scholarly journals Rhizosphere microbes and host plant genotype influence the plant metabolome and reduce insect herbivory

2018 ◽  
Author(s):  
Charley J. Hubbard ◽  
Baohua Li ◽  
Robby McMinn ◽  
Marcus T. Brock ◽  
Lois Maignien ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Flea Beetle ◽  
Insect Herbivory ◽  
Amplicon Sequencing ◽  
Plant Performance ◽  
Insect Herbivores ◽  
List Type ◽  
Plant Genotype ◽  
Herbivore Resistance ◽  
Rhizosphere Microbiome

SummaryRhizosphere microbes affect plant performance, including plant resistance against insect herbivores; yet, the relative influence of rhizosphere microbes vs. plant genotype on herbivory levels and on metabolites related to defense remains unclear.In Boechera stricta, we tested the effects of rhizosphere microbes and plant genotype on herbivore resistance, the primary metabolome, and select secondary metabolites.Plant populations differed significantly in the concentrations of 6 glucosinolates (GLS), secondary metabolites known to provide herbivore resistance in the Brassicaceae, and the population with lower GLS levels experienced ~60% higher levels of aphid (Aphis spp.) attack; no effect was observed of GLS on damage by a second herbivore, flea beetles (Altica spp.). Rhizosphere microbiome (intact vs. disrupted) had no effect on plant GLS concentrations. However, aphid number and flea beetle damage were respectively ~3-fold and 7-fold higher among plants grown in the disrupted rhizosphere microbiome treatment, and distinct (as estimated from 16s rRNA amplicon sequencing) intact native microbiomes also differed in their effects on herbivore damage. These differences may be attributable to shifts in primary metabolic pathways.The findings suggest that rhizosphere microbes can play a greater role than plant genotype in defense against insect herbivores, and act through mechanisms independent of plant genotype.

scholarly journals Analysis of field-grown Panax ginseng rhizosphere microbiome provides clues for preventing red skin root syndrome

2021 ◽  
Author(s):  
Xingbo Bian ◽  
Ling Dong ◽  
Yan Zhao ◽  
He Yang ◽  
Yonghua Xu ◽  
...  
Keyword(s):  
Biological Control ◽  
Ecological Niche ◽  
Interaction Network ◽  
Pathogenic Fungi ◽  
Niche Overlap ◽  
Amplicon Sequencing ◽  
Soil Improvement ◽  
Niche Separation ◽  
Key Factors ◽  
Rhizosphere Microbiome

Abstract Background Ginseng red skin root syndrome (GRS) is one of the most common ginseng diseases. It leads to a severe decline in ginseng quality and seriously affects the ginseng industry in China. However, as a root disease, the characteristics of GRS rhizosphere microbiome are still unclear. Methods The amplicon sequencing technology, combined with bioinformatics analysis, was used to explore the relationship between soil ecological environment and GRS. Results There were significant differences in the diversity and richness of soil microorganisms between the rhizosphere with different degrees of disease, especially between healthy ginseng (HG) and heavily diseased groups. We also found that bacterial communities underwent multiple changes between complex stability and simple instability in different ginseng rhizospheres through the established interaction networks. The GRS group also had more competition with each other and ecological niche separation than the HG group. The fungal community's stability decreased significantly in the early stages of the disease, followed by the formation of a stable and complex fungal community. The GRS groups significantly increased interspecies cooperation and ecological niche overlap in the fungal network than the HG group. Microbes closely related to potential pathogenic fungi were also identified according to the interaction network, which provided clues for looking for biological control agents. Finally, the Distance-based redundancy analysis (dbRDA) results indicated that total P (TP), available K (AK), available P (AP), catalase (CAT), invertase (INV) are the key factors that influence the microbial communities. Conclusions This study collectively analyzed the changing characteristics in ginseng rhizosphere and provided the basis for soil improvement and biological control of field-grown ginseng.

scholarly journals Relative and quantitative rhizosphere microbiome profiling result in distinct abundance patterns

2021 ◽  
Author(s):  
Hamed Azarbad ◽  
Julien Tremblay ◽  
Luke D. Bainard ◽  
Etienne Yergeau
Keyword(s):  
Water Stress ◽  
Relative Abundance ◽  
Its Region ◽  
Cost Effective ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Real Time Quantitative Pcr ◽  
Rhizosphere Microbiome ◽  
History Of ◽  
Almost All

AbstractNext-generation sequencing is recognized as one of the most popular and cost-effective way of characterizing microbiome in multiple samples. However, most of the currently available amplicon sequencing approaches are inherently limited, as they are often presented based on the relative abundance of microbial taxa, which may not fully represent actual microbiome profiles. Here, we combined amplicon sequencing (16S rRNA gene for bacteria and ITS region for fungi) with real-time quantitative PCR (qPCR) to characterize the rhizosphere microbiome of wheat. We show that the increase in relative abundance of major microbial phyla does not necessarily result in an increase in abundance. One striking observation when comparing relative and quantitative abundances was a substantial increase in the abundance of almost all phyla associated with the rhizosphere of plants grown in soil with no history of water stress as compared with the rhizosphere of plants growing in soil with a history of water stress, which was in contradiction with the trends observed in the relative abundance data. Our results suggest that the estimated absolute abundance approach gives a different perspective than the relative abundance approach, providing complementary information that helps to better understand the rhizosphere microbiome.

scholarly journals Insect herbivory on urban trees: Complementary effects of tree neighbours and predation

2020 ◽  
Author(s):  
Alex Stemmelen ◽  
Alain Paquette ◽  
Marie-Lise Benot ◽  
Yasmine Kadiri ◽  
Hervé Jactel ◽  
...  
Keyword(s):  
Insect Herbivory ◽  
Urban Ecosystems ◽  
Urban Environments ◽  
Tree Diversity ◽  
Urban Trees ◽  
List Type ◽  
Growth And Survival ◽  
Predator Attack ◽  
Peer Community ◽  
Survival Tree

AbstractInsect herbivory is an important component of forest ecosystems functioning and can affect tree growth and survival. Tree diversity is known to influence insect herbivory in natural forest, with most studies reporting a decrease in herbivory with increasing tree diversity. Urban ecosystems, on the other hand, differ in many ways from the forest ecosystem and the drivers of insect herbivory in cities are still debated.We monitored 48 urban trees from five species – three native and two exotic – in three parks of Montreal (Canada) for leaf insect herbivory and predator activity on artificial larvae, and linked herbivory with both predation and tree diversity in the vicinity of focal trees.Leaf insect herbivory decreased with increasing tree diversity and with increasing predator attack rate.Our findings indicate that tree diversity is a key determinant of multitrophic interactions between trees, herbivores and predators in urban environments and that managing tree diversity could contribute to pest control in cities.This article has been peer-reviewed and recommended by Peer Community in Ecologyhttps://doi.org/10.24072/pci.ecology.100061

scholarly journals Divergence in bidirectional plant-soil feedbacks between montane annual and coastal perennial ecotypes of yellow monkeyflower (Mimulus guttatus)

2020 ◽  
Author(s):  
Mariah M. McIntosh ◽  
Lorinda Bullington ◽  
Ylva Lekberg ◽  
Lila Fishman
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Plant Performance ◽  
Fungal Communities ◽  
Mechanistic Study ◽  
List Type ◽  
Mimulus Guttatus ◽  
Plant Variation ◽  
Plant Soil ◽  
Soil Origin

SUMMARYUnderstanding the physiological and genetic mechanisms underlying plant variation in interactions with root-associated biota (RAB) requires a micro-evolutionary approach. We use locally adapted montane annual and coastal perennial ecotypes of Mimulus guttatus (yellow monkeyflower) to examine population-scale differences in plant-RAB-soil feedbacks.We characterized fungal communities for the two ecotypes in-situ and used a full-factorial greenhouse experiment to investigate the effects of plant ecotype, RAB source, and soil origin on plant performance and endophytic root fungal communities.The two ecotypes harbored different fungal communities and responsiveness to soil biota was highly context-dependent. Soil origin, RAB source, and plant ecotype all affected the intensity of biotic feedbacks on plant performance. Feedbacks were primarily negative, and we saw little evidence of local adaptation to either soils or RAB. Both RAB source and soil origin significantly shaped fungal communities in roots of experimental plants. Further, the perennial ecotype was more colonized by arbuscular mycorrhizal fungi (AMF) than the montane ecotype, and preferentially recruited home AMF taxa.Our results suggest life history divergence and distinct edaphic habitats shape plant responsiveness to RAB and influence specific associations with potentially mutualistic root endophytic fungi. Our results advance the mechanistic study of intraspecific variation in plant–soil–RAB interactions.

Herbivore Resistance in Betula pendula: Effect of Fertilization, Defoliation, and Plant Genotype

Ecology ◽  
2000 ◽  
Vol 81 (1) ◽  
pp. 49 ◽  
Author(s):  
Pia Mutikainen ◽  
Mari Walls ◽  
Jari Ovaska ◽  
Markku Keinanen ◽  
Riitta Julkunen-Tiitto ◽  
...  
Keyword(s):  
Betula Pendula ◽  
Plant Genotype ◽  
Herbivore Resistance

scholarly journals Effect of UV Radiation and Salt Stress on the Accumulation of Economically Relevant Secondary Metabolites in Bell Pepper Plants

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 142 ◽  
Author(s):  
Jan Ellenberger ◽  
Nils Siefen ◽  
Priska Krefting ◽  
Jan-Bernd Schulze Lutum ◽  
Daniel Pfarr ◽  
...  
Keyword(s):  
Salt Stress ◽  
Secondary Metabolites ◽  
Negative Impact ◽  
Stress Conditions ◽  
Bell Pepper ◽  
Plant Performance ◽  
Production Cycle ◽  
Stress Effects ◽  
Leaf Level ◽  
Uv Stress

The green biomass of horticultural plants contains valuable secondary metabolites (SM), which can potentially be extracted and sold. When exposed to stress, plants accumulate higher amounts of these SMs, making the extraction and commercialization even more attractive. We evaluated the potential for accumulating the flavones cynaroside and graveobioside A in leaves of two bell pepper cultivars (Mavras and Stayer) when exposed to salt stress (100 mM NaCl), UVA/B excitation (UVA 4–5 W/m2; UVB 10–14 W/m2 for 3 h per day), or a combination of both stressors. Plant age during the trials was 32–48 days. HPLC analyses proved the enhanced accumulation of both metabolites under stress conditions. Cynaroside accumulation is effectively triggered by high-UV stress, whereas graveobioside A contents increase under salt stress. Highest contents of secondary metabolites were observed in plants exposed to combined stress. Effects of stress on overall plant performance differed significantly between treatments, with least negative impact on above ground biomass found for high-UV stressed plants. The usage of two non-destructive instruments (Dualex and Multiplex) allowed us to gain insights into the ontogenetical effects at the leaf level and temporal development of SM contents. Indices provided by those devices correlate fairly with amounts detected via HPLC (Cynaroside: r2 = 0.46–0.66; Graveobioside A: r2 = 0.51–0.71). The concentrations of both metabolites tend to decrease at leaf level during the ontogenetical development even under stress conditions. High-UV stress should be considered as a tool for enriching plant leaves with valuable SM. Effects on the performance of plants throughout a complete production cycle should be evaluated in future trials. All data is available online.

scholarly journals Influence of plant genotype and soil on the wheat rhizosphere microbiome: evidences for a core microbiome across eight African and European soils

2020 ◽  
Vol 96 (6) ◽  
Author(s):  
Marie Simonin ◽  
Cindy Dasilva ◽  
Valeria Terzi ◽  
Eddy L M Ngonkeu ◽  
Diégane Diouf ◽  
...  
Keyword(s):  
Community Structure ◽  
Agricultural Practices ◽  
Plant Genotype ◽  
Wheat Genotype ◽  
Limited Effect ◽  
Data Set ◽  
Core Microbiome ◽  
Taxa Richness ◽  
Wheat Rhizosphere ◽  
Rhizosphere Microbiome

ABSTRACT Here, we assessed the relative influence of wheat genotype, agricultural practices (conventional vs organic) and soil type on the rhizosphere microbiome. We characterized the prokaryotic (archaea and bacteria) and eukaryotic (fungi and protists) communities in soils from four different countries (Cameroon, France, Italy, Senegal) and determined if a rhizosphere core microbiome existed across these different countries. The wheat genotype had a limited effect on the rhizosphere microbiome (2% of variance) as the majority of the microbial taxa were consistently associated to multiple wheat genotypes grown in the same soil. Large differences in taxa richness and in community structure were observed between the eight soils studied (57% variance) and the two agricultural practices (10% variance). Despite these differences between soils, we observed that 177 taxa (2 archaea, 103 bacteria, 41 fungi and 31 protists) were consistently detected in the rhizosphere, constituting a core microbiome. In addition to being prevalent, these core taxa were highly abundant and collectively represented 50% of the reads in our data set. Based on these results, we identify a list of key taxa as future targets of culturomics, metagenomics and wheat synthetic microbiomes. Additionally, we show that protists are an integral part of the wheat holobiont that is currently overlooked.

scholarly journals Unraveling Arbuscular Mycorrhiza-Induced Changes in Plant Primary and Secondary Metabolome

Metabolites ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 335 ◽  
Author(s):  
Sukhmanpreet Kaur ◽  
Vidya Suseela
Keyword(s):  
Secondary Metabolites ◽  
Mycorrhizal Fungi ◽  
Tricarboxylic Acid Cycle ◽  
Abiotic Stress Tolerance ◽  
Plant Performance ◽  
Growth And Yield ◽  
Primary Metabolism ◽  
Symbiotic Association ◽  
Phytochemical Content ◽  
Primary And Secondary Metabolites

Arbuscular mycorrhizal fungi (AMF) is among the most ubiquitous plant mutualists that enhance plant growth and yield by facilitating the uptake of phosphorus and water. The countless interactions that occur in the rhizosphere between plants and its AMF symbionts are mediated through the plant and fungal metabolites that ensure partner recognition, colonization, and establishment of the symbiotic association. The colonization and establishment of AMF reprogram the metabolic pathways of plants, resulting in changes in the primary and secondary metabolites, which is the focus of this review. During initial colonization, plant–AMF interaction is facilitated through the regulation of signaling and carotenoid pathways. After the establishment, the AMF symbiotic association influences the primary metabolism of the plant, thus facilitating the sharing of photosynthates with the AMF. The carbon supply to AMF leads to the transport of a significant amount of sugars to the roots, and also alters the tricarboxylic acid cycle. Apart from the nutrient exchange, the AMF imparts abiotic stress tolerance in host plants by increasing the abundance of several primary metabolites. Although AMF initially suppresses the defense response of the host, it later primes the host for better defense against biotic and abiotic stresses by reprogramming the biosynthesis of secondary metabolites. Additionally, the influence of AMF on signaling pathways translates to enhanced phytochemical content through the upregulation of the phenylpropanoid pathway, which improves the quality of the plant products. These phytometabolome changes induced by plant–AMF interaction depends on the identity of both plant and AMF species, which could contribute to the differential outcome of this symbiotic association. A better understanding of the phytochemical landscape shaped by plant–AMF interactions would enable us to harness this symbiotic association to enhance plant performance, particularly under non-optimal growing conditions.

scholarly journals Effects of Actinomycete Secondary Metabolites on Sediment Microbial Communities

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Nastassia V. Patin ◽  
Michelle Schorn ◽  
Kristen Aguinaldo ◽  
Tommie Lincecum ◽  
Bradley S. Moore ◽  
...  
Keyword(s):  
Microbial Community ◽  
Secondary Metabolites ◽  
Microbial Communities ◽  
Community Composition ◽  
Marine Sediments ◽  
Microbial Community Composition ◽  
Amplicon Sequencing ◽  
Next Generation ◽  
Content Type ◽  
Predatory Bacteria

ABSTRACT Marine sediments harbor complex microbial communities that remain poorly studied relative to other biomes such as seawater. Moreover, bacteria in these communities produce antibiotics and other bioactive secondary metabolites, yet little is known about how these compounds affect microbial community structure. In this study, we used next-generation amplicon sequencing to assess native microbial community composition in shallow tropical marine sediments. The results revealed complex communities comprised of largely uncultured taxa, with considerable spatial heterogeneity and known antibiotic producers comprising only a small fraction of the total diversity. Organic extracts from cultured strains of the sediment-dwelling actinomycete genus Salinispora were then used in mesocosm studies to address how secondary metabolites shape sediment community composition. We identified predatory bacteria and other taxa that were consistently reduced in the extract-treated mesocosms, suggesting that they may be the targets of allelopathic interactions. We tested related taxa for extract sensitivity and found general agreement with the culture-independent results. Conversely, several taxa were enriched in the extract-treated mesocosms, suggesting that some bacteria benefited from the interactions. The results provide evidence that bacterial secondary metabolites can have complex and significant effects on sediment microbial communities. IMPORTANCE Ocean sediments represent one of Earth's largest and most poorly studied biomes. These habitats are characterized by complex microbial communities where competition for space and nutrients can be intense. This study addressed the hypothesis that secondary metabolites produced by the sediment-inhabiting actinomycete Salinispora arenicola affect community composition and thus mediate interactions among competing microbes. Next-generation amplicon sequencing of mesocosm experiments revealed complex communities that shifted following exposure to S. arenicola extracts. The results reveal that certain predatory bacteria were consistently less abundant following exposure to extracts, suggesting that microbial metabolites mediate competitive interactions. Other taxa increased in relative abundance, suggesting a benefit from the extracts themselves or the resulting changes in the community. This study takes a first step toward assessing the impacts of bacterial metabolites on sediment microbial communities. The results provide insight into how low-abundance organisms may help structure microbial communities in ocean sediments.

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