Overexpression of CsSAMT in Citrus sinensis Induces Defense Response and Increases Resistance to Xanthomonas citri subsp. citri

Autor(es)

Nascimento, Cesar Augusto ; Teixeira-Silva, Natalia Sousa ; Caserta, Raquel ; Marques, Marcia Ortiz Mayo ; Takita, Marco Aurelio ; de Souza, Alessandra A.

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN PLANT SCIENCE; v. 13, p. 13-pg., 2022-03-24.

Resumo

Citrus canker is a destructive disease caused by Xanthomonas citri subsp. citri, which affects all commercial sweet orange (Citrus sinensis [L.] Osbeck) cultivars. Salicylic acid (SA) and systemic-acquired resistance (SAR) have been demonstrated to have a crucial role in mediating plant defense responses against this phytopathogen. To induce SAR, SA is converted to methyl salicylate (MeSA) by an SA-dependent methyltransferase (SAMT) and translocated systemically to prime noninfected distal tissues. Here, we generated sweet orange transgenic plants (based on cvs. Hamlin and Valencia) overexpressing the SAMT gene from Citrus (CsSAMT) and evaluated their resistance to citrus canker. We obtained four independent transgenic lines and confirmed their significantly higher MeSA volatilization compared to wild-type controls. Plants overexpressing CsSAMT showed reduced symptoms of citrus canker and bacterial populations in all transgenic lines without compromising plant development. One representative transgenic line (V44SAMT) was used to evaluate resistance response in primary and secondary sites. Without inoculation, V44SAMT modulated CsSAMT, CsNPR1, CsNPR3, and CsWRKY22 expression, indicating that this plant is in a primed defense status. The results demonstrate that MeSA signaling prompts the plant to respond more efficiently to pathogen attacks and induces immune responses in transgenic plants at both primary and secondary infection sites. (AU)

• Processo FAPESP: 19/01447-5 - Obtenção de porta enxerto transgênico: possibilidade de aumento de níveis de resistência da copa a fitopatógenos através da translocação de moléculas difusíveis
• Beneficiário: Natália de Sousa Teixeira e Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/16142-0 - Translocação de moléculas de quorum sensing de porta-enxertos transgênicos para copas de laranja doce: efeito quanto à resistência a fitopatógenos
• Beneficiário: Raquel Caserta Salviatto
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/10957-0 - Interação Xylella fastidiosa-inseto vetor-planta hospedeira e abordagens para o controle da clorose variegada dos citros e cancro cítrico
• Beneficiário: Alessandra Alves de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Temático