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Beshah A, Muleta D, Legese G, Assefa F. Exploring stress-tolerant plant growth-promoting rhizobacteria from groundnut rhizosphere soil in semi-arid regions of Ethiopia. PLANT SIGNALING & BEHAVIOR 2024; 19:2365574. [PMID: 38912872 PMCID: PMC11197918 DOI: 10.1080/15592324.2024.2365574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 06/04/2024] [Indexed: 06/25/2024]
Abstract
The potential of rhizobacteria with plant growth promoting (PGP) traits in alleviating abiotic stresses, especially drought, is significant. However, their exploitation in the semi-arid regions of Ethiopian soils remains largely unexplored. This research aimed to isolate and evaluate the PGP potential of bacterial isolates collected from groundnut cultivation areas in Ethiopia. Multiple traits were assessed, including phosphate solubilization, indole-3-acetic acid (IAA) production, ammonia production, salt and heavy metal tolerance, drought tolerance, enzyme activities, hydrogen cyanide production, antibiotic resistance, and antagonistic activity against fungal pathogens. The identification of potent isolates was carried out using MALDI-TOF MS. Out of the 82 isolates, 63 were gram-negative and 19 were gram-positive. Among them, 19 isolates exhibited phosphate solubilization, with AAURB 34 demonstrating the highest efficiency, followed by AURB 12. Fifty-six isolates produce IAA in varying amounts and all isolates produce ammonia with AAURB12, AAURB19, and AAURB34 displaying strong production. Most isolates demonstrated tolerance to temperatures up to 40°C and salt concentrations up to 3%. Notably, AAURB12 and AAURB34 exhibited remarkable drought tolerance at an osmotic potential of -2.70 Mpa. When subjected to levels above 40%, the tested isolates moderately produced lytic enzymes and hydrogen cyanide. The isolates displayed resistance to antibiotics, except gentamicin, and all isolates demonstrated resistance to zinc, with 81-91% showing resistance to other heavy metals. AAURB34 and AAURB12 exhibited suppression against fungal pathogens, with percent inhibition of 38% and 46%, respectively. Using MALDI-TOF MS, the promising PGP isolates were identified as Bacillus megaterium, Bacillus pumilus, and Enterobacter asburiae. This study provides valuable insights into the potential of rhizobacteria as PGP agents for mitigating abiotic stresses and contribute to the understanding of sustainable agricultural practices in Ethiopia and similar regions facing comparable challenges.
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Affiliation(s)
- Asnake Beshah
- Department of Cellular, Microbial and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Driba Muleta
- Biotechnology Institute, Addis Ababa University, Addis Ababa, Ethiopia
| | - Gudina Legese
- Center for Environmental Science, Addis Ababa University, Addis Ababa, Ethiopia
| | - Fassil Assefa
- Department of Cellular, Microbial and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
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Campos EVR, Pereira ADES, Aleksieienko I, do Carmo GC, Gohari G, Santaella C, Fraceto LF, Oliveira HC. Encapsulated plant growth regulators and associative microorganisms: Nature-based solutions to mitigate the effects of climate change on plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 331:111688. [PMID: 36963636 DOI: 10.1016/j.plantsci.2023.111688] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/16/2023] [Accepted: 03/19/2023] [Indexed: 06/18/2023]
Abstract
Over the past decades, the atmospheric CO2 concentration and global average temperature have been increasing, and this trend is projected to soon become more severe. This scenario of climate change intensifies abiotic stress factors (such as drought, flooding, salinity, and ultraviolet radiation) that threaten forest and associated ecosystems as well as crop production. These factors can negatively affect plant growth and development with a consequent reduction in plant biomass accumulation and yield, in addition to increasing plant susceptibility to biotic stresses. Recently, biostimulants have become a hotspot as an effective and sustainable alternative to alleviate the negative effects of stresses on plants. However, the majority of biostimulants have poor stability under environmental conditions, which leads to premature degradation, shortening their biological activity. To solve these bottlenecks, micro- and nano-based formulations containing biostimulant molecules and/or microorganisms are gaining attention, as they demonstrate several advantages over their conventional formulations. In this review, we focus on the encapsulation of plant growth regulators and plant associative microorganisms as a strategy to boost their application for plant protection against abiotic stresses. We also address the potential limitations and challenges faced for the implementation of this technology, as well as possibilities regarding future research.
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Affiliation(s)
- Estefânia V R Campos
- Institute of Science and Technology of Sorocaba, São Paulo State University (UNESP), Av. Três de Março 511, 18087-180 Sorocaba, São Paulo, Brazil; B.Nano Soluções Tecnológicas Ltda, Rua Dr. Júlio Prestes, 355,18230-000 São Miguel Arcanjo, São Paulo, Brazil.
| | - Anderson do E S Pereira
- Institute of Science and Technology of Sorocaba, São Paulo State University (UNESP), Av. Três de Março 511, 18087-180 Sorocaba, São Paulo, Brazil; B.Nano Soluções Tecnológicas Ltda, Rua Dr. Júlio Prestes, 355,18230-000 São Miguel Arcanjo, São Paulo, Brazil
| | - Ivan Aleksieienko
- Aix Marseille University, CEA, CNRS, BIAM, LEMiRE, Microbial Ecology of the Rhizosphere, ECCOREV FR 3098, F-13108 Saint Paul Lez Durance, France
| | - Giovanna C do Carmo
- Department of Animal and Plant Biology, State University of Londrina (UEL), PR 445, Km 380, 86057-970 Londrina, Paraná, Brazil
| | - Gholamreza Gohari
- Department of Horticultural Science, Faculty of Agriculture, University of Maragheh, Maragheh, Iran
| | - Catherine Santaella
- Aix Marseille University, CEA, CNRS, BIAM, LEMiRE, Microbial Ecology of the Rhizosphere, ECCOREV FR 3098, F-13108 Saint Paul Lez Durance, France
| | - Leonardo F Fraceto
- Institute of Science and Technology of Sorocaba, São Paulo State University (UNESP), Av. Três de Março 511, 18087-180 Sorocaba, São Paulo, Brazil
| | - Halley C Oliveira
- Department of Animal and Plant Biology, State University of Londrina (UEL), PR 445, Km 380, 86057-970 Londrina, Paraná, Brazil.
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Abiala M, Sadhukhan A, Sahoo L. Isolation and Characterization of Stress-Tolerant Priestia Species from Cowpea Rhizosphere Under Drought and Nutrient Deficit Conditions. Curr Microbiol 2023; 80:140. [PMID: 36928438 DOI: 10.1007/s00284-023-03246-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 02/25/2023] [Indexed: 03/18/2023]
Abstract
This study aimed to isolate stress-tolerant phytobeneficial bacteria as bio-inoculants for cowpea's sustainable growth under drought and nutrient deficiency conditions. However, the application successful of phytobeneficial bacteria is subject to effective in vitro screening under different physiological conditions. We isolated several Priestia species from cowpea rhizosphere that tolerates polyethylene glycol (PEG6000)-induced drought and nutrient deficiency. Of them, C8 (Priestia filamentosa; basonym: Bacillus filamentosus), followed by C29 (Priestia aryabhattai; basonym: Bacillus aryabhattai), tolerated up to 20% PEG in a low-nutrient medium. In the presence of PEG, Priestia filamentosa and Bacillus aryabhattai exhibited optimal growth in different temperatures and pH but failed to survive at extreme temperatures of 45 °C and pH 11. Priestia filamentosa preferred L-proline and L-glutamate, while L-tryptophan and L-tyrosine were the least utilized. Interestingly, Priestia filamentosa and Bacillus aryabhattai used more complex nitrogen sources, peptone, and yeast extract, than inorganic nitrogen for growth. Most importantly, under drought and nutrient deficiency, Priestia filamentosa exhibited multiple plant growth-promoting traits and more amylase and protease production than C29. Our results indicate that Priestia filamentosa is a potential bacterium to enhance the growth of cowpea plants under stressful conditions.
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Affiliation(s)
- Moses Abiala
- Department of Biological Sciences, College of Basic and Applied Sciences, Mountain Top University, Prayer City, Ogun State, Nigeria.
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, Assam, India.
| | - Ayan Sadhukhan
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, India
| | - Lingaraj Sahoo
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, Assam, India
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Ali N, Swarnkar MK, Veer R, Kaushal P, Pati AM. Temperature-induced modulation of stress-tolerant PGP genes bioprospected from Bacillus sp. IHBT-705 associated with saffron ( Crocus sativus) rhizosphere: A natural -treasure trove of microbial biostimulants. FRONTIERS IN PLANT SCIENCE 2023; 14:1141538. [PMID: 36923125 PMCID: PMC10009223 DOI: 10.3389/fpls.2023.1141538] [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: 01/10/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
There is a renewed interest in sustainable agriculture wherein novel plant growth-promoting rhizobacteria (PGPR) are being explored for developing efficient biostimulants. The key requirement of a microbe to qualify as a good candidate for developing a biostimulant is its intrinsic plant growth-promoting (PGP) characteristics. Though numerous studies have been conducted to assess the beneficial effects of PGPRs on plant growth under normal and stressed conditions but not much information is available on the characterization of intrinsic traits of PGPR under stress. Here, we focused on understanding how temperature stress impacts the functionality of key stress tolerant and PGP genes of Bacillus sp. IHBT-705 isolated from the rhizosphere of saffron (Crocus sativus). To undertake the study, Bacillus sp. IHBT-705 was grown under varied temperature regimes, their PGP traits were assessed from very low to very high-temperature range and the expression trend of targeted stress tolerant and PGP genes were analyzed. The results illustrated that Bacillus sp. IHBT-705 is a stress-tolerant PGPR as it survived and multiplied in temperatures ranging from 4°C-50°C, tolerated a wide pH range (5-11), withstood high salinity (8%) and osmolarity (10% PEG). The PGP traits varied under different temperature regimes indicating that temperature influences the functionality of PGP genes. This was further ascertained through whole genome sequencing followed by gene expression analyses wherein certain genes like cspB, cspD, hslO, grpE, rimM, trpA, trpC, trpE, fhuC, fhuD, acrB5 were found to be temperature sensitive while, cold tolerant (nhaX and cspC), heat tolerant (htpX) phosphate solubilization (pstB1), siderophore production (fhuB and fhuG), and root colonization (xerC1 and xerC2) were found to be highly versatile as they could express well both under low and high temperatures. Further, the biostimulant potential was checked through a pot study on rice (Oryza sativa), wherein the application of Bacillus sp. IHBT-705 improved the length of shoots, roots, and number of roots over control. Based on the genetic makeup, stress tolerance potential, retention of PGP traits under stress, and growth-promoting potential, Bacillus sp. IHBT-705 could be considered a good candidate for developing biostimulants.
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Affiliation(s)
- Nilofer Ali
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Mohit Kumar Swarnkar
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
| | - Raj Veer
- Incubatee at Chief Minister Startup Scheme, Shimla, India
| | - Priya Kaushal
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
| | - Aparna Maitra Pati
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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Gohil RB, Raval VH, Panchal RR, Rajput KN. Plant growth promoting activities and effect of fermented panchagavya isolate Klebsiella sp. PG-64 on Vigna radiata. World J Microbiol Biotechnol 2022; 39:41. [PMID: 36512151 DOI: 10.1007/s11274-022-03482-3] [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: 04/09/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022]
Abstract
A natural bacterial isolate from fermented panchagavya named as PG-64, exhibits multiple plant growth-promoting traits. This Gram-negative bacteria was identified as Klebsiella sp. PG-64 by 16S rRNA gene sequencing. The Klebsiella sp. PG-64 has shown production of indole acetic acid (106.0 µg/ml), gibberellic acid (20.0 µg/ml), ammonia (7.12 µmol/ml), exopolysaccharide (2.04% w/v) and phosphate solubilization (106.0 µg/ml). It produced 437 µg/ml IAA with 0.75% (w/v) L-tryptophan supplementation and was increased to 575 µg/ml in a laboratory-scale fermenter. The PG-64 has shown tolerance to abiotic stress conditions like pH (5.0-12.0), temperature (28-46 °C), salt (0.5-10.0% w/v NaCl) and osmotic resistance (1-10% w/v PEG-6000). The PG-64 also produced 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (0.3 ng α-ketobutyrate/mg protein/h) indicating its potential for drought tolerance. Owing to its diverse properties, the effect of Klebsiella sp. PG-64 on Vigna radiata (Mung bean) was examined. The seeds treated with PG-64 culture showed 92% germination with a good seedling vigour index (202). In the pot study, Vigna radiata growth showed 2.23, 1.55, 2.00, 1.65, 1.73, 1.88, 5.00, 5.00, 1.57 times increase in primary root length, dry root weight, root hair numbers, leaf width, leaf numbers, leaf area, fruits number, flower number and chlorophyll content, respectively after 75 days. The application of Klebsiella sp. PG-64 culture resulted in substantial growth enhancement of Vigna radiata. The Klebsiella sp. PG-64 has multiple plant growth-promoting properties along with capabilities to tolerate abiotic stresses, making it a promising liquid biofertilizer contender for various crops.
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Affiliation(s)
- Rinkal B Gohil
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Vikram H Raval
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Rakeshkumar R Panchal
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Kiransinh N Rajput
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India.
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Anand U, Vaishnav A, Sharma SK, Sahu J, Ahmad S, Sunita K, Suresh S, Dey A, Bontempi E, Singh AK, Proćków J, Shukla AK. Current advances and research prospects for agricultural and industrial uses of microbial strains available in world collections. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 842:156641. [PMID: 35700781 DOI: 10.1016/j.scitotenv.2022.156641] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 06/08/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Microorganisms are an important component of the ecosystem and have an enormous impact on human lives. Moreover, microorganisms are considered to have desirable effects on other co-existing species in a variety of habitats, such as agriculture and industries. In this way, they also have enormous environmental applications. Hence, collections of microorganisms with specific traits are a crucial step in developing new technologies to harness the microbial potential. Microbial culture collections (MCCs) are a repository for the preservation of a large variety of microbial species distributed throughout the world. In this context, culture collections (CCs) and microbial biological resource centres (mBRCs) are vital for the safeguarding and circulation of biological resources, as well as for the progress of the life sciences. Ex situ conservation of microorganisms tagged with specific traits in the collections is the crucial step in developing new technologies to harness their potential. Type strains are mainly used in taxonomic study, whereas reference strains are used for agricultural, biotechnological, pharmaceutical research and commercial work. Despite the tremendous potential in microbiological research, little effort has been made in the true sense to harness the potential of conserved microorganisms. This review highlights (1) the importance of available global microbial collections for man and (2) the use of these resources in different research and applications in agriculture, biotechnology, and industry. In addition, an extensive literature survey was carried out on preserved microorganisms from different collection centres using the Web of Science (WoS) and SCOPUS. This review also emphasizes knowledge gaps and future perspectives. Finally, this study provides a critical analysis of the current and future roles of microorganisms available in culture collections for different sustainable agricultural and industrial applications. This work highlights target-specific potential microbial strains that have multiple important metabolic and genetic traits for future research and use.
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Affiliation(s)
- Uttpal Anand
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Anukool Vaishnav
- Department of Biotechnology, Institute of Applied Sciences & Humanities, GLA University, Mathura, Uttar Pradesh 281406, India; Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland; Plant-Soil Interaction Group, Agroscope (Reckenholz), Reckenholzstrasse 191, 8046 Zürich, Switzerland
| | - Sushil K Sharma
- National Agriculturally Important Microbial Culture Collection (NAIMCC), ICAR-National Bureau of Agriculturally Important Microorganisms (ICAR-NBAIM), Mau 275 103, Uttar Pradesh, India.
| | - Jagajjit Sahu
- GyanArras Academy, Gothapatna, Malipada, Bhubaneswar, Odisha 751029, India
| | - Sarfaraz Ahmad
- Department of Botany, Jai Prakash University, Saran, Chhapra 841301, Bihar, India
| | - Kumari Sunita
- Department of Botany, Faculty of Science, Deen Dayal Upadhyay Gorakhpur University, Gorakhpur, Uttar Pradesh 273009, India
| | - S Suresh
- Department of Chemical Engineering, Maulana Azad National Institute of Technology, Bhopal 462 003, Madhya Pradesh, India
| | - Abhijit Dey
- Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata 700073, West Bengal, India
| | - Elza Bontempi
- INSTM and Chemistry for Technologies Laboratory, Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze, 38, 25123 Brescia, Italy
| | - Amit Kishore Singh
- Department of Botany, Bhagalpur National College, (A Constituent unit of Tilka Manjhi Bhagalpur University), Bhagalpur 812007, Bihar, India
| | - Jarosław Proćków
- Department of Plant Biology, Institute of Environmental Biology, Wrocław University of Environmental and Life Sciences, Kożuchowska 5b, 51-631 Wrocław, Poland.
| | - Awadhesh Kumar Shukla
- Department of Botany, K.S. Saket P.G. College, Ayodhya (affiliated to Dr. Rammanohar Lohia Avadh University, Ayodhya) 224123, Uttar Pradesh, India.
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Nishu SD, No JH, Lee TK. Transcriptional Response and Plant Growth Promoting Activity of Pseudomonas fluorescens DR397 under Drought Stress Conditions. Microbiol Spectr 2022; 10:e0097922. [PMID: 35863006 PMCID: PMC9430913 DOI: 10.1128/spectrum.00979-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 06/23/2022] [Indexed: 11/20/2022] Open
Abstract
Drought is one of the most vulnerable factors that affect crop productivity. Little is known about plant-associated microbiomes and their functional roles in assisting plant growth under drought. We investigated the genetic and transcriptomic characteristics of opportunistic beneficial microorganisms that selectively alleviate stress through plant-bacteria interactions under drought. Pseudomonas fluorescens DR397 was isolated from the drought-prone rhizospheric soil of soybean and showed high metabolic activity at -1.25 Mpa. The genome of DR397 possesses several genes related to the synthesis of compatible solutes (choline and glycine-betaine), exopolysaccharides (alginate and cellulose), and secretion systems (type II, III, IV, and VI), as well as genes related to plant growth promotion (indole-3-acetic acid, transketolase, and thiamine phosphate synthesis). The expression of these genes was significantly upregulated (8- to 263-fold change) only under drought conditions with plant root exudate treatment, whereas subtle transcriptomic changes were observed under solely root exudate treatment. When DR397 was placed on both legume cultivars (Pisum sativum and Phaseolus vulgaris), growth was hardly affected under well-watered conditions, but the shoot and root growths were increased by up from 62.0% to 149.1% compared with the control group under drought conditions. These results provide fundamental insight on the plant-bacterial interactions that alleviate plant stress as an important ecological strategy for improving drought tolerance. IMPORTANCE Drought is a serious abiotic stress on plants as wells as the microbes that coexist with plants, which significantly lowers their fitness. The plant-bacterial interaction is an important strategy to enhance their fitness under drought. However, many knowledge gaps still exist in our understanding of transcriptomic features of bacteria interacting with plant under drought. Here, by investigating the transcriptomic profiles and pot cultivation with legume, we show that the interactions of Pseudomonas fluorescens DR397 with plants change with drought. We, therefore, provide a fundamental evidence of a hidden hero in the soil that promote plant fitness from external stress.
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Affiliation(s)
- Susmita Das Nishu
- Department of Environmental Engineering, Yonsei University, Wonju, Republic of Korea
| | - Jee Hyun No
- Department of Environmental Engineering, Yonsei University, Wonju, Republic of Korea
| | - Tae Kwon Lee
- Department of Environmental Engineering, Yonsei University, Wonju, Republic of Korea
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Abd El-Mageed TA, Abd El-Mageed SA, El-Saadony MT, Abdelaziz S, Abdou NM. Plant Growth-Promoting Rhizobacteria Improve Growth, Morph-Physiological Responses, Water Productivity, and Yield of Rice Plants Under Full and Deficit Drip Irrigation. RICE (NEW YORK, N.Y.) 2022; 15:16. [PMID: 35288814 PMCID: PMC8921367 DOI: 10.1186/s12284-022-00564-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/01/2022] [Indexed: 05/26/2023]
Abstract
Inoculating rice plants by plant growth promoting rhizobacteria (PGPR) may be used as a practical and eco-friendly approach to sustain the growth and yield of drought stressed rice plants. The effect of rice inoculation using plant growth hormones was investigated under drip full irrigation (FI; 100% of evapotranspiration (ETc), and deficit irrigation (DI; 80% of ETc) on growth, physiological responses, yields and water productivities under saline soil (ECe = 6.87 dS m-1) for 2017 and 2018 seasons. Growth (i.e. shoot length and shoot dry weight), leaf photosynthetic pigments (chlorophyll 'a' and chlorophyll 'b' content), air-canopy temperature (Tc-Ta), membrane stability index (MSI%), and relative water content, (RWC%) chlorophyll fluorescence (Fv/Fm) stomatal conductance (gs), total phenols, peroxidase (PO), polyphenol oxidase (PPO), nitrogen contents and water productivities (grain water productivity; G-WP and straw water productivity; S-WP) were positively affected and significantly (p < 0.05) differed in two seasons in response to the applied PGPR treatments. The highest yields (3.35 and 6.7 t ha-1 for grain and straw yields) as the average for both years were recorded under full irrigation and plants inoculated by PGPR. The results indicated that under water scarcity, application of (I80 + PGPR) treatment was found to be favorable to save 20% of the applied irrigation water, to produce not only the same yields, approximately, but also to save more water as compared to I100%.
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Affiliation(s)
- Taia A Abd El-Mageed
- Soil and Water Department, Faculty of Agriculture, Fayoum University, Fayoum, 63514, Egypt.
| | | | - Mohamed T El-Saadony
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, Zagazig, 44511, Egypt
| | - Sayed Abdelaziz
- Department of Agricultural Microbiology, Faculty of Agriculture, Fayoum University, Fayoum, 63514, Egypt
| | - Nasr M Abdou
- Soil and Water Department, Faculty of Agriculture, Fayoum University, Fayoum, 63514, Egypt
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Liu J, Abdelfattah A, Wasserman B, Wisniewski M, Droby S, Fazio G, Mazzola M, Wu X. Contrasting effects of genotype and root size on the fungal and bacterial communities associated with apple rootstocks. HORTICULTURE RESEARCH 2022; 9:6511261. [PMID: 35043188 PMCID: PMC8769040 DOI: 10.1093/hr/uhab013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/17/2021] [Accepted: 09/25/2021] [Indexed: 05/04/2023]
Abstract
The endophytic microbiome of plants is believed to have a significant impact on its physiology and disease resistance, however, the role of host genotype in determining the composition of the endophytic microbiome of apple root systems remains an open question that has important implications for defining breeding objectives. In the current study, the bacterial and fungal microbiota associated with four different apple rootstocks planted in April, 2018 in the same soil environment and harvested in May, 2019 were evaluated to determine the role of genotype on the composition of both the bacterial and fungal communities. Results demonstrated a clear impact of genotype and root size on microbial composition and diversity. The fungal community was more affected by plant genotype whereas the bacterial community was shaped by root size. Fungal and bacterial abundance was equal between different-sized roots however, significantly higher microbial counts were detected in rhizosphere samples compared to root endosphere samples. This study provides information that can be used to develop a comprehensive and readily applicable understanding of the impact of genotype and environmental factors on the establishment of plant microbiome, as well as its potential function and impact on host physiology.
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Affiliation(s)
- Jia Liu
- Chongqing Key Laboratory of Economic Plant Biotechnology, College of Landscape Architecture and Life Science/Institute of Special Plants, Chongqing University of Arts and Sciences, 317 Honghe Road, Yongchuan District, Chongqing 402160, China
| | - Ahmed Abdelfattah
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, Graz 8010, Austria
- Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB), Max-Eyth Allee 100, 14469 Potsdam, Germany
| | - Birgit Wasserman
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, Graz 8010, Austria
| | - Michael Wisniewski
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, 220 Ag Quad Ln, Blacksburg, VA 24061, USA
- Corresponding authors: E-mails: ;
| | - Samir Droby
- Department of Postharvest Science, Agricultural Research Organization, The Volcani Center, PO Box 15159 Rishon LeZion 7505101, Israel
| | - Gennaro Fazio
- United States Department of Agriculture - Agricultural Research Service (USDA-ARS), Plant Genetic Resources Unit, 21 Crabapple Drive, Geneva, NY 14456, USA
| | - Mark Mazzola
- USDA-ARS, Tree Fruit Research Laboratory,
1104 North Western Ave., Wenatchee, WA 98801, USA
| | - Xuehong Wu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, 2 Youanmingyuan West Road, Haidan District, Beijing 100193, China
- Corresponding authors: E-mails: ;
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Enhancement of drought tolerance in diverse Vicia faba cultivars by inoculation with plant growth-promoting rhizobacteria under newly reclaimed soil conditions. Sci Rep 2021; 11:24142. [PMID: 34921154 PMCID: PMC8683512 DOI: 10.1038/s41598-021-02847-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/17/2021] [Indexed: 11/12/2022] Open
Abstract
Water deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield‐related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.
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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: 42] [Impact Index Per Article: 14.0] [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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