In-vivo electrochemical monitoring of H2O2 production induced by root-inoculated endophytic bacteria in Agave tequilana leaves

Autor(es)

Lima, Alex S. ^[1] ; Prieto, Katia R. ^[2] ; Santos, Carla S. ^[1] ; Valerio, Hellen Paula ^[2] ; Garcia-Ochoa, Evelyn Y. ^[3] ; Huerta-Robles, Aurora ^[4] ; Beltran-Garcia, Miguel J. ^[3] ; Di Mascio, Paolo ^[2] ; Bertotti, Mauro ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Chem, Dept Biochem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[3] Univ Autonoma Guadalajara, Dept Chem ICET, Patria 1201, Zapopan, Jalisco - Mexico

^[4] Univ Autonoma Baja California, Inst Engn, Blvd B Juarez & Calle Normal S-N, Mexicali, BC - Mexico

• Tipo de documento: Artigo Científico
• Fonte: BIOSENSORS & BIOELECTRONICS; v. 99, p. 108-114, JAN 15 2018.
• Citações Web of Science: 10

Resumo

A dual-function platinum disc microelectrode sensor was used for in-situ monitoring of H2O2 produced in A. tequilana leaves after inoculation of their endophytic bacteria (Enterobacter cloacae). Voltammetric experiments were carried out from 0.0 to -1.0 V, a potential range where H2O2 is electrochemically reduced. A needle was used to create a small cavity in the upper epidermis of A. tequilana leaves, where the fabricated electrochemical sensor was inserted by using a manual three-dimensional micropositioner. Control experiments were performed with untreated plants and the obtained electrochemical results clearly proved the formation of H2O2 in the leaves of plants 3 h after the E. cloacae inoculation, according to a mechanism involving endogenous signaling pathways. In order to compare the sensitivity of the microelectrode sensor, the presence of H2O2 was detected in the root hairs by 3,3-diaminobenzidine (DAB) stain 72 h after bacterial inoculation. In-situ pH measurements were also carried out with a gold disc microelectrode modified with a film of iridium oxide and lower pH values were found in A. tequilana leaves treated with bacteria, which may indicate the plant produces acidic substances by biosynthesis of secondary metabolites. This microsensor could be an advantageous tool for further studies on the understanding of the mechanism of H2O2 production during the plant-endophyte interaction. (AU)

• Processo FAPESP: 15/02095-4 - Fabricação de nanossensores para microscopia eletroquímica de varredura e sua aplicação em sistemas biológicos (single-cell analysis)
• Beneficiário: Alex da Silva Lima
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/22396-6 - Desenvolvimento de microssensor acoplado à microscopia eletroquímica de varredura para a investigação da atividade respiratória mitocondrial
• Beneficiário: Carla Santana Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 13/07937-8 - Redoxoma
• Beneficiário: Ohara Augusto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 12/12663-1 - Oxigênio singlete e peróxidos em química biológica
• Beneficiário: Paolo Di Mascio
• Modalidade de apoio: Auxílio à Pesquisa - Temático