Arbuscular mycorrhizal fungi influence decomposition and the litter microbial community under saline-alkali conditions

doi:10.21203/rs.3.rs-2667441/v1

Download PDF

Research Article

Arbuscular mycorrhizal fungi influence decomposition and the litter microbial community under saline-alkali conditions

https://doi.org/10.21203/rs.3.rs-2667441/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Recent studies have indicated that arbuscular mycorrhizal fungi (AMF) can influence decomposition of organic materials. However, the underlying mechanisms remain unclear. Here we investigated whether AMF influence the decomposition of leaf litters and change the associated litter bacterial and fungal communities and whether this effect is altered by the level of soil saline-alkali. A pot experiment was conducted using Trifolium repens as host plant without or with AMF (Funneliformis mosseae) and with two levels of soil saline-alkali (0 and 200 mmol/L). Litterbags with different mesh size were used to measure the effect of AMF on decomposition. Our study found that AMF significantly accelerated litter decomposition under both non-saline-alkali and saline-alkali conditions. The composition of bacterial and fungal communities were also altered by AMF independent of soil saline-alkali conditions. For bacterial community, AMF increased the richness but not the diversity and increased the relative abundance of Firmicutes and Nitrospirota. For fungal community, the richness and diversity were higher in AMF than in non-AMF treatment. And AMF significantly resulted in a decrease of the relative abundance of Ascomycota but an increase of the relative abundance of Basidiomycota, Chytridiomycota, Mortierellomycota and Rozellomycota. Structural equation modelling (SEM) showed that AMF increased litter decomposition under saline-alkali conditions primarily by affecting bacterial community composition. Together, we show that AMF increase decomposition and alter the bacterial and fungal communities, and that these effects are not modulated by the level of soil saline-alkali.

Arbuscular mycorrhizal fungi (AMF)

Decomposition

Soil saline-alkali

Litter bacterial community

Litter fungal community

Litter decomposition is a key process for terrestrial ecosystems. It controls nutrient cycling and energy flow by releasing nutrients from organic matter and transforming them into inorganic forms (Gui et al. 2017). Traditionally, litter decomposition is regulated by litter quality (in terms of lignin and N content) (Zhang et al. 2016; Hong et al. 2021) and climatic factors such as temperature, water availability and soil acidity (Fernandez et al. 2017; Cao et al. 2022; Mei et al. 2022). However, recent studies suggest that litter quality and climatic factors do not fully explain decomposition, and the species, richness and diversity of decomposer microorganism may also exert strong controls on decomposition (Herzog et al. 2019; Zhang et al. 2019; Gui et al. 2020; Yuan and Li 2022; Zhou et al. 2022).

Arbuscular mycorrhizal fungi (AMF) form associations with > 80% of terrestrial plant species (Smith and Smith 2011) and obtain photosynthates from their host plants and deliver nutrients, such as nitrogen (N) and phosphorus (P), for their hosts (Brundrett and Tedersoo 2018). In addition to their contributions to plant nutrient uptake, AMF also play many ecological functions, including regulating litter decomposition process. Several studies have suggested that the presence of AMF significantly enhance litter decomposition. For example, Xu et al. (2018) showed that AMF increased litter decomposition when soil P availability was low; however, AMF did not promote litter decomposition when soil P availability was high. Mei et al. (2022) revealed that litter decomposition was enhanced by AMF independent of warming and N application. Other studies, by contrast, found that AMF had no beneficial effect on decomposition (Nottingham et al. 2013; Shahzad et al. 2015) or that they inhibited decomposition (Leifheit et al. 2015; Carrillo et al. 2016).

So far, the mechanisms by which AMF are able to influence litter decomposition remain unclear (Hodge 2014). Given that AMF does not have the saprophytic capacity (Hodge et al. 2001), one hypothesis that AMF affect decomposition processes in soil by exerting an indirect influence on associated microbes has gained more attention. AMF hyphal exudates contain H⁺, OH⁻ or HCO3⁻ and low molecular weight compounds such as sugars, amino acids and organic acids (Toljander et al. 2007). These ions and compounds likely change the local pH, phosphatase activity and soil carbon (C) economy in the hyphosphere and consequently influence microbial community composition and activity in the hyphosphere (Baldi et al. 2021; Mei et al. 2022). Xu et al. (2018) reported that under low soil P availability, during litter decomposition the presence of AMF shaped the structure of the bacterial and fungal communities, enhanced bacterial diversity, and increased the relative abundance of some bacterial taxa that participate in organic matter decomposition. Gui et al. (2020) found that soil fungal community structure and the relative abundance of some key genera including Mycena, Glomerella, Pholiotina and Sistotrema were altered by AMF inoculation during the later stages of litter decomposition. Cao et al. (2022) showed that AMF (Rhizophagus irregularis) stimulated the growth and activity of saprotrophic bacteria (Alcaligenes faecalis) to decompose litters. Bacteria and fungi play important roles in decomposition (Purahong et al. 2016). These changes of microbes affected by AMF may alter the production of bioactive metabolites and decomposition processes (Gui et al. 2017; Xu et al. 2018).

Saline-alkali stress is one of the most important environmental factors limiting plant growth and productivity (Munns and Gilliham 2015). Studies showed that saline-alkali stress affected the communities of bacteria and fungi (Liu et al. 2022a, b). AMF play a key role in growth of the plant hosts and they are expected to be more important for plant growth under saline-alkali conditions, but less beneficial for plants under non-saline-alkali conditions (Liu et al. 2022c). It is unclear, however, whether AMF promote litter decomposition under saline-alkali conditions and whether AMF affect bacterial and fungal communities during the decomposition. In this study, we investigated the effect of AMF on leaf litter decomposition under conditions of saline-alkali and non-saline-alkali conditions, and tested whether this effect associated with bacterial and fungal communities in the litter. We used Trifolium repens as a host plant. Decomposition influenced by AMF was quantified by analyzing the residual mass of tall fescue (Lolium arundinaceum) leaves. The litter microbial community was analyzed using Illumina MiSeq sequencing.

Materials used in the experiment

The microcosm experiments described in this paper were built from several major experimental materials including AMF inoculum, soil, host plants, and litterbags. The AMF inoculum was a mixture of the Funneliformis mosseae spores and the sterile rock flour materials. The soil applied in this experiment was sterilized vermiculite. The litterbags buried in the soil contained dried leaves of tall fescue. In this experiment, we selected T. repens, a major AMF plant, as the host plant.

Experiment design

We conducted a experiment with a three-factor rando-mized design. The first factor, saline-alkali treatment, included two concentrations: 0 and 200 mmol/L. Four salts, NaCl, Na₂SO₄, NaHCO₃, and Na₂CO₃, were mixed in 9:1:1:9 M ratios to simulate a range of mixed saline-alkali stress conditions. The second factor, AMF inoculum, included two treatments: with AMF inoculation (AMF, soil amended with a living mixture of AMF inoculum) and without AMF (NAMF, soil amended with an autoclaved mixture). The third factor, mesh size of litterbags, included three treatments: 0.3 mm, these bags allowed penetration by AMF hyphae and roots; 25 µm, these bags allowed penetration by AMF hyphae but did not permit penetration by roots; 0.45 µm, these bags allowed penetration by only a small amount of AMF hyphae.

Fifteen T. repens seeds were sown in each pot (21 cm in diameter × 16 cm in height) and were thinned to ten plants per pot after seedling emergence. Each pot received 500 g sterilized vermiculite (litter soil) and 10 g tall fescue leaf litter were cut into 5 cm long fragments and were inserted into litterbags. Litterbags were positioned on 18 April 2022 at 0.05 m of depth. Each treatment had five replicates, and a total of 60 pots were randomly arranged in a greenhouse (19℃–25℃, 40–50% relative humidity, and natural daylight). Litterbags from each treatment were sampled at 180 (25 October 2022) days. The litterbags were removed from the soil and the litter from the bag was then dried at 65°C to a constant weight and weighed to determine residual mass.

Mycorrhizal colonization rate

The colonization of T. repens roots by AMF was determined using fresh root samples. A subsample (ca. 2 g) of roots was cleared with 10% (w/v) KOH, which was stained with 0.05% trypan blue in lactic acid (v/v) according to the methods of Phillips and Hayman (1970). The stained roots were placed in a dish with grid lines and the AMF colonization rate was calculated under a dissecting microscope at×40 magnification (McGonigle et al. 1990).

DNA extraction, sequencing, and microbial community analysis

To analyze the composition of bacterial community and fungal community in the litter samples with different saline-alkali stress, microbial DNA from each sample was extracted by using the FastDNA® SPIN for soil kit (MP Biomedicals, Santa Ana, CA, United States). Extracted DNA was amplified using a 338F (5'-ACTCCTACGGGAGGCAGCAG-3') and 806R (5'-GGACTACHVGGGTWTCTAAT-3') universal primer set targeting the V3-V4 region of the bacterial 16S rRNA as well as a ITS1F (5'-CTTGGTCATTTAGAGGAAGTAA-3') and ITS2R (5'-GCTGCGTTCTTCATCGATGC-3') universal primer set targeting the ITS1 region of the fungi. PCR products were purified and sequenced on an Illumina MiSeq platform (Illumina, San Diego, United States) by the standard protocols of Majorbio Bio-Pharm Technology Co. Ltd. (Shanghai, China).

The sequences among all reads were used to define operational taxonomic units (OTUs) using UPARSE (version 7.11) with 97% sequence similarity. The sequences of all other samples were subsampled with the minimum number of reads to compare different samples at the same sequencing level (Fang et al. 2018). Final OTUs were taxonomically classified using the RDP Classifier algorithm² against the Unite7.2 ITS database and the Silva132 16S rRNA database at a confidence threshold of 70%.

Statistical analysis

One-way analysis of variance (ANOVA) procedure was performed by SPSS 20.0 (SPSS Inc., Chicago, IL, United States) to assess the effects of saline-alkali treatment on AMF colonization rate. Three-way ANOVAs were used to test the effects of saline-alkali treatment, AMF inoculation, mesh size of litterbags and their interactions on litter residual mass, bacterial and fungal OTU richness (Sobs, Ace and Chao) and diversity (Shannon and Simpson). The results were shown as mean values with standard error. The significant differences were determined by using Duncan's multiple range tests at p < 0.05. The similarities or differences in the composition of bacterial and fungal communities was visualized by nonmetric multidimensional scaling (NMDS) ordinations that were based on unweighted UniFrac dissimilarity matrices using the VEGAN package in R software. ANOSIM was performed to test whether the differences between groups were significant. Structural equation modeling (SEM) was fitted to our data using SPSS Amos 21.0 to identify potential causal relationships between explanatory variables (bacterial and fungal community composition in litter) and litter decomposition (litter residual mass).

AMF colonization rate

The AMF colonization rate was significantly higher with the non-saline-alkali treatment (42.07 ± 1.50%) than with the saline-alkali treatment (34.20 ± 1.40%) (F = 14.746, P < 0.001, Fig. 1).

Litter residual mass

Saline-alkali and AMF had significant interaction effects on litter decomposition (F = 4.490, P < 0.039). Saline-alkali had significant increased residual mass in the NAMF treatment but had no significant effects on residual mass in AMF treatment. Residual mass of the litter in AMF treatment were 18.1% and 27.2% lower than in NAMF treatment under non-saline-alkali conditions (0 mmol/L) and saline-alkali conditions (200 mmol/L), respectively (Fig. 2A). For mesh size of litterbags, residual mass increased with the decrease of mesh size of litterbags irrespective of saline-alkali and AMF (Fig. 2B).

Microbial diversity and richness

The diversity indices (Shannon's index and Simpson's index) of bacteria were not affected by the saline-alkali, AMF and mesh size (Table 1, Fig. 3). However, the richness indices (Sobs, Ace and Chao) of bacteria were significantly decreased by the saline-alkali treatment but increased by the AMF inoculation, and they decreased with the decrease of the mesh size of litterbags (Table 1, Fig. 3).

Table 1

Three-way ANOVA for the effects of saline-alkali stress (S), arbuscular mycorrhizal fungi (AMF), and mesh size (M) on α-diversity of leaf litter bacteria.
	Sobs		Shannon		Simpson		Ace		Chao
	F	P	F	P	F	P	F	P	F	P
Saline-alkali stress (S)	6.496	0.014	0.017	0.898	0.314	0.578	12.543	< 0.001	12.143	0.001
Arbuscular mycorrhizal fungi (AMF)	44.509	< 0.001	0.187	0.667	2.079	0.156	85.739	< 0.001	65.218	< 0.001
Mesh size (M)	5.011	0.011	1.819	0.173	0.810	0.451	10.813	< 0.001	8.957	< 0.001
S×AMF	0.106	0.746	2.446	0.124	1.350	0.251	0.620	0.435	0.058	0.810
S×M	0.279	0.758	0.163	0.850	0.992	0.378	0.214	0.808	0.711	0.496
AMF×M	0.491	0.615	1.299	0.282	0.838	0.439	0.721	0.491	0.638	0.533
S×AMF×M	0.901	0.413	0.583	0.562	0.049	0.952	0.072	0.930	0.286	0.752
Bold numbers indicate significant difference at 0.05 level.

For fungi, the diversity indices (Shannon's index and Simpson's index) were not affected by the saline-alkali treatment but were significantly affected by the interaction of AMF and mesh size of litterbags (Table 2). Shannon's index and Simpson's index were significantly higher in the AMF treatment than in the NAMF treatment regardless of the mesh size of litterbags (Table 3). While for the richness indices (Sobs, Ace and Chao), they were significantly affected by the interaction of saline-alkali, AMF and mesh size of litterbags (Table 2). Under non-saline-alkali (0 mmol/L) conditions, Sobs, Ace and Chao were significantly higher in the AMF treatment than in the NAMF treatment regardless of the mesh size of litterbags. Under saline-alkali conditions (200 mmol/L), AMF significantly increased those richness indices in 0.3 mm and 25 µm but not in 0.45 µm litterbags (Table 3).

Table 2

Three-way ANOVA for the effects of saline-alkali stress (S), arbuscular mycorrhizal fungi (AMF), and mesh size (M) on α-diversity of leaf litter fungi.
	Sobs		Shannon		Simpson		Ace		Chao
	F	P	F	P	F	P	F	P	F	P
Saline-alkali stress (S)	3.803	0.057	2.426	0.126	2.053	0.158	2.642	0.111	2.485	0.122
Arbuscular mycorrhizal fungi (AMF)	200.314	< 0.001	170.008	< 0.001	126.417	< 0.001	91.260	< 0.001	135.201	< 0.001
Mesh size (M)	3.272	0.047	1.887	0.163	4.363	0.018	4.521	0.016	5.442	0.007
S×AMF	0.580	0.450	2.745	0.104	1.731	0.195	0.006	0.940	0.043	0.837
S×M	1.174	0.318	1.420	0.252	1.160	0.322	0.557	0.577	1.468	0.241
AMF×M	6.722	0.003	6.271	0.004	\5.531	0.007	4.498	0.016	5.484	0.007
S×AMF×M	5.006	0.011	2.606	0.084	1.795	0.177	4.626	0.015	5.615	0.006
Bold numbers indicate significant difference at 0.05 level.

Table 3

Effects of saline-alkali, arbuscular mycorrhizal fungi (AMF) and litterbags mesh size on α-diversity of leaf litter fungi.
			Sobs	Shannon	Simpson	Ace	Chao
Non-saline-alkali (0 mmol/L)	0.3 mm	NAMF	151.4 ± 6.87d	1.2 ± 0.19d	0.6 ± 0.08a	234.4 ± 9.80e	210.8 ± 7.73d
	0.3 mm	AMF	324.4 ± 15.58a	3.1 ± 0.13ab	0.1 ± 0.02d	423.7 ± 15.53a	408.2 ± 21.77a
	25 µm	NAMF	211.6 ± 21.76bc	2.0 ± 0.32c	0.4 ± 0.08b	317.9 ± 15.39bc	293.5 ± 20.38b
	25 µm	AMF	305.6 ± 13.86a	3.2 ± 0.15ab	0.1 ± 0.02d	388.1 ± 13.23a	393.3 ± 14.79a
	0.45 µm	NAMF	178.0 ± 11.35cd	2.1 ± 0.26c	0.3 ± 0.07bc	249.3 ± 15.14de	226.3 ± 12.05d
	0.45 µm	AMF	294.2 ± 6.76a	3.2 ± 0.14ab	0.1 ± 0.01d	366.0 ± 13.41ab	360.5 ± 13.42a
Saline-alkali (200 mmol/L)	0.3 mm	NAMF	150.2 ± 23.45d	1.1 ± 0.12d	0.6 ± 0.04a	249.3 ± 45.55de	233.6 ± 34.30cd
	0.3 mm	AMF	326.6 ± 21.32a	3.4 ± 0.33a	0.1 ± 0.06d	405.4 ± 22.36a	405.5 ± 21.20a
	25 µm	NAMF	143.6 ± 19.15d	1.1 ± 0.12d	0.6 ± 0.08a	233.7 ± 34.77e	204.9 ± 29.51d
	25 µm	AMF	331.0 ± 11.52a	3.4 ± 0.33a	0.1 ± 0.02d	410.8 ± 16.18a	408.0 ± 19.42a
	0.45 µm	NAMF	169.6 ± 15.21cd	1.8 ± 0.31c	0.4 ± 0.08b	258.1 ± 26.93de	242.3 ± 22.40bcd
	0.45 µm	AMF	232.6 ± 20.25b	2.7 ± 0.20b	0.2 ± 0.03cd	295.3 ± 13.41cd	283.5 ± 21.10bc
Values are means ± standard error (SE). Different letters show significant differences between treatments (P < 0.05).

Table 2, Table 3

Microbial community composition

The phylum Proteobacteria was dominant, representing 29.62–44.07% of the bacteria in all treatments, followed by the Actinobacteriota, the Chloroflexi and the Firmicutes. AMF significantly promoted Firmicutes and Nitrospirota both under non-saline-alkali (Fig. 4A) and saline-alkali conditions (Fig. 4B). For fungi, the phylum Ascomycota was dominant, representing 66.16–98.26% in all treatments. Both under non-saline-alkali (0 mmol/L) (Fig. 5A) and saline-alkali (200 mmol/L) (Fig. 5B) conditions, AMF significantly decreased the relative abundance of Ascomycota, but increased the relative abundance of Basidiomycota, Chytridiomycota, Mortierellomycota and Rozellomycota whether in 0.3 mm, 25 µm or 0.45 µm litterbags.

Both under non-saline-alkali (0 mmol/L) and saline-alkali (200 mmol/L) conditions, NMDS analysis on OTU level showed that AMF statistically distincted bacterial (non-saline-alkali, ANOSIM: R = 0.7148, P = 0.001, Fig. 6A; saline-alkali, ANOSIM: R = 0.7214, P = 0.001, Fig. 6B) and fungal (non-saline-alkali, ANOSIM: R = 0.6848, P = 0.001, Fig. 6C; saline-alkali, ANOSIM: R = 0.5960, P = 0.001, Fig. 6D) communities whether in 0.3 mm, 25 µm or 0.45 µm litterbags.

Relationship between litter microbial community composition and decomposition

We used SEM to assess the extent of direct and indirect effects of AMF on litter decomposition under non-saline-alkali and saline-alkali conditions. Under non-saline-alkali conditions, AMF acted directly on litter decomposition (Fig. 7A). However, under saline-alkali conditions, AMF inoculation had no direct effects on litter decomposition, but effects were mediated through affecting bacterial community composition (Fig. 7B).

In this study, we found that AMF altered decomposition rates under both saline-alkali treatments. AMF significantly enhanced decomposition under both soil saline-alkali treatments, but this enhancement was significantly higher under saline-alkali conditions than at non-saline-alkali conditions. With the increase of the mesh size of the litterbags from 0.45 µm to 25 µm and then to 0.3 mm, the number of AMF hyphae gradually increased and plant roots also began to participate in the decomposition process, resulting in less and less residual mass. These findings are in agreement with past studies showing that AMF can increase litter decomposition rates (Gui et al. 2017; Kong et al. 2017; Xu et al. 2018; Cao et al. 2022; Mei et al. 2022).

Whether AMF affect decomposition through altering associated microbial communities has been discussed inconclusively in the past. Nuccio et al. (2012) revealed that approximately 10% of the bacterial community in decomposing litter were altered by AMF Glomus hoi. Cao et al. (2022) demonstrated that AMF R. irregularis interacted synergistically with saprotrophic bacteria (Alcaligenes faecalis) for litter decomposition. Leifheit et al. (2015) found that AMF R. irregularis inhibited the decomposition rates of woody material, independent of whether plant roots or a natural soil microbial community presence or not. In this study, we found that AMF inoculation increased bacterial richness but not diversity, and altered community composition in both non-saline-alkali and saline-alkali treatments. The phyla Firmicutes and Nitrospirae were significantly favored by AMF in both non-saline-alkali and saline-alkali treatments, although the relative abundances of these phyla were low, especially for Nitrospirae. Firmicutes are involved in reducing large macromolecules, such as proteins, complex fats and polycarbohydrates to their building blocks (Li et al. 2013), and are reported to be associated with the decomposition (Bayer et al. 1998; Lee et al. 2011; Nuccio et al. 2012). Thus, the increase in the relative abundance of Firmicutes in the presence of AMF may relative to the increased decomposition. Similar results were reported by Nuccio et al. (2012). AMF also positively affected the bacterial phylum Nitrospirae in both saline-alkali treatments. Many members of the Nitrospirae are known to be engaged in the second step of nitrification, which are capable of oxidizing nitrite (Lücker et al. 2010; Xu et al. 2018). Bukovská et al. (2016) and Xu et al. (2018) also found that the presence of AMF increased the relative abundance of Nitrospirae during the decomposition. Therefore, in our study, the microbial groups with nitrifying capacity increased by AMF may have an impact on the nitrogen cycle during decomposition.

We also detected fungal richness, diversity and community shifts in response to AMF. AMF inoculation significantly increased fungal richness and diversity in both saline-alkali treatments, only with an exception, which AMF had no effects on fungal richness (Ace and Chao) of 0.45 µm litterbag in saline-alkali treatment. The phylum Ascomycota and Basidiomycota were widely accepted as the main saprotrophic fungal decomposers (Vandenkoornhuyse et al. 2002; Blackwood et al. 2007; Purahong et al. 2016).Our results showed that the relative abundance of these two fungal taxa was affected differently by AMF. AMF inoculation led to a decline in the relative abundance of Ascomycota, which was the most abundant fungal group within our litter samples, and is in accordance with the work of Ma et al. (2013) and Gui et al. (2020). However, AMF inoculation caused an increase in the relative abundance of Basidiomycota in both saline-alkali treatments. The relative abundance of Basidiomycota was enhanced by AMF could explain the acceleration of litter decomposition caused by the AMF inoculation (Gui et al. 2017). In addition, similar to the bacterial community, the results of NMDS showed that AMF statistically distincted fungal communities in both saline-alkali treatments.

AMF inoculation caused differences in the litter microbial communities (diversity and community composition). An important question is, “Which of these factors contributes most to the decomposition differences between AMF and NAMF treatments under saline-alkali stress conditions?” In our study, we conducted SEM to examine the relationships between microbial diversity and community composition and litter decomposition and found that AMF inoculation increased litter decomposition by affecting litter bacterial community composition. Bacteria may play a more important role in leaf litter decomposition (Purahong et al. 2016; Keiblinger et al. 2012; Schneider et al. 2012).

We showed here that AMF accelerated litter decomposition, and this effect was not affected by the level of soil saline-alkali. We also revealed that the effect of AMF on the changes of bacterial and fungal communities was occurred independent of soil saline-alkali level. AMF increased litter decomposition under saline-alkali stress primarily by affecting bacterial community composition.

Ethical Approval Not applicable

Competing interests The authors declare no competing interests.

Authors' contributions Hui Liu and Jiazhen Zhang wrote the main manuscript text. Luying Zhang and Xi Zhang and Rui Yang prepared figures 1-7. All authors reviewed the manuscript.

Funding This work was supported by the National Natural Science Foundation of China (32001103) and Dezhou University Science Research Foundation (2019xjrc317).

Availability of data and materials The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Baldi E, Gioacchini P, Montecchio D et al (2021) Effect of biofertilizers application on soil biodiversity and litter degradation in a commercial apricot orchard. Agronomy 11:1116
Bayer EA, Shimon LJW, Shoham Y et al (1998) Cellulosomes—Structure and Ultrastructure. J Struct Biol 124:221-234
Blackwood CB, Waldrop MP, Zak DR et al (2007) Molecular analysis of fungal communities and laccase genes in decomposing litter reveals differences among forest types but no impact of nitrogen deposition. Environ Microbiol 9:1306-1316
Brundrett MC, Tedersoo L (2018) Evolutionary history of mycorrhizal symbioses and global host plant diversity. New Phytol 220:1108-1115.
Bukovská P, Gryndler M, Gryndlerová H et al (2016) Organic nitrogen-driven stimulation of arbuscular mycorrhizal fungal hyphae correlates with abundance of ammonia oxidizers. Front Microbiol 7:711
Cao TT, Fang Y, Chen YR et al (2022) Synergy of saprotrophs with mycorrhiza for litter decomposition and hotspot formation depends on nutrient availability in the rhizosphere. Geoderma 410:115662
Carrillo Y, Dijkstra FA, Dan LC et al (2016) Mediation of soil C decomposition by arbuscular mycorrhizal fungi in grass rhizospheres under elevated CO₂. Biogeochemistry 127:45-55
Fang DX, Zhao G, Xu XY et al (2018) Microbial community structures and functions of wastewater treatment systems in plateau and cold regions. Bioresour Technol 249:684-693
Fernandez CW, Nguyen NH, Stefanski A et al (2017) Ectomycorrhizal fungal response to warming is linked to poor host performance at the boreal-temperate ecotone. Global Change Biol 23:1598-1609
Gui H, Hyde K, Xu JC et al (2017) Mortimer, P. Arbuscular mycorrhiza enhance the rate of litter decomposition while inhibiting soil microbial community development. Sci Rep 7:42184
Gui H, Purahong W, Wubet T et al (2020) Funneliformis mosseae alters soil fungal community dynamics and composition during litter decomposition. Fungal Ecol 43:100864
Herzog C, Hartmann M, Frey B (2019) Microbial succession on decomposing root litter in a drought-prone Scots pine forest. ISME J
Hodge A (2014) Interactions between arbuscular mycorrhizal fungi and organic material substrates. Adv Appl Microbiol 89:47-99
Hodge A, Campbell CD, Fitter AH (2001) An arbuscular mycorrhizal fungus accelerates decomposition and acquires nitrogen directly from organic material. Nature 413:297-299
Hong JT, Lu XY, Ma XX et al (2021) Five-year study on the effects of warming and plant litter quality on litter decomposition rate in a Tibetan alpine grassland. Sci Total Environ 750:142306
Keiblinger KM, Schneider T, Roschitzki B et al (2012) Effects of stoichiometry and temperature perturbations on beech leaf litter decomposition, enzyme activities and protein expression. Biogeosciences 9:4537-4551
Kong XS, Jia YY, Song FQ et al (2017) Insight into litter decomposition driven by nutrient demands of symbiosis system through the hypha bridge of arbuscular mycorrhizal fungi. Environ Sci Pollut R
Lee CG, Watanabe T, Sato Y et al (2011) Bacterial populations assimilating carbon from ¹³C-labeled plant residue in soil: Analysis by a DNA-SIP approach. Soil Biol Biochem 43:814-822
Leifheit EF, Verbruggen E, Rillig MC (2015) Arbuscular mycorrhizal fungi reduce decomposition of woody plant litter while increasing soil aggregation. Soil Biol Biochem 81:323-328
Li A, Chu Y, Wang X et al (2013) A pyrosequencing-based metagenomic study of methane-producing microbial community in solid-state biogas reactor. Biotechnol Biofuels 6:1-17
Liu H, Tang HM, Ni XZ et al (2022a) Epichloë endophyte interacts with saline alkali stress to alter root phosphorus solubilizing fungal and bacterial communities in tall fescue. Front Microbiol 13:1027428
Liu H, Tang HM, Ni XZ et al (2022b) Effects of the endophyte Epichloë coenophiala on the root microbial community and growth performance of tall fescue in different saline-alkali soils. Fungal Ecol 57:101159
Liu H, Tang HM, Ni XZ et al (2022c) Interactive effects of Epichloë endophytes and arbuscular mycorrhizal fungi on saline-alkali stress tolerance in tall fescue. Front Microbiol 13:855890
Lücker S, Wagner M, Maixner F et al (2010) A Nitrospira metagenome illuminates the physiology and evolution of globally important nitrite-oxidizing bacteria. Proc Natl Acad Sci 107:13479
Ma AZ, Zhuang XL, Wu JM et al (2013) Ascomycota members dominate fungal communities during straw residue decomposition in arable soil. PLoS One 8
McGonigle TP, Miller MH, Evans DG (1990) A new method which gives an objective measure of colonization of roots by vesicular-arbuscular mycorrhizal fungi. New Phytol 115:495-501
Mei LL, Zhang P, Cui GW et al (2022) Arbuscular mycorrhizal fungi promote litter decomposition and alleviate nutrient limitations of soil microbes under warming and nitrogen application. Appl Soil Ecol 171:104318
Munns R, Gilliham M (2015) Salinity tolerance of crops–what is the cost? New Phytol 208:668-673
Nottingham AT, Turner BL, Winter K et al (2013) Root and arbuscular mycorrhizal mycelial interactions with soil microorganisms in lowland tropical forest. FEMS Microbiol Ecol 85:37-50
Nuccio EE, Hodge A, Pett-Ridge J et al (2012) An arbuscular mycorrhizal fungus modifies the soil microbial community and nitrogen cycling during litter decomposition. Environ Microbiol 15:1870-1881
Phillips JM, Hayman DS (1970) Improved procedures for clearing roots and staining parasitic and vesicular arbuscular mycorrhizal fungi for rapid assessment of infection. Tran. Br Mycol Soc 55:158-161
Purahong W, Wubet T, Lentendu G et al (2016) Life in leaf litter: novel insights into community dynamics of bacteria and fungi during litter decomposition. Mol Ecol 25:4059-4074.
Schneider T, Keiblinger KM, Schmid E et al (2012) Who is who in litter decomposition? Metaproteomics reveals major microbial players and their biogeochemical functions. ISME J 6:1749-1762
Shahzad T, Chenu C, Genet P et al (2015) Contribution of exudates, arbuscular mycorrhizal fungi and litter depositions to the rhizosphere priming effect induced by grassland species. Soil Biol Biochem 80:146-155
Smith SE, Smith FA (2011) Roles of arbuscular mycorrhizas in plant nutrition and growth: New paradigms from cellular to ecosystem scales. Annu Rev Plant Biol 62:227-250
Toljander JF, Lindahl BD, Paul LR et al (2007) Influence of arbuscular mycorrhizal mycelial exudates on soil bacterial growth and community structure. FEMS Microbiol Ecol 61:295-304
Vandenkoornhuyse P, Baldauf SL, Leyval C et al (2002) Evolution - extensive fungal diversity in plant roots. Science 295
Xu J, Liu SJ, Song SR et al (2018) Arbuscular mycorrhizal fungi influence decomposition and the associated soil microbial community under different soil phosphorus availability. Soil Biol Biochem 120:181-190
Yuan YG, Li JM (2022) Dodder parasitism limited the effect of arbuscular mycorrhizal fungi on litter decomposition. Soil Biol Biochem 174:108837
Zhang W, Chao L, Yang Q et al (2016) Litter quality mediated nitrogen effect on plant litter decomposition regardless of soil fauna presence. Ecology 97:2834-2843
Zhang WW, Yang K, Lyu ZT et al (2019) Microbial groups and their functions control the decomposition of coniferous litter: A comparison with broadleaved tree litters. Soil Biol Biochem 133:196-207
Zhou Y, Li X, Gao YB et al (2022) Plant endophytes and arbuscular mycorrhizal fungi alter the decomposition of Achnatherum sibiricum litter. Appl Soil Ecol 180:104616

No competing interests reported.

Download PDF

Version 1

posted

You are reading this latest preprint version

Arbuscular mycorrhizal fungi influence decomposition and the litter microbial community under saline-alkali conditions

Status:

Version 1

Abstract

Figures

Introduction

Materials And Methods

Materials used in the experiment

Experiment design

Mycorrhizal colonization rate

DNA extraction, sequencing, and microbial community analysis

Statistical analysis

Results

AMF colonization rate

Litter residual mass

Microbial diversity and richness

Microbial community composition

Relationship between litter microbial community composition and decomposition

Discussion

Conclusions

Declarations

References

Additional Declarations

Status:

Version 1