Browsing by Author "Ramakrishna, Wusirika"

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Anticancer Activities of Plant Secondary Metabolites: Rice Callus Suspension Culture as a New Paradigm
(Elsevier B.V., 2020-12-17T00:00:00) Ramakrishna, Wusirika; Kumari, Anuradha; Rahman, Nafeesa; Mandave, Pallavi
Plant natural products including alkaloids, polyphenols, terpenoids and flavonoids have been reported to exert anticancer activity by targeting various metabolic pathways. The biological pathways regulated by plant products can serve as novel drug targets. Plant natural compounds or their derivatives used for cancer treatment and some novel plant-based compounds which are used in clinical trials were discussed. Callus suspension culture with secondary metabolites can provide a continuous source of plant pharmaceuticals without time and space limitations. Previous research has shown that rice callus suspension culture can kill >95% cancer cells with no significant effect on the growth of normal cells. The role of candidate genes and metabolites which are likely to be involved in the process and their potential to serve as anticancer and anti-inflammatory agents were discussed. Large scale production of plant callus suspension culture and its constituents can be achieved using elicitors which enhance specific secondary metabolites combined with bioprocess technology. � 2020
Application of CRISPR�Cas9 in plant�plant growth-promoting rhizobacteria interactions for next Green Revolution
(Springer Science and Business Media Deutschland GmbH, 2021-11-13T00:00:00) Singh, Sudiksha; Ramakrishna, Wusirika
Agriculture's beginnings resulted in the domestication of numerous plant species as well as the use of natural resources. Food grain production took about 10,000�years to reach a billion tonnes in 1960, however, it took only 40�years to achieve 2 billion tonnes in year 2000. The creation of genetically modified crops, together with the use of enhanced agronomic practices, resulted in this remarkable increase, dubbed the "Green Revolution". Plants and bacteria that interact with each other in nature are co-evolving, according to Red Queen dynamics. Plant microorganisms, also known as plant microbiota, are an essential component of plant life. Plant�microbe (PM) interactions can be beneficial or harmful to hosts, depending on the health impact. The significance of microbiota in plant growth promotion (PGP) and stress resistance is well known. Our understanding of the community composition of the plant microbiome and important driving forces has advanced significantly. As a result, utilising the plant microbiota is a viable strategy for the next Green Revolution for meeting food demand. The utilisation of newer methods to understand essential genetic and molecular components of the multiple PM interactions is required for their application. The use of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas-mediated genome editing (GE) techniques to investigate PM interactions is of tremendous interest. The implementation of GE techniques to boost the ability of microorganisms or plants for agronomic trait development will be enabled by a comprehensive understanding of PM interactions. This review focuses on using GE approaches to investigate the principles of PM interactions, disease resistance, PGP activity, and future implications in agriculture in plants or associated microbiota. � 2021, King Abdulaziz City for Science and Technology.
Bacillus sp. and arbuscular mycorrhizal fungi consortia enhance wheat nutrient and yield in the second-year field trial: Superior performance in comparison with chemical fertilizers
(John Wiley and Sons Inc, 2021-11-20T00:00:00) Yadav, Radheshyam; Ror, Pankaj; Beniwal, Rahul; Kumar, Sanjeev; Ramakrishna, Wusirika
Aims: The aim of the study is to analyse the effect of microbial consortia for wheat biofortification, growth, yield and soil fertility as part of a 2-year field study and compare it with the use of chemical fertilizers. Methods and Results: A field trial (second year) was conducted with various combinations of plant growth�promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) treatments, ranging from a single inoculant to multiple combinations. The microbial consortia used were Bacillus sp. and AMF based on first-year field trial results. The consortia based on native (CP4) and non-native (AHP3) PGPB (Bacillus sp.) and AMF performed better in terms of nutrients content in wheat grain tissue and yield-related traits compared with chemical fertilizer treated and untreated control. Dual treatment of PGPB (CP4+AHP3) combined with AMF resulted in a significant increase in antioxidants. The spatial colonization of AMF in roots indicated that both the isolates CP4 and AHP3 were able to enhance the AMF colonization in root tissue. Furthermore, soil enzymes� activities were higher with the PGPB and AMF combination giving the best results. A positive correlation was recorded between plant growth, grain yield and soil physicochemical parameters. Conclusions: Our findings confirm that the combined treatment of CP4 and AHP3 and AMF functions as an effective microbial consortium with excellent application prospects for wheat biofortification, grain yield and soil fertility compared with chemical fertilizers. Significance and Impact of Study: The extensive application of chemical fertilizers on low-yielding field sites is a severe concern for cereal crops, especially wheat in the Asian continent. This study serves as a primer for implementing site-specific sustainable agricultural-management practices using a green technology leading to significant gains in agriculture. � 2021 The Society for Applied Microbiology
Bacillus sp. and arbuscular mycorrhizal fungi consortia enhance wheat nutrient and yield in the second-year field trial: Superior performance in comparison with chemical fertilizers
(John Wiley and Sons Inc, 2021-11-20T00:00:00) Yadav, Radheshyam; Ror, Pankaj; Beniwal, Rahul; Kumar, Sanjeev; Ramakrishna, Wusirika
Aims: The aim of the study is to analyse the effect of microbial consortia for wheat biofortification, growth, yield and soil fertility as part of a 2-year field study and compare it with the use of chemical fertilizers. Methods and Results: A field trial (second year) was conducted with various combinations of plant growth�promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) treatments, ranging from a single inoculant to multiple combinations. The microbial consortia used were Bacillus sp. and AMF based on first-year field trial results. The consortia based on native (CP4) and non-native (AHP3) PGPB (Bacillus sp.) and AMF performed better in terms of nutrients content in wheat grain tissue and yield-related traits compared with chemical fertilizer treated and untreated control. Dual treatment of PGPB (CP4+AHP3) combined with AMF resulted in a significant increase in antioxidants. The spatial colonization of AMF in roots indicated that both the isolates CP4 and AHP3 were able to enhance the AMF colonization in root tissue. Furthermore, soil enzymes� activities were higher with the PGPB and AMF combination giving the best results. A positive correlation was recorded between plant growth, grain yield and soil physicochemical parameters. Conclusions: Our findings confirm that the combined treatment of CP4 and AHP3 and AMF functions as an effective microbial consortium with excellent application prospects for wheat biofortification, grain yield and soil fertility compared with chemical fertilizers. Significance and Impact of Study: The extensive application of chemical fertilizers on low-yielding field sites is a severe concern for cereal crops, especially wheat in the Asian continent. This study serves as a primer for implementing site-specific sustainable agricultural-management practices using a green technology leading to significant gains in agriculture. � 2021 The Society for Applied Microbiology
Bacillus subtilis impact on plant growth, soil health and environment: Dr. Jekyll and Mr. Hyde
(John Wiley and Sons Inc, 2022-02-09T00:00:00) Mahapatra, Subhasmita; Yadav, Radheshyam; Ramakrishna, Wusirika
The increased dependence of farmers on chemical fertilizers poses a risk to soil fertility and ecosystem stability. Plant growth-promoting rhizobacteria (PGPR) are at the forefront of sustainable agriculture, providing multiple benefits for the enhancement of crop production and soil health. Bacillus subtilis is a common PGPR in soil that plays a key role in conferring biotic and abiotic stress tolerance to plants by induced systemic resistance (ISR), biofilm formation and lipopeptide production. As a part of bioremediating technologies, Bacillus spp. can purify metal contaminated soil. It acts as a potent denitrifying agent in agroecosystems while improving the carbon sequestration process when applied in a regulated concentration. Although it harbours several antibiotic resistance genes (ARGs), it can reduce the horizontal transfer of ARGs during manure composting by modifying the genetic makeup of existing microbiota. In some instances, it affects the beneficial microbes of the rhizosphere. External inoculation of B. subtilis has both positive and negative impacts on the endophytic and semi-synthetic microbial community. Soil texture, type, pH and bacterial concentration play a crucial role in the regulation of all these processes. Soil amendments and microbial consortia of Bacillus produced by microbial engineering could be used to lessen the negative effect on soil microbial diversity. The complex plant�microbe interactions could be decoded using transcriptomics, proteomics, metabolomics and epigenomics strategies which would be beneficial for both crop productivity and the well-being of soil microbiota. Bacillus subtilis has more positive attributes similar to the character of Dr. Jekyll and some negative attributes on plant growth, soil health and the environment akin to the character of Mr. Hyde. � 2022 Society for Applied Microbiology.
Biochar as an Environment-Friendly Alternative for Multiple Applications
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09-07T00:00:00) Yadav, Radheshyam; Ramakrishna, Wusirika
The climate crisis and years of unsustainable agricultural practices have reduced soil fertility and crop yield. In addition, agricultural lands contribute more than 10% of greenhouse gases (GHGs). These concerns can be addressed by using biochar for carbon neutralization, environmental restoration, and agricultural management. Biochar has a role in nitrous oxide and methane gas emission mitigation from agricultural soil. New methods are needed to link belowground processes to functioning in multi-species and multi-cultivar agroecosystems. The intricate relationship between biochar and the composition of soil microbial communities, along with its impacts on functions within the rhizosphere, constitutes a highly perplexing and elusive subject within microbial genomics. The present review discusses how biochar can mitigate climate change, enhance carbon sequestration, and support crop productivity. Biochar could be a potential solution to mitigate soil microplastics and heavy metal contamination. Applying a biochar-based microbiome reduces polycyclic aromatic hydrocarbons (PAHs) in soil. The current knowledge and perspectives on biochar�plant�microbial interactions for sustainable agriculture and ameliorating the adverse effects of climate change are highlighted. In this review, a holistic approach was used to emphasize the utility of biochar for multiple applications with positive and negative effects and its role in promoting a functional circular economy. � 2023 by the authors.
Co-occurrence and patterns of phosphate solubilizing, salt and metal tolerant and antibiotic-resistant bacteria in diverse soils
(Springer Science and Business Media Deutschland GmbH, 2021-06-24T00:00:00) Rathore, Parikshita; Joy, Sherina Sara; Yadav, Radheshyam; Ramakrishna, Wusirika
Soil is a treasure chest for beneficial bacteria with applications in diverse fields, which include agriculture, rhizoremediation, and medicine. Metagenomic analysis of four soil samples identified Proteobacteria as the dominant phylum (32�52%) followed by the phylum Acidobacteria (11�21% in three out of four soils). Bacteria that were prevalent at the highest level belong to the genus Kaistobacter (8�19%). PICRUSt analysis predicted KEGG functional pathways associated with the metagenomes of the four soils. The identified pathways could be attributed to metal tolerance, antibiotic resistance and plant growth promotion. The prevalence of phosphate solubilizing bacteria (PSB) was investigated in four soil samples, ranging from 26 to 59% of the total culturable bacteria. The abundance of salt-tolerant and metal-tolerant bacteria showed considerable variation ranging from 1 to 62% and 4�69%, respectively. In comparison, the soil with the maximum prevalence of temperature-tolerant and antibiotic-resistant bacteria was close 30%. In this study, the common pattern observed was that PSB were the most abundant in all types of soils compared to other traits. Conversely, most of the isolates, which are salt-tolerant, copper-tolerant, and ampicillin-resistant, showed phosphate solubilization activity. The sequencing of the partial 16S-rRNA gene revealed that PSB belonged to Bacillus genera. � 2021, King Abdulaziz City for Science and Technology.
Combing of picogram level DNA equivalent to genomic DNA present in single human cell by self propelled droplet motion over a stable gradient surface
(Academic Press Inc., 2023-11-08T00:00:00) Yadav, Hemendra; Algaonkar, Prashant S.; Chakraborty, Sudip; Ramakrishna, Wusirika
DNA combing is a powerful technique for studying replication profile, fork-directionality and fork velocity. At present, there is requirement of a methodology to comb DNA present in a single human cell for studying replication dynamics at early embryonic stage. In our study, a surface having dual characteristics i.e., affinity towards negatively charged single DNA molecules and a hydrophobic gradient for self propelled droplet motion of combing solution was developed. The surface was made by coating of TCOS (trichloro-octylsilane) by vapor diffusion on APTES (Aminopropyl-triethoxysilane) coated glass slides. A gradient surface having high deposition efficiency (DE) was developed on which 5 picogram DNA equivalent to genomic DNA present in one single human cell can be combed. The gradient surface was thermostable in nature having the ability to sustain boiling temperature for two hours and sustain anisotropy in 70 % ethanol for 80 h. Applicability for multiple runs was enhanced such that the surface can be used for 13�14 times. Factors associated with gradient surface are unidirectional movement of combing solution droplet over the gradient surface for combing straight DNA molecules and a longer gradient surface of more than 1 cm such that long size DNA molecules can be combed. Ellipsometry and contact angle hysteresis confirmed the presence of hydrophobic gradient. XPS (X-ray photoelectron spectroscopy) and FTIR (Fourier Transform Infrared Spectroscopy) confirmed the presence of characteristic affinity towards negatively charged DNA molecules on the gradient surface. Combing solution was optimized for increasing deposition efficiency and for increasing the applicability of gradient surface for multiple runs. High temperature of combing solution was found to increase Deposition Efficiency. Combing solution was also optimized for combing single DNA molecules over the gradient surface. Single DNA molecules were combed by reducing pH and lowering concentration of triton-X in the combing solution. Dye: bp ratio was optimized for high fluorescent intensity and low surface background. � 2023 Elsevier Inc.
Endophytes as nature's gift to plants to combat abiotic stresses
(Oxford University Press, 2022-12-20T00:00:00) Godara, Himanshi; Ramakrishna, Wusirika
In recent decades, scientists have recognized that plants' distinct and immensely dynamic microbial communities are more than just "passengers,"but instead, play an important role in their development, and shielding against abiotic and biotic stresses. Endophytes comprise fungi and bacteria that live within plant tissues and support growth when plants are under stress. All plants in nature are considered to have symbiotic association with endophytes. A comprehensive review of the accessible data suggests that mobility, cell-wall degradation capacity, and reactive oxygen species scavenging are critical attributes for the successful colonization of endophytes. Plants encounter several abiotic stresses caused by climate change and global warming, which have an effect on their growth and production. Abiotic stress like high temperature, salinity, and high precipitation can severely affect plants compared to biotic stress. This review aims to highlight what role endophytes play to aid plant growth under abiotic stress conditions like heat, salinity, and drought. In the current review, we discuss how endophytic microbes can be efficiently used for the improvement and promotion of plant growth and crop production under abiotic stress conditions. � 2022 The Author(s). Published by Oxford University Press on behalf of Applied Microbiology International.
Evolution of Nano-Biofertilizer as a Green Technology for Agriculture
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09-24T00:00:00) Patel, Chitranshi; Singh, Jyoti; Karunakaran, Anagha; Ramakrishna, Wusirika
Agriculture has long been the cornerstone of human civilization, providing sustenance and livelihoods for millennia. However, as the global population continues to burgeon, agriculture faces mounting challenges. Soil degradation, nutrient depletion, environmental pollution, and the need for sustainable farming practices are among the pressing issues that require innovative solutions. In this context, nano-biofertilizers have emerged as a groundbreaking technological advancement with the potential to reshape modern agriculture. nano-biofertilizers are innovative agricultural products that leverage the combined principles of nanotechnology and biotechnology to enhance nutrient uptake by plants, improve soil health, and promote sustainable farming practices. These specialized fertilizers consist of nanoscale materials and beneficial microorganisms. These fertilizers are eco-friendly and cost-effective and have shown promising results in various crop plants. In this review, we discuss the recent advances in the development of eco-friendly nano-biofertilizers along with an overview of the various types of nano-biofertilizers, their formulation, synthesis, and mode of application for next-generation agriculture. The importance of the interaction between nanoparticles and bacterial species and its impact on the effectiveness of nano-biofertilizers has also been discussed along with the potential benefits, challenges, and future perspectives of using eco-friendly nano-biofertilizers for sustainable agriculture, ensuring a greener and healthier future for generations to come. � 2023 by the authors.
Metabolomics, biomass and lignocellulosic total sugars analysis in foxtail millet (Setaria italica) inoculated with different combinations of plant growth promoting bacteria and mycorrhiza
(Communications in Plant Sciences, 2017) Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika
Foxtail millet (Setaria italica) is the second most widely produced millet with potential as a biofuel source. Employment of plant growth promoting bacteria (PGPB) and mycorrhiza could serve as environment-friendly alternatives for the use of excessive NPK fertilizers and producing biofuel. The highest increase of biomass was associated with endomycorrhiza combined with PGPB in comparison to control. Nuclear magnetic resonance (NMR) analysis detected 28 metabolites in foxtail shoot with most of them upregulated in ecto/endomycorrhiza group and combined with PGPB. The upregulation of metabolites associated with synthesis of amino acids correlated positively with biomass. The inoculation with both PGPB and endomycorrhiza gave the best results with reference to total sugar yield. Our study indicates that PGPB and endomycorrhiza combination is well suited for enhancing biomass and boosting sugar yield, which are useful attributes for utilizing foxtail millet as a biofuel source.
MicroRNAs Involved in Nutritional Regulation During Plant�Microbe Symbiotic and Pathogenic Interactions with Rice as a Model
(Springer, 2023-07-19T00:00:00) Yadav, Radheshyam; Ramakrishna, Wusirika
Plants are constantly challenged with numerous adverse environmental conditions, including biotic and abiotic stresses. Coordinated regulation of plant responses requires crosstalk between regulatory pathways initiated by different external cues. Stress induced by excessiveness or deficiency of nutrients has been shown to positively or negatively interact with pathogen-induced immune responses. Also, colonization by arbuscular mycorrhizal (AM) fungi can improve plant nutrition, mainly phosphorus and resistance to pathogen infection. The proposed review addresses these issues about a new question that integrates adaptation to nutrient stress and disease resistance. The main goal of the current review is to provide insights into the interconnected regulation between nutrient signaling and immune signaling pathways in rice, focusing on phosphate, potassium and iron signaling. The underpinnings of plant/pathogen/AM fungus interaction concerning rice/M. oryzae/R. irregularis is highlighted. The role of microRNAs (miRNAs) involved in Pi (miR399, miR827) and Fe (miR7695) homeostasis in pathogenic/symbiotic interactions in rice is discussed. The intracellular dynamics of membrane proteins that function in nutrient transport transgenic rice lines expressing fluorescent protein fusion genes are outlined. Integrating functional genomic, nutritional and metal content, molecular and cell biology approaches to understand how disease resistance is regulated by nutrient status leading to novel concepts in fundamental processes underlying plant disease resistance will help to devise novel strategies for crop protection with less input of pesticides and fertilizers. � 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Multifarious Effects of Arsenic on Plants and Strategies for Mitigation
(MDPI, 2023-02-09T00:00:00) Beniwal, Rahul; Yadav, Radheshyam; Ramakrishna, Wusirika
Arsenic contamination in soil and water is a major problem worldwide. Inorganic arsenic is widely present as arsenate and arsenite. Arsenic is transferred to crops through the soil and irrigation water. It is reported to reduce crop production in plants and can cause a wide array of diseases in humans, including different types of cancers, premature delivery, stillbirth, and spontaneous abortion. Arsenic methyltransferase (AS3MT) in the human body converts inorganic arsenic into monomethylarsonic acid and dimethylarsinic acid, which are later excreted from the body. Arsenic transfer from the soil to grains of rice involves different transporters such as Lsi1, Lsi2, and Lsi6. These transporters are also required for the transfer of silicate, which makes them important for the plant. Different mitigation strategies have been used to mitigate arsenic from crops, such as plant growth-promoting bacteria, fungi, and nanoparticles, as well as using different plant genotypes and plant extracts. Different factors such as nitric oxide, Fe, and jasmonate also affect the response of a plant to the oxidative stress caused by arsenic. This review highlights the various effects of arsenic on plants with respect to their biochemical, molecular, and physiological aspects and the employment of classical and innovative methods for their mitigation. The current review is expected to initiate further research to improve As remediation to mitigate the effect of heavy metal pollution on the environment. � 2023 by the authors.
Mycorrhiza and heavy metal resistant bacteria enhance growth, nutrient uptake and alter metabolic profile of sorghum grown in marginal soil
(Elsevier Ltd, 2016) Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika; Dhawi, F.; Datta, R.; Ramakrishna, W.
The main challenge for plants growing in nutrient poor, contaminated soil is biomass reduction, nutrient deficiency and presence of heavy metals. Our aim is to overcome these challenges using different microbial combinations in mining-impacted soil and focus on their physiological and biochemical impacts on a model plant system, which has multiple applications. In the current study, sorghum BTx623 seedlings grown in mining-impacted soil in greenhouse were subjected to plant growth promoting bacteria (PGPB or B) alone, PGPB with arbuscular mycorrhizal fungi (My), My alone and control group with no treatment. Root biomass and uptake of most of the elements showed significant increase in all treatment groups in comparison with control. Mycorrhiza group showed the best effect followed by My + B and B groups for uptake of majority of the elements by roots. On the contrary, biomass of both shoot and root was more influenced by B treatment than My + B and My treatments. Metabolomics identified compounds whose levels changed in roots of treatment groups significantly in comparison to control. Upregulation of stearic acid, sorbitol, sebacic acid and ferulic acid correlated positively with biomass and uptake of almost all elements. Two biochemical pathways, fatty acid biosynthesis and galactose metabolism, were regulated in all treatment groups. Three common pathways were upregulated only in My and My + B groups. Our results suggest that PGPB enhanced metabolic activities which resulted in increase in element uptake and sorghum root biomass whether accompanied with mycorrhiza or used solely. ? 2016 Elsevier Ltd.
Nutrient enhancement of chickpea grown with plant growth promoting bacteria in local soil of Bathinda, Northwestern India
(Springer, 2019) Dogra, Nitin; Yadav, Radheshyam; Kaur, Manpreet; Adhikary, Arindam; Kumar, Sanjeev; Ramakrishna, Wusirika
Plant growth promoting bacteria (PGPB) enhance crop productivity as part of green technology to reduce the use of chemical fertilizers. They also have the capability to enhance macro- and micronutrient content of plants. In the present study, PGPB isolates belonging to Pseudomonas citronellis (PC), Pseudomonas sp. RA6, Serratia sp. S2, Serratia marcescens CDP13, and Frateuria aurantia (Symbion-K) were tested on two chickpea varieties, PBG1 and PBG5 grown for 30 days in local soil from Bathinda region in Northwestern India. PC and CDP13 were found to be better chickpea growth stimulators compared to the commercial Symbion-K based on shoot length and biomass. Most PGPB enhanced macro- and micronutrients in shoots to varying degrees compared to the control. PBG5 gave better response compared to PBG1 with reference to plant growth attributes and enhancement of the macronutrients, calcium, nitrogen and phosphorus and micronutrients, boron, copper, iron, and zinc. PBG5 is a high yielding variety with better resistance compared to PBG1. Overall, PGPB isolated from the local soil and PGPB from other parts of India were shown to be useful for enhancement of nutrient content and plant growth.
Plant growth promoting bacteria in agriculture: Two sides of a coin
(Elsevier, 2019) Ramakrishna, Wusirika; Yadav, Radheshyam; Li, Kefeng
Plant growth promoting bacteria (PGPB) provide multiple benefits in agriculture by enhancing crop productivity and nutrient content and suppressing the growth of pathogens. Development of beneficial plant-microbe interactions based on genomics, transcriptomics, proteomics and metabolomic data of both PGPB and host will lead to optimized microbial inoculants for enhancing crop yield and nutrient content. PGPB are promoted as a green technology which will reduce the use of chemical fertilizers thereby improving soil health. Although a significant increase in the use of PGPB in agriculture was observed in the last two decades, there is a dearth of long-term studies addressing the effects of PGPB on existing microbial community structure. It is likely that most or all PGPB are resistant to common antibiotics used to treat human diseases. Antibiotic resistance of PGPB may be due to the presence of antibiotic resistance genes and intrinsic resistance due to the presence of efflux pumps. The biological significance of resistance to antibiotics and metals and their relation to plant growth promoting activity, if any, is not known. The consequences of harboring antibiotic resistance may be negative if the trait is transferred to other soil or environmental bacteria. Strategies to develop PGPB strains with useful traits of plant growth promotion but without resistance to common antibiotics used by humans, would enhance agricultural productivity without the negative effects on the environment. Alternately, harboring antibiotic resistance may be positive if it is due to intrinsic resistance involving proteins which also have other functions. Antibiotic resistance of PGPB may be an essential trait if it is related to their plant growth promoting activity. Overall, there is a need to conduct large-scale screening of PGPB for antibiotic resistance and long-term studies to see the effect of the introduction of biofertilizers on native soil microbial community.
Plant growth promoting rhizobacteria, arbuscular mycorrhizal fungi and their synergistic interactions to counteract the negative effects of saline soil on agriculture: Key macromolecules and mechanisms
(MDPI AG, 2021-07-14T00:00:00) Sagar, Alka; Rathore, Parikshita; Ramteke, Pramod W.; Ramakrishna, Wusirika; Reddy, Munagala S.; Pecoraro, Lorenzo
Soil saltiness is a noteworthy issue as it results in loss of profitability and development of agrarian harvests and decline in soil health. Microorganisms associated with plants contribute to their growth promotion and salinity tolerance by employing a multitude of macromolecules and pathways. Plant growth promoting rhizobacteria (PGPR) have an immediate impact on improving profitability based on higher crop yield. Some PGPR produce 1-aminocyclopropane-1-carboxylic (ACC) deami-nase (EC 4.1.99.4), which controls ethylene production by diverting ACC into ?-ketobutyrate and ammonia. ACC deaminase enhances germination rate and growth parameters of root and shoot in different harvests with and without salt stress. Arbuscular mycorrhizal fungi (AMF) show a symbiotic relationship with plants, which helps in efficient uptake of mineral nutrients and water by the plants and also provide protection to the plants against pathogens and various abiotic stresses. The dual inoculation of PGPR and AMF enhances nutrient uptake and productivity of several crops compared to a single inoculation in both normal and stressed environments. Positively interacting PGPR + AMF combination is an efficient and cost-effective recipe for improving plant tolerance against salinity stress, which can be an extremely useful approach for sustainable agriculture. � 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Proteomics provides insights into biological pathways altered by plant growth promoting bacteria and arbuscular mycorrhiza in sorghum grown in marginal soil
(Elsevier B.V., 2017) Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika; Dhawi, F.; Datta, R.; Ramakrishna, W.
Sorghum is an economically important crop, a model system for gene discovery and a biofuel source. Sorghum seedlings were subjected to three microbial treatments, plant growth promoting bacteria (B), arbuscular mycorrhizal (AM) fungi mix with two Glomus species (G. aggregatum and G. etunicatum), Funelliformis mosseae and Rhizophagus irregularis (My), and B and My combined (My + B). Proteomic analysis was conducted followed by integration with metabolite, plant biomass and nutrient data. Out of 366 differentially expressed proteins in sorghum roots, 44 upregulated proteins overlapping among three treatment groups showed positive correlation with sorghum biomass or element uptake or both. Proteins upregulated only in B group include asparagine synthetase which showed negative correlation with biomass and uptake of elements. Phosphoribosyl amino imidazole succinocarboxamide protein with more than 50-fold change in My and My + B groups correlated positively with Ca, Cu, S and sucrose levels in roots. The B group showed the highest number of upregulated proteins among the three groups with negative correlation with sorghum biomass and element uptake. KEGG pathway analysis identified carbon fixation as the unique pathway associated with common upregulated proteins while biosynthesis of amino acids and fatty acid degradation were associated with common downregulated proteins. Protein-protein interaction analysis using STRING identified a major network with thirteen downregulated proteins. These findings suggest that plant-growth-promoting-bacteria alone or in combination with mycorrhiza enhanced radical scavenging system and increased levels of specific proteins thereby shifting the metabolism towards synthesis of carbohydrates resulting in sorghum biomass increase and uptake of nutrients. ? 2016
Pseudomonas citronellolis alleviates arsenic toxicity and maintains cellular homeostasis in chickpea (Cicer arietinum L.)
(Elsevier Masson s.r.l., 2022-05-19T00:00:00) Adhikary, Arindam; Saini, Rashmi; Kumar, Rashpal; Singh, Inderjit; Ramakrishna, Wusirika; Kumar, Sanjeev
Arsenic is a hazardous metalloid that causes detrimental effects on plant growth and metabolism. Plants accumulate arsenic in edible parts that consequently enter the food chain leading to many health problems. Metal tolerant plant growth-promoting bacteria (PGPB) ameliorate heavy metal toxicity. In this study, the effect of arsenic (As5+) and the role of PGPB Pseudomonas citronellolis (PC) in mitigating As5+ toxicity and associated metabolic alterations in chickpea were assessed. Five chickpea varieties (PBG1, GPF2, PDG3, PDG4 and PBG5) were evaluated for arsenic accumulation, translocation, and its interference with metabolic and defense processes. As5+ (40 mg kg?1) interfered with plant metabolism and enhanced the antioxidative and carbohydrate metabolizing enzyme's activity but PC treatment maintained the activity at par with control. PC also facilitated the accumulation of As5+ in the root system and restricted its translocation to the shoot. Further, to map the metabolic changes, Gas chromatography Mass Spectroscopy (GC-MS) based metabolite profiling and gene expression analysis (qRT-PCR) were performed in the best and worst-performing chickpea varieties (PBG1 and PBG5). 48 metabolites of various metabolic pathways (amino acid, carbohydrate, and fatty acid) were altered in As5+ and PC treatment. Gene expressions showed correlation with biochemical analysis of the antioxidative enzymes and carbohydrate metabolizing enzymes while PC treatment improved chlorophyll biosynthesis enzyme CaDALA expression in As5+ treated plants. Therefore, PC mitigates As5+ toxicity by restricting it in the roots thereby maintaining the cellular homeostasis under As5+ stress in chickpeas. � 2022 Elsevier Masson SAS
Soil Diseases Suppressiveness Conferred by Organic Farming, Practices and Microbial Metabolites
(Taylor and Francis Ltd., 2023-05-08T00:00:00) Yadav, Radheshyam; Beniwal, Rahul; Ramakrishna, Wusirika
A major obstacle to the creation of efficient biobased disease management practices continues to be the poor integration of traditional agricultural practices and cutting-edge technical approaches. The present review will expand the understanding of organic amendments and metabolites-mediated microbial community metabolism and their mechanistic aspects in disease-suppressive soil (DSS). Organic amendments have been shown to promote the biocontrol potential of resident soil microbiota. Organic amendments positively affect the labile carbon, cation exchange content (CEC) and microbial enzymatic activity. DSS is considered a rich source of beneficial soil microbial community that produces a plethora of antibacterial metabolites. Multiple gene clusters associated with known metabolites offer mechanistic insights associated with disease-suppressive phenotypes. Organic amended soil has higher abundance of chemotaxis genes. Several strains of Bacillus and Pseudomonas produce key metabolites, phenazines, 2,4-diacetylphloroglucinol, pyoluteorin, pyrrolnitrin, cyclic lipopeptides and volatile organic compounds in DSS. High-resolution metagenomics combined with bioinformatics tools would be instrumental in the identification of biomarkers associated with suppressive soils. The integration of traditional and genomic approaches can be employed to infer the untapped potential of resident soil microbiomes. � 2023 Informa UK Limited, trading as Taylor & Francis Group.