Plant-Microbe Symbiosis
256.1K views | +190 today
Plant-Microbe Symbiosis
Beneficial associations between plants and microbes
Your new post is loading...
Your new post is loading...
Scooped by Jean-Michel Ané
Scoop.it!

Deciphering the Omics of Plant-Microbe Interaction: Perspectives and New Insights

Deciphering the Omics of Plant-Microbe Interaction: Perspectives and New Insights | Plant-Microbe Symbiosis | Scoop.it
Introduction: Plants do not grow in isolation, rather they are hosts to a variety of microbes in their natural environments. While, few thrive in the plants for their own benefit, others may have a direct impact on plants in a symbiotic manner. Unraveling plant-microbe interactions is a critical component in recognizing the positive and negative impacts of microbes on plants. Also, by affecting the environment around plants, microbes may indirectly influence plants. The progress in sequencing technologies in the genomics era and several omics tools has accelerated in biological science. Studying the complex nature of plant-microbe interactions can offer several strategies to increase the productivity of plants in an environmentally friendly manner by providing better insights. This review brings forward the recent works performed in building omics strategies that decipher the interactions between plant-microbiome. At the same time, it further explores other associated mutually beneficial aspects of plant-microbe interactions such as plant growth promotion, nitrogen fixation, stress suppressions in crops and bioremediation; as well as provides better insights on metabolic interactions between microbes and plants through omics approaches. It also aims to explore advances in the study of Arabidopsis as an important avenue to serve as a baseline tool to create models that help in scrutinizing various factors that contribute to the elaborate relationship between plants and microbes. Causal relationships between plants and microbes can be established through systematic gnotobiotic experimental studies to test hypotheses on biologically derived interactions.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

The Fungal Endophyte Serendipita williamsii Does Not Affect Phosphorus Status but Carbon and Nitrogen Dynamics in Arbuscular Mycorrhizal Tomato Plants

Some members of the root endophytic Serendipitaceae were observed to frequently coexist with arbuscular mycorrhizal fungi (AMF), but their interactions and potential synergistic effects in plants have not yet been well elucidated. Here, we inoculated three-week-old tomato seedlings with Serendipita indica or Serendipita williamsii alone or in combination with the arbuscular mycorrhizal fungus Funneliformis mosseae and cultivated the plants in a greenhouse until the late vegetative stage. Our data show that the simultaneous presence of Serendipita spp. did not affect root colonization by AMF, proving the feasibility of their combination for future agronomic uses. The photosynthetic performance was enhanced in AM tomato plants, although growth remained unresponsive following single or dual inoculation with Serendipita spp. and AMF. With regard to nutrient status under dual inoculation, AMF-induced phosphorus increases remained unaffected, but nitrogen and carbon dynamics were highly altered. Specifically, the application of S. williamsii to mycorrhizal tomato plants significantly enhanced nitrogen concentration in the shoots, but this effect was also compensated with a carbon cost. Our findings indicate that S. williamsii performs differently from S. indica when co-inoculated with AMF, and this suggests an unknown mechanism that needs more detailed investigation.
No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Associative nitrogen fixation linked with three perennial bioenergy grasses in field and greenhouse experiments

Associative nitrogen fixation linked with three perennial bioenergy grasses in field and greenhouse experiments | Plant-Microbe Symbiosis | Scoop.it
Associative nitrogen (N2)‐fixation (ANF) by bacteria in the root‐zone of perennial bioenergy grasses has the potential to replace or supplement N fertilizer and support sustainable production of biomass, but its application in marginal ecosystems requires further evaluation. In this study, we first combined both greenhouse and field experiments, to explore the N2 fixation effects of three temperate feedstocks Miscanthus × giganteus (giant miscanthus, Freedom), Panicum virgatum (switchgrass, Alamo), and Saccharum sp. (energycane, Ho 02‐147). In field studies across three growing seasons, plant and soil pools of candidate feedstocks were partially composed of N derived from the atmosphere (Ndfa). Energycane, giant miscanthus, and switchgrass were estimated to derive >30%, %Ndfa. Greenhouse studies were also performed to trace isotopically labeled 15N2 into plant biomass and soil pools. Evidence for Ndfa was detected in all three feedstock grasses (using reference 15N of soil, chicory, and sorghum, δ15N~+7.0). Isotopically labeled 15N2 was traced into biomass (during grass elongation stage) and soil pools. Extrapolation of rates during the 24 hr labeling period to 50 days estimated 30%–55% of plant Ndfa, with the greatest Ndfa for energycane. The findings of the field natural abundance and greenhouse 15N2 feeding experiments provided complementary evidence that perennial bioenergy grasses have the potential to support relatively high rates of ANF, and accumulate diazotroph‐derived N into biomass when grown on non‐fertilized soil.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Inoculation of arbuscular mycorrhizal fungi increases lettuce yield without altering natural soil communities

Inoculation of arbuscular mycorrhizal fungi increases lettuce yield without altering natural soil communities | Plant-Microbe Symbiosis | Scoop.it
Agricultural practices may lead to a decline in the presence and abundance of natural arbuscular mycorrhizal fungi (AMF). AMF inoculation can be an environmentally-friendly alternative or complement to chemical fertilizers in agriculture. Initially, through ribosomal DNA internal transcribed spacer (ITS) metabarcoding, we characterized the composition of fungal communities from three organic orchard soils, as well as from three adjacent non-cultivated soils. Organic orchard management had a negative impact on AMF community, leading to reduced alpha diversity and relative abundance of AMF taxa, compared to non-cultivated soil (e.g., 10 vs. 11 in richness and 2.1 vs. 2.6 in Shannon index). Using trap plants, we multiplied the AMF communities from the abovementioned orchard and non-cultivated soils. Afterwards, a microcosm experiment was carried out to study the effect of inoculation with these AMF communities on (i) lettuce (Lactuca sativa L.) yield and nutritional quality (two consecutive crops), and (ii) root fungal communities. During the second crop cycle, AMF inoculants led to higher lettuce yields (by an average of 186%, irrespective of the origin of the inoculum), but resulted in no substantial modification of lettuce nutritional quality. Moreover, AMF inoculants did not exert a significant effect on fungal (including AMF) or AMF communities.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Bradyrhizobium japonicum , B. elkanii and B. diazoefficiens Interact with Rice ( Oryza sativa ), Promote Growth and Increase Yield

Bradyrhizobium japonicum , B. elkanii and B. diazoefficiens Interact with Rice ( Oryza sativa ), Promote Growth and Increase Yield | Plant-Microbe Symbiosis | Scoop.it
Bradyrhizobium is a genus of plant growth-promoting rhizobacteria (PGPR) that have been studied for several decades mainly for the ability to fix diazotrophic nitrogen after having been established endosymbiotically inside root nodules of the legumes of Fabaceae. The aim of this work was to evaluate the capability of Bradyrhizobium to promote the growth of crops belonging to other families, in this case, rice (Oryza sativa), both in laboratory and in field trials. For laboratory test, surface-sterilized rice seeds were soaked with cultures of each strain and planted in pots. Plant length and dry weight were measured after 35 days. For the field test, rice seeds of varieties Yeruá La Plata and Gurí INTA were inoculated with the three best strains observed in the laboratory test and planted in plots. After 60 days of growth, plant length and dry weight were measured. At harvest time, we measured the dry weight of the aerial part, yield and thousand-grain weight. Inoculation with any of the three species described provoked significant increments compared to the uninoculated control at least in one of the parameters measured, both in the laboratory and in the field tests. Bradyrhizobium japonicum E109 was the strain that promoted rice growth the most in the lab while Bradyrhizobium elkanii SEMIA 587 was the strain that promoted rice growth the most in the field, with increments in yield of approximately 1000 kg/ha. Data obtained suggest that the Bradyrhizobium species promoted all rice growth and yield.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Identity and provenance of neighbors, genotype-specific traits and abiotic stress affect intraspecific interactions in the annual legume Medicago truncatula

Accounting for intraspecific variation may improve our understanding of species coexistence. However, our knowledge of what factors maintain intraspecific variation is limited. We predicted that 1) a plant grows larger when with non-kin (i.e. different genotypes) than kin (i.e. same genotype) neighbors, 2) abiotic stress alters the outcome of kin vs. non-kin interactions, 3) genetic identity of plants affects composition of soil microbiome. We set up mini-communities of Medicago truncatula, where focal genotypes were grown together with two kin or two non-kin neighbors from different origins. We analyzed how origin, identity of interacting genotypes and abiotic stress affected growth and fruit production. We also analyzed the composition of soil microbial communities. Focal plants grew larger in non-kin than in kin mini-communities. This pattern was stronger in low level of abiotic stress and when interacting genotypes were from similar origins. However, genotypic variation in growth and response to competition had a stronger effect on growth than mini-community type. Plant genotype identity did not affect soil microbiome. We find that intraspecific variation is affected by genotype-specific traits and abiotic stress. Geographic, rather than genetic, distance among interacting genotypes affects the outcome of intraspecific interactions.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Bio-Fertilizers Market is anticipated to exceed USD 3.27 billion by 2030

Bio-Fertilizers Market is anticipated to exceed USD 3.27 billion by 2030 | Plant-Microbe Symbiosis | Scoop.it
Sep 28, 2020 - Bio-Fertilizers Market is anticipated to exceed USD 3.27 billion by 2030 from USD 1.65 billion in 2019 at a CAGR of 12.94% throughout the forecast period, i.e., 2020-30...
No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

10 Tips to Solve Nutrient Deficiencies in Your Marijuana Plants

10 Tips to Solve Nutrient Deficiencies in Your Marijuana Plants | Plant-Microbe Symbiosis | Scoop.it
When it comes to the health of cannabis, the importance of nutrients cannot be overemphasized. The inadequate supply of nutrients leads to deficiency...
Jean-Michel Anés insight:

No... mycorrhizae are not nitrogen-fixing bacteria! 

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Evo-devo as a discovery tool

Evo-devo as a discovery tool | Plant-Microbe Symbiosis | Scoop.it
Plantae Presents – Evo-devo. What can we learn from comparative studies?Wednesday October 28 (10 am EDT, 2 pm GMT – note that on this date the clocks in Europe…...
No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Experimental evolution makes microbes more cooperative with their local host genotype

Experimental evolution makes microbes more cooperative with their local host genotype | Plant-Microbe Symbiosis | Scoop.it
Advances in microbiome science require a better understanding of how beneficial microbes adapt to hosts. We tested whether hosts select for more-cooperative microbial strains with a year-long evolution experiment and a cross-inoculation experiment designed to explore how nitrogen-fixing bacteria (rhizobia) adapt to legumes. We paired the bacterium Ensifer meliloti with one of five Medicago truncatula genotypes that vary in how strongly they “choose” bacterial symbionts. Independent of host choice, E. meliloti rapidly adapted to its local host genotype, and derived microbes were more beneficial when they shared evolutionary history with their host. This local adaptation was mostly limited to the symbiosis plasmids, with mutations in putative signaling genes. Thus, cooperation depends on the match between partner genotypes and increases as bacteria adapt to their local host.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Maize Endophytic Bacterial Diversity as Affected by Soil Cultivation History

Maize Endophytic Bacterial Diversity as Affected by Soil Cultivation History | Plant-Microbe Symbiosis | Scoop.it
The bacterial endophytic communities residing within roots of maize (Zea mays L.) plants cultivated by a sustainable management in soils from the Quechua maize belt (Peruvian Andes) were examined using tags pyrosequencing spanning the V4 and V5 hypervariable regions of the 16S rRNA. Across four replicate libraries, two corresponding to sequences of endophytic bacteria from long time maize-cultivated soils and the other two obtained from fallow soils, 793 bacterial sequences were found that grouped into 188 bacterial operational taxonomic units (OTUs, 97% genetic similarity). The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from fallow soils. A mean of 30 genera were found in the fallow soil libraries and 47 were in those from the maize-cultivated soils. Both alpha and beta diversity indexes showed clear differences between bacterial endophytic populations from plants with different soil cultivation history and that the soils cultivated for long time requires a higher diversity of endophytes. The number of sequences corresponding to main genera Sphingomonas, Herbaspirillum, Bradyrhizobium and Methylophilus in the maize-cultivated libraries were statistically more abundant than those from the fallow soils. Sequences of genera Dyella and Sreptococcus were significantly more abundant in the libraries from the fallow soils. Relative abundance of genera Burkholderia, candidatus Glomeribacter, Staphylococcus, Variovorax, Bacillus and Chitinophaga were similar among libraries. A canonical correspondence analysis of the relative abundance of the main genera showed that the four libraries distributed in two clearly separated groups. Our results suggest that cultivation history is an important driver of endophytic colonization of maize and that after a long time of cultivation of the soil the maize plants need to increase the richness of the bacterial endophytes communities.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Characterisation of Medicago truncatula CLE34 and CLE35 in nitrate and rhizobia regulation of nodulation

Legumes form a symbiosis with N2‐fixing soil rhizobia, resulting in new root organs called nodules that enable N2‐fixation. Nodulation is a costly process that is tightly regulated by the host through Autoregulation of Nodulation (AON) and nitrate‐dependent regulation of nodulation. Both pathways require legume‐specific CLAVATA/ESR‐related (CLE) peptides.
Nitrogen‐induced nodulation‐suppressing CLE peptides have not previously been investigated in Medicago truncatula, with only rhizobia‐induced MtCLE12 and MtCLE13 characterised. Here, we report on novel peptides MtCLE34 and MtCLE35 in nodulation control.
The nodulation‐suppressing CLE peptides of five legume species were classified into three clades based on sequence homology and phylogeny. This approached identified MtCLE34 and MtCLE35 and four new CLE peptide orthologues of Pisum sativum. Whereas MtCLE12 and MtCLE13 are induced by rhizobia, MtCLE34 and MtCLE35 respond to both rhizobia and nitrate. MtCLE34 was identified as a pseudogene lacking a functional CLE‐domain. MtCLE35 was found to inhibit nodulation in a SUNN‐ and RDN1‐dependent manner via overexpression analysis.
Together, our findings indicate that MtCLE12 and MtCLE13 have a specific role in AON, while MtCLE35 regulates nodule numbers in response to both rhizobia and nitrate. MtCLE34 likely had a similar role to MtCLE35 but its function was lost due to a premature nonsense mutation.
Jean-Michel Anés insight:

Nice and clean

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Tyrosine nitration of flagellins: a response of Sinorhizobium meliloti to nitrosative stress

Rhizobia are bacteria which can either live as free organisms in the soil or interact with plants of the legume family with, as a result, the formation of root organs called nodules in which differentiated endosymbiotic bacteria fix atmospheric nitrogen to the plant's benefit. In both lifestyles, rhizobia are exposed to nitric oxide (NO) which can be perceived as a signaling or toxic molecule. NO can act at the transcriptional level but can also modify proteins by S-nitrosylation of cysteine or nitration of tyrosine residues. However, only few molecular targets of NO have been described in bacteria and none of them have been characterized in rhizobia. Here we examined tyrosine nitration of Sinorhizobium meliloti proteins induced by NO. We found three tyrosine nitrated proteins in S. meliloti grown in free-living conditions, in response to an NO donor. Two nitroproteins were identified by mass spectrometry and correspond to flagellins A and B. We showed that one of the nitratable tyrosines is essential to flagellin function in motility.

Jean-Michel Anés insight:

Nice work!

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Unravelling the Role of Rhizospheric Plant-Microbe Synergy in Phytoremediation: A Genomic Perspective

Unravelling the Role of Rhizospheric Plant-Microbe Synergy in Phytoremediation: A Genomic Perspective | Plant-Microbe Symbiosis | Scoop.it
Background: Accretion of organic and inorganic contaminants in soil interferes in the food chain, thereby posing a serious threat to the ecosystem and adversely affecting crop productivity and human life. Both endophytic and rhizospheric microbial communities are responsible for the biodegradation of toxic organic compounds and have the capability to enhance the uptake of heavy metals by plants via phytoremediation approaches. The diverse set of metabolic genes encoding for the production of biosurfactants and biofilms, specific enzymes for degrading plant polymers, modification of cell surface hydrophobicity and various detoxification pathways for the organic pollutants, plays a significant role in bacterial driven bioremediation. Various genetic engineering approaches have been demonstrated to modulate the activity of specific microbial species in order to enhance their detoxification potential. Certain rhizospheric bacterial communities are genetically modified to produce specific enzymes that play a role in degrading toxic pollutants. Few studies suggest that the overexpression of extracellular enzymes secreted by plant, fungi or rhizospheric microbes can improve the degradation of specific organic pollutants in the soil. Plants and microbes dwell synergistically, where microbes draw benefit by nutrient acquisition from root exudates whereas they assist in plant growth and survival by producing certain plant growth promoting metabolites, nitrogen fixation, phosphate solubilization, auxin production, siderophore production, and inhibition or suppression of plant pathogens. Thus, the plant-microbe interaction establishes the foundation of the soil nutrient cycle as well as decreases soil toxicity by the removal of harmful pollutants.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Microbial interventions are an easier alternative to engineer higher organisms

Microbial interventions are an easier alternative to engineer higher organisms | Plant-Microbe Symbiosis | Scoop.it
Advances in synthetic biology have made microbes easier to engineer than ever before. However, synthetic biology in animals and plants has lagged behind. Since it is now known that the phenotype of higher organisms depends largely on their microbiota, we propose that this is an easier route to achieving synthetic biology applications in these organisms.

Jean-Michel Anés insight:

I agree that microbial engineering is faster but there is also value in engineering host plants. We need BOTH approaches.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Bacterial Community Members Increase Bacillus subtilis Maintenance on the Roots of Arabidopsis thaliana

Bacterial Community Members Increase Bacillus subtilis Maintenance on the Roots of Arabidopsis thaliana | Plant-Microbe Symbiosis | Scoop.it
Plant-growth-promoting bacteria (PGPB) are used to improve plant health and promote crop production. However, because some PGPB (including Bacillus subtilis) do not maintain substantial colonization on plant roots over time, it is unclear how effective PGPB are throughout the plant growing cycle. A better understanding of the dynamics of plant root community assembly is needed to develop and harness the potential of PGPB. Although B. subtilis is often a member of the root microbiome, it does not efficiently monoassociate with plant roots. We hypothesized that B. subtilis may require other primary colonizers to efficiently associate with plant roots. We utilized a previously designed hydroponic system to add bacteria to Arabidopsis thaliana roots and monitor their attachment over time. We inoculated seedlings with B. subtilis and individual bacterial isolates from the native A. thaliana root microbiome either alone or together. We then measured how the coinoculum affected the ability of B. subtilis to colonize and maintain on A. thaliana roots. We screened 96 fully genome-sequenced strains and identified five bacterial strains that were able to significantly improve the maintenance of B. subtilis. Three of these rhizobacteria also increased the maintenance of two strains of B. amyloliquefaciens commonly used in commercially available bioadditives. These results not only illustrate the utility of this model system to address questions about plant–microbe interactions and how other bacteria affect the ability of PGPB to maintain their relationships with plant roots but also may help inform future agricultural interventions to increase crop yields.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

The quantity of nitrogen derived from symbiotic N fixation but not the relative contribution of N fixation to total N uptake increased with breeding for greater soybean yields

The quantity of nitrogen derived from symbiotic N fixation but not the relative contribution of N fixation to total N uptake increased with breeding for greater soybean yields | Plant-Microbe Symbiosis | Scoop.it
Long-term soybean [Glycine max (L) Merr.] breeding for yield has increased plant nitrogen (N) demands. On one hand, because N fertilizer application in soybean production systems continues to be insignificant, increased plant N demands over time may have been satisfied from greater biological N fixation (BNF). On the other hand, increased soil residual N over time may have affected the sensitivity of nodulation and BNF. To understand the impact of breeding for greater yield and the effect of soil residual N on nodulation and BNF, two field and a greenhouse study were conducted. Field studies were conducted with maturity group IV soybean cultivars released from 1930 to 2005 and included experiments in four environments. Total shoot N and N from BNF increased with cultivar year of release in two of the four environments. Simulation of different levels of residual soil mineral N by application of 0, 34, 67, and 101 kg N ha−1 shortly after planting resulted in linear increases in shoot N content and δ15N, and linear decreases in nodule number and nodule dry matter in the field. Consistent with these results, fertigation of greenhouse-grown soybean cultivars with different levels of NH4NO3 led to a reduction in nodule number, dry matter, and size. Overall, results from these studies indicate that increases in seed yields with cultivar year of release were associated with greater amounts of N derived from BNF as well as greater total shoot N accumulation, but the relative contribution of BNF to total shoot N did not change over time. Analysis also suggest that the sensitivity of nodulation and BNF to soil mineral N has not been altered over the course of soybean breeding.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Role of plant growth-promoting bacteria in sustainable agriculture

Role of plant growth-promoting bacteria in sustainable agriculture | Plant-Microbe Symbiosis | Scoop.it
The requirement for chemical fertilizers is expected to increase to 200 million tonnes by the year 2022. Increased dependence of farmers on chemical formulations has strengthened agronomic production but has also increased environmental pollution and put the ecosystem stability at higher risk worldwide. Climatic changes have further aggravated the situation by an increase in the frequency of abiotic stresses. However, only 50% of the total habitable land is available for agricultural purposes and there is an urgent need to maintain its fertility and stability. Therefore, improved crop productivity and enhanced food security with a reduced or negligible application of chemical fertilizers and pesticides have become a major test these days. Plant growth-promoting rhizobacteria (PGPR) are at the forefront of sustainable agricultural practices. They are a secure and favorable alternative to chemical fertilizers as well as a useful option to decrease stress conditions. Many bacterial species act as PGPRs and have visibly improved plant growth, health, and productivity. This review emphasizes the role of PGPRs in sustainable agriculture, underlying mechanisms involved in growth promotion, and the exploitation of these rhizobacteria under different stress conditions.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

The Impacts of Domestication and Agricultural Practices on Legume Nutrient Acquisition Through Symbiosis With Rhizobia and Arbuscular Mycorrhizal Fungi

The Impacts of Domestication and Agricultural Practices on Legume Nutrient Acquisition Through Symbiosis With Rhizobia and Arbuscular Mycorrhizal Fungi | Plant-Microbe Symbiosis | Scoop.it
Legumes are unique among plants as they can obtain nitrogen through symbiosis with nitrogen-fixing rhizobia that form root nodules in the host plants. Therefore they are valuable crops for sustainable agriculture. Increasing nitrogen fixation efficiency is not only important for achieving better plant growth and yield, but it is also crucial for reducing the use of nitrogen fertilizer. Arbuscular mycorrhizal fungi (AMF) are another group of important beneficial microorganisms that form symbiotic relationships with legumes. AMF can promote host plant growth by providing mineral nutrients and improving the soil ecosystem. The trilateral legume-rhizobia-AMF symbiotic relationships also enhance plant development and tolerance against biotic and abiotic stresses. It is known that domestication and agricultural activities have led to the reduced genetic diversity of cultivated germplasms and higher sensitivity to nutrient deficiencies in crop plants, but how domestication has impacted the capability of legumes to establish beneficial associations with rhizospheric microbes (including rhizobia and fungi) is not well-studied. In this review, we will discuss the impacts of domestication and agricultural practices on the interactions between legumes and soil microbes, focusing on the effects on AMF and rhizobial symbioses and hence nutrient acquisition by host legumes. In addition, we will summarize the genes involved in legume-microbe interactions and studies that have contributed to a better understanding of legume symbiotic associations using metabolic modeling.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Arbuscular Mycorrhizas Regulate Photosynthetic Capacity and Antioxidant Defense Systems to Mediate Salt Tolerance in Maize

Arbuscular Mycorrhizas Regulate Photosynthetic Capacity and Antioxidant Defense Systems to Mediate Salt Tolerance in Maize | Plant-Microbe Symbiosis | Scoop.it
Salt stress inhibits photosynthetic process and triggers excessive formation of reactive oxygen species (ROS). This study examined the role of arbuscular mycorrhizal (AM) association in regulating photosynthetic capacity and antioxidant activity in leaves of two maize genotypes (salt-tolerant JD52 and salt-sensitive FSY1) exposed to salt stress (100 mM NaCl) in soils for 21 days. The leaf water content, chlorophyll content, and photosynthetic capacity in non-mycorrhizal (NM) plants were decreased by salt stress, especially in FSY1, with less reduction in AM plants than NM plants. Salinity increased the activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR)) in both genotypes regardless of AM inoculation, but decreased the contents of non-enzymatic antioxidants (reduced glutathione (GSH) and ascorbate (AsA)), especially in FSY1, with less decrease in AM plants than NM plants. The AM plants, especially JD52, maintained higher photosynthetic capacity, CO2 fixation efficiency, and ability to preserve membrane integrity than NM plants under salt stress, as also indicated by the higher antioxidant contents and lower malondialdehyde (MDA)/electrolyte leakage in leaves. To conclude, the higher salt tolerance in AM plants correlates with the alleviation of salinity-induced oxidative stress and membrane damage, and the better performance of photosynthesis could have also contributed to this effect through reduced ROS formation. The greater improvements in photosynthetic processes and antioxidant defense systems by AM fungi in FSY1 than JD52 under salinity demonstrate genotypic variation in antioxidant defenses for mycorrhizal amelioration of salt stress. View Full-Text
No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Impact of Nitrogen (N) Supply on N Fixation in Soybean Systems

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Review: Coumarin communication along the microbiome-root-shoot axis

Review: Coumarin communication along the microbiome-root-shoot axis | Plant-Microbe Symbiosis | Scoop.it
As the realm of microbiology expands, we see increasing ways in which eukaryotes depend on their microbiomes.For instance, in animals, the “microbiome-gut…...
No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

An immune receptor complex evolved in soybean to perceive a polymorphic bacterial flagellin

An immune receptor complex evolved in soybean to perceive a polymorphic bacterial flagellin | Plant-Microbe Symbiosis | Scoop.it
In both animals and plants, the perception of bacterial flagella by immune receptors elicits the activation of defence responses. Most plants are able to perceive the highly conserved epitope flg22 from flagellin, the main flagellar protein, from most bacterial species. However, flagellin from Ralstonia solanacearum, the causal agent of the bacterial wilt disease, presents a polymorphic flg22 sequence (flg22Rso) that avoids perception by all plants studied to date. In this work, we show that soybean has developed polymorphic versions of the flg22 receptors that are able to perceive flg22Rso. Furthermore, we identify key residues responsible for both the evasion of perception by flg22Rso in Arabidopsis and the gain of perception by the soybean receptors. Heterologous expression of the soybean flg22 receptors in susceptible plant species, such as tomato, enhances resistance to bacterial wilt disease, demonstrating the potential of these receptors to enhance disease resistance in crop plants.

Jean-Michel Anés insight:

So cool... @AlbertoPMacho

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

Identifying Genes Related to Symbiotic Nitrogen Fixation in Medicago Truncatula Tnt1 Insertion Mutants Using a Forward Genetics Approach

Nitrogen is an essential nutrient required by all plants. Although the earth’s atmosphere consists of approximately 78% nitrogen, it exists in an unusable form for plants. Current agricultural practices rely on industrial nitrogen fixation to produce fertilizers that improve crop productivity. However, this method requires the use of precious natural resources and can cause a variety of negative impacts on the environment and human health. Biologically fixed nitrogen is a favorable alternative accessible to leguminous plants through their symbiotic relationship with soil bacteria called rhizobia. Genetic studies aimed at identifying plant genes related to successful nodulation and nitrogen fixation are underway to help better understand this infection process and improve the performance of legumes in agriculture. To date, over 21,000 Tnt1 mutant lines of Medicago truncatula, a model legume used for genetic research, have been created. Several lines displaying defects in symbiotic nitrogen fixation (SNF) have been identified and are referred to as Fix- mutants. In this research, segregation analysis of the Fix- mutant NF18598 indicated loss of SNF function could be governed by a dominant mutation. A total of 114 Tnt1 insertions were identified in the NF18598 genome using three different sequencing methods. Tnt1-capture sequencing (SC) found the largest number of insertions (70) while the other two methods, thermal asymmetric interlaced PCR (TAIL-PCR) and whole genome sequencing (WGS), found a similar number of insertions (40 and 41, respectively). It was found that 50% of the insertions were located in coding regions. One of the Tnt1 insertions located on chromosome 5 is found within the exon of a phosphatase 2C family protein gene (Medtr5g009370) and is upregulated in nodules. While there was a significant SNF association with Medtr5g009370 in the R1 generation, this association was not detected in the R2 generation. Light microscopy analysis of nodules displayed clear differences between mutant samples identified as either Fix+ or Fix-. The Fix- mutant nodules displayed some cellular organization but distinct developmental zones could not be identified. Infection threads were observed in Fix- nodules that appeared to contain bacteria that had not been released; however, further microscopy analysis must be conducted to verify the presence of rhizobia. In addition, further research involving a larger sample population would help verify if the insertion located in Medtr5g009370 is responsible for the defective nodule phenotype observed and if the phosphatase gene is involved in symbiotic nitrogen fixation.

No comment yet.
Scooped by Jean-Michel Ané
Scoop.it!

MIR2111-5 locus and shoot-accumulated mature miR2111 systemically enhance nodulation depending on HAR1 in Lotus japonicus

MIR2111-5 locus and shoot-accumulated mature miR2111 systemically enhance nodulation depending on HAR1 in Lotus japonicus | Plant-Microbe Symbiosis | Scoop.it
Legumes utilize a shoot-mediated signaling system to maintain a mutualistic relationship with nitrogen-fixing bacteria in root nodules. In Lotus japonicus, shoot-to-root transfer of microRNA miR2111 that targets TOO MUCH LOVE, a nodulation suppressor in roots, has been proposed to explain the mechanism underlying nodulation control from shoots. However, the role of shoot-accumulating miR2111s for the systemic regulation of nodulation was not clearly shown. Here, we find L. japonicus has seven miR2111 loci, including those mapped through RNA-seq. MIR2111-5 expression in leaves is the highest among miR2111 loci and repressed after rhizobial infection depending on a shoot-acting HYPERNODULATION ABERRANT ROOT FORMATION1 (HAR1) receptor. MIR2111-5 knockout mutants show significantly decreased nodule numbers and miR2111 levels. Furthermore, grafting experiments using transformants demonstrate scions with altered miR2111 levels influence nodule numbers in rootstocks in a dose-dependent manner. Therefore, miR2111 accumulation in leaves through MIR2111-5 expression is required for HAR1-dependent systemic optimization of nodule number.

Jean-Michel Anés insight:

Great paper

No comment yet.