agronomy Review Tackling the Context-Dependency of Microbial-Induced Resistance Ana Shein Lee Díaz 1,*,† , Desiré Macheda 2,3,†, Haymanti Saha 4, Ursula Ploll 5, Dimitri Orine 6 and Arjen Biere 4 1 Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands 2 School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK;
[email protected] 3 Ecological Sciences, James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK 4 Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands;
[email protected] (H.S.);
[email protected] (A.B.) 5 Institute for Food and Resource Economics (ILR), University of Bonn, Nussalle 19, 53115 Bonn, Germany;
[email protected] 6 Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland;
[email protected] * Correspondence:
[email protected] † These authors contributed equally to this paper. Abstract: Plant protection with beneficial microbes is considered to be a promising alternative to chemical control of pests and pathogens. Beneficial microbes can boost plant defences via induced systemic resistance (ISR), enhancing plant resistance against future biotic stresses. Although the use of ISR-inducing microbes in agriculture seems promising, the activation of ISR is context-dependent: it often occurs only under particular biotic and abiotic conditions, thus making its use unpredictable Citation: Lee Díaz, A.S.; Macheda, and hindering its application. Although major breakthroughs in research on mechanistic aspects D.; Saha, H.; Ploll, U.; Orine, D.; Biere, of ISR have been reported, ISR research is mainly conducted under highly controlled conditions, A.