1
|
Geat N, Singh D, Singh D, Saha P, Jatoth R, Babu PL. Assessing the efficacy of phyllospheric growth-promoting and antagonistic bacteria for management of black rot disease of cauliflower incited by Xanthomonas campestris pv. campestris. Folia Microbiol (Praha) 2024; 69:789-804. [PMID: 38060139 DOI: 10.1007/s12223-023-01106-3] [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: 05/29/2023] [Accepted: 11/08/2023] [Indexed: 12/08/2023]
Abstract
The study aimed to assess the potential of phyllospheric bacterial strains isolated from cauliflower plants as biocontrol agents against black rot disease caused by Xanthomonas campestris pv. campestris, through both in vitro and in vivo evaluations. A total of 46 bacterial strains were isolated from healthy and infected cauliflower leaves of both resistant and susceptible plants, and evaluated them for various traits, including plant growth-promoting activities and in vitro antagonistic activity against Xanthomonas campestris pv. campestris. Further, a pot experiment was conducted with the susceptible cauliflower genotype (Pusa Sharad) and 10 selected phyllospheric bacterial isolates to assess their biocontrol efficacy against the disease. The results showed that 82.60% of phyllospheric bacterial isolates were positive for phosphate solubilization, 63.04% for ammonia production, 58.69% for HCN production, 36.95% for siderophore production, and 78.26% had the capacity to produce IAA. Out of the 46 isolates, 23 exhibited in vitro antagonistic activity against X. campestris pv. campestris and 10 isolates were selected for a pot experiment under glasshouse conditions based on their good plant growth-promoting activities and antagonistic assay. The results revealed that bacterial isolate CFLB-27 exhibited the highest biocontrol efficiency (65.41%), followed by CFLB-24 (58.30%), CFLB-31 (47.11%), and CFLB-26 (46.03%). These four isolates were identified as Pseudomonas fluorescens CFLB-27, Bacillus velezensis CFLB-24, Bacillus amyloliquefaciens CFLB-31, and Stenotrophomonas rhizophila CFLB-26. This study provides valuable insights into the potential of phyllospheric bacteria as an effective tool for disease management in sustainable agriculture.
Collapse
Affiliation(s)
- Neelam Geat
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
- Agricultural Research Station, Mandor, Agriculture University, Jodhpur, Rajasthan, 342304, India.
| | - Dinesh Singh
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
| | - Devendra Singh
- Division of Plant Improvement and Pest Management, ICAR-Central Arid Zone Research Institute, Jodhpur, 342003, India
| | - Partha Saha
- Division of Vegetable Science, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Rajender Jatoth
- Agriculture College, Sircilla, Professor Jayashanker Telangana State Agricultural University Hyderabad, Telangana, 500030, India
| | - Pedapudi Lokesh Babu
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| |
Collapse
|
2
|
Zahra ST, Tariq M, Abdullah M, Zafar M, Yasmeen T, Shahid MS, Zaki HEM, Ali A. Probing the potential of salinity-tolerant endophytic bacteria to improve the growth of mungbean [ Vigna radiata (L.) Wilczek]. Front Microbiol 2023; 14:1149004. [PMID: 38111636 PMCID: PMC10725929 DOI: 10.3389/fmicb.2023.1149004] [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: 01/20/2023] [Accepted: 11/15/2023] [Indexed: 12/20/2023] Open
Abstract
Soil salinity is one of the major limiting factors in plant growth regulation. Salinity-tolerant endophytic bacteria (STEB) can be used to alleviate the negative effects of salinity and promote plant growth. In this study, thirteen endophytic bacteria were isolated from mungbean roots and tested for NaCl salt-tolerance up to 4%. Six bacterial isolates, TMB2, TMB3, TMB5, TMB6, TMB7 and TMB9, demonstrated the ability to tolerate salt. Plant growth-promoting properties such as phosphate solubilization, indole-3-acetic acid (IAA) production, nitrogen fixation, zinc solubilization, biofilm formation and hydrolytic enzyme production were tested in vitro under saline conditions. Eight bacterial isolates indicated phosphate solubilization potential ranging from 5.8-17.7 μg mL-1, wherein TMB6 was found most efficient. Ten bacterial isolates exhibited IAA production ranging from 0.3-2.1 μg mL-1, where TMB7 indicated the highest potential. All the bacterial isolates except TMB13 exhibited nitrogenase activity. Three isolates, TMB6, TMB7 and TMB9, were able to solubilize zinc on tris-minimal media. All isolates were capable of forming biofilm except TMB12 and TMB13. Only TMB2, TMB6 and TMB7 exhibited cellulase activity, while TMB2 and TMB7 exhibited pectinase production. Based on in vitro testing, six efficient STEB were selected and subjected to the further studies. 16S rRNA gene sequencing of efficient STEB revealed the maximum similarity between TMB2 and Rhizobium pusense, TMB3 and Agrobacterium leguminum, TMB5 and Achromobacter denitrificans, TMB6 and Pseudomonas extremorientalis, TMB7 and Bradyrhizobium japonicum and TMB9 and Serratia quinivorans. This is the first international report on the existence of A. leguminum, A. denitrificans, P. extremorientalis and S. quinivorans inside the roots of mungbean. Under controlled-conditions, inoculation of P. extremorientalis TMB6, B. japonicum TMB7 and S. quinivorans TMB9 exhibited maximum potential to increase plant growth parameters; specifically plant dry weight was increased by up to 52%, 61% and 45%, respectively. Inoculation of B. japonicum TMB7 displayed the highest potential to increase plant proline, glycine betaine and total soluble proteins contents by 77%, 78% and 64%, respectively, compared to control under saline conditions. It is suggested that the efficient STEB could be used as biofertilizers for mungbean crop productivity under saline conditions after field-testing.
Collapse
Affiliation(s)
- Syeda Tahseen Zahra
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Mohsin Tariq
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Muhammad Abdullah
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Marriam Zafar
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Tahira Yasmeen
- Department of Environmental Sciences, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Muhammad Shafiq Shahid
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Muscat, Oman
| | - Haitham E. M. Zaki
- Horticulture Department, Faculty of Agriculture, Minia University, El-Minia, Egypt
- Applied Biotechnology Department, University of Technology and Applied Sciences-Sur, Sur, Oman
| | - Amanat Ali
- Nuclear Institute of Agriculture (NIA), Tandojam, Pakistan
| |
Collapse
|
3
|
Abdullah M, Tariq M, Zahra ST, Ahmad A, Zafar M, Ali S. Potential of psychrotolerant rhizobacteria for the growth promotion of wheat ( Triticum aestivum L.). PeerJ 2023; 11:e16399. [PMID: 38050608 PMCID: PMC10693821 DOI: 10.7717/peerj.16399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 10/12/2023] [Indexed: 12/06/2023] Open
Abstract
Wheat is the second most important staple crop grown and consumed worldwide. Temperature fluctuations especially the cold stress during the winter season reduces wheat growth and grain yield. Psychrotolerant plant growth-promoting rhizobacteria (PGPR) may improve plant stress-tolerance in addition to serve as biofertilizer. The present study aimed to isolate and identify PGPR, with the potential to tolerate cold stress for subsequent use in supporting wheat growth under cold stress. Ten psychrotolerant bacteria were isolated from the wheat rhizosphere at 4 °C and tested for their ability to grow at wide range of temperature ranging from -8 °C to 36 °C and multiple plant beneficial traits. All bacteria were able to grow at 4 °C to 32 °C temperature range and solubilized phosphorus except WR23 at 4 °C, whereas all the bacteria solubilized phosphorus at 28 °C. Seven bacteria produced indole-3-acetic acid at 4 °C, whereas all produced indole-3-acetic acid at 28 °C. Seven bacteria showed the ability to fix nitrogen at 4 °C, while all the bacteria fixed nitrogen at 28 °C. Only one bacterium showed the potential to produce cellulase at 4 °C, whereas four bacteria showed the potential to produce cellulase at 28 °C. Seven bacteria produced pectinase at 4 °C, while one bacterium produced pectinase at 28 °C. Only one bacterium solubilized the zinc at 4 °C, whereas six bacteria solubilized the zinc at 28 °C using ZnO as the primary zinc source. Five bacteria solubilized the zinc at 4 °C, while seven bacteria solubilized the zinc at 28 °C using ZnCO3 as the primary zinc source. All the bacteria produced biofilm at 4 °C and 28 °C. In general, we noticed behavior of higher production of plant growth-promoting substances at 28 °C, except pectinase assay. Overall, in vitro testing confirms that microbes perform their inherent properties efficiently at optimum temperatures rather than the low temperatures due to high metabolic rate. Five potential rhizobacteria were selected based on the in vitro testing and evaluated for plant growth-promoting potential on wheat under controlled conditions. WR22 and WR24 significantly improved wheat growth, specifically increasing plant dry weight by 42% and 58%, respectively. 16S rRNA sequence analysis of WR22 showed 99.78% similarity with Cupriavidus campinensis and WR24 showed 99.9% similarity with Enterobacter ludwigii. This is the first report highlighting the association of C. campinensis and E. ludwigii with wheat rhizosphere. These bacteria can serve as potential candidates for biofertilizer to mitigate the chilling effect and improve wheat production after field-testing.
Collapse
Affiliation(s)
- Muhammad Abdullah
- Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Mohsin Tariq
- Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Syeda Tahseen Zahra
- Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Azka Ahmad
- Center of Excellence in Molecular Biology (CEMB), University of the Punjab, Lahore, Punjab, Pakistan
| | - Marriam Zafar
- Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Shad Ali
- Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| |
Collapse
|
4
|
Caamal-Chan MG, Loera-Muro A, Romero-Geraldo RDJ, Ramírez-Serrano R. Bacterial Strains from Saline Environment Modulate the Expression of Saline Stress-Responsive Genes in Pepper ( Capsicum annuum). PLANTS (BASEL, SWITZERLAND) 2023; 12:3576. [PMID: 37896039 PMCID: PMC10610202 DOI: 10.3390/plants12203576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023]
Abstract
Salinity stress is one of the most important problems in crop productivity. Plant growth-promoting bacteria (PGPB) can also confer stress tolerance in plants under saline soil conditions. In a previous work, it was reported that bacteria strains isolated from hypersaline sites mitigated salt stress in chili pepper (Capsicum annuum var. Caballero) plants and promoted plant growth in some cases. The aim of this study was to evaluate the modulation of gene expression in C. annuum plants by bacteria strains isolated from saline environments. Two bacteria strains from high salinity ponds in Guerrero Negro, BCS, Mexico (Bacillus sp. strain 32 and Staphylococcus sp. strain 155) and Azospirillum brasilense Cd (DSM 1843) were used. Significant improvement in fresh weight yield (stem (28%), root (128.9%), and leaves (20%)) was observed in plants inoculated with Bacillus sp. strain 32. qPCR analysis showed that both strains modulated the expression of stress-responsive genes (MYB, ETR1, JAR1, WRKY, and LOX2) as well as heat shock factors and protein genes (CahsfA2, CahsfA3, CahsfB3a, CaDNaJ02, and CaDNaJ04). Finally, the expression levels of genes related to early salt stress and ISR showed differences in plants with dual treatment (bacteria-inoculated and salt-stressed) compared to plants with simple salinity stress. This work confirmed the differential modification of the transcriptional levels of genes observed in plants inoculated with bacteria under salinity stress.
Collapse
Affiliation(s)
- María Goretty Caamal-Chan
- CONAHCYT-Centro de Investigaciones Biológicas del Noroeste, SC. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz C.P. 23096, Baja California Sur, Mexico;
| | - Abraham Loera-Muro
- CONAHCYT-Centro de Investigaciones Biológicas del Noroeste, SC. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz C.P. 23096, Baja California Sur, Mexico;
| | - Reyna De Jesús Romero-Geraldo
- Instituto Tecnológico de La Paz, Boulevard Forjadores de Baja California Sur 4720, 8 de Octubre 2da Secc, La Paz C.P. 23080, Baja California Sur, Mexico;
| | - Rogelio Ramírez-Serrano
- Centro de Investigaciones Biológicas del Noroeste, SC. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz C.P. 23096, Baja California Sur, Mexico;
| |
Collapse
|
5
|
Sallam NMA, AbdElfatah HAS, Khalil Bagy HMM, Elfarash A, Abo-Elyousr KAM, Sikora EJ, Sallam A. Exploring the mechanisms of endophytic bacteria for suppressing early blight disease in tomato ( Solanum lycopersicum L.). Front Microbiol 2023; 14:1184343. [PMID: 37808317 PMCID: PMC10551630 DOI: 10.3389/fmicb.2023.1184343] [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: 03/11/2023] [Accepted: 08/24/2023] [Indexed: 10/10/2023] Open
Abstract
Controlling early blight of tomatoes using endophytic bacteria is an eco-friendly and sustainable approach to manage this common fungal disease caused by Alternaria solani, Alternaria alternata, and Curvularia lunata. Endophytic bacteria are microorganisms that live inside plant tissues without causing harm and can help protect the host plant from pathogens. In this work, twenty endophytic bacterial isolates from tomato healthy plants were tested against pathogenic fungal isolates that caused early blight disease in vitro. Out of the 20 tested isolates, three (B4, B7, and B17) were considered effective isolates against the growth of fungal pathogens. The three isolates were recognized as Enterobacter cloacae HS-6 (B4), Pseudomonas gessardii HS-5 (B 7), and Pseudomonas mediterranea HS-4 (B17) using 16s-rDNA sequencing. Different concentrations of bacterial cultural diltrates at 20, 40, and 60% were tested for their antagonistic effects on the development of pathogenic fungi in vitro. The lowest dry weights of pathogenic isolates in all bacterial culture filtrates were discovered at 60%. In all culture filtrates, phenolic compounds showed the largest peak area. Under greenhouse conditions, the least disease severity of tomato early blight was found for E. cloacae and its culture filtrate compared to other treatments. Real-time PCR was used to examine the expression pattern of the defense response gene β-1.3 glucanase gene in infected tomato plants with pathogenic fungi (control) as well as its relations with efficient biocontrol agent (E. cloacae). The expression of the gene increased substantially and significantly after three days from the inoculation-infected plants with C. lunata and E. cloacae while it reached the maximum after five days from the inoculation with A. alternata, A. solani and E. cloacae. Our study concluded that the endophytic bacterial isolate E. cloacae can be considered a promising biocontrol agent for preventing tomato early blight.
Collapse
Affiliation(s)
- Nashwa M. A. Sallam
- Department of Plant Pathology, Faculty of Agriculture, Assiut University, Assiut, Egypt
| | | | | | - Ameer Elfarash
- Department of Genetics, Faculty of Agriculture, Assiut University, Assiut, Egypt
| | - Kamal A. M. Abo-Elyousr
- Department of Plant Pathology, Faculty of Agriculture, Assiut University, Assiut, Egypt
- Department of Arid Land Agriculture, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Edward J. Sikora
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Ahmed Sallam
- Department of Genetics, Faculty of Agriculture, Assiut University, Assiut, Egypt
- Department Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| |
Collapse
|
6
|
Avila-Quezada GD, Rai M. Novel nanotechnological approaches for managing Phytophthora diseases of plants. TRENDS IN PLANT SCIENCE 2023; 28:1070-1080. [PMID: 37085411 DOI: 10.1016/j.tplants.2023.03.022] [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: 07/24/2022] [Revised: 03/20/2023] [Accepted: 03/23/2023] [Indexed: 05/03/2023]
Abstract
Members of the Phytophthora genus are soil-dwelling pathogens responsible for diseases of several important plants. Among these, Phytophthora infestans causes late blight of potatoes, which was responsible for the Irish potato famine during the mid-19th century. Various strategies have been applied to control Phytophthora, including integrated management programs (IMPs) and quarantine, but without successful full management of the disease. Thus, there is a need to search for alternative tools. Here, we discuss the emerging role of nanomaterials in the detection and treatment of Phytophthora species, including slow delivery of agrochemicals (microbicides and pesticides). We propose integrating these tools into an IMP, which could lead to a reduction in pesticide use and provide more effective and sustainable control of Phytophthora pathogens.
Collapse
Affiliation(s)
- Graciela Dolores Avila-Quezada
- Universidad Autonoma de Chihuahua, Facultad de Ciencias Agrotecnologicas, Escorza 900, Chihuahua, Chihuahua 31000, Mexico.
| | - Mahendra Rai
- Sant Gadge Baba Amravati University, Department of Biotechnology, Nanobiotechnology Laboratory, Amravati, Maharashtra 444602, India; Nicolaus Copernicus University, Department of Microbiology, 87-100 Toruń, Poland.
| |
Collapse
|
7
|
Kulkova I, Dobrzyński J, Kowalczyk P, Bełżecki G, Kramkowski K. Plant Growth Promotion Using Bacillus cereus. Int J Mol Sci 2023; 24:ijms24119759. [PMID: 37298706 DOI: 10.3390/ijms24119759] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 05/25/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023] Open
Abstract
Plant growth-promoting bacteria (PGPB) appear to be a sensible competitor to conventional fertilization, including mineral fertilizers and chemical plant protection products. Undoubtedly, one of the most interesting bacteria exhibiting plant-stimulating traits is, more widely known as a pathogen, Bacillus cereus. To date, several environmentally safe strains of B. cereus have been isolated and described, including B. cereus WSE01, MEN8, YL6, SA1, ALT1, ERBP, GGBSTD1, AK1, AR156, C1L, and T4S. These strains have been studied under growth chamber, greenhouse, and field conditions and have shown many significant traits, including indole-3-acetic acid (IAA) and aminocyclopropane-1-carboxylic acid (ACC) deaminase production or phosphate solubilization, which allows direct plant growth promotion. It includes an increase in biometrics traits, chemical element content (e.g., N, P, and K), and biologically active substances content or activity, e.g., antioxidant enzymes and total soluble sugar. Hence, B. cereus has supported the growth of plant species such as soybean, maize, rice, and wheat. Importantly, some B. cereus strains can also promote plant growth under abiotic stresses, including drought, salinity, and heavy metal pollution. In addition, B. cereus strains produced extracellular enzymes and antibiotic lipopeptides or triggered induced systemic resistance, which allows indirect stimulation of plant growth. As far as biocontrol is concerned, these PGPB can suppress the development of agriculturally important phytopathogens, including bacterial phytopathogens (e.g., Pseudomonas syringae, Pectobacterium carotovorum, and Ralstonia solanacearum), fungal phytopathogens (e.g., Fusarium oxysporum, Botrytis cinerea, and Rhizoctonia solani), and other phytopathogenic organisms (e.g., Meloidogyne incognita (Nematoda) and Plasmodiophora brassicae (Protozoa)). In conclusion, it should be noted that there are still few studies on the effectiveness of B. cereus under field conditions, particularly, there is a lack of comprehensive analyses comparing the PGP effects of B. cereus and mineral fertilizers, which should be reduced in favor of decreasing the use of mineral fertilizers. It is also worth mentioning that there are still very few studies on the impact of B. cereus on the indigenous microbiota and its persistence after application to soil. Further studies would help to understand the interactions between B. cereus and indigenous microbiota, subsequently contributing to increasing its effectiveness in promoting plant growth.
Collapse
Affiliation(s)
- Iryna Kulkova
- Institute of Technology and Life Sciences-National Research Institute, Falenty, 3 Hrabska Avenue, 05-090 Raszyn, Poland
| | - Jakub Dobrzyński
- Institute of Technology and Life Sciences-National Research Institute, Falenty, 3 Hrabska Avenue, 05-090 Raszyn, Poland
| | - Paweł Kowalczyk
- Department of Animal Nutrition, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 Str., 05-110 Jabłonna, Poland
| | - Grzegorz Bełżecki
- Department of Animal Nutrition, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 Str., 05-110 Jabłonna, Poland
| | - Karol Kramkowski
- Department of Physical Chemistry, Medical University of Białystok, Kilińskiego 1 Str., 15-089 Białystok, Poland
| |
Collapse
|
8
|
Exploring the Potentiality of Native Actinobacteria to Combat the Chilli Fruit Rot Pathogens under Post-Harvest Pathosystem. Life (Basel) 2023; 13:life13020426. [PMID: 36836783 PMCID: PMC9959883 DOI: 10.3390/life13020426] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Chilli is an universal spice cum solanaceous vegetable crop rich in vitamin A, vitamin C, capsaicin and capsanthin. Its cultivation is highly threatened by fruit rot disease which cause yield loss as high as 80-100% under congenial environment conditions. Currently actinobacteria are considered as eco-friendly alternatives to synthetic fungicides at pre and post-harvest pathosystems. Hence, this research work focuses on the exploitation of rhizospheric, phyllospheric and endophytic actinobacteria associated with chilli plants for their antagonistic activity against fruit rot pathogens viz., Colletotrichum scovillei, Colletotrichum truncatum and Fusarium oxysporum. In vitro bioassays revealed that the actinobacterial isolate AR26 was found to be the most potent antagonist with multifarious biocontrol mechanisms such as production of volatile, non-volatile, thermostable compounds, siderophores, extracellular lytic enzymes. 16S rRNA gene sequence confirmed that the isolate AR26 belongs to Streptomyces tuirus. The results of detached fruit assay revealed that application of liquid bio-formulation of Stretomyces tuirus @ 10 mL/L concentration completely inhibited the development of fruit rot symptoms in pepper fruits compared to methanol extracts. Hence, the present research work have a great scope for evaluating the biocontrol potential of native S. tuirus AR26 against chilli fruit rot disease under field condition as well against a broad spectrum of post-harvest plant pathogens.
Collapse
|
9
|
Volynchikova E, Kim KD. Anti-Oomycete Activity and Pepper Root Colonization of Pseudomonas plecoglossicida YJR13 and Pseudomonas putida YJR92 against Phytophthora capsici. THE PLANT PATHOLOGY JOURNAL 2023; 39:123-135. [PMID: 36760054 PMCID: PMC9929162 DOI: 10.5423/ppj.oa.01.2023.0001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/17/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Previously, Pseudomonas plecoglossicida YJR13 and Pseudomonas putida YJR92 from a sequential screening procedure were proven to effectively control Phytophthora blight caused by Phytophthora capsici. In this study, we further investigated the anti-oomycete activities of these strains against mycelial growth, zoospore germination, and germ tube elongation of P. capsici. We also investigated root colonization ability of the bacterial strains in square dishes, including cell motility (swimming and swarming motilities) and biofilm formation. Both strains significantly inhibited mycelial growth in liquid and solid V8 juice media and M9 minimal media, zoospore germination, and germ tube elongation compared with Bacillus vallismortis EXTN-1 (positive biocontrol strain), Sphingomonas aquatilis KU408 (negative biocontrol strain), and MgSO4 solution (untreated control). In diluted (nutrient-deficient) V8 juice broth, the tested strain populations were maintained at >108 cells/ml, simultaneously providing mycelial inhibitory activity. Additionally, these strains colonized pepper roots at a 106 cells/ml concentration for 7 days. The root colonization of the strains was supported by strong swimming and swarming activities, biofilm formation, and chemotactic activity towards exudate components (amino acids, organic acids, and sugars) of pepper roots. Collectively, these results suggest that strains YJR13 and YJR92 can effectively suppress Phytophthora blight of pepper through direct anti-oomycete activities against mycelial growth, zoospore germination and germ tube elongation. Bacterial colonization of pepper roots may be mediated by cell motility and biofilm formation together with chemotaxis to root exudates.
Collapse
Affiliation(s)
| | - Ki Deok Kim
- Corresponding author: Phone) +82-2-3290-3065, FAX) +82-2-925-1970, E-mail)
| |
Collapse
|
10
|
Tariq M, Hasnain N, Rasul I, Asad MA, Javed A, Rashid K, Shafique J, Iram W, Hameed A, Zafar M. Reconnoitering the capabilities of nodule endophytic Pantoea dispersa for improved nodulation and grain yield of chickpea (Cicer arietinum L.). World J Microbiol Biotechnol 2023; 39:85. [PMID: 36705812 DOI: 10.1007/s11274-023-03525-3] [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: 08/02/2022] [Accepted: 01/11/2023] [Indexed: 01/28/2023]
Abstract
Microorganisms belonging to root and soil provide a wide range of services and benefits to the plant by promoting plant growth and controlling phytopathogens. This study aimed to isolate endophytic bacteria from the root nodules of chickpea (Cicer arietinum L.) and determine their potential in improving plant growth. A total of nineteen different bacterial morphotypes were isolated from root nodules of chickpea and characterized in vitro for plant growth promotion abilities. All bacterial isolates were able to produce indole acetic acid at varying levels, out of which MCA19 was screened as the most efficient indole acetic acid producer (10.25 µg mL-1). MCA8, MCA9, MCA10, MCA11, MCA16, MCA17 and MCA19 were positive for phosphate solubilization, out of which MCA9 was best phosphate solubilizer (18.8 µg mL-1). All bacterial strains showed varying ability to grow on nitrogen-free media. Hydrogen cyanide, pectinase, and cellulase production ability were also observed in isolates, in which MCA9, MCA12, MCA17 and MCA19 were found best. Based on in vitro testing, five isolates MCA2, MCA9, MCA11, MCA17 and MCA19 were selected for further studies. Bacterial isolates MCA9, MCA11, MCA17 and MCA19 were identified by 16S rRNA gene sequence analysis as Pantoea dispersa while MCA2 as Rhizobium pusense. This is the first report on the existence of Pantoea dispersa in the root nodules of chickpea. In pot experiment, a maximum increase of 30% was recorded in plant dry weight upon the application of MCA19. Under field conditions, bacterial isolates, MCA2, MCA11 and MCA19 significantly enhanced nodulation and yield parameters of chickpea, compared to control. Pantoea dispersa MCA19 displayed the highest plant growth-promoting potential by increasing 38% grain yield. Our results indicate that Pantoea dispersa MCA19 is a promising biofertilizer for future applications.
Collapse
Affiliation(s)
- Mohsin Tariq
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan.
| | - Nayab Hasnain
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Ijaz Rasul
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | | | - Aqsa Javed
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Kamran Rashid
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Javeria Shafique
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Wajeeha Iram
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Amir Hameed
- Plant Breeding and Acclimatization Institute, National Research Institute, 05-870, Radzikow, Blonie, Poland
| | - Marriam Zafar
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| |
Collapse
|
11
|
Hernández-Huerta J, Tamez-Guerra P, Gomez-Flores R, Delgado-Gardea MCE, Robles-Hernández L, Gonzalez-Franco AC, Infante-Ramirez R. Pepper growth promotion and biocontrol against Xanthomonas euvesicatoria by Bacillus cereus and Bacillus thuringiensis formulations. PeerJ 2023; 11:e14633. [PMID: 36710864 PMCID: PMC9881471 DOI: 10.7717/peerj.14633] [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: 06/30/2022] [Accepted: 12/04/2022] [Indexed: 01/25/2023] Open
Abstract
Background Bacillus genus has been used in horticultural crops as a biocontrol agent against insect pests, microbial phytopathogens, and plant growth-promoting bacteria (PGPB), representing an alternative to agrochemicals. In particular, B. cereus (Bc) and B. thuringiensis (Bt) have been studied for their fungicidal and insecticidal activities. However, their use as biofertilizer formulations and biocontrol agents against phytopathogenic bacteria is limited. Objective To evaluate Bc and Bt formulations as PGPB and biocontrol agents against the bacterial spot agent Xanthomonas euvesicatoria (Xe) in greenhouse-grown chili peppers. Methods Bc and Bt isolates obtained from soil samples were identified and characterized using conventional biochemical and multiplex PCR identification methods. Bioassays to determine Bc and Bt isolates potential as PGPB were evaluated on chili pepper seedlings in seedbeds. In addition, formulations based on Bc (F-BC26 and F-BC08) and Bt (F-BT24) strains were assessed as biofertilizers on pepper, under controlled conditions. Furthermore, in vitro antagonism assays were performed by confronting Bc and Bt isolate formulations against Xe isolates in direct (foliage) and indirect (resistance induction) phytopathogen biocontrol assays on pepper plants, which were grown under controlled conditions for 15 d after formulations treatment. Results Isolates were identified as Bc and Bt. Formulations significantly improved pepper growth in seedbeds and pots, whereas in vitro bioassays demonstrated the bactericidal effect of Bc and Bt strains against Xe isolates. Furthermore, assays showed significant plant protection by F-BC26, F-BC08, and F-BT24 formulated strains against Xe. Conclusion Results indicated that F-BT24 and F-BC26 isolates formulations promoted pepper growth and protected it against Xanthomonas euvesicatoria.
Collapse
Affiliation(s)
- Jared Hernández-Huerta
- Facultad de Ciencias Agrotecnológicas, Universidad Autónoma de Chihuahua, Chihuahua, México
| | - Patricia Tamez-Guerra
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Ricardo Gomez-Flores
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | | | | | | | | |
Collapse
|
12
|
Zahra ST, Tariq M, Abdullah M, Azeem F, Ashraf MA. Dominance of Bacillus species in the wheat ( Triticum aestivum L.) rhizosphere and their plant growth promoting potential under salt stress conditions. PeerJ 2023; 11:e14621. [PMID: 36643649 PMCID: PMC9835707 DOI: 10.7717/peerj.14621] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/01/2022] [Indexed: 01/10/2023] Open
Abstract
Wheat (Triticum aestivum L.) is a major source of calorific intake in its various forms and is considered one of the most important staple foods. Improved wheat productivity can contribute substantially to addressing food security in the coming decades. Soil salinity is the most serious limiting factor in crop production and fertilizer use efficiency. In this study, 11 bacteria were isolated from wheat rhizosphere and examined for salt tolerance ability. WGT1, WGT2, WGT3, WGT6, WGT8, and WGT11 were able to tolerate NaCl salinity up to 4%. Bacterial isolates were characterized in vitro for plant growth-promoting properties including indole-3-acetic acid (IAA) production, phosphate solubilization, nitrogen fixation, zinc solubilization, biofilm formation, and cellulase-pectinase production. Six isolates, WGT1, WGT3, WGT4, WGT6, WGT8, and WGT9 showed IAA production ability ranging from 0.7-6 µg m/L. WGT8 displayed the highest IAA production. Five isolates, WGT1, WGT2, WGT5, WGT10, and WGT11, demonstrated phosphate solubilization ranging from 1.4-12.3 µg m/L. WGT2 showed the highest phosphate solubilization. Nitrogen fixation was shown by only two isolates, WGT1 and WGT8. Zinc solubilization was shown by WGT1 and WGT11 on minimal media. All isolates showed biofilm formation ability, where WGT4 exhibited maximum potential. Cellulase production ability was noticed in WGT1, WGT2, WGT4, and WGT5, while pectinase production was observed in WGT2 and WGT3. Phylogenetic identification of potential bacteria isolates confirmed their close relationship with various species of the genus Bacillus. WGT1, WGT2, and WGT3 showed the highest similarity with B. cereus, WGT6 with B. tianshenii, WGT8 with B. subtilis, and WGT11 with B. thuringiensis. Biofertilizer characteristics of salt-tolerant potential rhizospheric bacteria were evaluated by inoculating wheat plants under controlled conditions and field experiments. B. cereus WGT1 and B. thuringiensis WGT11 displayed the maximum potential to increase plant growth parameters and enhance grain yield by 37% and 31%, respectively. Potential bacteria of this study can tolerate salt stress, have the ability to produce plant growth promoting substances under salt stress and contribute significantly to enhance wheat grain yield. These bacterial isolates have the potential to be used as biofertilizers for improved wheat production under salinity conditions and contribute to the sustainable agriculture.
Collapse
Affiliation(s)
- Syeda Tahseen Zahra
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Mohsin Tariq
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Muhammad Abdullah
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Farrukh Azeem
- Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| | - Muhammad Arslan Ashraf
- Department of Botany, Government College University Faisalabad, Faisalabad, Punjab, Pakistan
| |
Collapse
|
13
|
Chang X, Wei D, Zeng Y, Zhao X, Hu Y, Wu X, Song C, Gong G, Chen H, Yang C, Zhang M, Liu T, Chen W, Yang W. Maize-soybean relay strip intercropping reshapes the rhizosphere bacterial community and recruits beneficial bacteria to suppress Fusarium root rot of soybean. Front Microbiol 2022; 13:1009689. [PMID: 36386647 PMCID: PMC9643879 DOI: 10.3389/fmicb.2022.1009689] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/29/2022] [Indexed: 11/29/2022] Open
Abstract
Rhizosphere microbes play a vital role in plant health and defense against soil-borne diseases. Previous studies showed that maize-soybean relay strip intercropping altered the diversity and composition of pathogenic Fusarium species and biocontrol fungal communities in the soybean rhizosphere, and significantly suppressed soybean root rot. However, whether the rhizosphere bacterial community participates in the regulation of this intercropping on soybean root rot is not clear. In this study, the rhizosphere soil of soybean healthy plants was collected in the continuous cropping of maize-soybean relay strip intercropping and soybean monoculture in the fields, and the integrated methods of microbial profiling, dual culture assays in vitro, and pot experiments were employed to systematically investigate the diversity, composition, and function of rhizosphere bacteria related to soybean root rot in two cropping patterns. We found that intercropping reshaped the rhizosphere bacterial community and increased microbial community diversity, and meanwhile, it also recruited much richer and more diverse species of Pseudomonas sp., Bacillus sp., Streptomyces sp., and Microbacterium sp. in soybean rhizosphere when compared with monoculture. From the intercropping, nine species of rhizosphere bacteria displayed good antagonism against the pathogen Fusarium oxysporum B3S1 of soybean root rot, and among them, IRHB3 (Pseudomonas chlororaphis), IRHB6 (Streptomyces), and IRHB9 (Bacillus) were the dominant bacteria and extraordinarily rich. In contrast, MRHB108 (Streptomyces virginiae) and MRHB205 (Bacillus subtilis) were the only antagonistic bacteria from monoculture, which were relatively poor in abundance. Interestingly, introducing IRHB3 into the cultured substrates not only significantly promoted the growth and development of soybean roots but also improved the survival rate of seedlings that suffered from F. oxysporum infection. Thus, this study proves that maize-soybean relay strip intercropping could help the host resist soil-borne Fusarium root rot by reshaping the rhizosphere bacterial community and driving more beneficial microorganisms to accumulate in the soybean rhizosphere.
Collapse
Affiliation(s)
- Xiaoli Chang
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Dengqin Wei
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Yuhan Zeng
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Xinyu Zhao
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Yu Hu
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Xiaoling Wu
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Chun Song
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Guoshu Gong
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Huabao Chen
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Chunping Yang
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Min Zhang
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Taiguo Liu
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Wanquan Chen
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| | - Wenyu Yang
- College of Agronomy and Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, China
| |
Collapse
|
14
|
Phazna TA, Ngashangva N, Yentrembam RBS, Maurya R, Mukherjee P, Sharma C, Verma PK, Sarangthem I. Draft genome sequence and functional analysis of Lysinibacillus xylanilyticus t26, a plant growth-promoting bacterium isolated from Capsicum chinense rhizosphere. J Biosci 2022. [DOI: 10.1007/s12038-022-00264-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
15
|
Liu H, Qi Y, Wang J, Jiang Y, Geng M. Synergistic effects of crop residue and microbial inoculant on soil properties and soil disease resistance in a Chinese Mollisol. Sci Rep 2021; 11:24225. [PMID: 34930990 PMCID: PMC8688499 DOI: 10.1038/s41598-021-03799-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/09/2021] [Indexed: 11/17/2022] Open
Abstract
The soil-borne disease caused by Fusarium graminearum seriously affects the corn quality. Straw can greatly improve soil quality, but the effect is limited by its nature and environmental factors. This study explored the impact of straw-JF-1(biocontrol bacteria) combination on soil environment and soil disease resistance. The results showed that the combined treatment increased the proportion of soil large and small macro-aggregates by 22.50 and 3.84%, with soil organic carbon (SOC) content by 16.18 and 16.95%, respectively. Compared to treatment with returning straw to the field alone, the straw-JF-1 combination increased the soil content of humic acid, fulvic acid, and humin by 14.06, 5.50, and 4.37%, respectively. Moreover, A metagenomics showed that returning straw to the field alone increased the abundance of disease-causing fungi (Fusarium and Plectosphaerella), however, the straw-JF-1 combination significantly suppressed this phenomenon as well as improved the abundance of probiotic microorganisms such as Sphingomonas, Mortierella, Bacillus, and Pseudomonas. Functional analysis indicated that the combination of straw and JF-1 improved some bacterial functions, including inorganic ion transport and metabolism, post-translational modification/protein turnover/chaperones and function unknown, fungal functions associated with plant and animal pathogens were effectively inhibited. Pot experiments showed that the straw-JF-1 combination effectively inhibited the Fusarium graminearum induced damage to maize seedlings. Therefore, the combination of straw and JF-1 could be a practical method for soil management.
Collapse
Affiliation(s)
- Haolang Liu
- Key Laboratory of Straw Biology and Utilization, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
| | - Yuqi Qi
- Institute for Environment and Climate Research, Jinan University, Guangzhou, Guangdong, China
| | - Jihong Wang
- Key Laboratory of Straw Biology and Utilization, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China.
| | - Yan Jiang
- Key Laboratory of Straw Biology and Utilization, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
| | - Mingxin Geng
- Key Laboratory of Straw Biology and Utilization, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
| |
Collapse
|
16
|
Screening and Biocontrol Potential of Rhizobacteria Native to Gangetic Plains and Hilly Regions to Induce Systemic Resistance and Promote Plant Growth in Chilli against Bacterial Wilt Disease. PLANTS 2021; 10:plants10102125. [PMID: 34685934 PMCID: PMC8541367 DOI: 10.3390/plants10102125] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/03/2021] [Accepted: 10/04/2021] [Indexed: 11/16/2022]
Abstract
Plant growth-promoting rhizobacteria (PGPR) is a microbial population found in the rhizosphere of plants that can stimulate plant development and restrict the growth of plant diseases directly or indirectly. In this study, 90 rhizospheric soil samples from five agro climatic zones of chilli (Capsicum annuum L.) were collected and rhizobacteria were isolated, screened and characterized at morphological, biochemical and molecular levels. In total, 38% of rhizobacteria exhibited the antagonistic capacity to suppress Ralstonia solanacearum growth and showed PGPR activities such as indole acetic acid production by 67.64% from total screened rhizobacteria isolates, phosphorus solubilization by 79.41%, ammonia by 67.75%, HCN by 58.82% and siderophore by 55.88%. We performed a principal component analysis depicting correlation and significance among plant growth-promoting activities, growth parameters of chilli and rhizobacterial strains. Plant inoculation studies indicated a significant increase in growth parameters and PDS1 strain showed maximum 71.11% biocontrol efficiency against wilt disease. The best five rhizobacterial isolates demonstrating both plant growth-promotion traits and biocontrol potential were characterized and identified as PDS1—Pseudomonas fluorescens (MN368159), BDS1—Bacillus subtilis (MN395039), UK4—Bacillus cereus (MT491099), UK2—Bacillus amyloliquefaciens (MT491100) and KA9—Bacillus subtilis (MT491101). These rhizobacteria have the potential natural elicitors to be used as biopesticides and biofertilizers to improve crop health while warding off soil-borne pathogens. The chilli cv. Pusa Jwala treated with Bacillus subtilis KA9 and Pseudomonas fluorescens PDS1 showed enhancement in the defensive enzymes PO, PPO, SOD and PAL activities in chilli leaf and root tissues, which collectively contributed to induced resistance in chilli plants against Ralstonia solanacearum. The induction of these defense enzymes was found higher in leave tissues (PO—4.87-fold, PP0—9.30-fold, SOD—9.49-fold and PAL—1.04-fold, respectively) in comparison to roots tissue at 48 h after pathogen inoculation. The findings support the view that plant growth-promoting rhizobacteria boost defense-related enzymes and limit pathogen growth in chilli plants, respectively, hence managing the chilli bacterial wilt.
Collapse
|
17
|
Streptomyces strains modulate dynamics of soil bacterial communities and their efficacy in disease suppression caused by Phytophthora capsici. Sci Rep 2021; 11:9317. [PMID: 33927238 PMCID: PMC8085009 DOI: 10.1038/s41598-021-88495-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/13/2021] [Indexed: 11/16/2022] Open
Abstract
The responses of rhizosphere bacterial communities of Streptomyces (SS14 and IT20 stains) treated-pepper plants following inoculation by Phytophthora capsici (PC) was investigated using Illumina MiSeq sequencing. Distinct modulation of the bacteriome composition was found for PC samples with the highest relative abundance (RA) of Chitinophaga (22 ± 0.03%). The RA of several bacterial operational taxonomic units (OTUs) was affected and caused changes in alpha and beta-diversity measures. In IT20, the RA of Cyanobacteria was enriched compared to SS14 (72%) and control samples (47%). Phylotypes belonging to Devosia, Promicromonospora, Kribbella, Microbacterium, Amylocolatopsis, and Pseudomonas genera in the rhizosphere were positively responding against the pathogen. Our findings show that the phosphate solubilizing strain IT20 has higher microbial community responders than the melanin-producing strain SS14. Also, positive interactions were identified by comparing bacterial community profiles between treatments that might allow designing synthetic bio-inoculants to solve agronomic problems in an eco-friendly way.
Collapse
|