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Sugarcane (Saccharum officinarum L.) is a highly valuable agricultural crop, cultivated globally in tropical and subtropical regions, primarily for its sugar content. Out of the 110 countries that grow sugarcane, India and Brazil together account for half of the world's total production. Being an annual crop, it is prone to many diseases. The major diseases that can affect the sugarcane are red rot, wilt, sett rot, grassy shoot and pokkah boeng. Among the diseases Colletotrichum falcatum, Fusarium sacchari, Ceratocystis paradoxa, Candidatus Phytoplasma and Fusarium fujikuroi pathogen leads to more yield loss. Traditional disease management strategies, such as chemical treatments, conventional methods and biological control, offer limited protection throughout the crop cycle and raise concerns regarding environmental impact and sustainability. In recent years, plant growth-promoting microorganisms (PGPMs) have emerged as a promising alternative, offering environmentally friendly solutions to enhance plant health and manage diseases. RNAi has been explored to manage various diseases caused by viruses, fungi, and bacteria. By silencing key pathogenicity genes in the causal organisms, sugarcane mosaic virus (SCMV), smut, and leaf scald. The integration of PGPMs with RNAi emerging biotechnological tools and transcriptomics presents a sustainable approach to disease control, potentially reducing the dependency on chemical pesticides and promoting eco-friendly agricultural practices. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Journal of Botany is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chilean avocado (Persea americana Mill.) exports have accounted for 60 % of the total production and are recognized for their high quality worldwide. However, avocado production has significantly decreased in recent years, which is mainly attributed to abiotic and biotic factors, among which are high and low temperatures, intense and sudden rains, unavailability of water resources, and agricultural salinity. Secondary factors include pests and diseases. Applying plant growth promoting microorganisms (PGPM)-based commercial biofertilizers is a potential practice to increase avocado production and resistance to edaphoclimatic factors. In this study, to determine the functionality of microbial communities present in three commercial biofertilizers (Biofert A, Biofert B, and Biofert C) and thus offer a structure of associated microbial communities, the rhizospheric soil of avocado was analysed using the Biolog EcoPlate™ technique, providing information on the community level physiologic profiles (CLPP) and biodiversity indices by denaturing gradient gel electrophoresis (DGGE). The findings revealed that the microbial diversity in the three commercial biofertilizers is highly different, showing a SIMPER overall dissimilarity of 83.9 % in the catabolic capacity. Concerning the impact on avocados’ rhizosphere soil bacterial communities, the results demonstrated significant changes in their composition, particularly with Biofert A and C. In contrast, Biofert B did not show significant changes, especially on days 15 and 30. Long-term studies are recommended to develop sustainable agricultural practices for Chilean avocados.

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of beneficial microorganisms is an important strategy to improve rice production in a sustainable way. The study was carried out to determine the effect of single and combined beneficial microorganism on the development of upland rice. The experiment was performed in greenhouse and arranged in a completely randomized design with 29 treatments and 4 replications. Treatments consisted of rice seeds cultivar BRS A501 CL treated with single and combined multifunctional microorganisms (1 (Serratia marcescens), 2 (Bacillus toyonensis), 3 (Phanerochaete australis), 4 (Trichoderma koningiopsis), 5 (Azospirillum brasilense), 6 (Azospirillum sp.), 7 (Bacillus sp.), 8 to 28 (combination of all these microorganisms in pairs) and 29 (control)). Inoculation of upland rice with sole and combined microorganism on upland rice increased the roots and shoots development, yield components and grain yield of upland rice. The combinations of Bacillus sp. (BRM 63573) and A. brasilense (AbV5), Azospirillum sp. (BRM 63574) + B. toyonensis (BRM 32110) and Phanerochaete australis (BRM 62389) + Serratia marcenscens (BRM 32114) led to improved roots and shoots development; increased number of panicles and grains per pot, 1000 grains weight and grain yield of rice plants. Besides, the combinations allow helped in increased accumulation of nutrients in roots, shoots and grains of rice plants. [ABSTRACT FROM AUTHOR]

The use of fertilizers and pesticides has resulted in enhanced crop productivity and disease management over the years. However, the prevalence of several abiotic and biotic stress factors has also enormously increased across diverse agroecosystems. This necessitates employing eco-friendly approaches like the application of plant growth promoting microorganisms (PGPMs) as bioinoculants for the establishment of agricultural sustainability. With conventional bioinoculants suffering from inherent limitations, efforts are underway to overcome these using novel approaches, which can lead to several beneficial impacts, ranging from plant growth promotion to stress mitigation in different crop systems. The current review focuses on the advancements made in the development of microbe-based next-generation bioformulations, using PGPMs in conjunction with several other efficacious microbial products, like metabolites, phytohormones, additives, and nanoparticles. In addition, a comparison of the limitations and advantages of both conventional and advanced next-generation bioformulations has been made. Since there is a scope for further improvement in this arena, key concerns related to the development of more effective next-generation bioformulations have been discussed. Overall, the review encompasses the recent advancements made on the various potent next-generation bioformulations developed so far, and offers deeper insights into the possible factors that can be modulated to further improve such eco-friendly products for application in diverse agricultural systems. [ABSTRACT FROM AUTHOR]

Nutrient use efficiency (NUE) is the part of a larger concept of resource use efficiency in agriculture which is a cause of concern for the present as well as the future of sustainability in agriculture. The nutrients applied to soil if not utilized by the plants find their way into the water resources and atmosphere which can increase the ecological cost. There are various measures of nutrient use efficiency which are suitable in different situations as well as for the nutrients. Among all the factors determining NUE, fertilizer factors are the most important. The various measures included in fertilizer factor are balanced fertilization, addition of organic matter, plant growth promoting micro-organisms, use of advanced form of fertilizers, use of modern equipment including Soil Plant Analysis Development and understanding of nutrient interaction and consequent antagonistic and synergistic effects on crop plants. [ABSTRACT FROM AUTHOR]

Background: The production of red fruits, such as blueberry, has been threatened by several stressors from severe periods of drought, nutrient scarcity, phytopathogens, and costs with fertilization programs with adverse consequences. Thus, there is an urgent need to increase this crop's resilience whilst promoting sustainable agriculture. Plant growth-promoting microorganisms (PGPMs) constitute not only a solution to tackle water and nutrient deficits in soils, but also as a control against phytopathogens and as green compounds for agricultural practices. Methods: In this study, a metagenomic approach of the local fungal and bacterial community of the rhizosphere of Vaccinium corymbosum plants was performed. At the same time, both epiphytic and endophytic microorganisms were isolated in order to disclose putative beneficial native organisms. Results: Results showed a high relative abundance of Archaeorhizomyces and Serendipita genera in the ITS sequencing, and Bradyrhizobium genus in the 16S sequencing. Diversity analysis disclosed that the fungal community presented a higher inter-sample variability than the bacterial community, and beta-diversity analysis further corroborated this result. Trichoderma spp., Bacillus spp., and Mucor moelleri were isolated from the V. corymbosum plants. Discussion: This work revealed a native microbial community capable of establishing mycorrhizal relationships, and with beneficial physiological traits for blueberry production. It was also possible to isolate several naturally-occurring microorganisms that are known to have plant growth-promoting activity and confer tolerance to hydric stress, a serious climate change threat. Future studies should be performed with these isolates to disclose their efficiency in conferring the needed resilience for this and several crops. [ABSTRACT FROM AUTHOR]

Backgorund The production of red fruits, such as blueberry, has been threatened by several stressors from severe periods of drought, nutrient scarcity, phytopathogens, and costs with fertilization programs with adverse consequences. Thus, there is an urgent need to increase this crop’s resilience whilst promoting sustainable agriculture. Plant growth-promoting microorganisms (PGPMs) constitute not only a solution to tackle water and nutrient deficits in soils, but also as a control against phytopathogens and as green compounds for agricultural practices. Methods In this study, a metagenomic approach of the local fungal and bacterial community of the rhizosphere of Vaccinium corymbosum plants was performed. At the same time, both epiphytic and endophytic microorganisms were isolated in order to disclose putative beneficial native organisms. Results Results showed a high relative abundance of Archaeorhizomyces and Serendipita genera in the ITS sequencing, and Bradyrhizobium genus in the 16S sequencing. Diversity analysis disclosed that the fungal community presented a higher inter-sample variability than the bacterial community, and beta-diversity analysis further corroborated this result. Trichoderma spp., Bacillus spp., and Mucor moelleri were isolated from the V. corymbosum plants. Discussion This work revealed a native microbial community capable of establishing mycorrhizal relationships, and with beneficial physiological traits for blueberry production. It was also possible to isolate several naturally-occurring microorganisms that are known to have plant growth-promoting activity and confer tolerance to hydric stress, a serious climate change threat. Future studies should be performed with these isolates to disclose their efficiency in conferring the needed resilience for this and several crops.

In this study, the combined effect of plant growth under different light quality and the application of plant-growth-promoting microbes (PGPM) was considered on spinach (Spinacia oleracea L.) to assess the influence of these factors on the photosynthetic performance. To pursue this goal, spinach plants were grown in a growth chamber at two different light quality regimes, full-spectrum white light (W) and red-blue light (RB), with (I) or without (NI) PGPM-based inoculants. Photosynthesis-light response curves (LRC) and photosynthesis-CO2 response curves (CRC) were performed for the four growth conditions (W-NI, RB-NI, W-I, and RB-I). At each step of LRC and CRC, net photosynthesis (PN), stomatal conductance (gs), Ci/Ca ratio, water use efficiency (WUEi), and fluorescence indexes were calculated. Moreover, parameters derived from the fitting of LRC, such as light-saturated net photosynthesis (PNmax), apparent light efficiency (Qpp), and dark respiration (Rd), as well as the Rubisco large subunit amount, were also determined. In not-inoculated plants, the growth under RB- regime improved PN compared to W-light because it increased stomatal conductance and favored the Rubisco synthesis. Furthermore, the RB regime also stimulates the processes of light conversion into chemical energy through chloroplasts, as indicated by the higher values of Qpp and PNmax in RB compared to W plants. On the contrary, in inoculated plants, the PN enhancement was significantly higher in W (30%) than in RB plants (17%), which showed the highest Rubisco content among all treatments. Our results indicate that the plant-growth-promoting microbes alter the photosynthetic response to light quality. This issue must be considered when PGPMs are used to improve plant growth performance in a controlled environment using artificial lighting. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is one of the essential macronutrients for plant growth, being a highly required resource to improve the productive performance of several crops, especially in highly weathered soils. However, a large part of the nutrients applied in the form of fertilizers becomes "inert" in the medium term and cannot be assimilated by plants. Rationalizing the use of phosphorus is a matter of extreme importance for environmental sustainability and socioeconomic development. Therefore, alternatives to the management of this nutrient are needed, and the use of P-solubilizing microorganisms is an option to optimize its use by crops, allowing the exploration of less available fractions of the nutrient in soils and reducing the demand for phosphate fertilizers. The objective of this study is to discuss the importance of phosphorus and how microorganisms can intermediate its sustainable use in agriculture. In this review study, we present several studies about the role of microorganisms as phosphorus mobilizers in the soil. We describe the importance of the nutrient for the plants and the main problems related to the unsustainable exploitation of its natural reserves and the use of chemical fertilizers. Mainly we highlight how microorganisms constitute a fundamental resource for the release of the inert portion of the nutrient, where we describe several mechanisms of solubilization and mineralization. We also discussed the benefits that the inoculation of P-solubilizing microorganisms provides to crops as well as practices of using them as bioinoculants. The use of microorganisms as inoculants is a viable resource for the future of sustainable agriculture, mainly because its application can significantly reduce the application of P and, consequently, reduce the exploitation of phosphorus and its reserves. In addition, new research must be conducted for the development of new technologies, prospecting new biological products, and improvement of management practices that allow for higher efficiency in the use of phosphorus in agriculture. [ABSTRACT FROM AUTHOR]

Many groups of microorganisms have been studied for their benefits towards humankind due to their capacity to produce natural compounds that can be valorized in many economic sectors such as agriculture. Due to the extensive use of chemicals pesticides and fertilizers, current agriculture systems facing several major problems such as emergence of resistant in pathogens and pests, soil infertility and bioaccumulation of toxic residues in the environment and particularly in foods which negatively affects human health. The use of natural products harmless to plants, humans and biodegradable constitute a promising way to overcome these problems. Modern agriculture systems are moving toward the use of beneficial microorganisms isolated from the soil, plant surfaces and inside tissues for developing eco-friendly products such as biofertilizers and biopesticides. Recent literatures show that colonization of plants by endophytes is the rule in nature and endophyte-free plant is a rare exception. Endophytes are microbes living inside plant tissues and supporting them in growth and development, as well as stresses tolerance without causing any apparent disease symptom. Abiotic stresses have a great impact on growth, production and health of plants. Many literatures show the role of endophytes in abiotic stress tolerance as well as mechanisms involved to cope with these constraints via the induction of stress-related genes and molecules. This review provides a summary of literature on how endophytes modulate plant growth and responses to abiotic stresses which may help to better understand their role in plant adaptation to environmental constraints and valorize their use in agriculture.

Biofertilizers are best complementary source for chemical fertilizers and are formed by the combination of different beneficial plant growth promoting microbes (PGPM). Liquid bio fertilizer consortium (LBFC) is more potential compared to carrier based biofertilizers because it has a longer shelf life. In the present study PGPM consortia of LMC is applied to finger millet by different modes namely, seed treatment, seedling root dip, soil application and combination of all the three to enhance its growth and yield. The treatment T4 (100 % NPK + Seed + Soil + Seedling root dip with LBFC) reported higher plant height, number of tillers per plant, number of leaves per plant and dry matter accumulation were superior when compared to other treatments. Higher yields obtained by PGPM, treatment demonstrate that it is effective in stimulating plant vegetative growth and enhancing crop productivity. The yield in T4 treatment recorded higher harvest index, grain and straw yield with 0.337, 4080 kg ha-1 and 7810 kg ha-1, respectively, when compared to the control (0.329, 1757 kg ha-1 and 3710 kg ha-1). Based on the analysis of microbial, plant and yield data, is evident that 100 per cent NPK with application of liquid biofertilizers consortia directly to the soil @ 625 ml in 500 kg of FYM / hectare can be recommended for finger millet crop in eastern dry zone (Zone-V). [ABSTRACT FROM AUTHOR]

Vermicompost has been promoted as a viable substrate component owing to its physicochemical properties, nutrient richness, and status as an excellent soil improver. It is considered the best organic fertilizer and is more eco-friendly than chemical fertilizers. Plant-growth-promoting microorganisms (PGPMs) are defined as plant biofertilizers that improve nutritional efficiency—that is, they transform nutrients within substrates from organic to inorganic forms, making them available for plants. The main objective of this research study is to evaluate the effects of the application of three PGPM microbial consortia on different mixtures of organic substrates based on vermicompost (V) and coconut fiber (CF) on two different horticultural crops. We performed a yield analysis and drainage nutrient tests and determined the plant nutritional status and enzymatic activity in organic substrates based on the two crops, Cucumis melo L. and Solanum lycopersicum L. A multivariate analysis of variance and principal component analysis was conducted using substrate types and PGPMs as factors. Differences (p < 0.05) in yield, dehydrogenase activity, the nutrient concentrations in a petiole sap, and drainage were observed at 30, 60, 75, and 90 days after transplant. PGPMs such as Trichoderma sp. and plant-growth-promoting rhizobacteria (PGPR) in organic substrates (40V + 60CF) can significantly improve the nutritional status of plants for use in organic soilless container agriculture. Biofertilization with PGPMs and suitable mixtures of organic substrates together with aqueous extracts (tea) of vermicompost, as nutrient solutions applied by fertigation, has allowed us to achieve an adequate level of production through environmentally friendly techniques. The results obtained allowed us to affirm that it was possible to replace conventional fertilization using no chemical products and ensure adequate crop nutrition by supplying main macronutrients with organic sources and biofertilizers. [ABSTRACT FROM AUTHOR]

Biochar as a soil amendment, increases soil fertility and better agricultural production. In addition, the utilization of microbial bio-fertilizers improves soil health and reduces the necessity of excessive chemical fertilizer application. In this regard, the present research was conducted to evaluate the effect of bio-inoculants and bagasse biochar on root colonization, grain nutrients uptake, growth, and yield of barley, and biological activities in a calcareous soil. An experiment was conducted as a factorial arrangement on a completely randomized design with three replications in a greenhouse condition for seven months. The treatments consisted of six bio-fertilizer levels including control, Rhizophagus intraradices, Funneliformis mosseae, Micrococcus yunnanensis, Rhizophagus intraradices + Micrococcus yunnanensis, Funneliformis mosseae + Micrococcus yunnanensis, and three bagasse biochar levels of 0, 1%, and 2% w/w. The application of 2% biochar significantly increased root colonization (32.3%), grain nutrients uptake of N, P, Zn and Cu (10%, 10%, 10%, and 4.3%, respectively), biological yield (5.08%), soil microbial respiration (SMR) (11.3%), and microbial biomass C (MBS) (12.7%) compared to that of B0. Individual application of bio-inoculants and their combination with biochar increased root colonization, grain nutrients (Fe, Zn, Cu, Mn, P, and N) uptake, biological and grain yield, 1000-kernel weight, SMR, and MBS. Application of plant growth promoting microorganisms and bagasse biochar simultaneously makes positive effects on barley and microbial activities, which is a promising strategy. [ABSTRACT FROM AUTHOR]

In this study, the combined effect of plant growth under different light quality and the application of plant-growth-promoting microbes (PGPM) was considered on spinach (Spinacia oleracea L.) to assess the influence of these factors on the photosynthetic performance. To pursue this goal, spinach plants were grown in a growth chamber at two different light quality regimes, full-spectrum white light (W) and red-blue light (RB), with (I) or without (NI) PGPM-based inoculants. Photosynthesis-light response curves (LRC) and photosynthesis-CO2 response curves (CRC) were performed for the four growth conditions (W-NI, RB-NI, W-I, and RB-I). At each step of LRC and CRC, net photosynthesis (PN), stomatal conductance (gs), Ci/Ca ratio, water use efficiency (WUEi), and fluorescence indexes were calculated. Moreover, parameters derived from the fitting of LRC, such as light-saturated net photosynthesis (PNmax), apparent light efficiency (Qpp), and dark respiration (Rd), as well as the Rubisco large subunit amount, were also determined. In not-inoculated plants, the growth under RB- regime improved PN compared to W-light because it increased stomatal conductance and favored the Rubisco synthesis. Furthermore, the RB regime also stimulates the processes of light conversion into chemical energy through chloroplasts, as indicated by the higher values of Qpp and PNmax in RB compared to W plants. On the contrary, in inoculated plants, the PN enhancement was significantly higher in W (30%) than in RB plants (17%), which showed the highest Rubisco content among all treatments. Our results indicate that the plant-growth-promoting microbes alter the photosynthetic response to light quality. This issue must be considered when PGPMs are used to improve plant growth performance in a controlled environment using artificial lighting.

Phosphorus (P) is one of the essential macronutrients for plant growth, being a highly required resource to improve the productive performance of several crops, especially in highly weathered soils. However, a large part of the nutrients applied in the form of fertilizers becomes “inert” in the medium term and cannot be assimilated by plants. Rationalizing the use of phosphorus is a matter of extreme importance for environmental sustainability and socioeconomic development. Therefore, alternatives to the management of this nutrient are needed, and the use of P-solubilizing microorganisms is an option to optimize its use by crops, allowing the exploration of less available fractions of the nutrient in soils and reducing the demand for phosphate fertilizers. The objective of this study is to discuss the importance of phosphorus and how microorganisms can intermediate its sustainable use in agriculture. In this review study, we present several studies about the role of microorganisms as phosphorus mobilizers in the soil. We describe the importance of the nutrient for the plants and the main problems related to the unsustainable exploitation of its natural reserves and the use of chemical fertilizers. Mainly we highlight how microorganisms constitute a fundamental resource for the release of the inert portion of the nutrient, where we describe several mechanisms of solubilization and mineralization. We also discussed the benefits that the inoculation of P-solubilizing microorganisms provides to crops as well as practices of using them as bioinoculants. The use of microorganisms as inoculants is a viable resource for the future of sustainable agriculture, mainly because its application can significantly reduce the application of P and, consequently, reduce the exploitation of phosphorus and its reserves. In addition, new research must be conducted for the development of new technologies, prospecting new biological products, and improvement of management practices that allow for higher efficiency in the use of phosphorus in agriculture.

Marigold flower leachate, an effluent from the marigold processing industry, was used in irrigation as a one-time amendment to nearby arable land. It has found to be a source of essential nutrients and no harmful effects for plants. Hence, the present study was taken up to evaluate the combined effect of untreated marigold flower leachate (UMFE) and plant growth promoting microorganisms (PGPM) as a supplement along with other combinations, on growth and yield of potato. The treatments T6 (RDF + UMFE + PGPM) and T7 (RDF + 50: 50 (Water: UMFE) + PGPM) reported higher plant height, number of shoots per plant, number of leaves per plant and chlorophyll content and were superior when compared to other treatments. Higher yields were obtained in the treatment received with PGPM, demonstrating that PGPM is effective in stimulating plant vegetative growth and enhancing crop productivity. The yield in T7 treatment was higher (19.68 t ha-1 of tubers), when compared to the control (5.90 t ha-1). The study found that applying UMFE in a 50:50 ratio (UFME: bore well water) to the agricultural land and PGPM, could be a feasible option for recycling the industrial wastewater without losing the essential nutrients. According to the study, UMFE, rich in nutrients improves the soil by adding organic matter, and beneficial bacteria aid in the solubilization and mobilization of nutrients in the soil to the plant system, resulting in a better supplement for improved growth and yield in potato. [ABSTRACT FROM AUTHOR]

Oil tea (Camellia spp.) is endemic to the hilly regions in the subtropics. Camellia yuhsienensis is resistant to diseases such as anthracnose and root rot, while Camellia oleifera is a high-yield species but susceptible to these diseases. We hypothesize that differences in the rhizosphere microbial communities and functions will elucidate the resistance mechanisms of these species. We used high-throughput sequencing over four seasons to characterize the rhizosphere microbiome of C. oleifera (Rhizo-Sus) and C. yuhsienensis (Rhizo-Res) and of the bulk soil control (BulkS). In Rhizo-Res, bacterial richness and diversity (Shannon index) in autumn and winter were both higher than that in Rhizo-Sus. In Rhizo-Res, fungal richness in autumn and winter and diversity in summer, autumn, and winter were higher than that in Rhizo-Sus. The seasonal variations in bacterial community structure were different, while that of fungal community structure were similar between Rhizo-Res and Rhizo-Sus. Gram-positive, facultatively anaerobic, and stress-tolerant bacteria were the dominant groups in Rhizo-Sus, while Gram-negative bacteria were the dominant group in Rhizo-Res. The significant differences in bacterial and fungal functions between Rhizo-Sus and Rhizo-Res were as follows: (1) in Rhizo-Sus, there were three bacterial and four fungal groups with plant growth promoting potentials, such as Brevibacterium epidermidis and Oidiodendron maius, and one bacterium and three fungi with pathogenic potentials, such as Gryllotalpicola sp. and Cyphellophora sessilis; (2) in Rhizo-Res, there were also three bacteria and four fungal groups with plant-growth-promoting potentials (e.g., Acinetobacter lwoffii and Cenococcum geophilum) but only one phytopathogen (Schizophyllum commune). In summary, the rhizosphere microbiome of disease-resistant C. yuhsienensis is characterized by a higher richness and diversity of microbial communities, more symbiotic fungal communities, and fewer pathogens compared to the rhizosphere of high-yield but disease-susceptible C. oleifera.

Oil tea (Camellia spp.) is endemic to the hilly regions in the subtropics. Camellia yuhsienensis is resistant to diseases such as anthracnose and root rot, while Camellia oleifera is a high-yield species but susceptible to these diseases. We hypothesize that differences in the rhizosphere microbial communities and functions will elucidate the resistance mechanisms of these species. We used high-throughput sequencing over four seasons to characterize the rhizosphere microbiome of C. oleifera (Rhizo-Sus) and C. yuhsienensis (Rhizo-Res) and of the bulk soil control (BulkS). In Rhizo-Res, bacterial richness and diversity (Shannon index) in autumn and winter were both higher than that in Rhizo-Sus. In Rhizo-Res, fungal richness in autumn and winter and diversity in summer, autumn, and winter were higher than that in Rhizo-Sus. The seasonal variations in bacterial community structure were different, while that of fungal community structure were similar between Rhizo-Res and Rhizo-Sus. Gram-positive, facultatively anaerobic, and stress-tolerant bacteria were the dominant groups in Rhizo-Sus, while Gram-negative bacteria were the dominant group in Rhizo-Res. The significant differences in bacterial and fungal functions between Rhizo-Sus and Rhizo-Res were as follows: (1) in Rhizo-Sus, there were three bacterial and four fungal groups with plant growth promoting potentials, such as Brevibacterium epidermidis and Oidiodendron maius , and one bacterium and three fungi with pathogenic potentials, such as Gryllotalpicola sp. and Cyphellophora sessilis ; (2) in Rhizo-Res, there were also three bacteria and four fungal groups with plant-growth-promoting potentials (e.g., Acinetobacter lwoffii and Cenococcum geophilum) but only one phytopathogen (Schizophyllum commune). In summary, the rhizosphere microbiome of disease-resistant C. yuhsienensis is characterized by a higher richness and diversity of microbial communities, more symbiotic fungal communities, and fewer pathogens compared to the rhizosphere of high-yield but disease-susceptible C. oleifera. [ABSTRACT FROM AUTHOR]

Smallholder agroecosystems play a key role in the world's food security providing more than 50% of the food produced globally. These unique agroecosystems face a myriad of challenges and remain largely unsupported, yet they are thought to be a critical resource for feeding the projected increasing human population in the coming years. The new challenge to increase food production through agricultural intensification in shrinking per capita arable lands, dwindling world economies, and unpredictable climate change, has led to over-dependence on agrochemical inputs that are often costly and hazardous to both human and animal health and the environment. To ensure healthy crop production approaches, the search for alternative ecofriendly strategies that best fit to the smallholder systems have been proposed. The most common and widely accepted solution that has gained a lot of interest among researchers and smallholder farmers is the use of biological agents; mainly plant growth promoting microorganisms (PGPMs) that provide essential agroecosystem services within a holistic vision of enhancing farm productivity and environmental protection. PGPMs play critical roles in agroecological cycles fundamental for soil nutrient amelioration, crop nutrient improvement, plant tolerance to biotic and abiotic stresses, biocontrol of pests and diseases, and water uptake. This review explores different research strategies involving the use of beneficial microorganisms, within the unique context of smallholder agroecosystems, to promote sustainable maintenance of plant and soil health and enhance agroecosystem resilience against unpredictable climatic perturbations.

Sustainable agriculture remains a focus for many researchers, in an effort to minimize environmental degradation and climate change. The use of plant growth promoting microorganisms (PGPM) is a hopeful approach for enhancing plant growth and yield. However, the technology faces a number of challenges, especially inconsistencies in the field. The discovery, that microbial derived compounds can independently enhance plant growth, could be a step toward minimizing shortfalls related to PGPM technology. This has led many researchers to engage in research activities involving such compounds. So far, the findings are promising as compounds have been reported to enhance plant growth under stressed and non-stressed conditions in a wide range of plant species. This review compiles current knowledge on microbial derived compounds, taking a reader through a summarized protocol of their isolation and identification, their relevance in present agricultural trends, current use and limitations, with a view to giving the reader a picture of where the technology has come from, and an insight into where it could head, with some suggestions regarding the probable best ways forward.

Vermicompost has been promoted as a viable substrate component owing to its physicochemical properties, nutrient richness, and status as an excellent soil improver. It is considered the best organic fertilizer and is more eco-friendly than chemical fertilizers. Plant-growth-promoting microorganisms (PGPMs) are defined as plant biofertilizers that improve nutritional efficiency—that is, they transform nutrients within substrates from organic to inorganic forms, making them available for plants. The main objective of this research study is to evaluate the effects of the application of three PGPM microbial consortia on different mixtures of organic substrates based on vermicompost (V) and coconut fiber (CF) on two different horticultural crops. We performed a yield analysis and drainage nutrient tests and determined the plant nutritional status and enzymatic activity in organic substrates based on the two crops, Cucumis melo L. and Solanum lycopersicum L. A multivariate analysis of variance and principal component analysis was conducted using substrate types and PGPMs as factors. Differences (p < 0.05) in yield, dehydrogenase activity, the nutrient concentrations in a petiole sap, and drainage were observed at 30, 60, 75, and 90 days after transplant. PGPMs such as Trichoderma sp. and plant-growth-promoting rhizobacteria (PGPR) in organic substrates (40V + 60CF) can significantly improve the nutritional status of plants for use in organic soilless container agriculture. Biofertilization with PGPMs and suitable mixtures of organic substrates together with aqueous extracts (tea) of vermicompost, as nutrient solutions applied by fertigation, has allowed us to achieve an adequate level of production through environmentally friendly techniques. The results obtained allowed us to affirm that it was possible to replace conventional fertilization using no chemical products and ensure adequate crop nutrition by supplying main macronutrients with organic sources and biofertilizers.

Sustainable agriculture remains a focus for many researchers, in an effort to minimize environmental degradation and climate change. The use of plant growth promoting microorganisms (PGPM) is a hopeful approach for enhancing plant growth and yield. However, the technology faces a number of challenges, especially inconsistencies in the field. The discovery, that microbial derived compounds can independently enhance plant growth, could be a step toward minimizing shortfalls related to PGPM technology. This has led many researchers to engage in research activities involving such compounds. So far, the findings are promising as compounds have been reported to enhance plant growth under stressed and non-stressed conditions in a wide range of plant species. This review compiles current knowledge on microbial derived compounds, taking a reader through a summarized protocol of their isolation and identification, their relevance in present agricultural trends, current use and limitations, with a view to giving the reader a picture of where the technology has come from, and an insight into where it could head, with some suggestions regarding the probable best ways forward. [ABSTRACT FROM AUTHOR]

Biofertilizer is a substance containing live microorganisms which exhibit beneficial properties toward plant growth and development. Various mechanisms are used by microbial strains in order to enhance nutrient uptake, improve soil fertility and increase crop yields such as nitrogen fixation, potassium and phosphorus solubilization, excretion of phytohormones, production of substances suppressing phytopathogens, guarding plants from abiotic and biotic stresses and detoxification of belowground pollutants. Taking into consideration growing consumption requirements on Earth and hazards arising from the excessive use of chemical fertilizers and pesticides, biofertilizers are thought to be a promising and non-toxic alternative to synthetic agro-chemicals, including fungal control and minimization of mycotoxins contamination. The implementation of microbial inoculants is considered to overcome the shortcomings associated with chemical-based farming techniques, therefore research into widespread use of biofertilizers is one of the mainstream in scientific work for the development of sustainable agriculture. [ABSTRACT FROM AUTHOR]

In most cases, plants act indirectly by stimulating beneficial rhizosphere and endophytic microbes, which could facilitate/accelerate phytoremediation process by improving plant growth, altering soil metal bioavailability or facilitating the degradation of organic pollutants (known as bioaugmentation). Plant-microbe interactions play a critical role in plant adaption to metalliferous environments, stimulation of plant growth, and thus can be explored to accelerate microbe-aided phytoremediation. [3] extensively reviewed the recent advances to understand the biochemical (e.g., chemotaxis, colonization, beneficial functioning) and molecular mechanisms (e.g., signal and volatiles, quorum sensing, chemical signal) of plant-microbe interactions and their potential in the phytoremediation process, which may contribute significantly to the practical application of phytoremediation techniques. To understand the roles of PGPR in microbe-aided phytoremediation, Fang et al. screened Cu/Zn-resistant PGPR isolates and assessed their bioremediation potential (plant growth enhancement and metal solubilization/tolerance/biosorption). [Extracted from the article]

Aims: The objective of this research was to study the effect of bio-liquid organic fertilizer on the growth of Dipterocarpus alatus Roxb seedlings (30 days old) in the pot experiment. Methodology and results: For the production of bio-liquid fertilizers, distillery slop; molasses and bio-methane waste water were fermented with plant growth promoting bacteria, which had potentials for nitrogen fixing, phosphate solubilizing and potassium solubilizing properties. It was found that treatment no. 13 (molasses + three bacterial isolates (PGPB), 30 days of fermentation) presented the best result on the growth parameters of D. alatus Roxb including root length (21.67 cm), shoot height (20.33 cm), root fresh weight (1.49 g), shoot fresh weight (3.61 g) and total biomass (4.13 g). Moreover, using liquid organic fertilizer produced from molasses supplemented with bacteria had higher growth-promoting effects on D. alatus than the effective microorganisms (EM). Conclusion, significance and impact of study: To covert agricultural residues to the valuable product was the aim of this work. In our experiment, we found that molasses and bio-methane waste water were suitable for using as a material to produce liquid organic fertilizers which were beneficial for promoting growth of D. alatus seedlings. [ABSTRACT FROM AUTHOR]

Introduction: Arbuscular mycorrhizal symbiosis is formed by approximately 80% of the vascular plant species in all terrestrial biomes. Using soil microbial potential including arbuscular mycorrhizal fungi (AMF) has been widely considered for improving plant growth, yield and nutrition. Medicinal herbs are known as sources of phyto chemicals or active compounds that are widely sought worldwide for their natural properties. Members of the Lamiaceae family have been used since ancient times as sources of spices and flavorings and for their pharmaceutical properties. Peppermint (Mentha piperita) has a long tradition of medicinal use, with archaeological evidence placing its use at least as far back as ten thousand years ago. Essential oils - are volatile, lipophilic mixtures of secondary plant compounds, mostly consisting of monoterpenes, sesquiterpenes and phenylproponoids.Arbuscularmycorrhizal fungi with colonizing plant roots improve nutrient uptake as well as improving essential oil yield of medicinal plants by increasing plant biomass. The aim of the present study was to evaluate the effect of AMF inoculation on essential oil content and some growth parameters of peppermint (Mentha piperita) plant under glasshouse condition. Materials and Methods: This study was performed on a loamy sand soil. The samples were air-dried, sieved (

Climate change has already affected food security in many parts of the world, and this situation will worsen if nothing is done to combat it. Unfortunately, agriculture is a meaningful driver of climate change, through greenhouse gas emissions from nitrogen-based fertilizer, methane from animals and animal manure, as well as deforestation to obtain more land for agriculture. Therefore, the global agricultural sector should minimize greenhouse gas emissions in order to slow climate change. The objective of this review is to point out the various ways plant growth promoting microorganisms (PGPM) can be used to enhance crop production amidst climate change challenges, and effects of climate change on more conventional challenges, such as: weeds, pests, pathogens, salinity, drought, etc. Current knowledge regarding microbial inoculant technology is discussed. Pros and cons of single inoculants, microbial consortia and microbial compounds are discussed. A range of microbes and microbe derived compounds that have been reported to enhance plant growth amidst a range of biotic and abiotic stresses, and microbe-based products that are already on the market as agroinputs, are a focus. This review will provide the reader with a clearer understanding of current trends in microbial inoculants and how they can be used to enhance crop production amidst climate change challenges.

Arbuscular mycorrhizal (AM) fungi and plant growth-promoting rhizobacteria, responsible for enhancing plant nutrition, vigour and growth, may be used to reduce dosages of chemical fertilisers. Technologies that allow an economically viable and efficient application of these beneficial microbes in large scale agriculture must be studied. Seed coating is a potential delivery system for efficiently introducing minor amounts of bioinoculants. Despite the dramatic reduction on inoculum dose per plant, inoculation of AM fungi via seed coating was as effective as conventional soil inoculation. Fertilisation and inoculation had a significant impact on maize shoots nutrient concentrations. Different fertilisation regimes did not influence mycorrhizal colonisation. Plants without fertilisation and singly inoculated with R. irregularis showed shoot nutrient concentration increments of 110, 93, 88 and 175% for nitrogen, phosphorus, potassium and zinc, respectively, comparing with non-inoculated controls. Plants singly inoculated with P. fluorescens via seed coating under full fertilisation, presented enhancements of 100, 75 and 141% for magnesium, zinc and manganese, respectively, comparing with non-inoculated controls. Seed coating is a promising tool for delivering microbial inoculants into the soil, while promoting sustainable production of maize. This technology is particularly pertinent in low input agriculture, with potential environmental profits and food quality improvements. [ABSTRACT FROM AUTHOR]

Along with the high temperatures generated during the composting process, the microbial community of a compost pile collaborates actively in the control of damping-off producing agents. Such collaboration could be justified on the basis of the ability of the microbiota to produce fungicide substances that are involved in the control of damping-off or other bioactive compounds that affect the growth promotion of plants. Thanks to ex situ experiments, a remarkable suppressive effect was corroborated against different agents producing damping-off. The microbial strains involved in this effect were detected mainly in the bio-oxidative and maturation phases of the composting process. However, only 3% of the total collection of strains proved to have a multipotential character with respect to its spectrum of action against the damping-off producing agents, as well as in relation to its capacity to produce substances of agronomic interest. It is worth mentioning the presence of two thermophilic isolates identified as Geobacillus thermodenitrificans and Bacillus aerius that showed the ability to inhibit the symptoms caused by Phytophthora capsici in vivo. Both strains were able to produce siderophores, salicylic acid and chitinase enzymes in vitro, but only G. thermodenitrificans was able to stimulate the development of the root in pepper seedlings. In this sense, it is suspected that the production of cyanide by this thermophilic bacteria could be related to this latter effect. [ABSTRACT FROM AUTHOR]

As the processes facilitated by plant growth promoting microorganisms (PGPMs) become better characterized, it is evident that PGPMs may be critical for successful sustainable agricultural practices. Microbes enrich plant growth through various mechanisms, such as enhancing resistance to disease and drought, producing beneficial molecules, and supplying nutrients and trace metals to the plant rhizosphere. Previous studies of PGPMs have focused primarily on soil-based crops. In contrast, aquaponics is a water-based agricultural system, in which production relies upon internal nutrient recycling to co-cultivate plants with fish. This arrangement has management benefits compared to soil-based agriculture, as system components may be designed to directly harness microbial processes that make nutrients bioavailable to plants in downstream components. However, aquaponic systems also present unique management challenges. Microbes may compete with plants for certain micronutrients, such as iron, which makes exogenous supplementation necessary, adding production cost and process complexity, and limiting profitability and system sustainability. Research on PGPMs in aquaponic systems currently lags behind traditional agricultural systems, however, it is clear that certain parallels in nutrient use and plant-microbe interactions are retained from soil-based agricultural systems.

As the processes facilitated by plant growth promoting microorganisms (PGPMs) become better characterized, it is evident that PGPMs may be critical for successful sustainable agricultural practices. Microbes enrich plant growth through various mechanisms, such as enhancing resistance to disease and drought, producing beneficial molecules, and supplying nutrients and trace metals to the plant rhizosphere. Previous studies of PGPMs have focused primarily on soil-based crops. In contrast, aquaponics is a water-based agricultural system, in which production relies upon internal nutrient recycling to co-cultivate plants with fish. This arrangement has management benefits compared to soil-based agriculture, as system components may be designed to directly harness microbial processes that make nutrients bioavailable to plants in downstream components. However, aquaponic systems also present unique management challenges. Microbes may compete with plants for certain micronutrients, such as iron, which makes exogenous supplementation necessary, adding production cost and process complexity, and limiting profitability and system sustainability. Research on PGPMs in aquaponic systems currently lags behind traditional agricultural systems, however, it is clear that certain parallels in nutrient use and plant-microbe interactions are retained from soil-based agricultural systems. [ABSTRACT FROM AUTHOR]

Eucalyptus benthamii is a tree species commonly planted in subtropical areas, including the Southern Brazil, due to its tolerance to low temperatures and frosts. The success of E. benthamii plantation depends on the seedlings vigor during transplantation. We hypothesized that improvement of chemical and biological properties of growth substrate would produce more vigorous E. benthamii seedlings. Thus, we applied increasing doses (0, 0.5, 1.0, 1.5 and 2.0 g per seedling) of the organic fertilizer Bacsol, which carries a consortium of potential plant growth promoting microorganisms, on the substrate and measured the growth and development of E. benthamii seedlings. Two experiments were performed in 2011 and 2012. The first experiment included measurements in four growth stages to estimate the relative growth rates. The second one ended at the time that seedlings reached standard heights for transplantation (about ± 20 cm). Measurements on plant height, stem diameter, shoot dry weight and relative growth rates indicated that the application of Bacsol improved E. benthamii seedlings vigor and decreased the time needed in nursery, from 150 days to 90 days. The best responses occurred at doses from 1.3 g to 1.5 g per seedling. The data demonstrated that application of Bacsol in substrate is a promising technology to increase E. benthamii seedlings vigor [ABSTRACT FROM AUTHOR]

Plants and microbes coexist or compete for survival and their cohesive interactions play a vital role in adapting to metalliferous environments, and can thus be explored to improve microbe-assisted phytoremediation. Plant root exudates are useful nutrient and energy sources for soil microorganisms, with whom they establish intricate communication systems. Some beneficial bacteria and fungi, acting as plant growth promoting microorganisms (PGPMs), may alleviate metal phytotoxicity and stimulate plant growth indirectly via the induction of defense mechanisms against phytopathogens, and/or directly through the solubilization of mineral nutrients (nitrogen, phosphate, potassium, iron, etc.), production of plant growth promoting substances (e.g., phytohormones), and secretion of specific enzymes (e.g., 1-aminocyclopropane-1-carboxylate deaminase). PGPM can also change metal bioavailability in soil through various mechanisms such as acidification, precipitation, chelation, complexation, and redox reactions. This review presents the recent advances and applications made hitherto in understanding the biochemical and molecular mechanisms of plant-microbe interactions and their role in the major processes involved in phytoremediation, such as heavy metal detoxification, mobilization, immobilization, transformation, transport, and distribution. [ABSTRACT FROM AUTHOR]

Avocado crop production in Colombia requires establishing environmentally friendly and inexpensive measures for wilt disease management, whose main causal agent is. Soil microorganisms use is an option for improving nutrition and health in Persea americana, looking to be more competitive in order to face the free trade agreements and to exploit the full export potential for this fruit. Understanding the complexity of the soil microbiota system, due to its great diversity and different ecological relationships that govern it, this study was designed to evaluate under greenhouse conditions the effect of Trichoderma sp, Glomus fasciculatum and Pseudomonas sp. isolates, on P. americana seedling development inoculated and non-inoculated with P. cinnamomi. Results found in this work suggest that G. fasciculatum and Pseudomonas sp., alone or in combination increase avocado seedling development, meanwhile Trichoderma sp. showed the best results in reducing the wilt disease progress on P. cinnamomi-inoculated plants. Soil microorganisms have a large potential for P. Americana development and pathogen protection, but it is necessary to understand all possible relationships in order to strengthen their use as biofertilizers and biocontrol agents. [ABSTRACT FROM AUTHOR]

Abstract: A considerable number of soil and rhizospheric fungi and bacteria collectively known as plant growth promoting microorganisms (PGPM) have demonstrated ability to colonize plant roots and to provide benefits to their hosts. Among these benefits, many authors documented improved root hydraulic conductance and alleviation of abiotic stresses such as drought and salinity. Today, it is accepted that movement through aquaporins represents a quite faster pathway of water movement across biological membranes. This review is intended to reflect the state of art in the knowledge of PGPM effects on plant water status and root hydraulic conductance, with special emphasis on the experimental data that prove or suggest an impact of PGPM on root aquaporins under both normal and water limiting conditions. [Copyright &y& Elsevier]

The effects of soil application of Bacillus subtilis, Pseudomonas fluorescens, Aspergillus awamori, A, niger and Penicillium digitatum on the plant growth, biomass production, yield and the rhizospheric population of Fusarium oxysporum f.sp. lycopersici on tomato were investigated in a field trial. Plant growth and yield variables of uninoculated plants were increased after application of all the tested phosphate solubilizers. Application of A. awamori and A. niger resulted in an 80% and 58% increase in the yield, respectively. The yield (weight of fruits/plant) of plants inoculated with F. oxysporum f.sp. lycopersici was significantly increased by all the phosphate-solubilizing microorganisms, especially with A. niger (53%), A. awamori (42%), P. digitatum (38%) and B. subtilis (28%). Application of phosphate-solubilizing microorganisms also decreased the rhizosphere population of the wilt fungus by 23–49%. [ABSTRACT FROM AUTHOR]