| Autor: |
Hael-Conrad V; 1 Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica 'Dr. Bernabé Bloj', Facultad de Bioquímica, Química y Farmacia, UNT. Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina., Perato SM; 1 Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica 'Dr. Bernabé Bloj', Facultad de Bioquímica, Química y Farmacia, UNT. Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina., Arias ME; 2 Cátedra de Anatomía Vegetal, Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán. Miguel Lillo 205, 4000, Tucumán, Argentina, and Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Catamarca. Av. Belgrano 300, 4700, San Fernando del Valle de Catamarca, Catamarca, Argentina; and., Martínez-Zamora MG; 1 Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica 'Dr. Bernabé Bloj', Facultad de Bioquímica, Química y Farmacia, UNT. Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina., Di Peto PLÁ; 3 Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA, CONICET-Estación Experimental Agroindustrial Obispo Colombres). Av. William Cross 3150, T4101XAC, Las Talitas, Tucumán, Argentina., Martos GG; 1 Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica 'Dr. Bernabé Bloj', Facultad de Bioquímica, Química y Farmacia, UNT. Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina., Castagnaro AP; 3 Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA, CONICET-Estación Experimental Agroindustrial Obispo Colombres). Av. William Cross 3150, T4101XAC, Las Talitas, Tucumán, Argentina., Díaz-Ricci JC; 1 Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica 'Dr. Bernabé Bloj', Facultad de Bioquímica, Química y Farmacia, UNT. Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina., Chalfoun NR; 3 Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA, CONICET-Estación Experimental Agroindustrial Obispo Colombres). Av. William Cross 3150, T4101XAC, Las Talitas, Tucumán, Argentina. |
| Abstrakt: |
The elicitor AsES (Acremonium strictum elicitor subtilisin) is a 34-kDa subtilisin-like protein secreted by the opportunistic fungus Acremonium strictum. AsES activates innate immunity and confers resistance against anthracnose and gray mold diseases in strawberry plants (Fragaria × ananassa Duch.) and the last disease also in Arabidopsis. In the present work, we show that, upon AsES recognition, a cascade of defense responses is activated, including: calcium influx, biphasic oxidative burst (O 2 ⋅- and H 2 O 2 ), hypersensitive cell-death response (HR), accumulation of autofluorescent compounds, cell-wall reinforcement with callose and lignin deposition, salicylic acid accumulation, and expression of defense-related genes, such as FaPR1, FaPG1, FaMYB30, FaRBOH-D, FaRBOH-F, FaCHI23, and FaFLS. All these responses occurred following a spatial and temporal program, first induced in infiltrated leaflets (local acquired resistance), spreading out to untreated lateral leaflets, and later, to distal leaves (systemic acquired resistance). After AsES treatment, macro-HR and macro-oxidative bursts were localized in infiltrated leaflets, while micro-HRs and microbursts occurred later in untreated leaves, being confined to a single cell or a cluster of a few epidermal cells that differentiated from the surrounding ones. The differentiated cells initiated a time-dependent series of physiological and anatomical changes, evolving to idioblasts accumulating H 2 O 2 and autofluorescent compounds that blast, delivering its content into surrounding cells. This kind of systemic cell-death process in plants is described for the first time in response to a single elicitor. All data presented in this study suggest that AsES has the potential to activate a wide spectrum of biochemical and molecular defense responses in F. ananassa that may explain the induced protection toward pathogens of opposite lifestyle, like hemibiotrophic and necrotrophic fungi. |
