The Role of Endophytic Insect-Pathogenic Fungi in Biotic Stress Management

Soil Biodiversity and Root Pathogens in Agroecosystems

“…Fungal Endophytes are other important functional group of fungi, and they enter and live inside the plants [25,42]. Here, endophytes are defined as those microorganisms (bacteria, fungi, virus) which live their life cycle or part of it inside a plant, within asymptomatic tissues, performing and promoting a beneficial functioning in Soil Biodiversity and Root Pathogens in Agroecosystems DOI: http://dx.doi.org/10.5772/intechopen.99317 the plant host, and enhancing its fitness in plant communities by conferring abiotic and biotic stress tolerance; therefore, this relationship has ecological and evolutionary importance [42,46,47]. Endophyte organisms can be found in different plant organs like roots, stems, leaves, reproductive organs (e.g., vanilla flower ovaries) and fruits (e.g., vanilla pods) [42,48].…”

“…Endophyte organisms can be found in different plant organs like roots, stems, leaves, reproductive organs (e.g., vanilla flower ovaries) and fruits (e.g., vanilla pods) [42,48]. Endophytic fungi participate in different plant functions, some of them enhance plant growth and nutrition and are referred as Plant-Growth Promoting Fungi (PGPF) [25], and they also strengthen plant defense against pathogens and insects below-and above-ground [46,47]. Endophyte fungi control plant pathogens attack through different processes: niche exclusion, antibiosis, predation, mycoparasitism and ISR induction [25]; it is also possible to find hypovirulent pathogen isolates which will control more virulent isolates as happens with Monosporascus cannonballus against monosporascus root rot vine decline [49], or with Fusarium oxysporum strain Fo47 [50,51].…”

“…Endophyte fungi can express simultaneously more than one control mechanism against plant pathogens as it was showed with Trichoderma isolates that besides attack directly Botrytis cinerea, also induced systemic resistance to this pathogen [52]. Other fungal endophytes additionally of increasing plant biomass, confer drought tolerance, and produce chemicals that are toxic to animals like insects [46,47], birds and small mammals and decrease herbivory [53]. Certain endophytic fungi have an important role in physiological and biochemical aspects during development of flower and chemical compounds, as is the case of Vanilla planifolia compound vanillin [48]; researchers have found that fungal endophytes inoculum from soil get into the roots through rhizosphere, but other endophytes come from the fungal airborne inoculum and enter into the flower ovaries, and later in the vanilla pods, participating in the vanillin process and therefore in the vanilla flavor [48].…”

“…Endophyte fungi described as PGPF include important genera like Fusarium, Trichoderma, Aspergillus, Penicillium, Colletotrichum, Cylindrocladium, and others; some of them are nonpathogenic or hypovirulent strains of plant pathogenic fungi [25,42]. Some soil fungi are pathogens of other microorganisms like bacteria [54], fungi and nematodes [55], plants [11], insects and arthropods [47]; for instance, Metarhizium anisopliae and Beauveria bassiana are endophytic and pathogenic in insects, while Paecelomyces lilacinus is endophytic and pathogenic in nematodes [55]; these fungi take part in the regulation of their hosts populations and they are of relevance in the biological control and management of agroecosystems [46]. As mentioned above soil fungi are included in several functional groups: decomposers, mutualists (mycorrhiza), endophytes, pathogens, parasites, and every one of these activities are of great relevance for the soil ecosystem function.…”

Observations on the Relationships between Endophytic Metarhizium robertsii, Spodoptera frugiperda (Lepidoptera: Noctuidae), and Maize

“…Endophytes are plant symbionts, often bacteria or fungi, that inhabit the tissues of terrestrial plants for at least part of their life cycle without causing apparent disease symptoms [25]. Several studies have reported the establishment of endophytic Metarhizium in a wide-variety of plant species within root, stem, and leaf tissues [24,[26][27][28][29][30][31][32]. However, some studies report that endophytic colonization by Metarhizium spp.…”