Dark Septate Endophyte Improves Drought Tolerance in Sorghum

Abstract

Dark septate endophytes (DSE) protect host plants against a variety of environmental stresses, however our knowledge about the roles of DSE in improving drought tolerance of crops is poor. In this study, sorghum (Sorghum bicolor L. Moench) was inoculated with a DSE strain (Exophiala pisciphila GM25) under two different soil water conditions (well-watered (WW), -0.11 MPa; drought-stressed (DS), -0.69 MPa) for one month. At the end of this experiment, sorghum roots were obviously colonized by DSE with 50.5%-62.5% colonization rate. When compared with non-inoculated seedlings under both WW and DS conditions, E. pisciphila-inoculated sorghum had greater plant height, collar diameter, shoot dry weight, net photosynthetic rate (Pn), stomatal conductance (g s ), transpiration rate (E), maximal photochemical efficiency of PSII photochemistry (Fv/Fm) and actual quantum yield (PSII), and lower intercellular CO 2 concentration (Ci). In addition, in comparison to noninoculation under DS conditions, E. pisciphila inoculation also improved the root dry weight, non-photochemical quenching values (NPQ), photochemical quenching values (qP), increased the content of related secondary metabolites including anthocyanin, polyphenol and flavonoid and enhanced the enzymatic activities related to secondary metabolism, such as cinnamyl alcohol dehydrogenase (CAD), phenylalanine ammonia-lyase (PAL), guaiacol peroxidase (G-POD) in sorghum seedlings. Our results demonstrated that the drought resistance of sorghum seedlings were positively improved by E. pisciphila inoculation with better plant growth, gas exchange, photosynthesis, chlorophyll fluorescence, secondary metabolites and enzyme activities related to secondary metabolism. Inoculation with E. pisciphila is an efficient strategy to survive for sorghum in drought environment.

Dark Septate Endophytic Fungi Help Tomato to Acquire Nutrients from Ground Plant Material

“…Currently, Mn has been recognized as an indicator of P acquisition efficiency by plants (Lambers et al, 2015 ). Thus, an increase in Fe, Mn, and Zn contents corroborates previous studies (Zhang et al, 2012 , 2017 ; Ban et al, 2017 ) which suggested involvement of DSE fungi in photosynthetic activity by increasing chlorophyll levels, photochemical efficiency of photosystem II, net photosynthetic rate, stomatal conductance, and transpiration rate, leading to higher glucose (Andrade-Linares et al, 2011b ) and soluble sugar contents (Vergara et al, 2017 ).…”

Dark Septate Endophyte Improves Drought Tolerance of Ormosia hosiei Hemsley & E. H. Wilson by Modulating Root Morphology, Ultrastructure, and the Ratio of Root Hormones

“…DSEs are widely distributed and have been found in almost all habitats. Recently, DSEs have been found to play an active role in improving host drought resistance [20,21]; however, our understanding of their role in drought resistance is still limited.…”

“…However, other ecological functions, such as the drought resistance of DSE fungi for O. hosiei, are still not well understood, and the mechanism by which DSEs improve plant growth under drought stress remains unclear. To date, the role of DSEs in improving host drought tolerance has only been reported sporadically in sorghum [20] and Ammopiptanthus mongolicus [21];…”

Plant-mycorrhizal fungi interaction and response to inoculation with different growth-promoting fungi

“…However, studies indicate that growth promotion may occur indirectly or directly. The first way would be through plant protection from abiotic stresses, such as drought (Santos et al, 2017;Zhang et al, 2017), salinity (Qin et al, 2017) and high concentrations of heavy metals (Wei et al, 2016), as well as through the production of phytohormones or similar substances (Berthelot et al, 2016). The second would be through the facilitation of nutrient absorption, mainly from organic sources (Usuki & Narisawa, 2007;Vergara et al, 2018b).…”