17 research outputs found
Regulation of the Na+/K+-ATPase Ena1 Expression by Calcineurin/Crz1 under High pH Stress: A Quantitative Study
[EN] Regulated expression of the Ena1 Na+-ATPase is a crucial event for adaptation to high
salt and/or alkaline pH stress in the budding yeast Saccharomyces cerevisiae. ENA1
expression is under the control of diverse signaling pathways, including that mediated
by the calcium-regulatable protein phosphatase calcineurin and its downstream
transcription factor Crz1. We present here a quantitative study of the expression of
Ena1 in response to alkalinization of the environment and we analyze the contribution
of Crz1 to this response. Experimental data and mathematical models substantiate the
existence of two stress-responsive Crz1-binding sites in the ENA1 promoter and
estimate that the contribution of Crz1 to the early response of the ENA1 promoter is
about 60%. The models suggest the existence of a second input with similar kinetics,
which would be likely mediated by high pH-induced activation of the Snf1 kinase.This work was supported by grants BFU2011-30197-C3-01, BFU2014-54591-C2-1-P and EUI2009-04147 (SysMo2) to JA. (Ministry of Industry and Competitivity, Spain, and Fondo Europeo de Desarrollo Regional [FEDER]). JA is the recipient of an Ajut 2014SGR-4 award (Generalitat de Catalunya). DC was recipient of a predoctoral fellowship from the Spanish Ministry of Education. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Petrezsélyová, S.; López-Malo, M.; Canadell, D.; Roque, A.; Serra-Cardona, A.; Marques Romero, MC.; Vilaprinyó, E.... (2016). Regulation of the Na+/K+-ATPase Ena1 Expression by Calcineurin/Crz1 under High pH Stress: A Quantitative Study. PLoS ONE. 11(6):e0158424-e0158424. https://doi.org/10.1371/journal.pone.0158424Se0158424e015842411
Dipeptides secreted by the grapevine endophyte Alternaria alternata cause structural damages to Plasmopara viticola
Antifungal activity of diketopiperazines extracted from Alternaria alternata against Plasmopara viticola: an ultrastructural study
Three dipeptides, belonging to the family of diketopiperazines (DKPs), were extracted from broth culture of the grapevine endophyte
Alternaria alternata, and were tested against Plasmopara viticola on leaves of grapevine plants grown in greenhouse. DKPs, used at different
concentrations (103, 104, 105 and 106 M) both singularly and in mixtures, demonstrated real effectiveness in inhibiting P. viticola sporulation
when applied 2 or 24 h after pathogen inoculation. Moreover, no necrotic lesions or other phytotoxicity symptoms were observed on DKP-treated
grapevine leaf tissues.
Ultrastructural analysis performed on grapevine leaf tissues revealed that the DKPs used singularly and in mixture, at above reported
concentrations, did not cause leaf tissue damages. By contrast, hyphae of P. viticola exhibited marked structural changes, similar to those induced
by the endophyte A. alternata. This demonstrates the involvement of these metabolites in the relationship of P. viticola and the endophyte. Further
experimental trials will be carried out in the next future in order to test the effectiveness of these molecules also under field conditions, and to better
understand the mechanism of action involved in the pathogen inhibition