Changes in root-associated fungal communities in Triticum aestivum ssp. spelta L. and Triticum aestivum ssp. vulgare L. under drought stress and in various soil processing

Abstract

Plant roots are inhabited by an enormous variety of microorganisms, including fungi, which can control the growth as well as regulate the health of the host plants. The mycobiome composition of the roots of wheat plants, especially spelt, under drought stress has been rarely investigated. Therefore, the aim of the present study was to examine the composition of fungal communities in the root endosphere and rhizosphere of three Triticum aestivum ssp. spelta L. cultivars and one Triticum aestivum ssp. vulgare L. cultivar, grown under drought and controlled conditions in different soil preparations. Culture-dependent fungal community profiling was performed to examine the impact of rhizocompartments (endosphere, rhizosphere), host genotype, watering status and different soil preparation on roots mycobiome structure. A total of 117 fungal strains, belonging to 22 genera, were found to colonize the internal and external parts of roots in T. aestivum ssp. spelta L. and T. aestivum ssp. vulgare L. cultivars. The results showed that the part of root and soil preparation type significantly determined the mycobiome composition of wheat roots.

Fungi Inhabiting the Wheat Endosphere

“…In research on wheat endophytes, before surface sterilization, plant samples are usually washed under running water [ 46 , 47 ], and soil residues are removed from the roots, for example by brushing or scraping [ 48 , 49 ]. Ethyl alcohol and sodium hypochlorite are usually used to remove microorganisms from the surface of plant fragments.…”

“…Separated for this purpose, the glumes, lemmas, paleas, and kernels were surface sterilized according to Comby et al [ 38 ]; however, they sterilized flower tissues in 96% ethanol for 1 min, 2% sodium hypochlorite for 3 min, and 96% ethanol for 30 s, and finally rinsed the tissues twice with sterile MilliQ water. In contrast, Cłapa et al [ 48 ] and Salamon et al [ 49 ] developed a protocol for wheat in which plant tissue fragments were rinsed in 70% ethyl alcohol for 30 s and then in 0.5% sodium hypochlorite for 2 min. In order to remove the reagents, the wheat tissues were rinsed several times with distilled water.…”

“…After surface sterilization, the plant material was aseptically cut into smaller pieces 5–10 mm in length [ 48 , 49 ], re-sterilized, and then placed on the agar medium. Many different media can be used, but the most common ones are potato dextrose agar (PDA), malt extract agar (MEA), corn meal agar (CMA), yeast extract peptone dextrose agar, as well as minimal plant tissues or extract media [ 51 , 52 , 53 , 54 ].…”

“…As in the case of sterilization, many variations of the incubation of plant tissue fragments on a solid medium exist. The temperature range used was 22 C [ 49 ]–27 C [ 47 ]. Cultures were maintained for a period of 5 days [ 47 ] to 28 days [ 41 ] or until the mycelium became visible [ 49 ], both in the dark [ 41 , 50 ] and in the photoperiod [ 47 , 49 ].…”

Root-associated entomopathogenic fungi manipulate host plants to attract herbivorous insects

“…Furthermore, no plant species is known to grow successfully without a relationship with fungi 2 . Root-associated fungi can colonize both the internal and external parts of developing roots without damaging the host plant 3 . The presence of root inhabiting fungi is associated with enhancements in plant growth, i.e.…”