Thanks so much Dr Nazir , I always try to bring something which is really not repetitive , and also incite our colleagues to interact in most constructive way . Lets see how our colleagues interact on the se issues pertaining to functioning of AMs.  

Dear Anoop

You can read these files.

Ahmad I do not find any attachments.  

This question from Anoop Kumar will help a lot in brain storming of researchers, especially working in Soil Microbiology and Mycorrhiza. Some of the new research works support role of Mycorrhizi very strongly. Some useful contribution of this group has been reported. Dr. Anoop! I think this topic will remain very hot topic.  

Thanks so much Dr Nazir , I always try to bring something which is really not repetitive , and also incite our colleagues to interact in most constructive way . Lets see how our colleagues interact on the se issues pertaining to functioning of AMs.  

Thanks so much Ahmad for attaching two fantastic publications . th efirst one throws some authoritative work on indicators of soil health in two parts , first part deals with practical application of soil microbes , and second part elaborately discusses about the microbes as indicators of soil health in terms of biodiversity ( Genetic , structural , and functional  ) , their role in carbon and nitrogen cycling , bioavailability of nutrients . The second publication again sis so good to conclude that plant type and soil type shape the structure and function of microbial communities within the rhizosphere. I request my learned colleagues to please have a look into these two PDFs enclosed by Ahmad.

Out of  different major soil microbial communities , AMF are reported highly dynamic in response on both soil and plant . Yes, AMF  mycelial growth constitute  CMN through which they establish communication between different plant species using different root  endohormones.  

The use of arbuscular mycorrhizae is greatly underestimated based on the subterrenan nature and the fact that they do no grow by themselves in the laboratory but need to always have a plant host. Arbuscular mycorrhizae impact the physical and biochemical nature of the soil through several mechanisms. One of the most important is their ability to stabilize and increase the soil aggregates. This allows a greater ability for water to percolate and because they add to soil organic matter then improve water retention. Studies show 20% of the plant photosynthesis may be exuded into the soil much related to mycorrhizae with also stimulate rhizosphere bacteria. 

The increase in root to soil surface area from mycorrhizae is calculated at 100's to 1000's of times based on the size and extension. The biggest areas of impact are in 1) water 2) immobile element movement into plants P, Zn, Cu etc 3) the stimulation of the plant metabolism which can help plant reaction to root pathogens. 

Using cover crops and having pastures intensively managed to recycle manures no till agriculture and avoiding over application of Phosphorus can help increase and preserve their impacts. In terms of Carbon sequestration the glycoprotein Glomalin from arbuscular mycorrhizae is very long lived and when soils become well aggregated and stabilized through mycorrhizae their Carbon life is extended and regeneration of soil properties become possible. In disturbed soils such as mines mycorrhizae are particularly critical for reclamation. 

In laboratory conditions onions are used by many of workers looking at the importance and role of mycorrhizae fungi. 

A group in Belgium has been culturing AM Fungi. For further details  those interested  may apply: 

http://www.mycorrhiza.be/training/in_vitro_culture_AMF/

There is also a book published  In Vitro Culture of Mycorrhizas

Editors: Declerck, Stéphane, Strullu, Désiré-Georges, Fortin, André (Eds.) http://www.springer.com/la/book/9783540240273

On farm or garden propagation of mycorrhizae depends on finding a natural grassed prairie area which have a diversity of mycorrhizae mix with vermiculite and sand and 10% mature compost and natural prairie soil. Plant a seed mixture of grass onion and clover in a 15 liter grow bag. The mycorrhiza from the prairie soil will be stimulated by the seedling roots allow the plants to grow a season and determine the population of sporangiospores by wet sieving. Mix the soil to dilute to 100 spores per seedling plant. Using this method a large diverse mycorrhizal population can be used of transplants ensuring optimal infection and the plants will give advantage especially under drought environments from better mycorrhizal colonization See Douds et al.

Paul can we segregate the soil mycorrhizal diversity according to crop type. Or can a mycorrhizal species be an indicator of crop type.

In relationship to the rhizosphere this the that halo mainly of bacterial proliferation from 1 to 2 mm around the root. Mycorhizosphere has been measured at least 100 to 150 mm around the root where the exploratory fungi reside. The mycorhizosphere thus comprised an advancement in the conceptualization of the soil biosphere. The plant the fungus and the bacterial all work together in a symbiotic synergistic fashion and to that equation I would add earthworms. Within several years from changing out inputs for covers and rotation and organic amendment the mycorrhizal activity in the Rodale Institute Farming systems trial showed an exponential increase in sporangiosphores this when the Carbon content of the soil and its increase was hardly perceptible.

When you ask about methodology there are 3 in use population count, diversity analysis and biochemical marker products. The gradients of population suggest that nutrient is a limiting factor in the bacterization of roots. Plants vary much in their capacitiy for having nutritive exudation among the plants legumes are particuliarly important and the tripatriate plant bnf and mycorrhizal advantages of biological systems involve optimizing all the players in synergistic fashion. Looking at the crop system as a biological one and tapping into synergistic symbiosis is much underestimated and not applied in general. 

Dr Mitra and other colleagues. These are PGPRs. Why are they not so popular for seed treatment as oppose to soil inoculation. How are these PGPRs effective as seed inoculation and as growing medium inoculation.

When you ask the role of arbuscular mycorrhizae the first importance would be in their ability to avoid drought issues compared to non AM plants. Close importance is the ability access immobile elements and the stimulation of probiosis and antibiosis would probably be the third.

The role of mycorrhizae is through the stimulation rooting over top growth. When conditions are favorable for plant growth the signaling to accept mycorrhizae are hampered. The establishment of mycorrhizae stimulated by stress environment favors a root proliferation and an inhibition of top growth. This mediated by the brassiosteroid hormones which are triggered when mycorrhizae are active.

Figure 4.. The strigolactone-deficient mutant of Arabidopsis shows exuberant branching. The wild-type plant (left) has few secondary shoots compared to the mutant (right). Figure reproduced with permission from [8].  Such a plant would be increased in its susceptibility to drought damage because tops would be formed at the sacrifice of roots.

When mycorrhizae are signaled and action the strigolactones will result in a plant where the roots will be favored allowing it to get nutrients and water while greatly reducing evapotranspiration.

This discussion is proving highly beneficial and we are acquainting very rich experience and knowledge of our colleagues with courtesy of Dr. Anoop Kumar who placed a so nice question. Because I do not have much experience of Mycorrhiza studies, this discussion is highly useful for me.  

Dr Hepperly and Dr Nazir very interesting discussion . When we declare a crop AM-dependent , we called it AM-responsive crop . How shall we select a specific species of  AM , so that maximum benefits could be derived out of AMs to the inoculated plant . My second point is how  to sustain the culture of AMs fro long use ?. Do you feel concept like shelf life of AM species operate to this very special class of fungi? 

Friends can you throw some lights on how to study the AMF diversity in field.

Dr Srivastava my this question is addressed to you. AMF are known as aggressive phosphate solubilizers, how come different micronutrients are also solubilized.

Dr Deka , AMs are known to be primary phosphate solubilizers , but in the process so much biological changes in the plant rhizosphere takes place   (For example,  increase in root surface area by 100-500 times  upon inoculation) that brings sufficient changes in redox potential of the rhizosphere , mostly associated with chelation , complexation and solubilisation of nutrients like Fe , Zn etc. The better carbohydrate partitioning upon AM-inoculation makes inoculated plant  photosynthetically more efficient , thereby improving the sink capacity of the plant to accumulate more nutrients. I am enclosing our  two PDFs explaining about the nutritional ability of AMs . Hope , you find these publications satisfying .

Dr  Deka , now I am trying to address your very intriguing question about the AMF-diversity . AMF-richness has been reported to vary from 1-5 per 2500m2 area. Infact , AMF- diversity determines the plant biodiversity ,ecosystem variability and productivity ( Marcel et al , 1998, Nature:396,69-72). Community composition of AMF(Lee at al. 2013, DOI: 10.5941/MYCO.2013.41.3.121) affects the magnitude of plant response. This review summarises the taxonomic ( Six genera reported with abundance of Glomus), genetic( little is known about role in ecosystem) ,and functional diversities( Vary grate deal  between species and different isolates of a species) of AMF and their role in natural ecosystem . However , despite low diversity and lack of host specificity , various functions have been associated with plant growth response to AMF-colonization.  

With time and participation of highly learned researchers, the discussion is extending and becoming very much interesting, as I expected in the beginning. So many aspects of AM are now unlocking. We, the beginners of this subject, are enjoying and happy to increase our understanding. 

Thanks so much Dr Nazir . As long as researchers  like you are online to discuss science , we are equally delighted to to receive the encouragements from you and my other very learned colleagues .

Let me introduce our exclusive  review article on drought tolerance of citrus with AMFs ( PDF enclosed).  This review provides an overview of possible mechanisms involved in DS tolerance through improved water and nutrient uptake (especially P nutrition) using extraradical hyphal growth; effective spatial configuration of root system; elevated concentration of tetramine spermine; osmotic adjustment through non-structural car-bohydrates, K+, Ca2+, and Mg2+, but not proline; scavenging reactive oxygen species through antioxidant enzymes and antioxidants; and glomalin-bound soil structural improvements, besides, some new excit-ing perspectives including water transport by mycorrhizal hyphae and molecular analysis are suggested . Hope , you will like the content of this work Dr Nazir and my other colleagues

Thank you Dr. Kumar fo uploading this nice review paper. I will go through it and give feedback here. 

Dear Folks One of the best ways to assure the persistent activity of mycorrhizal fungi is the have your agricultural system based dn living corers. Our experience at Rodale showed the including cover crops with emphasis on legumes was enough to wean the system off synthetic nitrogen applications and to result in Carbon and Nitrogen accural in the soil.

In the first 10 years this was 10% increase in the soil Carbon off the baseline and 5% relative increase from the Nitrogen base. These differences are hardily detectable based on statistics but their effects are dramatic under stress environments such as droughts.

When the mycorrhizal spores were harvested at that same time period the increase was over 100% over the baseline. When we assay this as a biolindicator of the coming changes in the chemical components of the soil they give a more conclusive estimate of how a very small chemical difference in the soil can be associated with profound microbial transformation. 

Paul nice supplement . What do you think , what are the bio-indicators of mycorrhizosphere . I think , there is a wide range of rhizosphere properties , which could be effectively used for evaluating the response of AM-inoculation . We have studied number of mycorrhizosphere  properties viz., Bradford reactive soil protein  ( popularly we call it as glycoprotein- related-soil-protein, GRSP), soil organic matter ( Labile pool ) , aggregate stability of different sizes , geometric mean diameter , mean weight diameter , root endoharmones etc... We also observed these responses through exogenous application of easily extractable GRSP. Find below few interesting PDFs for further supplements on these issues  for further feedbacks.    

When it comes to making sure the symbiosis is optimized it is very important to have micronutrients supplied and the best way is by seed treatment based on lots of potential for little capital investment. Ideally the legume component that drives the system is inoculated.

In terms of the glycoprotein this shows excellent ability to reflect the change in soil Carbon and Nitrogen. aggregate stability is very good and I see a lot of value in mineralizable Nitrogen by difference after anaerobic incubation. Ideally the wet sieving for sporangiospore recovery can be used in conjunction with the chemical assays such as Nitrogen and labile Carbon. These all intercorrelate to one another. 

The problem with biological assays is that they are labor intensive and have more variability associated with them. 

Rhizotrons can be good for investigating the mycorrhizosphere but very clumsy. The mycorrhizal research with split root systems can be an effective methodology.  I see all the mycorhizosphere work as being very much in its infant stages. 

It is mind boogling that the vast majority of soil microbes have not been cultured. 

Anoop you are doing a masterful job in leading these important discussion areas. A wonderful example of collective intelligence.Kudos to you Doctor I hope to meet you some day in person. 

Thanks Paul I am impressed with your quality inputs and clinical stewardship in such discussion.

Friends another point of  strong contention hits me , how should we define the symbiotic efficiency of AMs. Is it the amount of carbon gained by a growth response accrued from symbiotic relationship with AM minus the amount of carbon lost by investment  in maintaining the symbiotic relationship. Sometimes, it is also defined as the units of carbon gained for how many units of carbon assimilated by the inoculated plant against non-inoculated plant.  

Do you feel such mycorrhizal induced symbiosis efficiency is a funton of crop mycorrizal dependence. If not, how are two diferent from each other.

I strongly understand , both  are the two sides of the same coin , Dr Deka.  

Estimado Anoop   

Le expongo algunas consideraciones sobre la AMs y sus funciones, conociendo que es la simbiosis formada por la mayoría de las plantas.

Modifica la morfología de la raíz y desarrolla una compleja red de micelio que se ramifica en el suelo, aumentando la adherencia planta /suelo y la estabilidad del suelo (acción de unión y mejora de la estructura del suelo, disminuye los efectos de la erosión). Se plantea que hay 30 m de hifa fungica/g de suelo (Wilson et al., 2009) y unido a la secreción de la glomalina (Glicoproteína, sustancia pegajosa) en el suelo formando agregados (Andrade et al., 1998  y  Bedini et al., 2009) aumenta la estabilidad del suelo y la retención del agua (Rilling et al., 2002).

La red micelial puede ser el 50% de la biomasa fúngica, por lo que representa la mayor parte biomasa microbiana en el suelo (Rilling et al., 2004). Esta red comunica a las plantas por lo que una planta micorrizada puede servir de inóculo para otras plantas que forman micorrizas. Aumento de la interacción con otros microorganismos del suelo a través de la red micelial utilizándola para transferir los compuestos de estos hacia la planta.

El aumento de la absorción de nutrientes minerales y de agua por las plantas, promueve el crecimiento de las plantas al tiempo que reduce los requerimientos de fertilizantes químicos, con la absorción de fósforo contribuye a evitar la eutrofización de las aguas.

Efecto amortiguador  contra el estrés abiótico. Aumento de la resistencia de las plantas a la sequía, salinidad, contaminación de metales pesados y al agotamiento de los nutrientes minerales (Smith & Read 2008, Marulanda & Barea 2009).

Modificación de la fisiología y el metabolismo de la planta. Biorregulación del  desarrollo de la planta y aumento en la calidad de la planta para la salud humana. El 30% de los suelos son deficientes de Zn, particularmente las áreas tropicales  (Cavagnaro 2008) y la deficiencia de este causa enfermedades cardiovasculares y cáncer (Cummings & Kovacic 2009)

Protección contra patógenos que atacan  las raíces. Aumento de la resistencia de la planta contra el estrés biótico y al mismo tiempo reduce la aplicación de fitoquímicos.  Producción de metabolitos secundarios contra patógenos fúngicos.

Dear Anoop

I present some considerations about AMs and its functions, knowing that is the symbiosis formed by most plants.

Modifies root morphology and developed a complex network of mycelium that branches into the ground, increasing the plant / soil and soil stability adhesion (binding action and improvement of soil structure, reduces the effects of erosion) . It is stated that there are 30 m of fungal / g soil hyphae (Wilson et al., 2009) and joined the secretion Glomalin (glycoprotein, sticky substance) on the floor in aggregates (Andrade et al., 1998 Bedini et al., 2009) increases soil stability and water retention (Rilling et al., 2002).

The mycelial network may be 50% of the fungal biomass, which represents the most part microbial biomass in the soil (Rilling et al., 2004). This network communicates to the plants at a plant mycorrhizal inoculum may serve for other mycorrhizal plants. Increased interaction with other soil microorganism through the mycelial network using it for transferring their compounds to the plant.

The increased uptake of mineral nutrients and water by plants, promotes plant growth while reducing the requirements for chemical fertilizers, with phosphorus absorption helps prevent eutrophication.

Effect buffer against abiotic stress. Increased plant resistance to drought, salinity, heavy metal pollution and the depletion of mineral nutrients (Smith & Read 2008, Marulanda & Barea 2009).

Changing the physiology and metabolism of the plant. Biofeedback of plant development and increase in quality of the plant to human health. 30% of soils are deficient in Zn, particularly in tropical areas (Cavagnaro 2008) and this deficiency causes cardiovascular diseases and cancer (Cummings & Kovacic 2009)

Protection against pathogens that attack the roots. Increased plant resistance against biotic stress and simultaneously reduces the application of phytochemicals. Production of secondary metabolites against fungal pathogens.

 AMs are known to secrete glycoproteins , popularly known as glomalin-related -soil -protein , frequently assessed by  by the Bradford method . Very often , this method is claimed  not accurate. Indeed the drawbacks of determing glomalin-related proteins  are: Bradford method also detect other proteins and litter components affect ELISA (Rosier et al 2006);Phenolic compounds interfere with the Bradford assay (Whiffen et al 2007);NMR spectra of GRSPresemble those of humic substances and not those of typical glycoproteins(Schindel et al 2007).  What could be the best possible alternative to determine glycoproteins in mycorrhizosphere.  

The importance of the microbial communities cannot be separated with the plant and animal systems that work together with each other in a synergistic symbiotic function. Academically our rush to dissect problems and issues works against the utilization of these more complex  interactions.  

Just because our professional specializations constitute a hammer we must not forget the issues and problems may not be exclusively resolved from our particular tool or toolbox.

Indeed the real challenges need prolonged trials and interdisciplinary discovery. That is rarely the framework of our academic and business efforts however.

As the others point out 50% or more of the microbial biomass comes from mycorrhiza network. When we are talking about the result of our plants we are talking about this network whether we know so or not. Mycorrhizae are not working in isolation however.

The agricultural system is awash in a sea of atmospheric Nitrogen yet without the symbiotic synergistic Rhizobial community the plant will not be optimized and if synthetic fertilizer is the source of growth the synergism and symbiosis will suffer. So when we achieve this realization the emphasis needs to be on systems rather than components of systems.

For stabilizing and regenerative nature of the system the ability to understand cropping sequences and animal influences and the role of recyclers are part and parcel of the stewardship which ultimate goal is generation of ecological function which is lost in monocultural and input based agriculture.

Quintessence is 1) Plant 2) Rhizobium 3) Mycorrhizal Fungi 4) Rhizosphere microbes and 5) Consumer/Recyclers. They are a 5 in 1 and cannot be fully utilized without a conceptualization that they serve one end result.

Friends what do you think , AMF inoculation brings improvement in plant health either through improvement in plant defense  apparatus or indirectly by improving the rhizosphere properties.

Because AMF improves nutrition and stimulates rhizosphere populations and can engage the systemic acquired resistance it is likely that all of these are involved yet I am unaware of a whole lot of work on those interactions.  

 In our studies on Mycorrhizal-induced calmodulin mediated changes in antioxidant enzymes and growth response of drought-stressed trifoliate orange highly arbuscular mycorrhizal(AM)dependent for growth responses through a series of signal transductions in form of various physiological responses.The proposed study was carried out to evaluate the effect of an AMfungus(Funneliformis mosseae)on growth,antioxidant enzyme(catalase,CAT;superoxidedismutase,SOD)activities,leaf relative water content(RWC),calmodulin(CaM),superoxide anion(O•−2),and hydrogen peroxide(H2O2) concentrations in leaves of the plants exposed to both well-watered(WW)and drought stress(DS)conditions.

A58-day of DS significantly decreased mycorrhizal colonization by 60% than WW.Compared to non-AM seedlings, AM seedlings displayed significantly higher shoot morphological properties(plant height,stem diameter,and leaf number),biomass production(shoot and root fresh weight)and l eaf RWC, regardless of soil water status. AM inoculation significantly increased CaM and soluble protein concentrations and CAT activity, whereas significantly decreased O•−2 and H2O2concentration under both WW and DS conditions .The  AM seedlings also exhibited significantly higher Cu/Zn-SOD and Mn-SOD activities than the non-AMseedlings under DS but not under WW,which are triggered by higher CaM levels in AM plants on the basis of correlation studies. Further, the negative correlation of Cu/Zn-SOD and Mn-SOD activities with O•−2andH2O2concentration showed the DS-induced ROS scavenging ability of CaM mediated SODs under mycorrhization. Our results demonstrated that AM-inoculation elevated the synthesis of CaM in leaves and up-regulated activities of the antioxidant enzymes, thereby, repairing the possible oxidative damage to plants by lowering ROS accumulation under DOS conditions. Find below the required PDF for reference please. Such studies provide an excellent proof , how AM-inoculation acts in such an coordinated manner , where there is a significant improvements in plant health also . Hope Dr Deka and Hepperly find this information interesting .  

Doctor Anoop

Thank you for the your work on defensive enzymatic activation from the mycorrhizal state. From your work, would it be safe to say you see antioxidant capacity as improved by the symbiotic relationship as a prime mechanism in the advantages of mycorrhizal plants?

Since people have postulated oxidation as a principle senescence process does your work support any retarding of senescence or stay green effect?

What I find a little puzzling from my personal experience is much of work I was involved with pointed to best demonstration of advantage for mycoorhizal infected plants under drought conditions. Yet here you demonstrate most colonization for the well watered condition.

I was little puzzled how drought actually works against the establisment through root colonization as I supposed that stress was signaling the infection acceptance just as it apparently does the Phosphorus deficit.

It would appear water stress works fundamentally differently than Phosphorus stress.

Would like to hear your take.

Hope my uninformed  biochemical curiosity is not too irritating!

Interesting  supplement Paul . Yes Am-inoculation having capacity to establish the common mycorrhizal networking with non-inoculated plants , safeguards the plants from oxidative stresses imposed on account of water deficit stress ( Evident from accumulation of reactive oxygen species) by elevating the activation of CaM-induced SODs , the prime operators for plants defense mechanism . Somewhere, it also overtakes the P-deficit in the inoculated  soil. This is where the AM-inoculation offers better preparedness to plants to fight against various abiotic stresses. hope my supplement satisfies your quarry Paul. Thanks for steering such novel concepts for the larger benefits of our other friends .  

These are the reasons , we have no doubt whatsoever , AMs are the most influential class of  soil microbial community , having most diverse functions in terms of influencing soil properties as well as plant health , coupled with C-accredition capacity ( Especially the labile C fraction of soil SOC). However ,  perhaps our most limited efforts are with respect to exploiting the AMs- diversity and plant response functions at various levels of ecological service , that AMs offer so comprehensively. And without doubt , AMs are the most researched soil microbial community . 

I agree with you Dr Srivastava. Mycorrhizal functions are so elaborately studied. Perhaps this is the class of microbial community fits so well as a part adoption technique to address climate change issues.

I´m agree with Dr.  Paul Reed Hepperly.   Symbiosis is a key and universal concept.  We talk about systems not only one specie.  Human body have an arsenal of bacteria that help us stay healthy, some bacteria produce vitamins, some other important fatty acids, substances that the body don´t produce but needs them, so the microbiome is regarded as an organ more. The same applies to animals, insects and plants are no exception, I believe that as humans occupy some combination of bacterial species depending on race, region, country, likewise the plants depends on where are, on the species, the type of soil for the most suitable combination for plant healthy. Plant scientific will work to determine the best combination of microorganisms for every crop in the different cultivable soils in the world. Regards! 

Bacteria 

Interesting answers from both of you , Abu-Bakr and Abhshek. How shall we arrive at conclusion as  which microbial community is more prudent in action within rhizosphere of one crop to another crop..?

I believe that the microbial communities that positively influence the properties of the soil (physical, chemical and biological) are nitrogen fixing bacteria, free-living bacteria and the arbuscular mycorrhiza, favor the growth and development of the plants in soils with adverse conditions.

Interesting feedback Elizabeth. It is often seen , huge diversification of these microbial communities according to land uses and climates ,. Here is an interesting work by Soka and Ritchie ( 2016) Rhizosphere 1 (2016) 45–52

Two grass species, Zea mays and Themeda triandra, were grown for 12 weeks in 8 replicates of each soil type and sterilization treatment. About 52.4% and 62.6% of Z. mays roots grown in non-sterilized soils were colonized by AM fungi in low and high SOM, respectively, and 38.1% and 46.7% of T. triandra roots grown in non-sterilized soils were colonized by AM fungi in low and high SOM respectively. Overall, plant biomass of both plant species was significantly higher on control soils than sterilized soils, indicating that AM fungi likely contributed to productivity, and on soils with higher SOM. However, the separate contribution to productivity of SOM and soil microbes varied significantly among plant species and soils from different land uses. Z. mays productivity increased most strongly to higher SOM, and declined with sterilization in agricultural, but not livestock or wildlife grazed soils. In contrast,  triandra production was largely insensitive to SOM or sterilization except on wildlife-grazed soils, where it increased most strongly in unsterilized soils. AM fungi impacts on productivity therefore may be driven more by host plant species than by lower nutrient supply, as associated with lower SOM. Furthermore, efforts to enhance productivity in uncultivated lands should perhaps focus on altering plant species composition, while efforts to enhance productivity in agriculture soils might not depend on beneficial soil microbes or additional fertilizer but instead on effective crop rotations. PDF enclosed for further reading ..

I think AM's though less than bacterial population they are more comprehensive in their effect on both soil and plant. AM's compared to other soil microbial communities keep the plant physiologically more active. 

The nature of nature is mostly collaborative. The ability of mycorrhizae to work their magic is only because a plant was providing its room and board. In nature the life forces are compelled to join together. This joining multiples the forces. The Scripture of Old Testament says if one is alone he/she is overcome but if two are joined at least they can defend themselves. In reality it then says a 3 stranded cord is difficult to sever. Now in the case of plant and mycorrhizae the plant is central but the the accessory role of biological Nitrogen fixation and fungal phosphorus ensure a health ability to provide N and P and water plus stimulates the transfer of C and N from the atmosphere where it can cause mischief through climate change and repatriates it to soil where it largely beneficial. This is done mostly out of thin air which greatly reduces any negative footprint from synthetic fertilizer. The legume plants with their rhizobia bacteria and mycorrhizal fungi are the 3 stranded cord. If the food system with concentrate on this the rest of the system is promoted and even more so when animals are involved as the get amenders. The excrement of man and cow is rich in probiotic Bacilli which are the best agents to stimulate improved plant and animal health. As the Nazi war machine run through North Africa the soldiers fell to dysentary and the arab scouts advised that be simply digesting dung from the camel their troop were saved and recovered. The Bacillus in dung is something that is proven to promote plant and animal health. Early modern science stressed the isolated factor approach but it is becoming more and more apparent that our natural systems demand a more nuanced study which focuses on whole system especially in key food production capacity. I whole heartedly support the encourage of Anoop and researchers to investigate the role of consortia of biological agents for resolving many of festering issues. 

AMs have the strongest ability through ERM establishment with host plant under extreme weather which except Bacillus no other microbes possess.

This is an issue, we will always have divided opinions. However , by and large , Bacillus and AMs are the two most  influencial classes of soil microbial communities , that have been widely reported across soils , crops and geographical regions.  Looking at the limitations of single inoculation , multiple inoculation in form of microbial consortium came into practice , however still not so popular practice in many of the crops. but , some breakthroughs have been made . and , now consortium of endophytes  is also being propogated...

Good discussion Dr Srivastava, I agree with you on the point you have raised.