasing viral loads. Gene ontology enrichment analysis revealed the induction of cell growth-related processes at the early stages of the infection and the triggering of the SA-mediated pathway, ROS burst and hypersensitive response (HR) at the presymptomatic stage. Conversely, infected plants downregulated JA/ET-mediated pathways and processes involved in the primary metabolism including photosynthesis. Marker genes of unfolded protein response were also induced, suggesting a contribution of the endoplasmic reticulum stress to the cell death caused by the viral infection. Finally, we transiently expressed CiLV-C proteins inNicotiana benthamianaplants to undertake their roles in the elicited plant responses. Expression of the CiLV-C P61 protein consistently triggered ROS burst, upregulated SA- and HR-related genes, increased SA levels, reduced JA levels, and caused cell death. Mimicry of responses typically observed during CiLV-C-plant interaction indicates P61 as a putative viral effector causing the HR-like symptoms associated with the infection. Our data strengthen the hypothesis that symptoms of CiLV-C infection might be the outcome of a hypersensitive-like response during an incompatible interaction. Consequently, the locally restricted infection of CiLV-C, commonly observed across infections by kitavirids, supports the thesis that these viruses, likely arising from an ancestral arthropod-infecting virus, are unable to fully circumvent plant defenses. (AU)

• Processo FAPESP: 16/23870-9 - Infecção por Cilevirus: uma abordagem para a interação entre as proteínas do vírus e da planta
• Beneficiário: Gabriella Dias Arena
• Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 17/50222-0 - Compreensão sobre a biologia molecular e ecologia da relações planta-vírus-vetor: rumo a estratégias sustentáveis e integradas de manejo de vírus
• Beneficiário: Juliana de Freitas Astúa
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/00366-8 - Arabidopsis thaliana e Citrus leprosis virus-C: um modelo para o estudo da interação planta-patógeno
• Beneficiário: Gabriella Dias Arena
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 19/02137-0 - P61 dos cilevirus: caracterização bioquímica e funcional
• Beneficiário: Gabriella Dias Arena
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/50880-0 - INCT 2014: de genômica comparativa e funcional e melhoramento assistido de citros
• Beneficiário: Marcos Antonio Machado
• Linha de fomento: Auxílio à Pesquisa - Temático