Root bacterial endophytes confer drought resistance and enhance expression and activity of a vacuolar H+-pumping pyrophosphatase in pepper plants

The authors declare an absence of competing financial interests. This research was supported by funding from the Italian MIUR FIRB project no. RBIN047MBH “Strategy to improve crop productivity under water stress”, the EU project BIODESERT (European Community’s Seventh Framework Programme CSA-SA REGPOT-2008-2) under grant agreement no. 245746, and King Abdullah University of Science and Technology (KAUST) baseline research funds to DD. ER acknowledges support from Universita degli Studi di Milano, DeFENS, Regione Lombardia (contract ‘Dote Ricerca’). The authors thank (i) Dr. Vasco Meneghini for support with the confocal microscopy analysis and interpretation, and a critical reading of the manuscript; (ii) Dr. Umberto Fascio at the Centro Interdipartimentale di Microscopia Applicata of the University of Milan for technical support with the confocal microscope; (iii) Dr. M. Maeshima of Nagoya University, Nagoya, Japan, for the kind gift of antibodies against V-ATPase and V-PPase; (iv) Dr. Bessem Chouaia of the University of Milan for the help in the bacterial genome assembly and (v) Dr. Alessia Perego and Dr. Patrizia Zaccheo of the University of Milan and (vi) Dr. Marco Fusi of King Abdullah University of Science and Technology for assistance with the statistical analysis; (vii) Francesco Della Valle of King Abdullah University of Science and Technology for help in critical revision of the manuscript. The authors declare that they have no conflict of interest.