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Borker SS, Sharma P, Thakur A, Kumar A, Kumar A, Kumar R. Physiological and genomic insights into a psychrotrophic drought-tolerant bacterial consortium for crop improvement in cold, semiarid regions. Microbiol Res 2024; 286:127818. [PMID: 38970906 DOI: 10.1016/j.micres.2024.127818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/12/2024] [Accepted: 06/20/2024] [Indexed: 07/08/2024]
Abstract
The agricultural land in the Indian Himalayan region (IHR) is susceptible to various spells of snowfall, which can cause nutrient leaching, low temperatures, and drought conditions. The current study, therefore, sought an indigenous psychrotrophic plant growth-promoting (PGP) bacterial inoculant with the potential to alleviate crop productivity under cold and drought stress. Psychrotrophic bacteria preisolated from the night-soil compost of the Lahaul Valley of northwestern Himalaya were screened for phosphate (P) and potash (K) solubilization, nitrogen fixation, indole acetic acid (IAA) production, siderophore and HCN production) in addition to their tolerance to drought conditions for consortia development. Furthermore, the effects of the selected consortium on the growth and development of wheat (Triticum aestivum L.) and maize (Zea mays L.) were assessed in pot experiments under cold semiarid conditions (50 % field capacity). Among 57 bacteria with P and K solubilization, nitrogen fixation, IAA production, siderophore and HCN production, Pseudomonas protegens LPH60, Pseudomonas atacamensis LSH24, Psychrobacter faecalis LUR13, Serratia proteamaculans LUR44, Pseudomonas mucidolens LUR70, and Glutamicibacter bergerei LUR77 exhibited tolerance to drought stress (-0.73 MPa). The colonization of wheat and maize seeds with these drought-tolerant PGP strains resulted in a germination index >150, indicating no phytotoxicity under drought stress. Remarkably, a particular strain, Pseudomonas sp. LPH60 demonstrated antagonistic activity against three phytopathogens Ustilago maydis, Fusarium oxysporum, and Fusarium graminearum. Treatment with the consortium significantly increased the foliage (100 % and 160 %) and root (200 % and 133 %) biomasses of the wheat and maize plants, respectively. Furthermore, whole-genome sequence comparisons of LPH60 and LUR13 with closely related strains revealed genes associated with plant nutrient uptake, phytohormone synthesis, siderophore production, hydrogen cyanide (HCN) synthesis, volatile organic compound production, trehalose and glycine betaine transport, cold shock response, superoxide dismutase activity, and gene clusters for nonribosomal peptide synthases and polyketide synthetases. With their PGP qualities, biocontrol activity, and ability to withstand environmental challenges, the developed consortium represents a promising cold- and drought-active PGP bioinoculant for cereal crops grown in cold semiarid regions.
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Affiliation(s)
- Shruti Sinai Borker
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Pallavi Sharma
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India
| | - Aman Thakur
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Aman Kumar
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Anil Kumar
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Rakshak Kumar
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India; Department of Molecular Biology & Bioinformatics, Tripura University (A Central University), Suryamaninagar, Tripura 799022, India.
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Feng D, Liu W, Chen K, Ning S, Gao Q, Chen J, Liu J, Sun X, Xu W. Exogenous Substances Used to Relieve Plants from Drought Stress and Their Associated Underlying Mechanisms. Int J Mol Sci 2024; 25:9249. [PMID: 39273198 PMCID: PMC11395679 DOI: 10.3390/ijms25179249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Revised: 08/21/2024] [Accepted: 08/23/2024] [Indexed: 09/15/2024] Open
Abstract
Drought stress (DS) is one of the abiotic stresses that plants encounter commonly in nature, which affects their life, reduces agricultural output, and prevents crops from growing in certain areas. To enhance plant tolerance against DS, abundant exogenous substances (ESs) have been attempted and proven to be effective in helping plants relieve DS. Understanding the effect of each ES on alleviation of plant DS and mechanisms involved in the DS relieving process has become a research focus and hotspot that has drawn much attention in the field of botany, agronomy, and ecology. With an extensive and comprehensive review and summary of hundred publications, this paper groups various ESs based on their individual effects on alleviating plant/crop DS with details of the underlying mechanisms involved in the DS-relieving process of: (1) synthesizing more osmotic adjustment substances; (2) improving antioxidant pathways; (3) promoting photosynthesis; (4) improving plant nutritional status; and (5) regulating phytohormones. Moreover, a detailed discussion and perspective are given in terms of how to meet the challenges imposed by erratic and severe droughts in the agrosystem through using promising and effective ESs in the right way and at the right time.
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Affiliation(s)
- Di Feng
- Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Saline-Alkali Land in Arid and Semi-Arid Regions), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Soil Fertilizer and Agricultural Water Conservation, Xinjiang Academy of Agricultural Sciences, Urumchi 830091, China
| | - Wenxin Liu
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Ke Chen
- College of Agriculture, South China Agricultural University, Guangzhou 510640, China
| | - Songrui Ning
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China
| | - Qian Gao
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jiao Chen
- Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Saline-Alkali Land in Arid and Semi-Arid Regions), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Soil Fertilizer and Agricultural Water Conservation, Xinjiang Academy of Agricultural Sciences, Urumchi 830091, China
| | - Jiao Liu
- Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Saline-Alkali Land in Arid and Semi-Arid Regions), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Soil Fertilizer and Agricultural Water Conservation, Xinjiang Academy of Agricultural Sciences, Urumchi 830091, China
| | - Xiaoan Sun
- Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Saline-Alkali Land in Arid and Semi-Arid Regions), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Soil Fertilizer and Agricultural Water Conservation, Xinjiang Academy of Agricultural Sciences, Urumchi 830091, China
| | - Wanli Xu
- Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Saline-Alkali Land in Arid and Semi-Arid Regions), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Soil Fertilizer and Agricultural Water Conservation, Xinjiang Academy of Agricultural Sciences, Urumchi 830091, China
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Saadaoui M, Faize M, Rifai A, Tayeb K, Omri Ben Youssef N, Kharrat M, Roeckel-Drevet P, Chaar H, Venisse JS. Evaluation of Tunisian wheat endophytes as plant growth promoting bacteria and biological control agents against Fusarium culmorum. PLoS One 2024; 19:e0300791. [PMID: 38758965 PMCID: PMC11101125 DOI: 10.1371/journal.pone.0300791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 03/05/2024] [Indexed: 05/19/2024] Open
Abstract
Plant growth-promoting rhizobacteria (PGPR) applications have emerged as an ideal substitute for synthetic chemicals by their ability to improve plant nutrition and resistance against pathogens. In this study, we isolated fourteen root endophytes from healthy wheat roots cultivated in Tunisia. The isolates were identified based from their 16S rRNA gene sequences. They belonged to Bacillota and Pseudomonadota taxa. Fourteen strains were tested for their growth-promoting and defense-eliciting potentials on durum wheat under greenhouse conditions, and for their in vitro biocontrol power against Fusarium culmorum, an ascomycete responsible for seedling blight, foot and root rot, and head blight diseases of wheat. We found that all the strains improved shoot and/or root biomass accumulation, with Bacillus mojavensis, Paenibacillus peoriae and Variovorax paradoxus showing the strongest promoting effects. These physiological effects were correlated with the plant growth-promoting traits of the bacterial endophytes, which produced indole-related compounds, ammonia, and hydrogen cyanide (HCN), and solubilized phosphate and zinc. Likewise, plant defense accumulations were modulated lastingly and systematically in roots and leaves by all the strains. Testing in vitro antagonism against F. culmorum revealed an inhibition activity exceeding 40% for five strains: Bacillus cereus, Paenibacillus peoriae, Paenibacillus polymyxa, Pantoae agglomerans, and Pseudomonas aeruginosa. These strains exhibited significant inhibitory effects on F. culmorum mycelia growth, sporulation, and/or macroconidia germination. P. peoriae performed best, with total inhibition of sporulation and macroconidia germination. These finding highlight the effectiveness of root bacterial endophytes in promoting plant growth and resistance, and in controlling phytopathogens such as F. culmorum. This is the first report identifying 14 bacterial candidates as potential agents for the control of F. culmorum, of which Paenibacillus peoriae and/or its intracellular metabolites have potential for development as biopesticides.
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Affiliation(s)
- Mouadh Saadaoui
- Université Clermont Auvergne, INRAE, PIAF, Clermont-Ferrand, France
- Université de Tunis El Manar, Campus Universitaire Farhat Hached, Tunis, Tunisia
- Field Crops Laboratory, National Institute for Agricultural Research of Tunisia, Tunisia, Tunisia
| | - Mohamed Faize
- Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization CNRST-URL10, Faculty of Sciences, University Chouaib Doukkali, El Jadida, Morocco
| | - Aicha Rifai
- Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization CNRST-URL10, Faculty of Sciences, University Chouaib Doukkali, El Jadida, Morocco
| | - Koussa Tayeb
- Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization CNRST-URL10, Faculty of Sciences, University Chouaib Doukkali, El Jadida, Morocco
| | - Noura Omri Ben Youssef
- Field Crops Laboratory, National Institute for Agricultural Research of Tunisia, Tunisia, Tunisia
- National Institute of Agronomy of Tunisia, Tunis, Tunisia
| | - Mohamed Kharrat
- Field Crops Laboratory, National Institute for Agricultural Research of Tunisia, Tunisia, Tunisia
| | | | - Hatem Chaar
- Field Crops Laboratory, National Institute for Agricultural Research of Tunisia, Tunisia, Tunisia
- National Institute of Agronomy of Tunisia, Tunis, Tunisia
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Agunbiade VF, Fadiji AE, Agbodjato NA, Babalola OO. Isolation and Characterization of Plant-Growth-Promoting, Drought-Tolerant Rhizobacteria for Improved Maize Productivity. PLANTS (BASEL, SWITZERLAND) 2024; 13:1298. [PMID: 38794369 PMCID: PMC11125291 DOI: 10.3390/plants13101298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 05/26/2024]
Abstract
Drought is one of the main abiotic factors affecting global agricultural productivity. However, the application of bioinocula containing plant-growth-promoting rhizobacteria (PGPR) has been seen as a potential environmentally friendly technology for increasing plants' resistance to water stress. In this study, rhizobacteria strains were isolated from maize (Zea mays L.) and subjected to drought tolerance tests at varying concentrations using polyethylene glycol (PEG)-8000 and screened for plant-growth-promoting activities. From this study, 11 bacterial isolates were characterized and identified molecularly, which include Bacillus licheniformis A5-1, Aeromonas caviae A1-2, A. veronii C7_8, B. cereus B8-3, P. endophytica A10-11, B. halotolerans A9-10, B. licheniformis B9-5, B. simplex B15-6, Priestia flexa B12-4, Priestia flexa C6-7, and Priestia aryabhattai C1-9. All isolates were positive for indole-3-acetic acid (IAA), siderophore, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, ammonia production, nitrogen fixation, and phosphate solubilization, but negative for hydrogen cyanide production. Aeromonas strains A1-2 and C7_8, showing the highest drought tolerance of 0.71 and 0.77, respectively, were selected for bioinoculation, singularly and combined. An increase in the above- and below-ground biomass of the maize plants at 100, 50, and 25% water-holding capacity (WHC) was recorded. Bacterial inoculants, which showed an increase in the aerial biomass of plants subjected to moderate water deficiency by up to 89%, suggested that they can be suitable candidates to enhance drought tolerance and nutrient acquisition and mitigate the impacts of water stress on plants.
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Affiliation(s)
| | | | | | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho 2735, South Africa
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Yang Y, Xu N, Zhang Z, Lei C, Chen B, Qin G, Qiu D, Lu T, Qian H. Deciphering Microbial Community and Nitrogen Fixation in the Legume Rhizosphere. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:5659-5670. [PMID: 38442360 DOI: 10.1021/acs.jafc.3c09160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Nitrogen is the most limiting factor in crop production. Legumes establish a symbiotic relationship with rhizobia and enhance nitrogen fixation. We analyzed 1,624 rhizosphere 16S rRNA gene samples and 113 rhizosphere metagenomic samples from three typical legumes and three non-legumes. The rhizosphere microbial community of the legumes had low diversity and was enriched with nitrogen-cycling bacteria (Sphingomonadaceae, Xanthobacteraceae, Rhizobiaceae, and Bacillaceae). Furthermore, the rhizosphere microbiota of legumes exhibited a high abundance of nitrogen-fixing genes, reflecting a stronger nitrogen-fixing potential, and Streptomycetaceae and Nocardioidaceae were the predominant nitrogen-fixing bacteria. We also identified helper bacteria and confirmed through metadata analysis and a pot experiment that the synthesis of riboflavin by helper bacteria is the key factor in promoting nitrogen fixation. Our study emphasizes that the construction of synthetic communities of nitrogen-fixing bacteria and helper bacteria is crucial for the development of efficient nitrogen-fixing microbial fertilizers.
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Affiliation(s)
- Yaohui Yang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Nuohan Xu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Zhenyan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Chaotang Lei
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Bingfeng Chen
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Guoyan Qin
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Danyan Qiu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Tao Lu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, P. R. China
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Malhotra P, Basu S, Lee BW, Oeller L, Crowder DW. Effects of Soil Rhizobia Abundance on Interactions between a Vector, Pathogen, and Legume Plant Host. Genes (Basel) 2024; 15:273. [PMID: 38540332 PMCID: PMC10970239 DOI: 10.3390/genes15030273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/13/2024] [Accepted: 02/20/2024] [Indexed: 06/15/2024] Open
Abstract
Soil rhizobia promote nitrogen fixation in legume hosts, maximizing their tolerance to different biotic stressors, plant biomass, crop growth, and yield. While the presence of soil rhizobia is considered beneficial for plants, few studies have assessed whether variation in rhizobia abundance affects the tolerance of legumes to stressors. To address this, we assessed the effects of variable soil rhizobia inoculum concentrations on interactions between a legume host (Pisum sativum), a vector insect (Acyrthosiphon pisum), and a virus (Pea enation mosaic virus, PEMV). We showed that increased rhizobia abundance reduces the inhibitory effects of PEMV on the nodule formation and root growth in 2-week-old plants. However, these trends were reversed in 4-week-old plants. Rhizobia abundance did not affect shoot growth or virus prevalence in 2- or 4-week-old plants. Our results show that rhizobia abundance may indirectly affect legume tolerance to a virus, but effects varied based on plant age. To assess the mechanisms that mediated interactions between rhizobia, plants, aphids, and PEMV, we measured the relative expression of gene transcripts related to plant defense signaling. Rhizobia concentrations did not strongly affect the expression of defense genes associated with phytohormone signaling. Our study shows that an abundance of soil rhizobia may impact a plant's ability to tolerate stressors such as vector-borne pathogens, as well as aid in developing sustainable pest and pathogen management systems for legume crops. More broadly, understanding how variable rhizobia concentrations can optimize legume-rhizobia symbiosis may enhance the productivity of legume crops.
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Affiliation(s)
| | - Saumik Basu
- Department of Entomology, Washington State University, Pullman, WA 99164, USA; (P.M.); (B.W.L.); (L.O.); (D.W.C.)
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Yasmeen T, Arif MS, Tariq M, Akhtar S, Syrish A, Haidar W, Rizwan M, Hussain MI, Ahmad A, Ali S. Biofilm producing plant growth promoting bacteria in combination with glycine betaine uplift drought stress tolerance of maize plant. FRONTIERS IN PLANT SCIENCE 2024; 15:1327552. [PMID: 38405588 PMCID: PMC10884199 DOI: 10.3389/fpls.2024.1327552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/05/2024] [Indexed: 02/27/2024]
Abstract
Introduction The escalating threat of drought poses a significant challenge to sustainable food production and human health, as water scarcity adversely impacts various aspects of plant physiology. Maize, a cornerstone in staple cereal crops, faces the formidable challenge of drought stress that triggers a series of transformative responses in the plant. Methods The present study was carried out in two sets of experiments. In first experiment, drought stress was applied after maintaining growth for 45 days and then irrigation was skipped, and plant samples were collected at 1st, 3rd and 6th day of drought interval for evaluation of changes in plant growth, water relation (relative water content) and antioxidants activity by inoculating indigenously isolated drought tolerant biofilm producing rhizobacterial isolates (Bacillus subtilis SRJ4, Curtobacterium citreum MJ1). In the second experiment, glycine betaine was applied as osmoregulator in addition to drought tolerant PGPR to perceive modulation in photosynthetic pigments (Chlorophyll a and b) and plant growth under varying moisture stress levels (100, 75 and 50% FC). Results and discussion Results of the study revealed upsurge in root and shoot length, fresh and dry biomass of root and shoot besides increasing chlorophyll contents in water stressed inoculated plants compared to uninoculated plants. Glycine betaine application resulted in an additional boost to plant growth and photosynthetic pigments, when applied in combination with bacterial inoculants. However, both bacterial inoculants behaved differently under drought stress as evident from their biochemical and physiological attributes. Isolate SRJ4 proved to be superior for its potential to express antioxidant activity, leaf water potential and relative water contents and drought responsive gene expression while isolate MJ1 showed exclusive increase in root dry biomass and plant P contents. Though it is quite difficult to isolate the bacterial isolates having both plant growth promoting traits and drought tolerance together yet, such biological resources could be an exceptional option to be applied for improving crop productivity and sustainable agriculture under abiotic stresses. By exploring the combined application of PGPR and glycine betaine, the study seeks to provide insights into potential strategies for developing sustainable agricultural practices aimed at improving crop resilience under challenging environmental conditions.
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Affiliation(s)
- Tahira Yasmeen
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Pakistan
| | - Muhammad Saleem Arif
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Pakistan
| | - Mohsin Tariq
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Sadia Akhtar
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Pakistan
| | - Afira Syrish
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Pakistan
| | - Waqas Haidar
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Pakistan
| | - Muhammad Rizwan
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Pakistan
| | | | - Ajaz Ahmad
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Shafaqat Ali
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Pakistan
- Department of Biological Sciences and Technology, China Medical University, Taichung, Taiwan
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Mukhopadhyay M, Mukherjee A, Ganguli S, Chakraborti A, Roy S, Choudhury SS, Subramaniyan V, Kumarasamy V, Sayed AA, El-Demerdash FM, Almutairi MH, Şuţan A, Dhara B, Mitra AK. Marvels of Bacilli in soil amendment for plant-growth promotion toward sustainable development having futuristic socio-economic implications. Front Microbiol 2023; 14:1293302. [PMID: 38156003 PMCID: PMC10752760 DOI: 10.3389/fmicb.2023.1293302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 11/14/2023] [Indexed: 12/30/2023] Open
Abstract
Microorganisms are integral components of ecosystems, exerting profound impacts on various facets of human life. The recent United Nations General Assembly (UNGA) Science Summit emphasized the critical importance of comprehending the microbial world to address global challenges, aligning with the United Nations Sustainable Development Goals (SDGs). In agriculture, microbes are pivotal contributors to food production, sustainable energy, and environmental bioremediation. However, decades of agricultural intensification have boosted crop yields at the expense of soil health and microbial diversity, jeopardizing global food security. To address this issue, a study in West Bengal, India, explored the potential of a novel multi-strain consortium of plant growth promoting (PGP) Bacillus spp. for soil bioaugmentation. These strains were sourced from the soil's native microbial flora, offering a sustainable approach. In this work, a composite inoculum of Bacillus zhangzhouensis MMAM, Bacillus cereus MMAM3), and Bacillus subtilis MMAM2 were introduced into an over-exploited agricultural soil and implications on the improvement of vegetative growth and yield related traits of Gylcine max (L) Meril. plants were evaluated, growing them as model plant, in pot trial condition. The study's findings demonstrated significant improvements in plant growth and soil microbial diversity when using the bacterial consortium in conjunction with vermicompost. Metagenomic analyses revealed increased abundance of many functional genera and metabolic pathways in consortium-inoculated soil, indicating enhanced soil biological health. This innovative bioaugmentation strategy to upgrade the over-used agricultural soil through introduction of residual PGP bacterial members as consortia, presents a promising path forward for sustainable agriculture. The rejuvenated patches of over-used land can be used by the small and marginal farmers for cultivation of resilient crops like soybean. Recognizing the significance of multi-strain PGP bacterial consortia as potential bioinoculants, such technology can bolster food security, enhance agricultural productivity, and mitigate the adverse effects of past agricultural activities.
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Affiliation(s)
- Meenakshi Mukhopadhyay
- Department of Botany, Vivekananda College (Affiliated to University of Calcutta), Kolkata, West Bengal, India
| | - Ashutosh Mukherjee
- Department of Botany, Vivekananda College (Affiliated to University of Calcutta), Kolkata, West Bengal, India
| | - Sayak Ganguli
- Department of Biotechnology, St. Xavier’s College (Autonomous), Kolkata, West Bengal, India
| | - Archisman Chakraborti
- Department of Physics, St. Xavier’s College (Autonomous), Kolkata, West Bengal, India
| | - Samrat Roy
- Depatrment of Commerce, St. Xavier’s College (Autonomous), Kolkata, West Bengal, India
| | - Sudeshna Shyam Choudhury
- Post Graduate Department of Microbiology, St. Xavier’s College (Autonomous), Kolkata, West Bengal, India
| | - Vetriselvan Subramaniyan
- Pharmacology Unit, Jeffrey Cheah School of Medicine and Health Sciences, Monash University, Bandar Sunway, Malaysia
- Center for Transdisciplinary Research, Department of Pharmacology, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India
| | - Vinoth Kumarasamy
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Amany A. Sayed
- Zoology Department, Faculty of Science, Cairo University, Giza, Egypt
| | - Fatma M. El-Demerdash
- Department of Environmental Studies, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt
| | - Mikhlid H. Almutairi
- Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Anca Şuţan
- Department of Natural Sciences, Faculty of Science, Physical Education and Informatics, University of Pitești, Pitești, Romania
| | - Bikram Dhara
- Post Graduate Department of Microbiology, St. Xavier’s College (Autonomous), Kolkata, West Bengal, India
- Center for Global Health Research, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India
| | - Arup Kumar Mitra
- Post Graduate Department of Microbiology, St. Xavier’s College (Autonomous), Kolkata, West Bengal, India
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Win KT, Wasai-Hara S, Tanaka F, Oo AZ, Minamisawa K, Shimoda Y, Imaizumi-Anraku H. Synergistic N 2-fixation and salt stress mitigation in soybean through dual inoculation of ACC deaminase-producing Pseudomonas and Bradyrhizobium. Sci Rep 2023; 13:17050. [PMID: 37816850 PMCID: PMC10564950 DOI: 10.1038/s41598-023-43891-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/29/2023] [Indexed: 10/12/2023] Open
Abstract
We investigated the potential dual application of two Bradyrhizobium strains (B. diazoefficiens USDA110 and B. ottawaense SG09) and plant growth-promoting bacteria, PGPB (Pseudomonas spp.: OFT2 and OFT5), to improve nodulation and N2-fixation in soybean plants. The growth-promoting effects of dual inoculation were observed on plant growth, physiology, and nodulation of soybean under normal conditions compared with plants individually inoculated with either USDA110 or SG09. Both OFT2 and OFT5 promoted N2-fixation by 11% and 56%, respectively, when dual inoculation with USDA110 and by 76% and 81%, respectively, when dual inoculation with SG09. Salinity stress significantly reduces soybean growth, physiology, nutrient uptake, nodulation, and N2-fixation. However, these adverse effects were attenuated by the dual inoculation of PGPB and rhizobia depending on the combination of inoculants. In particular, dual inoculation of PGPB with SG09 was more effective in enhancing the salt tolerance of soybean by reducing salt-induced ethylene production and improving nutrient uptake. However, no such effect was observed with the combined inoculation of USDA110 and OFT5. An effective symbiotic association between SG09 and two Pseudomonas bacteria can be considered a beneficial approach to improving the symbiotic efficiency of nodulation and mitigating salinity stress in soybeans.
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Affiliation(s)
- Khin Thuzar Win
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan.
| | - Sawa Wasai-Hara
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Fukuyo Tanaka
- Research Center for Advanced Analysis, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Aung Zaw Oo
- Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, Japan
| | - Kiwamu Minamisawa
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Yoshikazu Shimoda
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Haruko Imaizumi-Anraku
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan.
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Ansari M, Devi BM, Sarkar A, Chattopadhyay A, Satnami L, Balu P, Choudhary M, Shahid MA, Jailani AAK. Microbial Exudates as Biostimulants: Role in Plant Growth Promotion and Stress Mitigation. J Xenobiot 2023; 13:572-603. [PMID: 37873814 PMCID: PMC10594471 DOI: 10.3390/jox13040037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/18/2023] [Accepted: 09/21/2023] [Indexed: 10/25/2023] Open
Abstract
Microbes hold immense potential, based on the fact that they are widely acknowledged for their role in mitigating the detrimental impacts of chemical fertilizers and pesticides, which were extensively employed during the Green Revolution era. The consequence of this extensive use has been the degradation of agricultural land, soil health and fertility deterioration, and a decline in crop quality. Despite the existence of environmentally friendly and sustainable alternatives, microbial bioinoculants encounter numerous challenges in real-world agricultural settings. These challenges include harsh environmental conditions like unfavorable soil pH, temperature extremes, and nutrient imbalances, as well as stiff competition with native microbial species and host plant specificity. Moreover, obstacles spanning from large-scale production to commercialization persist. Therefore, substantial efforts are underway to identify superior solutions that can foster a sustainable and eco-conscious agricultural system. In this context, attention has shifted towards the utilization of cell-free microbial exudates as opposed to traditional microbial inoculants. Microbial exudates refer to the diverse array of cellular metabolites secreted by microbial cells. These metabolites enclose a wide range of chemical compounds, including sugars, organic acids, amino acids, peptides, siderophores, volatiles, and more. The composition and function of these compounds in exudates can vary considerably, depending on the specific microbial strains and prevailing environmental conditions. Remarkably, they possess the capability to modulate and influence various plant physiological processes, thereby inducing tolerance to both biotic and abiotic stresses. Furthermore, these exudates facilitate plant growth and aid in the remediation of environmental pollutants such as chemicals and heavy metals in agroecosystems. Much like live microbes, when applied, these exudates actively participate in the phyllosphere and rhizosphere, engaging in continuous interactions with plants and plant-associated microbes. Consequently, they play a pivotal role in reshaping the microbiome. The biostimulant properties exhibited by these exudates position them as promising biological components for fostering cleaner and more sustainable agricultural systems.
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Affiliation(s)
- Mariya Ansari
- Department of Mycology and Plant Pathology, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India; (M.A.); (A.S.); (L.S.)
| | - B. Megala Devi
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India;
| | - Ankita Sarkar
- Department of Mycology and Plant Pathology, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India; (M.A.); (A.S.); (L.S.)
| | - Anirudha Chattopadhyay
- Pulses Research Station, S.D. Agricultural University, Sardarkrushinagar 385506, Gujarat, India;
| | - Lovkush Satnami
- Department of Mycology and Plant Pathology, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India; (M.A.); (A.S.); (L.S.)
| | - Pooraniammal Balu
- Department of Biotechnology, Sastra Deemed University, Thanjavur 613401, Tamil Nadu, India;
| | - Manoj Choudhary
- Plant Pathology Department, University of Florida, Gainesville, FL 32611, USA;
| | - Muhammad Adnan Shahid
- Horticultural Science Department, North Florida Research and Education Center, University of Florida/IFAS, Quincy, FL 32351, USA;
| | - A. Abdul Kader Jailani
- Plant Pathology Department, University of Florida, Gainesville, FL 32611, USA;
- Plant Pathology Department, North Florida Research and Education Center, University of Florida, Quincy, FL 32351, USA
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Cembrowska-Lech D, Krzemińska A, Miller T, Nowakowska A, Adamski C, Radaczyńska M, Mikiciuk G, Mikiciuk M. An Integrated Multi-Omics and Artificial Intelligence Framework for Advance Plant Phenotyping in Horticulture. BIOLOGY 2023; 12:1298. [PMID: 37887008 PMCID: PMC10603917 DOI: 10.3390/biology12101298] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/28/2023]
Abstract
This review discusses the transformative potential of integrating multi-omics data and artificial intelligence (AI) in advancing horticultural research, specifically plant phenotyping. The traditional methods of plant phenotyping, while valuable, are limited in their ability to capture the complexity of plant biology. The advent of (meta-)genomics, (meta-)transcriptomics, proteomics, and metabolomics has provided an opportunity for a more comprehensive analysis. AI and machine learning (ML) techniques can effectively handle the complexity and volume of multi-omics data, providing meaningful interpretations and predictions. Reflecting the multidisciplinary nature of this area of research, in this review, readers will find a collection of state-of-the-art solutions that are key to the integration of multi-omics data and AI for phenotyping experiments in horticulture, including experimental design considerations with several technical and non-technical challenges, which are discussed along with potential solutions. The future prospects of this integration include precision horticulture, predictive breeding, improved disease and stress response management, sustainable crop management, and exploration of plant biodiversity. The integration of multi-omics and AI holds immense promise for revolutionizing horticultural research and applications, heralding a new era in plant phenotyping.
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Affiliation(s)
- Danuta Cembrowska-Lech
- Department of Physiology and Biochemistry, Institute of Biology, University of Szczecin, Felczaka 3c, 71-412 Szczecin, Poland;
- Polish Society of Bioinformatics and Data Science BIODATA, Popiełuszki 4c, 71-214 Szczecin, Poland; (A.K.); (T.M.)
| | - Adrianna Krzemińska
- Polish Society of Bioinformatics and Data Science BIODATA, Popiełuszki 4c, 71-214 Szczecin, Poland; (A.K.); (T.M.)
- Institute of Biology, University of Szczecin, Wąska 13, 71-415 Szczecin, Poland;
| | - Tymoteusz Miller
- Polish Society of Bioinformatics and Data Science BIODATA, Popiełuszki 4c, 71-214 Szczecin, Poland; (A.K.); (T.M.)
- Institute of Marine and Environmental Sciences, University of Szczecin, Wąska 13, 71-415 Szczecin, Poland
| | - Anna Nowakowska
- Department of Physiology and Biochemistry, Institute of Biology, University of Szczecin, Felczaka 3c, 71-412 Szczecin, Poland;
| | - Cezary Adamski
- Institute of Biology, University of Szczecin, Wąska 13, 71-415 Szczecin, Poland;
| | | | - Grzegorz Mikiciuk
- Department of Horticulture, Faculty of Environmental Management and Agriculture, West Pomeranian University of Technology in Szczecin, Słowackiego 17, 71-434 Szczecin, Poland;
| | - Małgorzata Mikiciuk
- Department of Bioengineering, Faculty of Environmental Management and Agriculture, West Pomeranian University of Technology in Szczecin, Słowackiego 17, 71-434 Szczecin, Poland;
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Sun W, Shahrajabian MH. The Application of Arbuscular Mycorrhizal Fungi as Microbial Biostimulant, Sustainable Approaches in Modern Agriculture. PLANTS (BASEL, SWITZERLAND) 2023; 12:3101. [PMID: 37687348 PMCID: PMC10490045 DOI: 10.3390/plants12173101] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/16/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023]
Abstract
Biostimulant application can be considered an effective, practical, and sustainable nutritional crop supplementation and may lessen the environmental problems related to excessive fertilization. Biostimulants provide beneficial properties to plants by increasing plant metabolism, which promotes crop yield and improves the quality of crops; protecting plants against environmental stresses such as water shortage, soil salinization, and exposure to sub-optimal growth temperatures; and promoting plant growth via higher nutrient uptake. Other important benefits include promoting soil enzymatic and microbial activities, changing the architecture of roots, increasing the solubility and mobility of micronutrients, and enhancing the fertility of the soil, predominantly by nurturing the development of complementary soil microbes. Biostimulants are classified as microbial, such as arbuscular mycorrhizae fungi (AMF), plant-growth-promoting rhizobacteria (PGPR), non-pathogenic fungi, protozoa, and nematodes, or non-microbial, such as seaweed extract, phosphite, humic acid, other inorganic salts, chitin and chitosan derivatives, protein hydrolysates and free amino acids, and complex organic materials. Arbuscular mycorrhizal fungi are among the most prominent microbial biostimulants and have an important role in cultivating better, healthier, and more functional foods in sustainable agriculture. AMF assist plant nutrient and water acquisition; enhance plant stress tolerance against salinity, drought, and heavy metals; and reduce soil erosion. AMF are proven to be a sustainable and environmentally friendly source of crop supplements. The current manuscript gives many examples of the potential of biostimulants for the production of different crops. However, further studies are needed to better understand the effectiveness of different biostimulants in sustainable agriculture. The review focuses on how AMF application can overcome nutrient limitations typical of organic systems by improving nutrient availability, uptake, and assimilation, consequently reducing the gap between organic and conventional yields. The aim of this literature review is to survey the impacts of AMF by presenting case studies and successful paradigms in different crops as well as introducing the main mechanisms of action of the different biostimulant products.
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Affiliation(s)
- Wenli Sun
- Correspondence: ; Tel.: +86-13-4260-83836
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13
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Nwachukwu BC, Ayangbenro AS, Babalola OO. Structural diversity of bacterial communities in two divergent sunflower rhizosphere soils. ANN MICROBIOL 2023. [DOI: 10.1186/s13213-023-01713-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Abstract
Purpose
Farming practices on farmlands aim to improve nutrients in the fields or crops, soil quality and functions, as well as boost and sustain crop yield; however, the effect of loss of ecological diversity and degradation have impacted ecosystem functions. The beneficial rhizosphere-microorganism network and crop rotation may enhance a stable ecosystem. The use of next-generation sequencing technique will help characterize the entire bacterial species in the sunflower rhizosphere compared with the nearby bulk soils. We investigated the potential of the bacterial community structure of sunflower rhizosphere and bulk soils cultivated under different agricultural practices at two geographical locations in the North West Province of South Africa.
Methods
DNA was extracted from rhizosphere and bulk soils associated with sunflower plants from the crop rotation (rhizosphere soils from Lichtenburg (LTR) and bulk soils from Lichtenburg (LTB) and mono-cropping (rhizosphere soils from Krayburg (KRPR) and bulk soils from Krayburg (KRPB) sites, and sequenced employing 16S amplicon sequencing. Bioinformatics tools were used to analyse the sequenced dataset.
Results
Proteobacteria and Planctomycetes dominated the rhizosphere, while Firmicutes and Actinobacteria were predominant in bulk soils. Significant differences in bacterial structure at phyla and family levels and predicted functional categories between soils (P < 0.05) across the sites were revealed. The effect of physicochemical parameters was observed to influence bacterial dispersal across the sites.
Conclusion
This study provides information on the predominant bacterial community structure in sunflower soils and their predictive functional attributes at the growing stage, which suggests their future study for imminent crop production and management for enhanced agricultural yields.
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Ojuederie OB, Babalola OO. Growth enhancement and extenuation of drought stress in maize inoculated with multifaceted ACC deaminase producing rhizobacteria. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2023. [DOI: 10.3389/fsufs.2022.1076844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
IntroductionMaize is a major staple cereal crop grown and consumed globally. However, due to climate change, extreme heat and drought stresses are greatly affecting its production especially in sub-Saharan Africa. The use of a bio-based approach to mitigate drought stress is therefore suggested using plant growth-promoting rhizobacteria (PGPR).MethodsThis study investigated the abilities of 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing PGPR Pseudomonas sp. MRBP4, Pseudomonas sp. MRBP13 and Bacillus sp. MRBP10 isolated from maize rhizosphere soil, to ameliorate the effect of drought stress in maize genotypes MR44 and S0/8/W/I137TNW//CML550 under two water regimes; mild drought stress (50% FC) and well-watered conditions (100% FC). The rhizobacterial strains were identified by 16S rRNA sequencing and biochemical tests, and evaluated for plant growth-promoting and abiotic stress tolerance traits.Results and discussionThe synergistic effect of the bacterial strains had a highly significant (p < 0.001) effect on the total soluble sugar, soil moisture content and relative water content, which were enhanced under water-stress in the inoculated plants. Relative water content was significantly highest (p < 0.001) in maize plants co-inoculated with Pseudomonas sp. MRBP4 + Bacillus sp. MRBP10 (60.55%). Total chlorophyll content was significantly enhanced in maize seedlings sole inoculated with Pseudomonas sp. MRBP4, Pseudomonas sp. MRBP13, and co-inoculated with Pseudomonas sp. MRBP13 + Bacillus sp. MRBP10 by 15.91%, 14.99% and 15.75% respectively, over the un-inoculated control. Soil moisture content increased by 28.67% and 30.71% compared to the un-inoculated control when plants were inoculated with Pseudomonas sp. MRBP4 + Bacillus sp. MRBP10 and Pseudomonas sp. MRBP4 + Bacillus sp. MRBP10 respectively. The interactive effect of genotype × bacteria significantly enhanced biomass production. Leaf area was highest in maize plants co-inoculated with Pseudomonas sp. MRBP4 + Pseudomonas sp. MRBP13 (212.45 ± 0.87 cm2) under drought stress. Treatment of maize seeds with Pseudomonas sp. MRBP 4 + Pseudomonas sp. MRBP13 + Bacillus sp. MRBP10 significantly increased the root length (10.32 ± 0.48 cm) which enhanced survival of the maize seedlings. Bioinoculation of maize seeds with these strains could boost maize production cultivated in arid regions.
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Mazoyon C, Hirel B, Pecourt A, Catterou M, Gutierrez L, Sarazin V, Dubois F, Duclercq J. Sphingomonas sediminicola Is an Endosymbiotic Bacterium Able to Induce the Formation of Root Nodules in Pea ( Pisum sativum L.) and to Enhance Plant Biomass Production. Microorganisms 2023; 11:microorganisms11010199. [PMID: 36677491 PMCID: PMC9861922 DOI: 10.3390/microorganisms11010199] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Abstract
The application of bacterial bio-inputs is a very attractive alternative to the use of mineral fertilisers. In ploughed soils including a crop rotation pea, we observed an enrichment of bacterial communities with Sphingomonas (S.) sediminicola. Inoculation experiments, cytological studies, and de novo sequencing were used to investigate the beneficial role of S. sediminicola in pea. S. sediminicola is able to colonise pea plants and establish a symbiotic association that promotes plant biomass production. Sequencing of the S. sediminicola genome revealed the existence of genes involved in secretion systems, Nod factor synthesis, and nitrogenase activity. Light and electron microscopic observations allowed us to refine the different steps involved in the establishment of the symbiotic association, including the formation of infection threads, the entry of the bacteria into the root cells, and the development of differentiated bacteroids in root nodules. These results, together with phylogenetic analysis, demonstrated that S. sediminicola is a non-rhizobia that has the potential to develop a beneficial symbiotic association with a legume. Such a symbiotic association could be a promising alternative for the development of more sustainable agricultural practices, especially under reduced N fertilisation conditions.
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Affiliation(s)
- Candice Mazoyon
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Bertrand Hirel
- Unité Mixte de Recherche 1318 INRA-AgroParisTech, Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique et de l'Environnement (INRAE), 78026 Versailles, France
| | - Audrey Pecourt
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Manuella Catterou
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Laurent Gutierrez
- Centre de Ressources Régionales en Biologie Moléculaire (CRRBM), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | | | - Fréderic Dubois
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Jérôme Duclercq
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
- Correspondence: ; Tel.: +33-3-22827612
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Agyekum DVA, Kobayashi T, Dastogeer KMG, Yasuda M, Sarkodee-Addo E, Ratu STN, Xu Q, Miki T, Matsuura E, Okazaki S. Diversity and function of soybean rhizosphere microbiome under nature farming. Front Microbiol 2023; 14:1130969. [PMID: 36937301 PMCID: PMC10014912 DOI: 10.3389/fmicb.2023.1130969] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 02/10/2023] [Indexed: 03/05/2023] Open
Abstract
Nature farming is a farming system that entails cultivating crops without using chemical fertilizers and pesticides. The present study investigated the bacterial and fungal communities in the rhizosphere of soybean grown in conventional and nature farming soils using wild-type and non-nodulating mutant soybean. The effect of soil fumigant was also analyzed to reveal its perturbation of microbial communities and subsequent effects on the growth of soybean. Overall, the wild-type soybean exhibited a better growth index compared to mutant soybean and especially in nature farming. Nodulation and arbuscular mycorrhiza (AM) fungi colonization were higher in plants under nature farming than in conventionally managed soil; however, fumigation drastically affected these symbioses with greater impacts on plants in nature farming soil. The rhizosphere microbiome diversity in nature farming was higher than that in conventional farming for both cultivars. However, the diversity was significantly decreased after fumigation treatment with a greater impact on nature farming. Principal coordinate analysis revealed that nature farming and conventional farming soil harbored distinct microbial communities and that soil fumigation significantly altered the communities in nature farming soils but not in conventional farming soils. Intriguingly, some beneficial microbial taxa related to plant growth and health, including Rhizobium, Streptomyces, and Burkholderia, were found as distinct microbes in the nature farming soil but were selectively bleached by fumigant treatment. Network analysis revealed a highly complex microbial network with high taxa connectivity observed under nature farming soil than in conventional soil; however, fumigation strongly broke it. Overall, the results highlighted that nature farming embraced higher microbial diversity and the abundance of beneficial soil microbes with a complex and interconnected network structure, and also demonstrated the underlying resilience of the microbial community to environmental perturbations, which is critical under nature farming where chemical fertilizers and pesticides are not applied.
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Affiliation(s)
- Dominic V. A. Agyekum
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Tatsuyuki Kobayashi
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Khondoker M. G. Dastogeer
- Department of Plant Pathology, Faculty of Agriculture, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Michiko Yasuda
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Elsie Sarkodee-Addo
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Safirah T. N. Ratu
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Qicong Xu
- International Nature Farming Research Center, Nagano, Japan
| | - Takaaki Miki
- International Nature Farming Research Center, Nagano, Japan
| | - Eri Matsuura
- College of Agriculture, Ibaraki University, Mito, Japan
| | - Shin Okazaki
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Japan
- *Correspondence: Shin Okazaki,
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Kumari M, Swarupa P, Kesari KK, Kumar A. Microbial Inoculants as Plant Biostimulants: A Review on Risk Status. LIFE (BASEL, SWITZERLAND) 2022; 13:life13010012. [PMID: 36675961 PMCID: PMC9860928 DOI: 10.3390/life13010012] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
Modern agriculture systems are copiously dependent on agrochemicals such as chemical fertilizers and pesticides intended to increase crop production and yield. The indiscriminate use of these chemicals not only affects the growth of plants due to the accumulation of toxic compounds, but also degrades the quality and life-supporting properties of soil. There is a dire need to develop some green approach that can resolve these issues and restore soil fertility and sustainability. The use of plant biostimulants has emerged as an environmentally friendly and acceptable method to increase crop productivity. Biostimulants contain biological substances which may be capable of increasing or stimulating plant growth in an eco-friendly manner. They are mostly biofertilizers that provide nutrients and protect plants from environmental stresses such as drought and salinity. In contrast to the protection of crop products, biostimulants not only act on the plant's vigor but also do not respond to direct actions against pests or diseases. Plant biostimulants improve nutrient mobilization and uptake, tolerance to stress, and thus crop quality when applied to plants directly or in the rhizospheric region. They foster plant growth and development by positively affecting the crop life-cycle starting from seed germination to plant maturity. Legalized application of biostimulants causes no hazardous effects on the environment and primarily provides nutrition to plants. It nurtures the growth of soil microorganisms, which leads to enhanced soil fertility and also improves plant metabolism. Additionally, it may positively influence the exogenous microbes and alter the equilibrium of the microfloral composition of the soil milieu. This review frequently cites the characterization of microbial plant biostimulants that belong to either a high-risk group or are closely related to human pathogens such as Pueudomonas, Klebsiella, Enterobacter, Acinetobacter, etc. These related pathogens cause ailments including septicemia, gastroenteritis, wound infections, inflammation in the respiratory system, meningitis, etc., of varied severity under different conditions of health status such as immunocompromized and comorbidity. Thus it may attract the related concern to review the risk status of biostimulants for their legalized applications in agriculture. This study mainly emphasizes microbial plant biostimulants and their safe application concerns.
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Affiliation(s)
- Menka Kumari
- Department of Life Sciences, School of Natural Sciences, Central University of Jharkhand Cheri-Manatu, Kamre, Kanke, Rachi 835222, India
| | - Preeti Swarupa
- Department of Microbiology, Patna Women’s College, Patna 800001, India
| | - Kavindra Kumar Kesari
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, 02150 Espoo, Finland
- Department of Applied Physics, School of Science, Aalto University, 02150 Espoo, Finland
- Correspondence: or (K.K.K.); (A.K.)
| | - Anil Kumar
- Department of Life Sciences, School of Natural Sciences, Central University of Jharkhand Cheri-Manatu, Kamre, Kanke, Rachi 835222, India
- Correspondence: or (K.K.K.); (A.K.)
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Dietrich M, Montesinos-Navarro A, Gabriel R, Strasser F, Meier DV, Mayerhofer W, Gorka S, Wiesenbauer J, Martin V, Weidinger M, Richter A, Kaiser C, Woebken D. Both abundant and rare fungi colonizing Fagus sylvatica ectomycorrhizal root-tips shape associated bacterial communities. Commun Biol 2022; 5:1261. [DOI: 10.1038/s42003-022-04178-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 10/27/2022] [Indexed: 11/18/2022] Open
Abstract
AbstractEctomycorrhizal fungi live in close association with their host plants and form complex interactions with bacterial/archaeal communities in soil. We investigated whether abundant or rare ectomycorrhizal fungi on root-tips of young beech trees (Fagus sylvatica) shape bacterial/archaeal communities. We sequenced 16S rRNA genes and fungal internal transcribed spacer regions of individual root-tips and used ecological networks to detect the tendency of certain assemblies of fungal and bacterial/archaeal taxa to inhabit the same root-tip (i.e. modularity). Individual ectomycorrhizal root-tips hosted distinct fungal communities associated with unique bacterial/archaeal communities. The structure of the fungal-bacterial/archaeal association was determined by both, dominant and rare fungi. Integrating our data in a conceptual framework suggests that the effect of rare fungi on the bacterial/archaeal communities of ectomycorrhizal root-tips contributes to assemblages of bacteria/archaea on root-tips. This highlights the potential impact of complex fine-scale interactions between root-tip associated fungi and other soil microorganisms for the ectomycorrhizal symbiosis.
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Prudence Dlamini S, Olalekan Akanmu A, Emmanuel Fadiji A, Oluranti Babalola O. Maize rhizosphere modulates the microbiome diversity and community structure to enhance plant health. Saudi J Biol Sci 2022; 30:103499. [DOI: 10.1016/j.sjbs.2022.103499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 10/24/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022] Open
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Kumar P, Singh S, Pranaw K, Kumar S, Singh B, Poria V. Bioinoculants as mitigators of multiple stresses: A ray of hope for agriculture in the darkness of climate change. Heliyon 2022; 8:e11269. [PMID: 36339753 PMCID: PMC9634370 DOI: 10.1016/j.heliyon.2022.e11269] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/04/2022] [Accepted: 10/21/2022] [Indexed: 11/28/2022] Open
Abstract
Plant encounters various biotic and abiotic stresses, that affect agricultural productivity and reduce farmer's income especially under changing global climate. These environmental stresses can advance plant senescence by inducing osmotic stress, nutrient stress, hormonal imbalance, production of oxygen radicals, and ion toxicity, etc. Additionally, these stresses are not limited to plant health but also deteriorate soil health by affecting the microbial diversity of soil. To tackle this global delinquent of agriculture, several methods are suggested to ameliorate the negative effect of different types of stresses, the application of beneficial microorganisms or bioinoculants is one of them. Beneficial microorganisms that are used as bioinoculants not only facilitate plant growth by fulfilling the nutrient requirements but also assist the plant to withstand these stresses. These microorganisms produce certain chemicals such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase, phytohormones, antioxidants, extracellular polysaccharide (EPS), siderophores, antibiotics, and volatile organic compounds (VOCs), etc. which help the plants to mitigate various stresses. Besides, these microbes also activate plant defence responses. Thus, these bioinoculants can effectively replace chemical inputs to supplement nutrient requirements and mitigation of multiple stresses in plants.
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Affiliation(s)
- Pawan Kumar
- Department of Microbiology, Central University of Haryana, Mahendergarh 123031, Haryana, India
| | - Surender Singh
- Department of Microbiology, Central University of Haryana, Mahendergarh 123031, Haryana, India
| | - Kumar Pranaw
- Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, University of Warsaw, Miecznikowa, 102-096 Warsaw, Poland
| | - Sandeep Kumar
- Department of Microbiology, Central University of Haryana, Mahendergarh 123031, Haryana, India
| | - Balkar Singh
- Department of Botany, Arya PG College, Panipat, Haryana, 132103, India
| | - Vikram Poria
- Department of Microbiology, Central University of Haryana, Mahendergarh 123031, Haryana, India
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21
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Bunyoo C, Roongsattham P, Khumwan S, Phonmakham J, Wonnapinij P, Thamchaipenet A. Dynamic Alteration of Microbial Communities of Duckweeds from Nature to Nutrient-Deficient Condition. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11212915. [PMID: 36365369 PMCID: PMC9658847 DOI: 10.3390/plants11212915] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 06/12/2023]
Abstract
Duckweeds live with complex assemblages of microbes as holobionts that play an important role in duckweed growth and phytoremediation ability. In this study, the structure and diversity of duckweed-associated bacteria (DAB) among four duckweed subtypes under natural and nutrient-deficient conditions were investigated using V3-V4 16S rRNA amplicon sequencing. High throughput sequencing analysis indicated that phylum Proteobacteria was predominant in across duckweed samples. A total of 24 microbial genera were identified as a core microbiome that presented in high abundance with consistent proportions across all duckweed subtypes. The most abundant microbes belonged to the genus Rhodobacter, followed by other common DAB, including Acinetobacter, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, and Pseudomonas. After nutrient-deficient stress, diversity of microbial communities was significantly deceased. However, the relative abundance of Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Pelomonas, Roseateles and Novosphingobium were significantly enhanced in stressed duckweeds. Functional prediction of the metagenome data displayed the relative abundance of essential pathways involved in DAB colonization, such as bacterial motility and biofilm formation, as well as biodegradable ability, such as benzoate degradation and nitrogen metabolism, were significantly enriched under stress condition. The findings improve the understanding of the complexity of duckweed microbiomes and facilitate the establishment of a stable microbiome used for co-cultivation with duckweeds for enhancement of biomass and phytoremediation under environmental stress.
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Affiliation(s)
- Chakrit Bunyoo
- Interdisciplinary Graduate Program in Bioscience, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Duckweed Holobiont Resource & Research Center (DHbRC), Kasetsart University, Bangkok 10900, Thailand
| | - Peerapat Roongsattham
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Duckweed Holobiont Resource & Research Center (DHbRC), Kasetsart University, Bangkok 10900, Thailand
| | - Sirikorn Khumwan
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Duckweed Holobiont Resource & Research Center (DHbRC), Kasetsart University, Bangkok 10900, Thailand
| | - Juthaporn Phonmakham
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Duckweed Holobiont Resource & Research Center (DHbRC), Kasetsart University, Bangkok 10900, Thailand
| | - Passorn Wonnapinij
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Duckweed Holobiont Resource & Research Center (DHbRC), Kasetsart University, Bangkok 10900, Thailand
- Omics Center for Agriculture, Bioresource, Food and Health Kasetsart University (OmiKU), Bangkok 10900, Thailand
| | - Arinthip Thamchaipenet
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Duckweed Holobiont Resource & Research Center (DHbRC), Kasetsart University, Bangkok 10900, Thailand
- Omics Center for Agriculture, Bioresource, Food and Health Kasetsart University (OmiKU), Bangkok 10900, Thailand
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22
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Cowan DA, Lebre PH, Amon C, Becker RW, Boga HI, Boulangé A, Chiyaka TL, Coetzee T, de Jager PC, Dikinya O, Eckardt F, Greve M, Harris MA, Hopkins DW, Houngnandan HB, Houngnandan P, Jordaan K, Kaimoyo E, Kambura AK, Kamgan-Nkuekam G, Makhalanyane TP, Maggs-Kölling G, Marais E, Mondlane H, Nghalipo E, Olivier BW, Ortiz M, Pertierra LR, Ramond JB, Seely M, Sithole-Niang I, Valverde A, Varliero G, Vikram S, Wall DH, Zeze A. Biogeographical survey of soil microbiomes across sub-Saharan Africa: structure, drivers, and predicted climate-driven changes. MICROBIOME 2022; 10:131. [PMID: 35996183 PMCID: PMC9396824 DOI: 10.1186/s40168-022-01297-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/15/2022] [Indexed: 05/20/2023]
Abstract
BACKGROUND Top-soil microbiomes make a vital contribution to the Earth's ecology and harbor an extraordinarily high biodiversity. They are also key players in many ecosystem services, particularly in arid regions of the globe such as the African continent. While several recent studies have documented patterns in global soil microbial ecology, these are largely biased towards widely studied regions and rely on models to interpolate the microbial diversity of other regions where there is low data coverage. This is the case for sub-Saharan Africa, where the number of regional microbial studies is very low in comparison to other continents. RESULTS The aim of this study was to conduct an extensive biogeographical survey of sub-Saharan Africa's top-soil microbiomes, with a specific focus on investigating the environmental drivers of microbial ecology across the region. In this study, we sampled 810 sample sites across 9 sub-Saharan African countries and used taxonomic barcoding to profile the microbial ecology of these regions. Our results showed that the sub-Saharan nations included in the study harbor qualitatively distinguishable soil microbiomes. In addition, using soil chemistry and climatic data extracted from the same sites, we demonstrated that the top-soil microbiome is shaped by a broad range of environmental factors, most notably pH, precipitation, and temperature. Through the use of structural equation modeling, we also developed a model to predict how soil microbial biodiversity in sub-Saharan Africa might be affected by future climate change scenarios. This model predicted that the soil microbial biodiversity of countries such as Kenya will be negatively affected by increased temperatures and decreased precipitation, while the fungal biodiversity of Benin will benefit from the increase in annual precipitation. CONCLUSION This study represents the most extensive biogeographical survey of sub-Saharan top-soil microbiomes to date. Importantly, this study has allowed us to identify countries in sub-Saharan Africa that might be particularly vulnerable to losses in soil microbial ecology and productivity due to climate change. Considering the reliance of many economies in the region on rain-fed agriculture, this study provides crucial information to support conservation efforts in the countries that will be most heavily impacted by climate change. Video Abstract.
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Affiliation(s)
- D A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.
| | - P H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.
| | - Cer Amon
- Institut National Polytechnique Houphouet-Boigny, Cote d'Ivoire, Yamoussoukro, South Africa
| | - R W Becker
- Biodiversity Research Centre, Department of Agriculture and Natural Resources Sciences, Namibia University of Science and Technology, Windhoek, Namibia
| | - H I Boga
- Taita Taveta University, Voi, Kenya
| | - A Boulangé
- Centro de Biotecnologia, Universidade Eduardo Mondlane, Maputo, Mozambique
- UMR InterTryp, CIRAD-IRD, 34398, Montpellier, France
| | - T L Chiyaka
- Department of Biotechnology and Biochemistry, University of Zimbabwe, Harare, Zimbabwe
| | - T Coetzee
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - P C de Jager
- Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa
| | - O Dikinya
- Department of Environmental Science, University of Botswana, Gaborone, Botswana
| | - F Eckardt
- Department of Geography, University of Cape Town, Cape Town, South Africa
| | - M Greve
- Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa
| | - M A Harris
- Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa
| | - D W Hopkins
- Scotland's Rural College, Edinburgh, EH9 3JG, UK
| | - H B Houngnandan
- Université Nationale d'Agriculture, Porto-Novo, Benin (Laboratoire de Microbiologie Des Sols Et d'Ecologie Microbienne), Porto-Novo, Benin
| | - P Houngnandan
- Université Nationale d'Agriculture, Porto-Novo, Benin (Laboratoire de Microbiologie Des Sols Et d'Ecologie Microbienne), Porto-Novo, Benin
| | - K Jordaan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Departamento de Genética Molecular Y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - E Kaimoyo
- University of Zambia, Lusaka, Zambia
| | | | - G Kamgan-Nkuekam
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - T P Makhalanyane
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | | | - E Marais
- Gobabeb-Namib Research Institute, Walvis Bay, Namibia
| | - H Mondlane
- Centro de Biotecnologia, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - E Nghalipo
- Biodiversity Research Centre, Department of Agriculture and Natural Resources Sciences, Namibia University of Science and Technology, Windhoek, Namibia
| | - B W Olivier
- Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa
| | - M Ortiz
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - L R Pertierra
- Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa
| | - J-B Ramond
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Departamento de Genética Molecular Y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - M Seely
- Gobabeb-Namib Research Institute, Walvis Bay, Namibia
| | - I Sithole-Niang
- Department of Biotechnology and Biochemistry, University of Zimbabwe, Harare, Zimbabwe
| | - A Valverde
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - G Varliero
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - S Vikram
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - D H Wall
- Department of Biology, Colorado State University, Fort Collins, USA
| | - A Zeze
- Institut National Polytechnique Houphouet-Boigny, Cote d'Ivoire, Yamoussoukro, South Africa
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Chaudhary P, Singh S, Chaudhary A, Sharma A, Kumar G. Overview of biofertilizers in crop production and stress management for sustainable agriculture. FRONTIERS IN PLANT SCIENCE 2022; 13:930340. [PMID: 36082294 PMCID: PMC9445558 DOI: 10.3389/fpls.2022.930340] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/21/2022] [Indexed: 05/09/2023]
Abstract
With the increase in world population, the demography of humans is estimated to be exceeded and it has become a major challenge to provide an adequate amount of food, feed, and agricultural products majorly in developing countries. The use of chemical fertilizers causes the plant to grow efficiently and rapidly to meet the food demand. The drawbacks of using a higher quantity of chemical or synthetic fertilizers are environmental pollution, persistent changes in the soil ecology, physiochemical composition, decreasing agricultural productivity and cause several health hazards. Climatic factors are responsible for enhancing abiotic stress on crops, resulting in reduced agricultural productivity. There are various types of abiotic and biotic stress factors like soil salinity, drought, wind, improper temperature, heavy metals, waterlogging, and different weeds and phytopathogens like bacteria, viruses, fungi, and nematodes which attack plants, reducing crop productivity and quality. There is a shift toward the use of biofertilizers due to all these facts, which provide nutrition through natural processes like zinc, potassium and phosphorus solubilization, nitrogen fixation, production of hormones, siderophore, various hydrolytic enzymes and protect the plant from different plant pathogens and stress conditions. They provide the nutrition in adequate amount that is sufficient for healthy crop development to fulfill the demand of the increasing population worldwide, eco-friendly and economically convenient. This review will focus on biofertilizers and their mechanisms of action, role in crop productivity and in biotic/abiotic stress tolerance.
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Affiliation(s)
- Parul Chaudhary
- Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India
| | - Shivani Singh
- Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India
| | - Anuj Chaudhary
- School of Agriculture and Environmental Science, Shobhit University, Gangoh, India
| | - Anita Sharma
- Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India
| | - Govind Kumar
- Department of Crop Production, Central Institute for Subtropical Horticulture, Lucknow, India
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24
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Koza NA, Adedayo AA, Babalola OO, Kappo AP. Microorganisms in Plant Growth and Development: Roles in Abiotic Stress Tolerance and Secondary Metabolites Secretion. Microorganisms 2022; 10:1528. [PMID: 36013946 PMCID: PMC9415082 DOI: 10.3390/microorganisms10081528] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 11/23/2022] Open
Abstract
Crops aimed at feeding an exponentially growing population are often exposed to a variety of harsh environmental factors. Although plants have evolved ways of adjusting their metabolism and some have also been engineered to tolerate stressful environments, there is still a shortage of food supply. An alternative approach is to explore the possibility of using rhizosphere microorganisms in the mitigation of abiotic stress and hopefully improve food production. Several studies have shown that rhizobacteria and mycorrhizae organisms can help improve stress tolerance by enhancing plant growth; stimulating the production of phytohormones, siderophores, and solubilizing phosphates; lowering ethylene levels; and upregulating the expression of dehydration response and antioxidant genes. This article shows the secretion of secondary metabolites as an additional mechanism employed by microorganisms against abiotic stress. The understanding of these mechanisms will help improve the efficacy of plant-growth-promoting microorganisms.
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Affiliation(s)
- Ntombikhona Appear Koza
- Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3886, South Africa
| | - Afeez Adesina Adedayo
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Science, North-West University, Mmabatho 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Science, North-West University, Mmabatho 2735, South Africa
| | - Abidemi Paul Kappo
- Molecular Biophysics and Structural Biology Group, Department of Biochemistry, University of Johannesburg, Auckland Park 2006, South Africa
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25
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Singh P, Chauhan PK, Upadhyay SK, Singh RK, Dwivedi P, Wang J, Jain D, Jiang M. Mechanistic Insights and Potential Use of Siderophores Producing Microbes in Rhizosphere for Mitigation of Stress in Plants Grown in Degraded Land. Front Microbiol 2022; 13:898979. [PMID: 35898908 PMCID: PMC9309559 DOI: 10.3389/fmicb.2022.898979] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/09/2022] [Indexed: 12/20/2022] Open
Abstract
Plant growth performance under a stressful environment, notably in the agriculture field, is directly correlated with the rapid growth of the human population, which triggers the pressure on crop productivity. Plants perceived many stresses owing to degraded land, which induces low plant productivity and, therefore, becomes a foremost concern for the future to face a situation of food scarcity. Land degradation is a very notable environmental issue at the local, regional, and global levels for agriculture. Land degradation generates global problems such as drought desertification, heavy metal contamination, and soil salinity, which pose challenges to achieving many UN Sustainable Development goals. The plant itself has a varied algorithm for the mitigation of stresses arising due to degraded land; the rhizospheric system of the plant has diverse modes and efficient mechanisms to cope with stress by numerous root-associated microbes. The suitable root-associated microbes and components of root exudate interplay against stress and build adaptation against stress-mediated mechanisms. The problem of iron-deficient soil is rising owing to increasing degraded land across the globe, which hampers plant growth productivity. Therefore, in the context to tackle these issues, the present review aims to identify plant-stress status owing to iron-deficient soil and its probable eco-friendly solution. Siderophores are well-recognized iron-chelating agents produced by numerous microbes and are associated with the rhizosphere. These siderophore-producing microbes are eco-friendly and sustainable agents, which may be managing plant stresses in the degraded land. The review also focuses on the molecular mechanisms of siderophores and their chemistry, cross-talk between plant root and siderophores-producing microbes to combat plant stress, and the utilization of siderophores in plant growth on degraded land.
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Affiliation(s)
- Pratiksha Singh
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Prabhat K. Chauhan
- Department of Environmental Science, Veer Bahadur Singh Purvanchal University, Jaunpur, India
| | - Sudhir K. Upadhyay
- Department of Environmental Science, Veer Bahadur Singh Purvanchal University, Jaunpur, India
- Sudhir K. Upadhyay
| | - Rajesh Kumar Singh
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Padmanabh Dwivedi
- Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India
| | - Jing Wang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Devendra Jain
- Department of Molecular Biology and Biotechnology, Maharana Pratap University of Agriculture and Technology, Udaipur, India
| | - Mingguo Jiang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
- *Correspondence: Mingguo Jiang
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26
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Adeleke BS, Ayangbenro AS, Babalola OO. In vitro Screening of Sunflower Associated Endophytic Bacteria With Plant Growth-Promoting Traits. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.903114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Harnessing endophytic microbes as bioinoculants promises to solve agricultural problems and improve crop yield. Out of fifty endophytic bacteria of sunflowers, 20 were selected based on plant growth-promoting. These plant growth-promoting bacteria were identified as Bacillus, Pseudomonas, and Stenotrophomonas. The qualitative screening showed bacterial ability to produce hydrogen cyanide, ammonia, siderophore, indole-3-acetic acid (IAA), exopolysaccharide, and solubilize phosphate. The high quantity of siderophore produced by B. cereus T4S was 87.73%. No significant difference was observed in the Bacillus sp. CAL14 (33.83%), S. indicatrix BOVIS40 (32.81%), S. maltophilia JVB5 (32.20%), S. maltophilia PK60 (33.48%), B. subtilis VS52 (33.43%), and P. saponiphilia J4R (33.24%), exhibiting high phosphate-solubilizing potential. S. indicatrix BOVIS40, B. thuringiensis SFL02, B. cereus SFR35, B. cereus BLBS20, and B. albus TSN29 showed high potential for the screened enzymes. Varied IAA production was recorded under optimized conditions. The medium amended with yeast extract yielded high IAA production of 46.43 μg/ml by S. indicatrix BOVIS40. Optimum IAA production of 23.36 and 20.72 μg/ml at 5% sucrose and 3% glucose by S. maltophilia JVB5 and B. cereus T4S were recorded. At pH 7, maximum IAA production of 25.36 μg/ml was obtained by S. indicatrix BOVIS40. All the isolates exhibited high IAA production at temperatures 25, 30, and 37°C. The in vitro seed inoculation enhanced sunflower seedlings compared to the control. Therefore, exploration of copious endophytic bacteria as bioinoculants can best be promising to boost sunflower cultivation.
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Adeleke BS, Babalola OO. Meta-omics of endophytic microbes in agricultural biotechnology. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102332] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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28
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Nwachukwu BC, Babalola OO. Metagenomics: A Tool for Exploring Key Microbiome With the Potentials for Improving Sustainable Agriculture. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.886987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Microorganisms are immense in nature and exist in every imaginable ecological niche, performing a wide range of metabolic processes. Unfortunately, using traditional microbiological methods, most microorganisms remain unculturable. The emergence of metagenomics has resolved the challenge of capturing the entire microbial community in an environmental sample by enabling the analysis of whole genomes without requiring culturing. Metagenomics as a non-culture approach encompasses a greater amount of genetic information than traditional approaches. The plant root-associated microbial community is essential for plant growth and development, hence the interactions between microorganisms, soil, and plants is essential to understand and improve crop yields in rural and urban agriculture. Although some of these microorganisms are currently unculturable in the laboratory, metagenomic techniques may nevertheless be used to identify the microorganisms and their functional traits. A detailed understanding of these organisms and their interactions should facilitate an improvement of plant growth and sustainable crop production in soil and soilless agriculture. Therefore, the objective of this review is to provide insights into metagenomic techniques to study plant root-associated microbiota and microbial ecology. In addition, the different DNA-based techniques and their role in elaborating plant microbiomes are discussed. As an understanding of these microorganisms and their biotechnological potentials are unlocked through metagenomics, they can be used to develop new, useful and unique bio-fertilizers and bio-pesticides that are not harmful to the environment.
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29
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Ferreira EGC, Gomes DF, Delai CV, Barreiros MAB, Grange L, Rodrigues EP, Henning LMM, Barcellos FG, Hungria M. Revealing potential functions of hypothetical proteins induced by genistein in the symbiosis island of Bradyrhizobium japonicum commercial strain SEMIA 5079 (= CPAC 15). BMC Microbiol 2022; 22:122. [PMID: 35513812 PMCID: PMC9069715 DOI: 10.1186/s12866-022-02527-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 04/11/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Bradyrhizobium japonicum strain SEMIA 5079 (= CPAC 15) is a nitrogen-fixing symbiont of soybean broadly used in commercial inoculants in Brazil. Its genome has about 50% of hypothetical (HP) protein-coding genes, many in the symbiosis island, raising questions about their putative role on the biological nitrogen fixation (BNF) process. This study aimed to infer functional roles to 15 HP genes localized in the symbiosis island of SEMIA 5079, and to analyze their expression in the presence of a nod-gene inducer. RESULTS A workflow of bioinformatics tools/databases was established and allowed the functional annotation of the HP genes. Most were enzymes, including transferases in the biosynthetic pathways of cobalamin, amino acids and secondary metabolites that may help in saprophytic ability and stress tolerance, and hydrolases, that may be important for competitiveness, plant infection, and stress tolerance. Putative roles for other enzymes and transporters identified are discussed. Some HP proteins were specific to the genus Bradyrhizobium, others to specific host legumes, and the analysis of orthologues helped to predict roles in BNF. CONCLUSIONS All 15 HP genes were induced by genistein and high induction was confirmed in five of them, suggesting major roles in the BNF process.
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Affiliation(s)
- Everton Geraldo Capote Ferreira
- Londrina State University (UEL), Celso Garcia Cid Road (PR 445), km 380, CEP 86057-970 Londrina, PR Brazil
- Embrapa Soja, Rodovia Carlos João Strass, C.P. 231, CEP 86001-970 Londrina, PR Brazil
| | | | - Caroline Vanzzo Delai
- Federal University of Paraná (UFPR), Estrada dos Pioneiros 2153, CEP 85950-000 Palotina, PR Brazil
| | | | - Luciana Grange
- Federal University of Paraná (UFPR), Estrada dos Pioneiros 2153, CEP 85950-000 Palotina, PR Brazil
| | - Elisete Pains Rodrigues
- Londrina State University (UEL), Celso Garcia Cid Road (PR 445), km 380, CEP 86057-970 Londrina, PR Brazil
| | | | - Fernando Gomes Barcellos
- Londrina State University (UEL), Celso Garcia Cid Road (PR 445), km 380, CEP 86057-970 Londrina, PR Brazil
| | - Mariangela Hungria
- Londrina State University (UEL), Celso Garcia Cid Road (PR 445), km 380, CEP 86057-970 Londrina, PR Brazil
- Embrapa Soja, Rodovia Carlos João Strass, C.P. 231, CEP 86001-970 Londrina, PR Brazil
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30
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Nwachukwu BC, Ayangbenro AS, Babalola OO. Effects of soil properties and carbon substrates on bacterial diversity of two sunflower farms. AMB Express 2022; 12:47. [PMID: 35460382 PMCID: PMC9035202 DOI: 10.1186/s13568-022-01388-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/09/2022] [Indexed: 11/24/2022] Open
Abstract
The sustainable production of sunflower (Helianthus annuus) is crucial and one way to accomplish this feat is to have an understanding of the beneficial bacteria of sunflower rhizosphere. Similarly, the respiratory response of these bacteria needs to be studied to understand their roles in the ecosystem. This study was therefore conceptualized to gain insights into the effects of soil properties and carbon substrate utilization on bacterial community diversity of sunflower rhizosphere grown in Ditsobottla and Kraaipan, North West Province, South Africa. Extracted DNA from sunflower rhizosphere and bulk soils was subjected to 16S amplicon sequencing. Significant differences were observed in the alpha and beta diversities of the soil bacterial communities (p < 0.05). At the order level, among all the bacterial taxa captured in the farms, Bacillales were the most dominant. The abundance of Lactobacillales, Bacillales, Rhizobiales, Enterobacteriales, Burkholderiales, Flavobacteriales, Sphingomonadales, Myxococcales, and Nitrosomonadales obtained from Ditsobottla rhizosphere soil (R1) was positively influenced by organic matter (OM), while the abundance of Planctomycetales, Cytophagales, Gemmatimonadales, Nitrospirales and Caulobacteriales from Kraaipan rhizosphere soil (R2) was positively influenced by total N and pH. Bacterial communities of all the soil samples utilized the different carbon substrates (three amino acids, six carbohydrates, and three carboxylic acids) as an energy source. Significant differences (p < 0.05) were only observed in tryptophan and methionine amended soils. Unclassified bacteria were also captured in this study, such bacteria can further be harnessed for sustainable production of sunflower and other agricultural crops.
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Nakei MD, Venkataramana PB, Ndakidemi PA. Soybean-Nodulating Rhizobia: Ecology, Characterization, Diversity, and Growth Promoting Functions. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.824444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The worldwide increase in population continues to threaten the sustainability of agricultural systems since agricultural output must be optimized to meet the global rise in food demand. Sub-Saharan Africa (SSA) is among the regions with a fast-growing population but decreasing crop productivity. Pests and diseases, as well as inadequate nitrogen (N) levels in soils, are some of the biggest restrictions to agricultural production in SSA. N is one of the most important plant-limiting elements in agricultural soils, and its deficit is usually remedied by using nitrogenous fertilizers. However, indiscriminate use of these artificial N fertilizers has been linked to environmental pollution calling for alternative N fertilization mechanisms. Soybean (Glycine max) is one of the most important legumes in the world. Several species of rhizobia from the four genera, Bardyrhizobium, Rhizobium, Mesorhizobium, and Ensifer (formerly Sinorhizobium), are observed to effectively fix N with soybean as well as perform various plant-growth promoting (PGP) functions. The efficiency of the symbiosis differs with the type of rhizobia species, soybean cultivar, and biotic factors. Therefore, a complete understanding of the ecology of indigenous soybean-nodulating rhizobia concerning their genetic diversity and the environmental factors associated with their localization and dominance in the soil is important. This review aimed to understand the potential of indigenous soybean-nodulating rhizobia through a synthesis of the literature regarding their characterization using different approaches, genetic diversity, symbiotic effectiveness, as well as their functions in biological N fixation (BNF) and biocontrol of soybean soil-borne pathogens.
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Khairnar M, Hagir A, Parmar K, Sayyed RZ, James EK, Rahi P. Phylogenetic diversity and plant growth-promoting activities of rhizobia nodulating fenugreek (Trigonella foenum-graecum Linn.) cultivated in different agroclimatic regions of India. FEMS Microbiol Ecol 2022; 98:6526309. [PMID: 35142840 DOI: 10.1093/femsec/fiac014] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 12/15/2021] [Accepted: 02/08/2022] [Indexed: 11/15/2022] Open
Abstract
Fenugreek (Trigonella foenum-graecum Linn.), is an extensively cultivated legume crop used as a herb, spice, and traditional medicine in India. The symbiotic efficiency and plant growth-promoting potential of fenugreek rhizobia depend on the symbiont strain and environmental factors. We isolated 176 root-nodulating bacteria from fenugreek cultivated in different agroclimatic regions of India. MALDI-TOF MS-based identification and phylogenetic analyses based on 16S rRNA and five housekeeping genes classified the fenugreek-rhizobia as Ensifer (Sinorhizobium) meliloti. However, the strains represent separate sub-lineages of E. meliloti, distinct from all reported sub-lineages across the globe. We also observed the spatial distribution of fenugreek rhizobia, as the three sub-lineages of E. meliloti recorded during this study were specific to their respective agroclimatic regions. According to the symbiotic gene (nodC and nifH) phylogenies, all three sub-lineages of E. meliloti harboured symbiotic genes similar to symbiovar meliloti; as with the housekeeping genes, these also revealed a spatial distribution for different clades of sv. meliloti. The strains could nodulate fenugreek plants and they showed plant growth-promoting potential. Significant differences were found in the plant growth parameters in response to inoculation with the various strains, suggesting strain-level differences. This study demonstrates that fenugreek rhizobia in India are diverse and spatially distributed in different agro-climatic regions.
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Affiliation(s)
- Mitesh Khairnar
- National Centre for Microbial Resource, National Centre for Cell Science, Pune 411007, India
| | - Ashwini Hagir
- National Centre for Microbial Resource, National Centre for Cell Science, Pune 411007, India
| | - Krupa Parmar
- National Centre for Microbial Resource, National Centre for Cell Science, Pune 411007, India
| | - Riyazali Zafarali Sayyed
- Department of Microbiology, PSGVP Mandal's, Arts, Science, and Commerce College, Shahada 425409, India
| | - Euan K James
- The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Praveen Rahi
- National Centre for Microbial Resource, National Centre for Cell Science, Pune 411007, India
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Comparative Genome Analysis Reveals Phylogenetic Identity of Bacillus velezensis HNA3 and Genomic Insights into Its Plant Growth Promotion and Biocontrol Effects. Microbiol Spectr 2022; 10:e0216921. [PMID: 35107331 PMCID: PMC8809340 DOI: 10.1128/spectrum.02169-21] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Bacillus velezensis HNA3, a potential plant growth promoter and biocontrol rhizobacterium, was isolated from plant rhizosphere soils in our previous work. Here, we sequenced the entire genome of the HNA3 strain and performed a comparative genome analysis. We found that HNA3 has a 3,929-kb chromosome with 46.5% GC content and 4,080 CDSs. We reclassified HNA3 as a Bacillus velezensis strain by core genome analysis between HNA3 and 74 previously defined Bacillus strains in the evolutionary tree. A comparative genomic analysis among Bacillus velezensis HNA3, Bacillus velezensis FZB42, Bacillus amyloliquefaciens DSM7, and Bacillus subtilis 168 showed that only HNA3 has one predicated secretory protein feruloyl esterase that catalyzes the hydrolysis of plant cell wall polysaccharides. The analysis of gene clusters revealed that whole biosynthetic gene clusters type Lanthipeptide was exclusively identified in HNA3 and might lead to the synthesis of new bioactive compounds. Twelve gene clusters were detected in HNA3 responsible for the synthesis of 14 secondary metabolites including Bacillaene, Fengycin, Bacillomycin D, Surfactin, Plipastatin, Mycosubtilin, Paenilarvins, Macrolactin, Difficidin, Amylocyclicin, Bacilysin, Iturin, Bacillibactin, Paenibactin, and others. HNA3 has 77 genes encoding for possible antifungal and antibacterial secreting carbohydrate active enzymes. It also contains genes involved in plant growth promotion, such as 11 putative indole acetic acid (IAA)-producing genes, spermidine and polyamine synthase genes, volatile compound producing genes, and multiple biofilm related genes. HNA3 also has 19 phosphatase genes involved in phosphorus solubilization. Our results provide insights into the genetic characteristics responsible for the bioactivities and potential application of HNA3 as plant growth-promoting strain in ecological agriculture. IMPORTANCE This study is the primary initiative to identify Bacillus velezensis HNA3 whole genome sequence and reveal its genomic properties as an effective biocontrol agent against plant pathogens and a plant growth stimulator. HNA3 genetic profile can be used as a reference for future studies that can be applied as a highly effective biofertilizer and biofungicide inoculum to improve agriculture productivity. HNA3 reclassified in the phylogenetic tree which may be helpful for highly effective strain engineering and taxonomy. The genetic comparison among HNA3 and closely similar species B. velezensis FZB42, B. amyloliquefaciens DSM7, and B. subtilis 168 demonstrates some distinctive genetic properties of HNA3 and provides a basis for the genetic diversity of the Bacillus genus, which allows developing more effective eco-friendly resources for agriculture and separation of Bacillus velezensis as distinct species in the phylogenetic tree.
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Fadiji AE, Babalola OO, Santoyo G, Perazzolli M. The Potential Role of Microbial Biostimulants in the Amelioration of Climate Change-Associated Abiotic Stresses on Crops. Front Microbiol 2022; 12:829099. [PMID: 35095828 PMCID: PMC8795815 DOI: 10.3389/fmicb.2021.829099] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 12/29/2021] [Indexed: 02/05/2023] Open
Abstract
Crop plants are more often exposed to abiotic stresses in the current age of fast-evolving climate change. This includes exposure to extreme and unpredictable changes in climatic conditions, phytosanitary hazards, and cultivation conditions, which results in drastic losses in worldwide agricultural productions. Plants coexist with microbial symbionts, some of which play key roles in the ecosystem and plant processes. The application of microbial biostimulants, which take advantage of symbiotic relationships, is a long-term strategy for improving plant productivity and performance, even in the face of climate change-associated stresses. Beneficial filamentous fungi, yeasts, and bacteria are examples of microbial biostimulants, which can boost the growth, yield, nutrition and stress tolerance in plants. This paper highlights recent information about the role of microbial biostimulants and their potential application in mitigating the abiotic stresses occurring on crop plants due to climate change. A critical evaluation for their efficient use under diverse climatic conditions is also made. Currently, accessible products generally improve cultural conditions, but their action mechanisms are mostly unknown, and their benefits are frequently inconsistent. Thus, further studies that could lead to the more precisely targeted products are discussed.
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Affiliation(s)
- Ayomide Emmanuel Fadiji
- Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, South Africa
| | - Gustavo Santoyo
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
| | - Michele Perazzolli
- Center Agriculture Food Environment (C3A), University of Trento, San Michele all’Adige, Italy
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige, Italy
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Kumar S, Diksha, Sindhu SS, Kumar R. Biofertilizers: An ecofriendly technology for nutrient recycling and environmental sustainability. CURRENT RESEARCH IN MICROBIAL SCIENCES 2021; 3:100094. [PMID: 35024641 PMCID: PMC8724949 DOI: 10.1016/j.crmicr.2021.100094] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 12/09/2021] [Accepted: 12/09/2021] [Indexed: 01/02/2023] Open
Abstract
Modern intensive agricultural practices face numerous challenges that pose major threats to global food security. In order to address the nutritional requirements of the ever-increasing world population, chemical fertilizers and pesticides are applied on large scale to increase crop production. However, the injudicious use of agrochemicals has resulted in environmental pollution leading to public health hazards. Moreover, agriculture soils are continuously losing their quality and physical properties as well as their chemical (imbalance of nutrients) and biological health. Plant-associated microbes with their plant growth- promoting traits have enormous potential to solve these challenges and play a crucial role in enhancing plant biomass and crop yield. The beneficial mechanisms of plant growth improvement include enhanced nutrient availability, phytohormone modulation, biocontrol of phytopathogens and amelioration of biotic and abiotic stresses. Solid-based or liquid bioinoculant formulation comprises inoculum preparation, addition of cell protectants such as glycerol, lactose, starch, a good carrier material, proper packaging and best delivery methods. Recent developments of formulation include entrapment/microencapsulation, nano-immobilization of microbial bioinoculants and biofilm-based biofertilizers. This review critically examines the current state-of-art on use of microbial strains as biofertilizers and the important roles performed by these beneficial microbes in maintaining soil fertility and enhancing crop productivity.
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Key Words
- ABA, Abscisic acid
- ACC, 1-aminocyclopropane-1-carboxylic acid
- AM, Arbuscular mycorrhiza
- APX, Ascorbate peroxidase
- BGA, Blue green algae
- BNF, Biological nitrogen fixation
- Beneficial microorganisms
- Biofertilizers
- CAT, Catalase
- Crop production
- DAPG, 2, 4-diacetyl phloroglucinol
- DRB, Deleterious rhizospheric bacteria
- GA, Gibberellic acid
- GPX, Glutathione/thioredoxin peroxidase
- HCN, Hydrogen cyanide
- IAA, Indole acetic acid
- IAR, Intrinsic antibiotic resistance
- ISR, Induced systemic resistance
- KMB, Potassium mobilizing bacteria
- KSMs, Potassium-solubilizing microbes
- MAMPs, Microbes associated molecular patterns
- PAMPs, Pathogen associated molecular patterns
- PCA, Phenazine-1-carboxylic acid
- PGP, Plant growth-promoting
- PGPR, Plant growth-promoting rhizobacteria
- POD, Peroxidase
- PSB, Phosphate-solubilizing bacteria
- Rhizosphere
- SAR, Systemic acquired resistance
- SOB, Sulphur oxidizing bacteria
- Soil fertility
- Sustainable agriculture
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Affiliation(s)
- Satish Kumar
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
| | - Diksha
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
| | - Satyavir S. Sindhu
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
| | - Rakesh Kumar
- Department of Microbiology, CCS Haryana Agricultural University, Hisar 125004, India
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Nwachukwu BC, Ayangbenro AS, Babalola OO. Comparative study of microbial structure and functional profile of sunflower rhizosphere grown in two fields. BMC Microbiol 2021; 21:337. [PMID: 34886803 PMCID: PMC8656072 DOI: 10.1186/s12866-021-02397-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 11/24/2021] [Indexed: 12/28/2022] Open
Abstract
Background Microbial communities inhabiting the rhizosphere play pivotal roles in determining plant health and yield. Manipulation of the rhizosphere microbial community is a promising means to enhance the productivity of economically viable and important agricultural crops such as sunflower (Helianthus annuus). This study was designed to gain insights into the taxonomic and functional structures of sunflower rhizosphere and bulk soil microbiome at two different locations (Sheila and Itsoseng) in South Africa. Results Microbial DNA extracted from the sunflower rhizosphere and bulk soils was subjected to next-generation sequencing using 16S amplicon sequencing technique. Firmicutes, Actnobacteria and Proteobacteria predominated sunflower rhizosphere soils. Firmicutes, Cyanobacteria, Deinococcus-Thermus and Fibrobacteres were positively influenced by Na+ and clay content, while Actinobacteria, Thaumarchaeota, Bacteroidetes, Planctomycetes, Aquificae and Chloroflexi were positively influenced by soil resistivity (Res) and Mg2+. The community-level physiological profiling (CLPP) analysis showed that the microbial communities in SHR and ITR used the amino acids tryptophan and malic acid efficiently. The metabolisms of these carbon substrates may be due to the dominant nature of some of the organisms, such as Actinobacteria in the soils. Conclusion The CLPP measurements of soil from sunflower rhizosphere were different from those of the bulk soil and the degree of the variations were based on the type of carbon substrates and the soil microbial composition. This study has shown the presence of certain taxa of rhizobacteria in sunflower rhizosphere which were positively influenced by Na+ and Mg2+, and taxa obtained from SHR and ITR were able to effectively utilized tryptophan and malic acid. Many unclassified microbial groups were also discovered and it is therefore recommended that efforts should further be made to isolate, characterize and identify these unclassified microbial species, as it might be plausible to discover new microbial candidates that can further be harnessed for biotechnological purpose.
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Affiliation(s)
- Blessing Chidinma Nwachukwu
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, Private Mail Bag X2046, North-West University, Mmabatho, 2735, South Africa
| | - Ayansina Segun Ayangbenro
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, Private Mail Bag X2046, North-West University, Mmabatho, 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, Private Mail Bag X2046, North-West University, Mmabatho, 2735, South Africa.
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Adeleke BS, Ayangbenro AS, Babalola OO. Genomic assessment of Stenotrophomonas indicatrix for improved sunflower plant. Curr Genet 2021. [PMID: 34195871 DOI: 10.1007/s00294-00021-01199-00298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Diverse agriculturally important microbes have been studied with known potential in plant growth promotion. Providing several opportunities, Stenotrophomonas species are characterized as promising plant enhancers, inducers, and protectors against environmental stressors. The S. indicatrix BOVIS40 isolated from the sunflower root endosphere possessed unique features, as genome insights into the Stenotrophomonas species isolated from oilseed crops in Southern Africa have not been reported. Plant growth-promotion screening and genome analysis of S. indicatrix BOVIS40 were presented in this study. The genomic information reveals various genes underlining plant growth promotion and resistance to environmental stressors. The genome of S. indicatrix BOVIS40 harbors genes involved in the degradation and biotransformation of organic molecules. Also, other genes involved in biofilm production, chemotaxis, and flagellation that facilitate bacterial colonization in the root endosphere and phytohormone genes that modulate root development and stress response in plants were detected in strain BOVIS40. IAA activity of the bacterial strain may be a factor responsible for root formation. A measurable approach to the S. indicatrix BOVIS40 lifestyle can strategically provide several opportunities in their use as bioinoculants in developing environmentally friendly agriculture sustainably. The findings presented here provide insights into the genomic functions of S. indicatrix BOVIS40, which has set a foundation for future comparative studies for a better understanding of the synergism among microbes inhabiting plant endosphere. Hence, highlighting the potential of S. indicatrix BOVIS40 upon inoculation under greenhouse experiment, thus suggesting its application in enhancing plant and soil health sustainably.
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Affiliation(s)
- Bartholomew Saanu Adeleke
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho, 2735, South Africa
| | - Ayansina Segun Ayangbenro
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho, 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho, 2735, South Africa.
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Mir MI, Kumar BK, Gopalakrishnan S, Vadlamudi S, Hameeda B. Characterization of rhizobia isolated from leguminous plants and their impact on the growth of ICCV 2 variety of chickpea ( Cicer arietinum L.). Heliyon 2021; 7:e08321. [PMID: 34820538 PMCID: PMC8601996 DOI: 10.1016/j.heliyon.2021.e08321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/14/2021] [Accepted: 11/01/2021] [Indexed: 12/20/2022] Open
Abstract
Six rhizobia-like-bacterial strains in total, secluded from the root and stem nodules of various leguminous plants were characterized for growth promoting ability on ICCV 2 variety of chickpea. Bacterial strains showed production of IAA, NH3, siderophore, HCN, ACC deaminase, hydrolytic enzyme production such as chitinase, amylase, protease, lipase, β-1, 3-glucanase and solubilization of nutrients such as phosphate, zinc and potassium. However the performance of PGP traits characterized in-vitro varied among the six bacterial strains. The sequences of 16S rRNA gene of bacterial strains IHSR, IHRG, IHAA, IHGN-3, IHCP-1 and IHCP-2 showed maximum identity with Rhizobium sp., Rhizobium tropici, Rhizobium multihospitium, Mesorhizobium sp., Burkholderia cepacia and Rhizobium pusense. In plate culture conditions the bacterial strains changed the colour of media (NFB) from green to blue and showed amplification of nifH gene by PCR, and also enhanced nodule formation in chickpea under greenhouse conditions, which explains their nitrogen fixing ability. Scanning electron microscopy studies of chickpea roots showed colonization by all the six bacterial strains in solo and by consortium (IHRG + IHGN-3). Under greenhouse conditions, chickpea plants inoculated with different strains showed improvement in plant height, number of branches, total chlorophyll, nodule number, nodule weight, shoot weight, root weight, root volume and root surface area at 30 and 45 days after sowing (DAS) over the uninoculated control plants. It was also observed at the crop maturity stage all the bacterial strains inoculated separately enhanced pod number, seed number and total NPK compared to uninoculated control plants. This study suggests that bacteria associated with root and stem nodules can be a promising resource to enhance nodulation, PGP and crop yields in chickpea.
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Affiliation(s)
- Mohammad Imran Mir
- Department of Botany, UCS, Osmania University, Hyderabad, 500007, Telangana, India
| | - B Kiran Kumar
- Department of Botany, UCS, Osmania University, Hyderabad, 500007, Telangana, India
| | - Subramaniam Gopalakrishnan
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Hyderabad, 502319, Telangana, India
| | - Srinivas Vadlamudi
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Hyderabad, 502319, Telangana, India
| | - Bee Hameeda
- Department of Microbiology, UCS, Osmania University, Hyderabad, 500007, Telangana, India
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Omomowo OI, Babalola OO. Constraints and Prospects of Improving Cowpea Productivity to Ensure Food, Nutritional Security and Environmental Sustainability. FRONTIERS IN PLANT SCIENCE 2021; 12:751731. [PMID: 34745184 PMCID: PMC8570086 DOI: 10.3389/fpls.2021.751731] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 09/30/2021] [Indexed: 05/23/2023]
Abstract
Providing safe and secure food for an increasing number of people globally is challenging. Coping with such a human population by merely applying the conventional agricultural production system has not proved to be agro-ecologically friendly; nor is it sustainable. Cowpea (Vigna unguiculata (L) Walp) is a multi-purpose legume. It consists of high-quality protein for human consumption, and it is rich in protein for livestock fodder. It enriches the soil in that it recycles nutrients through the fixation of nitrogen in association with nodulating bacteria. However, the productivity of this multi-functional, indigenous legume that is of great value to African smallholder farmers and the rural populace, and also to urban consumers and entrepreneurs, is limited. Because cowpea is of strategic importance in Africa, there is a need to improve on its productivity. Such endeavors in Africa are wrought with challenges that include drought, salinity, the excessive demand among farmers for synthetic chemicals, the repercussions of climate change, declining soil nutrients, microbial infestations, pest issues, and so forth. Nevertheless, giant strides have already been made and there have already been improvements in adopting sustainable and smart biotechnological approaches that are favorably influencing the production costs of cowpea and its availability. As such, the prospects for a leap in cowpea productivity in Africa and in the enhancement of its genetic gain are good. Potential and viable means for overcoming some of the above-mentioned production constraints would be to focus on the key cowpea producer nations in Africa and to encourage them to embrace biotechnological techniques in an integrated approach to enhance for sustainable productivity. This review highlights the spectrum of constraints that limit the cowpea yield, but looks ahead of the constraints and seeks a way forward to improve cowpea productivity in Africa. More importantly, this review investigates applications and insights concerning mechanisms of action for implementing eco-friendly biotechnological techniques, such as the deployment of bio inoculants, applying climate-smart agricultural (CSA) practices, agricultural conservation techniques, and multi-omics smart technology in the spheres of genomics, transcriptomics, proteomics, and metabolomics, for improving cowpea yields and productivity to achieve sustainable agro-ecosystems, and ensuring their stability.
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Affiliation(s)
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
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Bhagat N, Raghav M, Dubey S, Bedi N. Bacterial Exopolysaccharides: Insight into Their Role in Plant Abiotic Stress Tolerance. J Microbiol Biotechnol 2021; 31:1045-1059. [PMID: 34226402 PMCID: PMC9706007 DOI: 10.4014/jmb.2105.05009] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/17/2021] [Accepted: 06/17/2021] [Indexed: 12/15/2022]
Abstract
Various abiotic stressors like drought, salinity, temperature, and heavy metals are major environmental stresses that affect agricultural productivity and crop yields all over the world. Continuous changes in climatic conditions put selective pressure on the microbial ecosystem to produce exopolysaccharides. Apart from soil aggregation, exopolysaccharide (EPS) production also helps in increasing water permeability, nutrient uptake by roots, soil stability, soil fertility, plant biomass, chlorophyll content, root and shoot length, and surface area of leaves while also helping maintain metabolic and physiological activities during drought stress. EPS-producing microbes can impart salt tolerance to plants by binding to sodium ions in the soil and preventing these ions from reaching the stem, thereby decreasing sodium absorption from the soil and increasing nutrient uptake by the roots. Biofilm formation in high-salinity soils increases cell viability, enhances soil fertility, and promotes plant growth and development. The third environmental stressor is presence of heavy metals in the soil due to improper industrial waste disposal practices that are toxic for plants. EPS production by soil bacteria can result in the biomineralization of metal ions, thereby imparting metal stress tolerance to plants. Finally, high temperatures can also affect agricultural productivity by decreasing plant metabolism, seedling growth, and seed germination. The present review discusses the role of exopolysaccharide-producing plant growth-promoting bacteria in modulating plant growth and development in plants and alleviating extreme abiotic stress condition. The review suggests exploring the potential of EPS-producing bacteria for multiple abiotic stress management strategies.
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Affiliation(s)
- Neeta Bhagat
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector 125, Noida 201301, India,Corresponding author Phone: +7042420808 E-mail:
| | - Meenu Raghav
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector 125, Noida 201301, India
| | - Sonali Dubey
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector 125, Noida 201301, India
| | - Namita Bedi
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector 125, Noida 201301, India
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Adeleke BS, Ayangbenro AS, Babalola OO. Genomic Analysis of Endophytic Bacillus cereus T4S and Its Plant Growth-Promoting Traits. PLANTS 2021; 10:plants10091776. [PMID: 34579311 PMCID: PMC8467928 DOI: 10.3390/plants10091776] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/24/2021] [Accepted: 07/25/2021] [Indexed: 11/19/2022]
Abstract
Insights into plant endophytic microbes and their exploration in agriculture have provided opportunities for sustainable plant health and food safety. Notable endophytic Bacillus species with plant growth-promoting traits have been documented; nevertheless, information on genome analysis of B. cereus associated with the sunflower in South Africa has not been studied. Therefore, we present whole-genome sequence of agriculturally important B. cereus strain T4S isolated from sunflower plants. The NextSeq Illumina sequencing yielded 7,255,762 bp sequence reads, 151 bp average read length, 5,945,881 bp genome size, 56 tRNA, 63 rRNA, and G + C content of 34.8%. The phylogeny analysis of strain T4S was similar to B. cereus NJ-W. Secondary metabolites, such as petrobactin, bacillibactin, bacitracin, molybdenum factor, zwittermicin, and fengycin underlining bacterial biocontrol efficacy against phytopathogens were found in the T4S genome. The predicted novel genes in the bacterial genome mediating the complex metabolic pathways can provide a genetic basis in understanding endosphere biology and their multiple functions thereof in crop improvement. Interestingly, seed and root inoculation with strain T4S contributed to sunflower yield under greenhouse experiments. Hence, the detection of notable genes specific for plant growth promotion as validated under in vitro screening, promisingly, suggests the relevance of strain T4S in agricultural biotechnology.
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Adeleke BS, Ayangbenro AS, Babalola OO. Genomic assessment of Stenotrophomonas indicatrix for improved sunflower plant. Curr Genet 2021; 67:891-907. [PMID: 34195871 DOI: 10.1007/s00294-021-01199-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/21/2021] [Accepted: 06/21/2021] [Indexed: 11/29/2022]
Abstract
Diverse agriculturally important microbes have been studied with known potential in plant growth promotion. Providing several opportunities, Stenotrophomonas species are characterized as promising plant enhancers, inducers, and protectors against environmental stressors. The S. indicatrix BOVIS40 isolated from the sunflower root endosphere possessed unique features, as genome insights into the Stenotrophomonas species isolated from oilseed crops in Southern Africa have not been reported. Plant growth-promotion screening and genome analysis of S. indicatrix BOVIS40 were presented in this study. The genomic information reveals various genes underlining plant growth promotion and resistance to environmental stressors. The genome of S. indicatrix BOVIS40 harbors genes involved in the degradation and biotransformation of organic molecules. Also, other genes involved in biofilm production, chemotaxis, and flagellation that facilitate bacterial colonization in the root endosphere and phytohormone genes that modulate root development and stress response in plants were detected in strain BOVIS40. IAA activity of the bacterial strain may be a factor responsible for root formation. A measurable approach to the S. indicatrix BOVIS40 lifestyle can strategically provide several opportunities in their use as bioinoculants in developing environmentally friendly agriculture sustainably. The findings presented here provide insights into the genomic functions of S. indicatrix BOVIS40, which has set a foundation for future comparative studies for a better understanding of the synergism among microbes inhabiting plant endosphere. Hence, highlighting the potential of S. indicatrix BOVIS40 upon inoculation under greenhouse experiment, thus suggesting its application in enhancing plant and soil health sustainably.
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Affiliation(s)
- Bartholomew Saanu Adeleke
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho, 2735, South Africa
| | - Ayansina Segun Ayangbenro
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho, 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho, 2735, South Africa.
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Goyal RK, Mattoo AK, Schmidt MA. Rhizobial-Host Interactions and Symbiotic Nitrogen Fixation in Legume Crops Toward Agriculture Sustainability. Front Microbiol 2021; 12:669404. [PMID: 34177848 PMCID: PMC8226219 DOI: 10.3389/fmicb.2021.669404] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/29/2021] [Indexed: 11/13/2022] Open
Abstract
Symbiotic nitrogen fixation (SNF) process makes legume crops self-sufficient in nitrogen (N) in sharp contrast to cereal crops that require an external input by N-fertilizers. Since the latter process in cereal crops results in a huge quantity of greenhouse gas emission, the legume production systems are considered efficient and important for sustainable agriculture and climate preservation. Despite benefits of SNF, and the fact that chemical N-fertilizers cause N-pollution of the ecosystems, the focus on improving SNF efficiency in legumes did not become a breeder’s priority. The size and stability of heritable effects under different environment conditions weigh significantly on any trait useful in breeding strategies. Here we review the challenges and progress made toward decoding the heritable components of SNF, which is considerably more complex than other crop allelic traits since the process involves genetic elements of both the host and the symbiotic rhizobial species. SNF-efficient rhizobial species designed based on the genetics of the host and its symbiotic partner face the test of a unique microbiome for its success and productivity. The progress made thus far in commercial legume crops with relevance to the dynamics of host–rhizobia interaction, environmental impact on rhizobial performance challenges, and what collectively determines the SNF efficiency under field conditions are also reviewed here.
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Affiliation(s)
- Ravinder K Goyal
- Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, AB, Canada
| | - Autar K Mattoo
- Sustainable Agricultural Systems Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville Agricultural Research Center, Beltsville, MD, United States
| | - Maria Augusta Schmidt
- Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, AB, Canada
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Akinola SA, Ayangbenro AS, Babalola OO. The diverse functional genes of maize rhizosphere microbiota assessed using shotgun metagenomics. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:3193-3201. [PMID: 33215702 DOI: 10.1002/jsfa.10948] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 10/31/2020] [Accepted: 11/20/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The geographical diversification in chemical, biological and physical properties of plant biospheres instigates heterogenicity in the proliferation of important soil microbiome. Controlling functions and structure of plant rhizosphere from a better understanding and prediction of a plant's immediate environment will help assess plant-microbe interplay, improve the productivity of plant ecosystems and improve plant response to adverse soil conditions. Here we characterized functional genes of the microbial community of maize rhizosphere using a culture-independent method. RESULTS Our metadata showed microbial genes involved in nitrogen fixation, phosphate solubilization, quorum sensing molecules, trehalose, siderophore production, phenazine biosynthesis protein, daunorubicin resistance, acetoin, 1-aminocyclopropane-1-carboxylate deaminase, 4-hydroxybenzoate, disease control and stress-reducing genes (superoxidase dismutase, catalase, peroxidase, etc.). β-Diversity showed that there is a highly significant difference between most of the genes mined from rhizosphere soil samples and surrounding soils. CONCLUSIONS The high relative abundance of stress-reducing genes mined from this study showed that the sampling sites harbor not only important plant-beneficial organisms but also a hotspot for developing bio-fertilizers. Nevertheless, since most of these organisms are unculturable, mapping cultivation strategies for their growth could make them readily available as bio-inoculants and possible biotechnological applications in the future. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Saheed Adekunle Akinola
- Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
| | - Ayansina Segun Ayangbenro
- Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
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Ali S, Khan N. Delineation of mechanistic approaches employed by plant growth promoting microorganisms for improving drought stress tolerance in plants. Microbiol Res 2021; 249:126771. [PMID: 33930840 DOI: 10.1016/j.micres.2021.126771] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/01/2021] [Accepted: 04/17/2021] [Indexed: 11/24/2022]
Abstract
Drought stress is expected to increase in intensity, frequency, and duration in many parts of the world, with potential negative impacts on plant growth and productivity. The plants have evolved complex physiological and biochemical mechanisms to respond and adjust to water-deficient environments. The physiological and biochemical mechanisms associated with water-stress tolerance and water-use efficiency have been extensively studied. Besides these adaptive and mitigating strategies, the plant growth-promoting rhizobacteria (PGPR) play a significant role in alleviating plant drought stress. These beneficial microorganisms colonize the endo-rhizosphere/rhizosphere of plants and enhance drought tolerance. The common mechanism by which these microorganisms improve drought tolerance included the production of volatile compounds, phytohormones, siderophores, exopolysaccharides, 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase), accumulation of antioxidant, stress-induced metabolites such as osmotic solutes proline, alternation in leaf and root morphology and regulation of the stress-responsive genes. The PGPR is an easy and efficient alternative approach to genetic manipulation and crop enhancement practices because plant breeding and genetic modification are time-consuming and expensive processes for obtaining stress-tolerant varieties. In this review, we will elaborate on PGPR's mechanistic approaches in enhancing the plant stress tolerance to cope with the drought stress.
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Affiliation(s)
- Shahid Ali
- Plant Epigenetic and Development, Northeast Forestry University, Harbin, 150040, China
| | - Naeem Khan
- Department of Agronomy, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, 32611, USA.
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Igiehon ON, Babalola OO. Rhizobium and Mycorrhizal Fungal Species Improved Soybean Yield Under Drought Stress Conditions. Curr Microbiol 2021; 78:1615-1627. [PMID: 33686507 PMCID: PMC7997835 DOI: 10.1007/s00284-021-02432-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 02/16/2021] [Indexed: 01/07/2023]
Abstract
Food insecurity is a serious threat due to the increasing human population particularly in developing countries and may be minimized by the use of microbial inoculants. Also, the problems of excessive use of chemical fertilizers including the fact that most of the fertilizers are relatively non-affordable and that they also contaminate underground and surface water, which can increase the risk of blue baby syndrome in infants and stomach cancer in adults. There is therefore the need to harness a more cost-effective, eco-friendly and beneficial biological agents to improve crops productivity especially under drought conditions. Thus, in this study, the ability of rhizobia species and arbuscular mycorrhizal fungi (AMF) to enhance soybean tolerance to drought stress under water regimens of 100, 70 and 40% field capacity (FC) was investigated. It was observed that co-inoculation of soybean with Rhizobium spp. (R1+R3) as well as with Rhizobium spp. and mycorrhizal consortium (R1+R3MY) had significant impacts (P < 0.05) on soybean leaf relative water content and electrolyte leakage, respectively. The levels of proline increased mainly in microbially amended soybean exposed to drought stress. Plants inoculated with R1+R3MY showed the highest number of spore and % mycorrhization in all the water regimes. At 40% FC, R1+R3MY treatment was found to promote soybean growth compared to the non-inoculated plants. Similarly, at 40% FC, R1+R3MY inoculum had the greatest impacts on soybean pod number, seed number, seed fresh weight, highest seed number per pod and seed dry weight while at 70% water stress, significant impacts of R1MY inoculation were observed on pod number, pod fresh weight and seed dry weight. These results revealed that co-inoculation of rhizobia and mycorrhizal fungi can be harnessed biotechnologically to proffer solution to food insecurity.
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Affiliation(s)
- Ozede N Igiehon
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, North-West University, Private Mail Bag X2046, Mmabatho, 2735, South Africa
| | - Olubukola O Babalola
- Food Security and Safety Niche, Faculty of Natural and Agricultural Science, North-West University, Private Mail Bag X2046, Mmabatho, 2735, South Africa.
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Sarapat S, Songwattana P, Longtonglang A, Umnajkitikorn K, Girdthai T, Tittabutr P, Boonkerd N, Teaumroong N. Effects of Increased 1-Aminocyclopropane-1-Carboxylate (ACC) Deaminase Activity in Bradyrhizobium sp. SUTN9-2 on Mung Bean Symbiosis under Water Deficit Conditions. Microbes Environ 2021; 35. [PMID: 32554939 PMCID: PMC7511786 DOI: 10.1264/jsme2.me20024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Bacteria exhibiting 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, which inhibits the biosynthesis of ethylene in higher plants, promote plant growth through the degradation of ethylene precursors, such as ACC. ACC deaminase activity in Bradyrhizobium sp. SUTN9-2 was enhanced by genetic engineering and adaptive laboratory evolution (ALE)-based methods. The transferal of a plasmid containing the acdR and acdS genes into SUTN9-2 was genetic engineering improved, while the ALE method was performed based on the accumulation of an adaptive bacterial population that continuously grew under specified growth conditions for a long time. ACC deaminase enzyme activity was 8.9–fold higher in SUTN9-2:pMG103::acdRS and 1.4–fold higher in SUTN9-2 (ACCDadap) than in the wild-type strain. The effects of increased activity were examined in the host plant (Vigna radiata (L.) R.Wilczek SUT1). The improved strains enhanced nodulation in early stage of plant growth. SUTN9-2:pMG103::acdRS also maintained nitrogen fixation under water deficit conditions and increased the plant biomass after rehydration. Changes in nucleotides and amino acids in the AcdS protein of SUTN9-2 (ACCDadap) were then investigated. Some nucleotides predicted to be located in the ACC-binding site were mutated. These mutations may have increased ACC deaminase activity, which enhanced both symbiotic interactions and drought tolerance and promoted recovery after rehydration more than lower ACC deaminase activity. Adaptive evolution represents a promising strategy for further applications in the field.
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Affiliation(s)
- Sukanlaya Sarapat
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology
| | - Pongpan Songwattana
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology
| | - Aphakorn Longtonglang
- Suranaree University of Technology Farm (SUT Farm), Suranaree University of Technology
| | - Kamolchanok Umnajkitikorn
- School of Crop Production Technology, Institute of Agricultural Technology, Suranaree University of Technology
| | - Teerayoot Girdthai
- School of Crop Production Technology, Institute of Agricultural Technology, Suranaree University of Technology
| | - Panlada Tittabutr
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology
| | - Nantakorn Boonkerd
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology
| | - Neung Teaumroong
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology
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Rhizosphere Microbiome Cooperations: Strategies for Sustainable Crop Production. Curr Microbiol 2021; 78:1069-1085. [PMID: 33611628 DOI: 10.1007/s00284-021-02375-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 02/05/2021] [Indexed: 01/29/2023]
Abstract
Interactions between microorganisms and host plants determine the growth and development as well as the health of the host plant. Various microbial groups inhabit the rhizosphere, each with its peculiar function. The survival of each microbial group depends to a large extent on its ability to colonize the plant root and outcompete the native organisms. The role of the rhizospheric microbiome in enhancing plant growth has not been fully maximized. An understanding of the complexities of microbial interactions and factors affecting their assembly in the community is necessary to benefit maximally from the cooperations of various microbial communities for sustainable crop production. In this review, we outline the various organisms associated with the plant rhizosphere with emphasis on their interactions and mechanisms used in plant growth promotion.
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Chaudhary T, Gera R, Shukla P. Deciphering the Potential of Rhizobium pusense MB-17a, a Plant Growth-Promoting Root Endophyte, and Functional Annotation of the Genes Involved in the Metabolic Pathway. Front Bioeng Biotechnol 2021; 8:617034. [PMID: 33537293 PMCID: PMC7848175 DOI: 10.3389/fbioe.2020.617034] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 11/30/2020] [Indexed: 11/13/2022] Open
Abstract
Plant growth-promoting rhizobacteria (PGPR) are root endophytic bacteria used for growth promotion, and they have broader applications in enhancing specific crop yield as a whole. In the present study, we have explored the potential of Rhizobium pusense MB-17a as an endophytic bacterium isolated from the roots of the mung bean (Vigna radiata) plant. Furthermore, this bacterium was sequenced and assembled to reveal its genomic potential associated with plant growth-promoting traits. Interestingly, the root endophyte R. pusense MB-17a showed all essential PGPR traits which were determined by biochemical and PGPR tests. It was noted that this root endophytic bacterium significantly produced siderophores, indole acetic acid (IAA), ammonia, and ACC deaminase and efficiently solubilized phosphate. The maximum IAA and ammonia produced were observed to be 110.5 and 81 μg/ml, respectively. Moreover, the PGPR potential of this endophytic bacterium was also confirmed by a pot experiment for mung bean (V. radiata), whose results show a substantial increase in the plant's fresh weight by 76.1% and dry weight by 76.5% on the 60th day after inoculation of R. pusense MB-17a. Also, there is a significant enhancement in the nodule number by 66.1% and nodule fresh weight by 162% at 45th day after inoculation with 100% field capacity after the inoculation of R. pusense MB-17a. Besides this, the functional genomic annotation of R. pusense MB-17a determined the presence of different proteins and transporters that are responsible for its stress tolerance and its plant growth-promoting properties. It was concluded that the unique presence of genes like rpoH, otsAB, and clpB enhances the symbiosis process during adverse conditions in this endophyte. Through Rapid Annotation using Subsystem Technology (RAST) analysis, the key genes involved in the production of siderophores, volatile compounds, indoles, nitrogenases, and amino acids were also predicted. In conclusion, the strain described in this study gives a novel idea of using such type of endophytes for improving plant growth-promoting traits under different stress conditions for sustainable agriculture.
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Affiliation(s)
- Twinkle Chaudhary
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
| | - Rajesh Gera
- Department of Microbiology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, India
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
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Gitonga NM, Njeru EM, Cheruiyot R, Maingi JM. Genetic and Morphological Diversity of Indigenous Bradyrhizobium Nodulating Soybean in Organic and Conventional Family Farming Systems. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2021. [DOI: 10.3389/fsufs.2020.606618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Organic farming systems are gaining popularity as agronomically and environmentally sound soil management strategies with potential to enhance soil microbial diversity and fertility, environmental quality and sustainable crop production. This work aimed at understanding the effect of organic and conventional farming on the diversity of soybean nodulating bradyrhizobia species. Field trapping of indigenous soybean Bradyrhizobium was done by planting promiscuous soybeans varieties SB16 and SC squire as well as non-promiscuous Gazelle in three organic and three conventional farms in Tharaka-Nithi County of Kenya. After 45 days of growth, 108 nodule isolates were obtained from the soybean nodules and placed into 13 groups based on their morphological characteristics. Genetic diversity was done by polymerase chain reaction (PCR) targeting 16S rDNA gene using universal primers P5-R and P3-F and sequencing was carried out using the same primer. High morphological and genetic diversity of the nodule isolates was observed in organic farms as opposed to conventional farms. There was little or no genetic differentiation between the nodule isolates from the different farms with the highest molecular variation (91.12%) being partitioned within populations as opposed to among populations (8.88%). All the isolates were identified as bradyrhizobia with close evolutionary ties with Bradyrhizobium japonicum and Bradyrhizobium yuanminense. Organic farming systems favor the proliferation of bradyrhizobia species and therefore a suitable environmentally friendly alternative for enhancing soybean production.
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