scholarly journals Opprimo ergo sum—Evasion and Suppression in the Root Endophytic Fungus Piriformospora indica

2012 ◽  
Vol 25 (6) ◽  
pp. 727-737 ◽  
Author(s):  
Urs Lahrmann ◽  
Alga Zuccaro
Keyword(s):  
Endophytic Fungus ◽  
Large Scale ◽  
Growth Promotion ◽  
Plant Root ◽  
Hydrolytic Enzymes ◽  
Piriformospora Indica ◽  
Host Cells ◽  
Suitable Model ◽  
Beneficial Effects ◽  
Small Proteins

The genetically tractable endophytic fungus Piriformospora indica is able to colonize the root cortex of a great variety of different plant species with beneficial effects to its hosts, and it represents a suitable model system to study symbiotic interactions. Recent cytological studies in barley and Arabidopsis showed that, upon penetration of the root, P. indica establishes a biotrophic interaction during which fungal cells are encased by the host plasma membrane. Large-scale transcriptional analyses of fungal and plant responses have shown that perturbance of plant hormone homeostasis and secretion of fungal lectins and other small proteins (effectors) may be involved in the evasion and suppression of host defenses at these early colonization steps. At later stages, P. indica is found more often in moribund host cells where it secretes a large variety of hydrolytic enzymes that degrade proteins. This strategy of colonizing plants is reminiscent of that of hemibiotrophic fungi, although a defined shift to necrotrophy with massive host cell death is missing. Instead, the association with the plant root leads to beneficial effects for the host such as growth promotion, increased resistance to root as well as leaf pathogens, and increased tolerance to abiotic stresses. This review describes current advances in understanding the components of the P. indica endophytic lifestyle from molecular and genomic analyses.

scholarly journals Growth Promotion-Related miRNAs in Oncidium Orchid Roots Colonized by the Endophytic Fungus Piriformospora indica

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e84920 ◽  
Author(s):  
Wei Ye ◽  
Chin-Hui Shen ◽  
Yuling Lin ◽  
Peng-Jen Chen ◽  
Xuming Xu ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Growth Promotion ◽  
Piriformospora Indica

scholarly journals The Distribution of Tryptophan-Dependent Indole-3-Acetic Acid Synthesis Pathways in Bacteria Unraveled by Large-Scale Genomic Analysis

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1411 ◽  
Author(s):  
Pengfan Zhang ◽  
Tao Jin ◽  
Sunil Kumar Sahu ◽  
Jin Xu ◽  
Qiong Shi ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Large Scale ◽  
Growth Promotion ◽  
Plant Root ◽  
Genomic Analysis ◽  
Acid Synthesis ◽  
Metagenomic Data ◽  
Bacterial Genomes ◽  
Bacterial Phyla ◽  
Indole 3 Acetic Acid

Bacterial indole-3-acetic acid (IAA), an effector molecule in microbial physiology, plays an important role in plant growth-promotion. Here, we comprehensively analyzed about 7282 prokaryotic genomes representing diverse bacterial phyla, combined with root-associated metagenomic data to unravel the distribution of tryptophan-dependent IAA synthesis pathways and to quantify the IAA synthesis-related genes in the plant root environments. We found that 82.2% of the analyzed bacterial genomes were potentially capable of synthesizing IAA from tryptophan (Trp) or intermediates. Interestingly, several phylogenetically diverse bacteria showed a preferential tendency to utilize different pathways and tryptamine and indole-3-pyruvate pathways are most prevalent in bacteria. About 45.3% of the studied genomes displayed multiple coexisting pathways, constituting complex IAA synthesis systems. Furthermore, root-associated metagenomic analyses revealed that rhizobacteria mainly synthesize IAA via indole-3-acetamide (IAM) and tryptamine (TMP) pathways and might possess stronger IAA synthesis abilities than bacteria colonizing other environments. The obtained results refurbished our understanding of bacterial IAA synthesis pathways and provided a faster and less labor-intensive alternative to physiological screening based on genome collections. The better understanding of IAA synthesis among bacterial communities could maximize the utilization of bacterial IAA to augment the crop growth and physiological function.

Bacterial endophytes in agricultural crops

1997 ◽  
Vol 43 (10) ◽  
pp. 895-914 ◽  
Author(s):  
J. Hallmann ◽  
A. Quadt-Hallmann ◽  
W. F. Mahaffee ◽  
J. W. Kloepper
Keyword(s):  
Endophytic Bacteria ◽  
Plant Pathogens ◽  
Growth Promotion ◽  
Abiotic Factors ◽  
Hydrolytic Enzymes ◽  
Dynamic Structure ◽  
Plant Tissues ◽  
Beneficial Effects ◽  
Weakly Virulent ◽  
Planting Materials

Endophytic bacteria are ubiquitous in most plant species, residing latently or actively colonizing plant tissues locally as well as systemically. Several definitions have been proposed for endophytic bacteria; in this review endophytes will be defined as those bacteria that can be isolated from surface-disinfested plant tissue or extracted from within the plant, and that do not visibly harm the plant. While this definition does not include nonextractable endophytic bacteria, it is a practical definition based on experimental limitations and is inclusive of bacterial symbionts, as well as internal plant-colonizing nonpathogenic bacteria with no known beneficial or detrimental effects on colonized plants. Historically, endophytic bacteria have been thought to be weakly virulent plant pathogens but have recently been discovered to have several beneficial effects on host plants, such as plant growth promotion and increased resistance against plant pathogens and parasites. In general, endophytic bacteria originate from the epiphytic bacterial communities of the rhizosphere and phylloplane, as well as from endophyte-infested seeds or planting materials. Besides gaining entrance to plants through natural openings or wounds, endophytic bacteria appear to actively penetrate plant tissues using hydrolytic enzymes like cellulase and pectinase. Since these enzymes are also produced by pathogens, more knowledge on their regulation and expression is needed to distinguish endophytic bacteria from plant pathogens. In general, endophytic bacteria occur at lower population densities than pathogens, and at least some of them do not induce a hypersensitive response in the plant, indicating that they are not recognized by the plant as pathogens. Evolutionarily, endophytes appear to be intermediate between saprophytic bacteria and plant pathogens, but it can only be speculated as to whether they are saprophytes evolving toward pathogens, or are more highly evolved than plant pathogens and conserve protective shelter and nutrient supplies by not killing their host. Overall, the endophytic microfloral community is of dynamic structure and is influenced by biotic and abiotic factors, with the plant itself constituting one of the major influencing factors. Since endophytic bacteria rely on the nutritional supply offered by the plant, any parameter affecting the nutritional status of the plant could consequently affect the endophytic community. This review summarizes part of the work being done on endophytic bacteria, including their methodology, colonization, and establishment in the host plant, as well as their role in plant–microbe interactions. In addition, speculative conclusions are raised on some points to stimulate thought and research on endophytic bacteria.Key words: endophytic bacteria, methods, localization, diversity, biological control.

scholarly journals The Distribution of Tryptophan-Dependent Indole-3-Acetic Acid Synthesis Pathways in Bacteria Unraveled by Large-Scale Genomic Analysis

2019 ◽  
Author(s):  
Pengfan Zhang ◽  
Tao Jin ◽  
Sunil Kumar Sahu ◽  
Jin Xu ◽  
Qiong Shi ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Large Scale ◽  
Growth Promotion ◽  
Plant Root ◽  
Genomic Analysis ◽  
Acid Synthesis ◽  
Metagenomic Data ◽  
Bacterial Genomes ◽  
Bacterial Phyla ◽  
Indole 3 Acetic Acid

Bacterial indole-3-acetic acid (IAA), an effector molecule in microbial physiology, plays an important role in plant growth-promotion. Here, we comprehensively analyzed about 7282 prokaryotic genomes representing diverse bacterial phyla, combined with root-associated metagenomic data to unravel the distribution of tryptophan-dependent IAA synthesis pathways and to quantify the IAA synthesis-related genes in the plant root environments. We found that 82.2% of the analyzed bacterial genomes were potentially capable of synthesizing IAA from tryptophan (Trp) or intermediates. Interestingly, several phylogenetically diverse bacteria showed a preferential tendency to utilize different pathways and tryptamine and indole-3-pyruvate pathways are most prevalent in bacteria. About 45.3% of the studied genomes displayed multiple coexisting pathways, constituting complex IAA synthesis systems. Furthermore, root-associated metagenomic analyses revealed that rhizobacteria mainly synthesize IAA via IAM and tryptamine (TMP) pathways and might possess stronger IAA synthesis abilities than bacteria colonizing other environments. The obtained results refurbished our understanding of bacterial IAA synthesis pathways and provided a faster and less labor-intensive alternative to physiological screening based on genome collections. The better understanding of IAA synthesis among bacterial communities could maximize the utilization of bacterial IAA to augment the crop growth and physiological function.

scholarly journals The fungal root endophyte Serendipita vermifera displays inter-kingdom synergistic beneficial effects with the microbiota in Arabidopsis thaliana and barley

2021 ◽  
Author(s):  
Lisa K. Mahdi ◽  
Shingo Miyauchi ◽  
Charles Uhlmann ◽  
Ruben Garrido-Oter ◽  
Gregor Langen ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Growth Promotion ◽  
Plant Root ◽  
List Type ◽  
Microbiota Composition ◽  
Pathogen Infection ◽  
Associated Bacteria ◽  
Root Endophyte ◽  
Beneficial Effects ◽  
Bacterial Microbiota

AbstractPlant root-associated bacteria can confer protection against pathogen infection. By contrast, the beneficial effects of root endophytic fungi and their synergistic interactions with bacteria remain poorly defined. We demonstrate that the combined action of a fungal root endophyte from a widespread taxon with core bacterial microbiota members provides synergistic protection against an aggressive soil-borne pathogen in Arabidopsis thaliana and barley. We additionally show early inter-kingdom growth promotion benefits which are host and microbiota composition dependent.HighlightsThe root endophytic fungus Serendipita vermifera can functionally replace core bacterial microbiota members in mitigating pathogen infection and disease symptoms.S. vermifera additionally stabilizes and potentiates the protective activities of root-associated bacteria and mitigates the negative effects of a non-native bacterial community in A. thaliana.Inter-kingdom synergistic beneficial effects do not require extensive host transcriptional reprogramming nor high levels of S. vermifera colonisation.Inter-kingdom protective benefits are largely independent of the host while synergism leading to early inter-kingdom growth promotion is driven by host species and microbiota composition.

scholarly journals The fungal root endophyte Serendipita vermifera displays inter-kingdom synergistic beneficial effects with the microbiota in Arabidopsis thaliana and barley

2021 ◽  
Author(s):  
Lisa K. Mahdi ◽  
Shingo Miyauchi ◽  
Charles Uhlmann ◽  
Ruben Garrido-Oter ◽  
Gregor Langen ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Growth Promotion ◽  
Plant Root ◽  
Root Endophyte ◽  
Beneficial Effects ◽  
Synergistic Interactions ◽  
Transcriptional Reprogramming ◽  
Bacterial Microbiota ◽  
Root Endophytic Fungi ◽  
Combined Action

AbstractPlant root-associated bacteria can confer protection against pathogen infection. By contrast, the beneficial effects of root endophytic fungi and their synergistic interactions with bacteria remain poorly defined. We demonstrate that the combined action of a fungal root endophyte from a widespread taxon with core bacterial microbiota members provides synergistic protection against an aggressive soil-borne pathogen in Arabidopsis thaliana and barley. We additionally reveal early inter-kingdom growth promotion benefits which are host and microbiota composition dependent. Using RNA-sequencing, we show that these beneficial activities are not associated with extensive host transcriptional reprogramming but rather with the modulation of expression of microbial effectors and carbohydrate-active enzymes.

scholarly journals Molecular mechanism underlying Piriformospora indica-mediated plant improvement/protection for sustainable agriculture

2019 ◽  
Vol 51 (3) ◽  
pp. 229-242 ◽  
Author(s):  
Muhammad Khalid ◽  
Saeed-ur- Rahman ◽  
Danfeng Huang
Keyword(s):  
Sustainable Agriculture ◽  
Stress Tolerance ◽  
Molecular Mechanisms ◽  
Growth Promotion ◽  
Plant Root ◽  
Water Status ◽  
Abiotic Stress Tolerance ◽  
Crop Improvement ◽  
Piriformospora Indica ◽  
Symbiotic Association

Abstract The beneficial endophytic microorganisms have received significant attention in agriculture because of their exceptional capabilities to facilitate functions like nutrient enrichment, water status, and stress tolerance (biotic and abiotic). This review signifies the molecular mechanisms to better understand the Piriformospora indica-mediated plants improvement or protection for sustainable agriculture. P. indica, an endophytic fungus, belonging to the order Sebacinales (Basidiomycota), is versatile in building mutualistic associations with a variety of plants including pteridophytes, bryophytes, gymnosperms, and angiosperms. P. indica has enormous potential to manipulate the hormonal pathway such as the production of indole-3-acetic acid which in turn increases root proliferation and subsequently improves plant nutrient acquisition. P. indica also enhances components of the antioxidant system and expression of stress-related genes which induce plant stress tolerance under adverse environmental conditions. P. indica has tremendous potential for crop improvement because of its multi-dimensional functions such as plant growth promotion, immunomodulatory effect, biofertilizer, obviates biotic (pathogens) and abiotic (metal toxicity, water stress, soil structure, salt, and pH) stresses, phytoremediator, and bio-herbicide. Considering the above points, herein, we reviewed the physiological and molecular mechanisms underlying P. indica-mediated plants improvement or protection under diverse agricultural environment. The first part of the review focuses on the symbiotic association of P. indica with special reference to biotic and abiotic stress tolerance and host plant root colonization mechanisms, respectively. Emphasis is given to the expression level of essential genes involved in the processes that induce changes at the cellular level. The last half emphasizes critical aspects related to the seed germination, plant yield, and nutrients acquisition.

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