Though several outstanding reviews have focused on 4EGI-1 endophyte impacts on host physiology in response to stress (Rodriguez and Redman 2005 and 2008; Rouhier and Jacquot 2008; White and Torres 2010; Shoresh et al. 2010) this review provides hypotheses for future empirical and theoretical studies, and aims to increase dialogue between physiologists, ecologist, and evolutionary biologists to increase understanding of fungus-plant symbioses. Literature survey We reviewed the published experimental studies in order to identify the strength of support for or against the hypothesis that endophyte colonization can be mutualistic via increased production of antioxidants.

The following combinations of words were used as search criteria in Web of Science®: 1) endophyte antioxidant, 2) endophyte antioxidant pathogen, 3)

endophyte reactive PI3K Inhibitor Library oxygen species, Daporinad solubility dmso 4) endophyte reactive oxygen species pathogen, 5) dark septate endophyte reactive oxygen species, 6) dark septate endophyte reactive oxygen species pathogen, 7) dark septate antioxidant, 8) dark septate antioxidant pathogen, 9) endophyte metab*, 10) dark septate metab*, 11) fung* reactive oxygen species, and 12) fung* antioxidant. Among the 3077 papers resulting from this search, a subsequent screen excluded papers not involving plant and fungal endophytes. A third screening was performed to identify papers containing experimental manipulations Flucloronide of stress and measuring at least one antioxidant (enzymatic or non-enzymatic) or reactive oxygen species. The experimental papers were classified according to type of plant-fungus system, stress response, endophyte identity, stress treatment, experimental context, and fitness proxy (Table 1). Table 1 Review of experimental literature specific to fungal endophyte effects on host plant production of reactive

oxygen species (ROS) or antioxidant activity (A) levels in response to stress. See text for list of search terms used to identify papers fitting these criteria. Endophytes are either localized to root or shoot tissues or found in both. Fitness proxy refers to direct measures on seed and/or reproductive output. The symbols ‘+’, ‘−‘, and ‘0’ refer to positive, negative, and unknown or commensalistic effects (respectively; from host point of view) on host performance measures Plant Endophyte + Effect (ROS (R) measure, Antioxidant (A) measure) Root endophyte, Foliar (shoot) endophyte Stress Plant Age and Experimental Context Fitness Proxy? Reference Theobroma cacao Trichoderma hamatum (A) Root drought seedlings; growth chamber no Bae et al. 2009 Hordeum vulgare Piriformaspora indica (A) Root salt seedlings, plants; growth chamber no Baltruschat et al. 2008 Vitis vinifera T. viride (A) Root none cell culture no Calderón et al. 1993 Nicotiana benthamiana, Lycopersicum esculentum T. harzianum (R) Root none seedlings, plants; growth chamber, hydroponics no Chacón et al. 2007 Festuca spp.