scholarly journals Plant-microbe specificity varies as a function of elevation

2019 ◽  
Author(s):  
Gerald M. Cobian ◽  
Cameron Egan ◽  
Anthony S. Amend

AbstractSpecialized associations between interacting species are a fundamental determinant of the diversity and distribution of both partners. How specialization of guilds of organisms varies along environmental gradients underpins popular theories of biogeography and macroecology, whereas the degree of specialization of a species is typically considered fixed. However, the extent to which environmental context impacts specialization dynamics is seldom examined empirically. In this study, we examine how specialization within a bipartite network consisting of three co-occurring plant species and their foliar fungal endophyte symbionts changes along a 1 000-meter elevation gradient where host species were held constant. The gradient, along the slope of Mauna Loa shield volcano, represents the entire elevational range of two of the three plants. Network and plant specialization values displayed a parabolic relationship with elevation, and were highest at middle elevations, whereas bipartite associations were least specific at low and high elevations. Shannon’s diversity of fungal endophytes negatively correlated with specificity, and was highest at the ends of the transects. Although plant host was a strong determinant of fungal community composition within sites, fungal species turnover was high among sites and plant host predicted a weak, though significant proportion of compositional variance. There was no evidence of spatial or elevational patterning in fungal community compositon. Our work demonstrates that specificity can be a plastic trait which is influenced by the environment and centrality of the host within its natural range.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Deepak Bokati ◽  
José Herrera ◽  
Ravin Poudel

Root-associated fungal endophytes are vital component of root microbiome as some mitigate their host’s abiotic and biotic stress. We characterized root-associated fungal endophytes in cereal grains and their progenitors grown on two different soil-types. We aimed at determining how clay and desert soil affects the colonization of root fungal community. Both culture-dependent and culture-independent methods were employed to identify endophytes that successfully colonized greenhouse-grown host plants. The Internal Transcriber Spacer region of fungal ribosomal DNA was utilized for identification purposes. This study revealed soil as a prominent factor influencing the composition of microfungal communities inhabiting the roots of maize (Zea mays subsp. mays) and its conspecific progenitor, teosinte (Zea mays subsp. parviglumis). Similar results were found in wheat (Triticum aestivum subsp. aestivum) and its progenitor (Triticum monococcum subsp. monococcum). The multidimensional comparisons of Morisita-Horn similarity values of fungal colonists of various host plant taxa indicated that soil plays a primary role in shaping the root fungal community; a secondary effect was plant host identity, even when the plant host is a conspecific. Future studies focused on characterizing root endophytes in other cereal grains, and studying the effect of edaphic factors on fungal colonization, can ultimately contribute to crop productivity.


2021 ◽  
Author(s):  
Ying Yang ◽  
Yu Shi ◽  
Dorsaf Kerfahi ◽  
Matthew C Ogwu ◽  
Jianjun Wang ◽  
...  

AbstractAlthough many studies have explored patterns of fungal community diversity and composition along various environmental gradients, the trends of co-occurrence networks across similar gradients remain elusive. Here, we constructed co-occurrence networks for fungal community along a 2300 m elevation gradient on Mt Norikura, Japan, hypothesizing a progressive decline in network connectivity with elevation due to reduced niche differentiation caused by declining temperature and ecosystem productivity. Results agreed broadly with predictions, with an overall decline in network connectivity with elevation for all fungi and the high abundance phyla. However, trends were not uniform with elevation, most decline in connectivity occurred between 700 m and 1500 m elevation, remaining relatively stable above this. Temperature and precipitation dominated variation in network properties, with lower mean annual temperature (MAT) and higher mean annual precipitation (MAP) at higher elevations giving less network connectivity, largely through indirect effects on soil properties. Among keystone taxa that played crucial roles in network structure, the variation in abundance along the elevation gradient was also controlled by climate and also pH. Our findings point to a major role of climate gradients in mid-latitude mountain areas in controlling network connectivity. Given the importance of the orographic precipitation effect, microbial community trends seen along elevation gradients might not be mirrored by those seen along latitudinal temperature gradients.ImportanceAlthough many studies have explored patterns of fungal community diversity and composition along various environmental gradients, it is unclear how the topological structure of co-occurrence networks shifts across environmental gradients. In this study, we found that the connectivity of the fungal community decreased with increasing elevation, and that climate was the dominant factor regulating co-occurrence patterns, apparently acting indirectly through soil characteristics. Assemblages of keystone taxa playing crucial roles in network structure varied along the elevation gradient and were also largely controlled by climate. Our results provide insight into the shift of soil fungal community co-occurrence structure along elevational gradients, and possible driving mechanisms behind this.Graphic abstract


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Franziska Wemheuer ◽  
Bernd Wemheuer ◽  
Rolf Daniel ◽  
Stefan Vidal

Abstract Green islands (the re-greening of senescent leaf tissues) are particularly evident on leaves infected with fungal pathogens. To date, there is only a limited number of studies investigating foliar endophytic microorganisms in phytopathogen-infected leaves. Here, we analysed bacterial and fungal endophyte communities in leaves without green islands (control leaves; CL), within green island areas (GLA) and the surrounding yellow leaf areas (YLA) of leaves with green islands of Acer campestre and A. platanoides. GLA samples of A. campestre and A. platanoides were dominated by Sawadaea polyfida and S. bicornis, respectively, suggesting that these fungi might be responsible for the green islands. We detected a higher fungal richness and diversity in CL compared to GLA samples of A. campestre. Leaf status (CL, GLA, YLA) significantly altered the composition of fungal communities of A. campestre. This was related to differences in fungal community composition between YLA and GLA samples. Site was the main driver of bacterial communities, suggesting that bacterial and fungal endophytes are shaped by different factors. Overall, we observed Acer species-specific responses of endophyte communities towards the presence of green islands and/or leaf type, which might be attributed to several fungi and bacteria specifically associated with one Acer species.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7463 ◽  
Author(s):  
Beatriz Andreo-Jimenez ◽  
Philippe Vandenkoornhuyse ◽  
Amandine Lê Van ◽  
Arvid Heutinck ◽  
Marie Duhamel ◽  
...  

Background and Aim Water is an increasingly scarce resource while some crops, such as paddy rice, require large amounts of water to maintain grain production. A better understanding of rice drought adaptation and tolerance mechanisms could help to reduce this problem. There is evidence of a possible role of root-associated fungi in drought adaptation. Here, we analyzed the endospheric fungal microbiota composition in rice and its relation to plant genotype and drought. Methods Fifteen rice genotypes (Oryza sativa ssp. indica) were grown in the field, under well-watered conditions or exposed to a drought period during flowering. The effect of genotype and treatment on the root fungal microbiota composition was analyzed by 18S ribosomal DNA high throughput sequencing. Grain yield was determined after plant maturation. Results There was a host genotype effect on the fungal community composition. Drought altered the composition of the root-associated fungal community and increased fungal biodiversity. The majority of OTUs identified belonged to the Pezizomycotina subphylum and 37 of these significantly correlated with a higher plant yield under drought, one of them being assigned to Arthrinium phaeospermum. Conclusion This study shows that both plant genotype and drought affect the root-associated fungal community in rice and that some fungi correlate with improved drought tolerance. This work opens new opportunities for basic research on the understanding of how the host affects microbiota recruitment as well as the possible use of specific fungi to improve drought tolerance in rice.


2013 ◽  
Vol 91 (10) ◽  
pp. 717-725 ◽  
Author(s):  
R.E. Feldman ◽  
B.J. McGill

One intriguing hypothesis about range limits of species along environmental gradients is that interspecific interference competition limits the activity of the better exploitation competitor. The hypothesis works if the costs of interference and (or) exploitation vary along the gradient. However, in some systems, species turnover happens over gradients that may be too short to induce changes in costs associated with competition. An example is breeding Black-chinned Hummingbirds (Archilochus alexandri (Bourcier and Mulsant, 1846)) and Broad-tailed Hummingbirds (Selasphorus platycercus (Swainson, 1827)) in western Colorado, USA, where turnover happens over ∼400 m. We recorded foraging and chasing activity of the two species at feeders and found that their foraging activity changed with elevation but interspecific competition did not. Because the foraging activity of the two species changed inversely with each other, it may be the presence of Black-chinned Hummingbirds rather than active interference that limits the activity of Broad-tailed Hummingbirds. Importantly, the relationship between foraging activity and elevation depended on the distance between the two feeders, which shows that relationships with elevation are contingent on other factors such as spatial distribution of resources. Our results suggest that interspecific differences in flight performance are not manifested over the short elevation gradient and do not account for changes in activity. Flight performance may indirectly affect patterns in breeding-season activity by influencing how species interact with other competitors during the nonbreeding season.


2008 ◽  
Vol 24 (05) ◽  
pp. 525-534 ◽  
Author(s):  
John A. Barone ◽  
John Thomlinson ◽  
Pedro Anglada Cordero ◽  
Jess K. Zimmerman

Abstract:The development of metacommunity theory, which suggests that the diversity and composition of communities is influenced by interactions with other communities, has produced new tools for evaluating patterns of community change along environmental gradients. These techniques were used to examine how plant communities changed along elevation gradients in montane tropical forests. Two transects of 0.1-ha vegetation plots were established every 50 m in elevation in the mountains of eastern Puerto Rico. The transects ranged from 300 m to 1000 m asl and 400 m to 900 m. In each plot, all free-standing woody stems greater than 1 cm in diameter at 130 cm in height were marked, measured and identified. Additional data on three similar transects were taken from the literature. The upper or lower boundaries of species ranges were significantly clumped along all five transects. Coherence, a measure of the number of gaps in species distributions, was also significant across all transects, and three transects showed significant, albeit low, nestedness. Four sites had significant species turnover. These results suggest that metacommunity techniques can be useful in searching for patterns of community change present in montane tropical forests.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Domínguez ◽  
Manuel Aira ◽  
Keith A. Crandall ◽  
Marcos Pérez-Losada

AbstractWastewater treatment plants produce hundreds of million tons of sewage sludge every year all over the world. Vermicomposting is well established worldwide and has been successful at processing sewage sludge, which can contribute to alleviate the severe environmental problems caused by its disposal. Here, we utilized 16S and ITS rRNA high-throughput sequencing to characterize bacterial and fungal community composition and structure during the gut- and cast-associated processes (GAP and CAP, respectively) of vermicomposting of sewage sludge. Bacterial and fungal communities of earthworm casts were mainly composed of microbial taxa not found in the sewage sludge; thus most of the bacterial (96%) and fungal (91%) taxa in the sewage sludge were eliminated during vermicomposting, mainly through the GAP. Upon completion of GAP and during CAP, modified microbial communities undergo a succession process leading to more diverse microbiotas than those found in sewage sludge. Consequently, bacterial and fungal community composition changed significantly during vermicomposting. Vermicomposting of sewage resulted in a stable and rich microbial community with potential biostimulant properties that may aid plant growth. Our results support the use of vermicompost derived from sewage sludge for sustainable agricultural practices, if heavy metals or other pollutants are under legislation limits or adequately treated.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 892
Author(s):  
Lingli Cui ◽  
Hamza Armghan Noushahi ◽  
Yipeng Zhang ◽  
Jinxin Liu ◽  
Andreea Cosoveanu ◽  
...  

As the population ages globally, there seem to be more people with Alzheimer’s disease. Unfortunately, there is currently no specific treatment for the disease. At present, Huperzine A (HupA) is one of the best drugs used for the treatment of Alzheimer’s disease and has been used in clinical trials for several years in China. HupA was first separated from Huperzia serrata, a traditional medicinal herb that is used to cure fever, contusions, strains, hematuria, schizophrenia, and snakebite for several hundreds of years in China, and has been confirmed to have acetylcholinesterase inhibitory activity. With the very slow growth of H. serrata, resources are becoming too scarce to meet the need for clinical treatment. Some endophytic fungal strains that produce HupA were isolated from H. serrate in previous studies. In this article, the diversity of the endophytic fungal community within H. serrata was observed and the relevance to the production of HupA by the host plant was further analyzed. A total of 1167 strains were obtained from the leaves of H. serrata followed by the stems (1045) and roots (824). The richness as well as diversity of endophytic fungi within the leaf and stem were higher than in the root. The endophytic fungal community was similar within stems as well as in leaves at all taxonomic levels. The 11 genera (Derxomyces, Lophiostoma, Cyphellophora, Devriesia, Serendipita, Kurtzmanomyces, Mycosphaerella, Conoideocrella, Brevicellicium, Piskurozyma, and Trichomerium) were positively correlated with HupA content. The correlation index of Derxomyces with HupA contents displayed the highest value (CI = 0.92), whereas Trichomerium showed the lowest value (CI = 0.02). Through electrospray ionization mass spectrometry (ESI-MS), it was confirmed that the HS7-1 strain could produce HupA and the total alkaloid concentration was 3.7 ug/g. This study will enable us to screen and isolate the strain that can produce HupA and to figure out the correlation between endophytic fungal diversity with HupA content in different plant organs. This can provide new insights into the screening of strains that can produce HupA more effectively.


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