Arbuscular Mycorrhizal Fungal Communities in the Soils of Desert Habitats

Abstract

Deserts cover a significant proportion of the Earth’s surface and continue to expand as a consequence of climate change. Mutualistic arbuscular mycorrhizal (AM) fungi are functionally important plant root symbionts, and may be particularly important in drought stressed systems such as deserts. Here we provide a first molecular characterization of the AM fungi occurring in several desert ecosystems worldwide. We sequenced AM fungal DNA from soil samples collected from deserts in six different regions of the globe using the primer pair WANDA-AML2 with Illumina MiSeq. We recorded altogether 50 AM fungal phylotypes. Glomeraceae was the most common family, while Claroideoglomeraceae, Diversisporaceae and Acaulosporaceae were represented with lower frequency and abundance. The most diverse site, with 35 virtual taxa (VT), was in the Israeli Negev desert. Sites representing harsh conditions yielded relatively few reads and low richness estimates, for example, a Saudi Arabian desert site where only three Diversispora VT were recorded. The AM fungal taxa recorded in the desert soils are mostly geographically and ecologically widespread. However, in four sites out of six, communities comprised more desert-affiliated taxa (according to the MaarjAM database) than expected at random. AM fungal VT present in samples were phylogenetically clustered compared with the global taxon pool, suggesting that nonrandom assembly processes, notably habitat filtering, may have shaped desert fungal assemblages.

Alterations in Arbuscular Mycorrhizal Community Along a Chronosequence of Teak (Tectona grandis) Plantations in Tropical Forests of China

“…Similar results for the dominance of Glomus were observed in teak plantations in Thailand using different methods (Chaiyasen et al, 2014(Chaiyasen et al, , 2017. The Glomus was the most abundant genus reported in forest ecosystems (Chen et al, 2007;Lu et al, 2019;Jing et al, 2020;Ji et al, 2021), reclamation land (Ezeokoli et al, 2020), desert vegetative sites (Vasar et al, 2021), agroecosystems (Wang et al, 2020) and saline ecosystems (Sheng et al, 2019) indicating its wide adaptation to diverse ecosystems. Additionally, studies found that the AMV4.5NF/AMDGR primers favored the amplification of Glomeraceae sequences (Luo et al, 2020), which may also have resulted in the dominance of Glomeraceae and Glomus at the family and genus levels, respectively.…”

“…Evidence in the literature has reported that pH plays a central role in the assembly of soil AM fungal communities (Qin et al, 2015;Wang et al, 2020). The underlying mechanisms may be related to the effect of pH on nutrient availability (Vasar et al, 2021). Due to the major impact of pH on the mobility of multiple substances, the biological processes in the soil were affected (Neina, 2019).…”

Soil Bacterial Community Shifts Are Driven by Soil Nutrient Availability along a Teak Plantation Chronosequence in Tropical Forests in China

“…The results showed that pH had a significant impact on the bacterial community structure in the rhizosphere and bulk soil. Substantial studies have revealed that pH is a key regulator in shaping the distribution of soil bacterial communities [ 10 , 61 , 62 , 63 ]. The strong linkage between soil pH and microbial communities could be attributed to the narrow pH range for the optimal growth of bacteria [ 8 , 63 ].…”

“…Hence, a slight change in pH might cause microbes to respond quickly. Moreover, the effects of pH on the structures of the microbial communities may be associated with their ability to mediate nutrient availability [ 62 ]. pH has a major impact on the mobility of multiple compounds in the soil and affects many connected biological processes [ 64 ].…”

Elucidating the Mechanisms Underlying Enhanced Drought Tolerance in Plants Mediated by Arbuscular Mycorrhizal Fungi

“…Therefore, AM fungi must invest more resources in the storage capacity of roots to tolerate a DS environment ( Lenoir et al, 2016 ). AM fungi are an important component of the drought resistance of plants growing in desert ecosystems ( Vasar et al, 2021 ). Water-deficient soils, however, can limit the development of AM fungi in the soil and the rhizosphere, although some AM fungal species can adapt to dry soils and still maintain a relatively high level of root colonization, which is essential for the survival and growth of host plants ( Zou et al, 2017 ).…”