Advances in the Role of Dark Septate Endophytes in the Plant Resistance to Abiotic and Biotic Stresses

Abstract

Endophytic fungi have been studied in recent decades to understand how they interact with their hosts, the types of relationships they establish, and the potential effects of this interaction. Dark septate endophytes (DSE) are isolated from healthy plants and form melanised structures in the roots, including inter- and intracellular hyphae and microsclerotia, causing low host specificity and covering a wide geographic range. Many studies have revealed beneficial relationships between DSE and their hosts, such as enhanced plant growth, nutrient uptake, and resistance to biotic and abiotic stress. Furthermore, in recent decades, studies have revealed the ability of DSE to mitigate the negative effects of crop diseases, thereby highlighting DSE as potential biocontrol agents of plant diseases (BCAs). Given the importance of these fungi in nature, this article is a review of the role of DSE as BCAs. The findings of increasing numbers of studies on these fungi and their relationships with their plant hosts are also discussed to enable their use as a tool for the integrated management of crop diseases and pests.

Effects of the Dark Septate Endophyte (DSE) Exophiala pisciphila on the Growth of Root Cell Wall Polysaccharides and the Cadmium Content of Zea mays L. under Cadmium Stress

“…Pb mainly accumulates in the root system of maize and the phytotoxicity of Pb to the shoot is alleviated [75]. One of the reasons for that DSE colonization increases plant growth under metal addition is that DSE enhances metal tolerance and improves plant growth by altering metal repartitioning into the root and shoot [19,48,52,54]. In our results, we found that more Cd accumulated in maize with increasing concentration of Cd, and the Cd content in roots was higher than that in the shoots.…”

“…DSEs extend mucilaginous hyphae to promote the transportation of water and nutrients in arid environments, helping rice and sorghum survive in arid environments and improving their drought resistance [46,47]. The DSE-host interaction is crucial to plant survival [48]. In particular, the DSE strain, Exophiala pisciphila, which was isolated from heavy metal contaminated soil, has a strong tolerance to heavy metals under in vitro culture conditions [49].…”

Mycorrhized Wheat Plants and Nitrogen Assimilation in Coexistence and Antagonism with Spontaneous Colonization of Pathogenic and Saprophytic Fungi in a Soil of Low Fertility

“…The analyses show that A. tellustris can diminish the nutrients and space available to both terrestrial pathogens. These results appear to indicate that DSE have an important role in diminishing the nutritional and spatial resources available to terrestrial plant pathogens, using different mechanisms of action, as mentioned by Santos et al [ 56 ]. The present research suggests that endophytic fungi, such as A. tellustris , may have a role in the induction of a plant’s defensive responses, such as systemic acquired resistance (SAR) and induced systemic resistance (ISR).…”

Unearthing the plant–microbe quid pro quo in root associations with beneficial fungi

“…In addition, S. indica enhances salt tolerance in its host A. thaliana via sodium (Na) and potassium (K) efflux transporters, thereby decreasing the Na content in the plant (Lanza et al ., 2019). Similarly, some DSE fungi are thought to improve drought resistance and salt tolerance in different plant species (Santos et al ., 2021). Under current global change scenarios, the abundance of plant pathogens in soil is predicted to increase (Delgado‐Baquerizo et al ., 2020), implying that plant protection by endophytic mycorrhizal‐like fungi could improve plant adaptation to increased disease pressure.…”