Tomato Inoculation With the Endophytic Strain Fusarium solani K Results in Reduced Feeding Damage by the Zoophytophagous Predator Nesidiocoris tenuis

Abstract

Belowground symbiosis of plants with beneficial microbes is known to confer resistance to aboveground pests such as herbivorous arthropods and pathogens. Similarly, microbe-induced plant responses may also impact natural enemies of pests via the elicitation of plant defense responses and/or alteration of plant quality and growth. Nesidiocoris tenuis is a zoophytophagous predator and an efficient biological control agent of greenhouse pests. Its usefulness in plant protection is often hindered by its ability to damage plants at high predator population densities or when prey is scarce. In this study, we investigated the effect of Fusarium solani strain K (FsK), an endophytic fungal isolate that colonizes tomato root tissues, on the capability of N. tenuis to cause necrotic rings, an easily discernible symptom, on tomato stems and leaves. We found significantly less necrotic rings formed on FsK-inoculated plants for all tomato cultivars tested. FsK has been previously shown to confer ethylene-mediated tomato resistance to both foliar and root fungal pathogens; thus, the ethylene-insensitive Never ripe (Nr) and epinastic (epi) tomato plant mutant lines were included in our study to assess the role of ethylene in the recorded FsK-mediated plant damage reduction. The jasmonic acid (JA)-biosynthesis tomato mutant def-1 was also used since JA is known to mediate major anti-herbivore plant responses. We show that ethylene and JA are required for FsK to efficiently protect tomato plants from N. tenuis feeding. No necrotic rings were recorded on FsK-inoculated epi plants suggesting that ethylene overproduction may be key to tomato resistance to N. tenuis feeding.

Phytochemical, antioxidant, enzyme activity and antifungal properties of Satureja khuzistanica in vitro and in vivo explants stimulated by some chemical elicitors

“…We hypothesised that reduction in FsK growth may be related to the RA inhibitory effect which was produced in plants and activated resistance mechanisms in natural condition. The same results observed in tomato plants (Garantonakis et al 2018) confirmed our understanding. It is clear that all the extracts and callus showed an inhibitory effect on FsK aggregation ( Figure 6) and diameter growth (Figure 7).…”

From Evolutionary Aspects of Zoophytophagy to Biological Control

“…A selection that reduces phytophagy in a zoophytophagous predator will result in minimizing this path by which the predator can affect their prey. In addition, plants defensive responses can be induced by an endophytic fungus, and reduce damage from both zoophytophagous predators (Garantonakis et al, 2018) and pests (Pappas et al, 2018). Garantonakis et al (2018) observed less damage from the zoophytophagous predator N. tenuis on tomato plants inoculated with the fungal endophyte Fusarium solani strain K than on uninoculated plants.…”

“…In addition, plants defensive responses can be induced by an endophytic fungus, and reduce damage from both zoophytophagous predators (Garantonakis et al, 2018) and pests (Pappas et al, 2018). Garantonakis et al (2018) observed less damage from the zoophytophagous predator N. tenuis on tomato plants inoculated with the fungal endophyte Fusarium solani strain K than on uninoculated plants. The authors have not determined whether the symbiosis between the plant and the fungal endophyte confers on the plant the ability to repair damage or repel N. tenuis (reduction of phytophagy).…”

Editorial: Ecosystem Services and Disservices Provided by Plant-Feeding Predatory Arthropods

“…Underlining this, Eschweiler et al studied the interaction in tomato between an endophytic, non-pathogenic strain of Fusarium oxysporum (Fo162) restricted to roots, the greenhouse whitefly Trialeurodes vaporariorum and the zoophytophagous predator M. pygmaeus. Adding to recent studies highlighting the ability of beneficial soil microbes to impact the performance and behavior of aboveground zoophytophagous mirid predators via the plant (Battaglia et al, 2013;Prieto et al, 2017;Garantonakis et al, 2018;Pappas et al, 2018), they show that tomato inoculation with Fo162 results in enhanced whitefly control, increased yield and reduced number of fruits with blossomend rot potentially providing a new preventive biological control strategy against the greenhouse whitefly.…”