The ability of beneficial Azotobacter strains to secrete plant growth promoting and regulating substances such as phytohormones, vitamins, and antifungal metabolites have been studied. Phosphate solubilization Hariprasad and Niranjana, ; Rojas-Tapias et al.
Furthermore, the Azotobacter -mediated synthesis of superoxide dismutase SOD , catalase CAT , proline, and high levels of 1-aminocyclopropanecarboxylate ACC activity Glick, can influence plant health and bring benefits to a wide variety of crops such as tomato Viscardi et al. Barra et al. Similarly, a model proposed by Hermosa et al. These treatments may activate nitrogen fixation, phosphate solubilization, siderophore, phytohormone, and exopolysaccharide production known to enhance growth while protecting the plant from abiotic stresses, e.
Even though knowledge is limited on the survival of the microbial inoculants, the ability of rhizosphere competent bacteria and fungi to establish close associations with the native microbiota and soil fauna has been sufficiently demonstrated Hardoim et al. The synthetic bacteria-fungi consortia have the potential to establish novel microbial communities Ahmad et al. To this end, the extensive studies on Trichoderma and Azotobacter suggest that these fungi and bacteria could be functionally complementary in a PGP consortium, although the effects on the resident rhizosphere microbiota have not been sufficiently elucidated.
Furthermore, the Trichoderma - Azotobacter consortia could be integrated with botanical and inorganic compounds, seaweeds, polymers, animal-derived products to develop truly effective, and reliable beneficial plant products. The new frontier for plant biostimulants should profit from the beneficial associations of microorganisms and compounds, by building on a deeper understanding of plant-microbe interactions developed by Nature. New microbial consortium can be designed, e. SW and OP conceived the concepts and wrote the manuscript in collaboration.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Regione Puglia, n. National Center for Biotechnology Information , U. Journal List Front Plant Sci v. Front Plant Sci. Published online Dec 4. Sheridan L.
Author information Article notes Copyright and License information Disclaimer. Woo ti.
Olimpia Pepe ti. Received Sep 30; Accepted Nov Keywords: beneficial microbes, plant growth promotion, Trichoderma , Azotobacter , improved crop production. The use, distribution or reproduction in other forums is permitted, provided the original author s and the copyright owner s are credited and that the original publication in this journal is cited, in accordance with accepted academic practice.
No use, distribution or reproduction is permitted which does not comply with these terms. This article has been cited by other articles in PMC. Regulatory Legislation—Plant Protection Products vs. Plant Growth Promoting Microbes PGPM in Beneficial Microbial Consortia Important examples of positive plant-microbe interactions associated to plant growth promotion include PGP rhizobacteria: non-pathogenic Pseudomonas and Bacillus, Azotobacter, Serratia, Azospirillum capable of improving nutrient availability in soil, plant nutrient uptake and assimilation, as well as supporting nitrogen cycling Raaijmakers et al.
Azotobacter : Rhizocompetent Stress Tolerant N 2 Free-Living Bacteria Azotobacter includes free-living species that directly influence nutrition in agroecosystems through nitrogen fixation, thus increasing the soil level of this vital element for plants. Conflict of Interest Statement The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References Ahmad I. Microbial applications in agriculture and the environment: a broad perspective, in Microbes and Microbial Technology: Agricultural and Environmental Applications , eds Ahmad I. New York, NY: Springer; , 1— Solubilization of phosphates and micronutrients by the plant-growth-promoting and biocontrol fungus Trichoderma harzianum Rifai Inoculating wheat seedlings with exopolysaccharide-producing bacteria restricts sodium uptake and stimulates plant growth under salt stress.
Soils 40 , — Beneficial bacteria of agricultural importance.
Formulation of bacterial consortia from avocado Persea americana Mill. Soil Ecol. Plant nitrogen uptake drives rhizosphere bacterial community assembly during plant growth. Soil Biol. The rhizosphere microbiome and plant health.
Bernstein , James B. Please enter a valid email address. Product Highlights There has been a resurgence of interest in environmental friendly, sustainable and organic cultural practices that warrants high yield and quality in agricultural crops. Shamsudan Z. The role and activities of surfactants produced by bacteria are multifarious in nature. Faik Kantar E-mail address: faik tratauniatvm. Trade-offs in arbuscular mycorrhizal symbiosis: disease resistance, growth responses and perspectives for crop breeding.
Trends Plant Sci. Unraveling the plant microbiome: looking back and future perspectives. Plant growth-promoting rhizobacteria PGPR : emergence in agriculture. World J. Organic amendments, beneficial microbes, and soil microbiota: toward a unified framework for disease suppression. Trichoderma -plant root colonization: escaping early plant defense responses and activation of the antioxidant machinery for saline stress tolerance.
Mycorrhiza-induced resistance: more than the sum of its parts? Use of plant growth-promoting bacteria for biocontrol of plant diseases: principles, mechanisms of action, and future prospects. Mitogen-activated protein kinase 6 and ethylene and auxin signaling pathways are involved in Arabidopsis root-system architecture alterations by Trichoderma atroviride. Plant-Microbe Interact. Below-ground connections underlying above-ground food production: a framework for optimising ecological connections in the rhizosphere. Free-living N 2 -fixing bacteria as potential enhancers of tomato growth under salt stress.
Acta Hortic. Plant biostimulants: definition, concept, main categories and regulation.
Available online at: www. Trichoderma -based biostimulants modulate rhizosphere microbial populations and improve N uptake efficiency, yield, and nutritional quality of leafy vegetables. Plant Sci. Growth promotion and induction of resistance in tomato plant against Xanthomonas euvesicatoria and Alternaria solani by Trichoderma spp. Crop Prot. Inside the root microbiome: bacterial root endophytes and plant growth promotion. Bacteria with ACC deaminase can promote plant growth and help to feed the world. Plant growth promoting rhizobia: challenges and opportunities.
The hidden world within plants: ecological and evolutionary considerations for defining functioning of microbial endophytes. Isolation and characterization of phosphate solubilizing rhizobacteria to improve plant health of tomato. Plant Soil , 13— Trichoderma species - opportunistic, avirulent plant symbionts. The contribution of Trichoderma to balancing the costs of plant growth and defense. Plant-beneficial effects of Trichoderma and of its genes.
Microbiology , 17— Singapore: Springer; , — Longevity of Azotobacter cysts and a model for optimization of cyst density in liquid bioinoculants. Unraveling the efficient applications of secondary metabolites of various Trichoderma spp. Designing microbial consortia with defined social interactions.