Influence of the plant interacting entomopathogenic fungus Beauveria bassiana on parasitoid host choice-behavior, development, and plant defense pathways

Abstract

Inoculating plants with entomopathogenic fungi may influence plant nutrient uptake and growth, and herbivore performance. Knowledge is limited concerning the effects of this symbiosis on higher trophic levels. We examined how fungal treatment of faba bean seeds with the entomopathogenic fungus Beauveria bassiana influenced the choice-behavior and development of the aphid parasitoid Aphidius colemani . We also sampled plant material for analysis of changes in expression of genes related to plant defense pathways. While parasitoids were compatible with plants inoculated with B . bassiana initially (66 vs. 65% parasitization on inoculated and control plants, respectively; similar development times of parasitoids: 9.2 days), the emergence of adult parasitoids originating from aphids on fungus treated plants was significantly lower (67 vs. 76%, respectively). We also found that the defense response changed, similar to induced systemic resistance, when plants were treated with B . bassiana , similarly to what has been found for other plant symbiotic microorganisms. These novel findings show that although the application of entomopathogenic fungi to plants can alter the plants’ defense against herbivores, it may also have an impact on beneficial insects, so their function and use should be evaluated on a case-by-case basis.

Effect of entomopathogenic fungus Metarhizium robertsii on disease incidence of Faba beans (Vicia faba L.) in field conditions

“…This may have been because the entomopathogenic fungus M. robertsii suppressed the germination of pathogens on a nutrient medium. This has been confirmed by a number of studies carried out in vitro when studying the antagonistic effect of entomopathogenic fungi on a number of phytopathogens (Sasan and Bidochka, 2013; St. Leger and Wang, 2020).…”

“…Most likely, these effects were observed due to an increase in the supply of nitrogen to plant roots through the mycelium of entomopathogenic fungi and their synthesis of hormone-like compounds and regulatory proteins that changed the metabolism of the plants (Behie and Bidochka, 2014). The interaction of M. robertsii with plants can manifest in the form of symbiotic endophytic colonization, which allows obtaining nutrients, protecting the host plant from phytopathogens, and reducing damage from phytophages, which was summarized in a review by Vega (2018) and shown in several later works (St. Leger and Wang, 2020; Barelli et al .…”

“…To assess the infection of plant parts with root rot pathogens, a part of the stem adjacent to the root was isolated (Jensen et al . 2020).…”

Biological and molecular characterization of Cladosporium sp. and Acremonium zeylanicum as biocontrol agents of Aphis fabae in a tri‐trophic system

“…and avoid them (Oreste et al, 2016). Jensen et al (2020) showed that infected seed of broad bean can affect choice behavior and developmental characteristics of Aphidius colemani Viereck, a parasitoid wasp of A. fabae…”

Biopriming of broad bean seeds with entomopathogenic fungusMetarhizium robertsiidoes not affect invertebrate communities of the agroecosystem

“…However, to our knowledge, there are no studies on inoculation of V. faba with entomopathogenic fungi that would assess its effects on target and non-target invertebrates in field conditions. In addition, even though many studies have focused on assessing the effects found after treatment of plants with entomopathogenic fungi (20,21), the effects of seed treatment with entomopathogenic fungi on the structure of invertebrate communities are still insufficiently studied, and the degree of possible negative impact on non-target invertebrates may be underestimated. This work is a part of a comprehensive study of the effect of endophytes on the entire agricultural system of the broad bean field, including agricultural plants, fungi and invertebrates, both pests and accompanying species.…”