Role of antibiosis in antagonism of Streptomyces hygroscopicus var. geldanus to Rhizoctonia solani in soil

1984 ◽  
Vol 30 (12) ◽  
pp. 1440-1447 ◽  
Author(s):  
Craig S. Rothrock ◽  
David Gottlieb
Keyword(s):  
Disease Control ◽  
Rhizoctonia Solani ◽  
Root Rot ◽  
Antibiotic Production ◽  
Streptomyces Hygroscopicus ◽  
Soil Extracts ◽  
Rhizoctonia Root Rot ◽  
Inhibitory Compounds ◽  
Affected Plant

Streptomyces hygroscopicus var. geldanus controlled rhizoctonia root rot of pea in previously sterilized soil if incubated for 2 or more days prior to infesting soil with Rhizoctonia solani and planting. Streptomyces hygroscopicus also reduced saprophytic growth and the population of R. solani in soil. Growth of R. solani was inhibited by geldanamycin, an antibiotic produced by S. hygroscopicus, on nutrient media. Methanol extracts of soils in which the antagonist was incubated for 2 or more days inhibited growth of R. solani. Geldanamycin concentration was 88 μg per gram of soil after 7 days of incubation. Bioautography of soil extracts indicated that the inhibitory compounds were geldanamycin and two other compounds, also found in the geldanamycin standard. The period of incubation necessary for antibiotic production and disease control was similar, with no disease control occurring where no antibiotic was detected. Amending soil with geldanamycin, in amounts equivalent to that produced after 2 or 7 days of incubation, controlled disease and reduced saprophytic growth of the pathogen. Lesser amounts of the antibiotic did neither. No evidence for antagonism owing to competition (nitrogen, carbon) or parasitism was found. Streptomyces hygroscopicus and geldanamycin also affected plant growth.

scholarly journals Role of Bradyrhizobium japonicum and Trichoderma spp. in the control of root rot disease of soybean

2014 ◽  
Vol 30 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Syed Ehteshamul-Haque ◽  
Abdul Ghaffar
Keyword(s):  
Grain Yield ◽  
Rhizoctonia Solani ◽  
Trichoderma Harzianum ◽  
Root Rot ◽  
Bradyrhizobium Japonicum ◽  
Seed Treatment ◽  
Trichoderma Spp ◽  
Root Rot Disease ◽  
Rot Disease

Seed treatment of soybean with <i>Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii</i> and <i>T. pseudokoningii</i> significantly controlled the infection of 30-day-old seedlingsby <i>Maerophomina phaseolina, Rhizoctonia solani</i> and <i>Fusarium</i> spp. In 60-day-old plants <i>Trichoderma</i> spp.. and <i>B. japonicum</i> inhibited the grouth of <i>R. solani</i> and <i>Fusarium</i> spp., whereas the use of <i>B. japonicum</i> (TAL-102) with <i>T. harzianum. T. viride, T. koningii</i> and <i>T. pseudokoningii</i> controlled the infection by <i>M. phaseolina. Greater grain yield was recorded when B. <i>japonium</i> (TAI-102) was used with <i>T. hamatum</i>.

Effects of Meloidogyne incognita, Pectobacterium betavasculorum and Rhizoctonia solani interactions on growth, physiological and biochemical changes of beetroot

2020 ◽  
pp. 1-18
Author(s):  
Manzoor R. Khan ◽  
Zaki A. Siddiqui
Keyword(s):  
Antioxidant Enzymes ◽  
Plant Growth ◽  
Rhizoctonia Solani ◽  
Meloidogyne Incognita ◽  
Root Rot ◽  
Dry Weight ◽  
Soft Rot ◽  
Maximum Reduction ◽  
Physiological And Biochemical

Abstract Effect of Meloidogyne incognita, Pectobacterium betavasculorum and Rhizoctonia solani alone, pre, post and simultaneous inoculations to find out role of each pathogen on growth, chlorophyll and carotenoid, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR) activities and proline, H2O2 and malondialdehyde (MDA) of beetroot (Beta vulgaris L). Inoculation of plants with M. incognita / P. betavasculorum or R. solani reduced plant growth (root dry weight) (42.0%), chlorophyll (24.2%) and carotenoid (47.7%) while inoculation of pathogens under study resulted in increased activities of antioxidant enzymes, proline, H2O2 and MDA. Combined inoculation of pathogens under study resulted in greater reduction of plant growth (74.9%), chlorophyll (55.3%) and carotenoid (83.7%) than individual pathogen. Greatest reduction in plant growth, chlorophyll and carotenoid and maximum activities of antioxidant enzymes, proline, H2O2 and MDA were observed when M. incognita was inoculated 20 days prior to P. betavasculorum plus R. solani. P. betavasculorum and R. solani reduced galling and nematode multiplication but maximum reduction in galling (82.8%) and nematode multiplication (82.7%) was observed when P. betavasculorum plus R. solani were inoculated prior to nematodes. Necrosis soft rot and root rot indices by P. betavasculorum and R. solani were 3 respectively. Disease indices were 5 when two or more pathogens were inoculated together. Prior inoculation of M. incognita predisposed beetroots to P. betavasculorum and R. solani and aggravates the disease.

Effect of nitrogen and residual copper on the occurrence of Rhizoctonia bare patch in wheat grown near Esperance, Western Australia

1991 ◽  
Vol 31 (2) ◽  
pp. 259 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Grain Yield ◽  
Rhizoctonia Solani ◽  
Ammonium Nitrate ◽  
Western Australia ◽  
Root Rot ◽  
Plant Nutrition ◽  
Bare Patch ◽  
Grain Yields ◽  
Cu Deficiency ◽  
Rhizoctonia Root Rot

The area of rhizoctonia bare patch and the incidence and severity of rhizoctonia root rot (caused by Rhizoctonia solani Khnn) were reduced by the application of ammonium nitrate fertiliser. Residual copper (Cu) from a Cu fertiliser treatment in 1967 had no effect on the area of rhizoctonia bare patch or the incidence and severity of root rot. With no applied nitrogen (N), 17.6% (mean of residual Cu levels) of the plot was affected by patches while the area of plot affected by patches declined to 4.2% where 92 kg N/ha had been applied. The incidence and severity of rhizoctonia root rot declined from 45.9 and 27.0% to 32.7 and 9.1%, respectively, with the application of N fertiliser. The grain yield of wheat supplied with adequate Cu increased although the level of N fertiliser exceeded that considered adequate for plant nutrition. The response is explained by the control of rhizoctonia bare patch. The area of rhizoctonia patches and the incidence and severity of rhizoctonia root rot decreased with the application of N, and with adequate Cu fertiliser (2.2 kg Cu/ha), the grain yields increased. However, with marginal and deficient levels of applied Cu fertiliser, the application of N fertiliser induced Cu deficiency in wheat plants, and the grain yields declined although rhizoctonia patches were reduced.

Organic matter input influences incidence of root rot caused by Rhizoctonia solani AG8 and microorganisms associated with plant root disease suppression in three Australian agricultural soils

Soil Research ◽  
2019 ◽  
Vol 57 (4) ◽  
pp. 321 ◽  
Author(s):  
Rowena S. Davey ◽  
Ann M. McNeill ◽  
Stephen J. Barnett ◽  
Vadakattu V. S. R. Gupta
Keyword(s):  
Rhizoctonia Solani ◽  
Root Rot ◽  
Microbial Biomass Carbon ◽  
Plant Root ◽  
Abiotic Factors ◽  
Root Disease ◽  
Disease Suppression ◽  
Gaeumannomyces Graminis ◽  
Wheat Seedlings ◽  
Rhizoctonia Root Rot

Soil-borne plant root disease caused by Rhizoctonia solani AG8 is prevalent in cereal farming systems worldwide, particularly in semiarid agricultural regions. A controlled environment study was undertaken using three Australian soils to test the hypothesis that OM input from crop roots and residues decreases infection by Rhizoctonia root rot via biologically mediated disease suppression. The specific aim was to determine the relative effect of two different OM inputs (wheat stubble or roots) on (a) abundance (DNA) of the pathogen R. solani AG8 and soil organisms putatively associated with disease suppression, and (b) incidence of Rhizoctonia root rot infection of wheat seedlings (% root infected). An increase in microbial biomass carbon (C) following OM amendment indicated a potential for enhanced general biological disease suppression in all soils. OM inputs also increased the population size (DNA) of certain bacteria and fungi putatively associated with specific suppression for Rhizoctonia root rot, suggesting a C resource-mediated change in microbial functions related to disease suppression. There were no significant changes to measured pathogens with stubble addition. However, OM inputs via root residues and rhizodeposits from living roots increased the populations of R. solani AG8 and Gaeumannomyces graminis var. tritici so that in subsequently planted wheat there was greater incidence of root disease infection and reduced plant shoot and root DM compared with that following OM input as stubble. Differences between soils in terms of plant and soil organism responses to each OM input suggest that abiotic factors modify the development of biological disease suppression and the expression of the disease.

scholarly journals Roles of rapH and rapG in Positive Regulation of Rapamycin Biosynthesis in Streptomyces hygroscopicus

2007 ◽  
Vol 189 (13) ◽  
pp. 4756-4763 ◽  
Author(s):  
Enej Kuščer ◽  
Nigel Coates ◽  
Iain Challis ◽  
Matt Gregory ◽  
Barrie Wilkinson ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Antibiotic Production ◽  
Biosynthetic Gene Cluster ◽  
Streptomyces Hygroscopicus ◽  
Reporter System ◽  
Antitumor Activities ◽  
Chalcone Synthase Gene ◽  
Supportive Role ◽  
Pharmacological Potential

ABSTRACT Rapamycin is an important macrocyclic polyketide produced by Streptomyces hygroscopicus and showing immunosuppressive, antifungal, and antitumor activities as well as displaying anti-inflammatory and neuroregenerative properties. The immense pharmacological potential of rapamycin has led to the production of an array of analogues, including through genetic engineering of the rapamycin biosynthetic gene cluster. This cluster contains several putative regulatory genes. Based on DNA sequence analysis, the products of genes rapH and rapG showed high similarities with two different families of transcriptional activators, LAL and AraC, respectively. Overexpression of either gene resulted in a substantial increase in rapamycin biosynthesis, confirming their positive regulatory role, while deletion of both from the chromosome of S. hygroscopicus resulted in a complete loss of antibiotic production. Complementation studies indicated an essential role of the RapG regulator for rapamycin biosynthesis and a supportive role of RapH. A direct effect of rapH and rapG gene products on the promoter of the rapamycin polyketide synthase operon, rapA-rapB, was observed using the chalcone synthase gene rppA as a reporter system.

scholarly journals Synergy of Anaerobic Soil Disinfestation and Trichoderma spp. in Rhizoctonia Root Rot Suppression

2021 ◽  
Vol 5 ◽  
Author(s):  
Ram B. Khadka ◽  
Sally A. Miller
Keyword(s):  
Carbon Source ◽  
Rhizoctonia Solani ◽  
Wheat Bran ◽  
Root Rot ◽  
Carbon Sources ◽  
Chicken Manure ◽  
Treated Soil ◽  
Soil Disinfestation ◽  
Anaerobic Soil Disinfestation ◽  
Rhizoctonia Root Rot

Potential synergy between anaerobic soil disinfestation (ASD) and Trichoderma spp. in suppression of Rhizoctonia root rot in radish was evaluated. A split-plot design with three replications was used; main plots were Trichoderma harzianum T22, Trichoderma asperellum NT25 and a non-Trichoderma control. Subplots were ASD carbon sources wheat bran, molasses, chicken manure, and mustard greens and two non-amended controls: anaerobic (covered and flooded) and aerobic (not covered or flooded). Carbon sources and Rhizoctonia solani inoculant were mixed with soil, placed in pots, and flooded, followed by drenching Trichoderma spore suspensions and sealing the pots in zip-lock bags. After 3 weeks, bags were removed, soil was aired for 1 week and radish “SSR-RR-27” was seeded. Rhizoctonia root rot severity and incidence were lowest in radish plants grown in ASD-treated soil amended with wheat bran, molasses, or mustard greens across all Trichoderma treatments. Disease severity was lower in radish plants treated with NT25 than with T22 or the non-Trichoderma control across all ASD treatments, and in radish grown in ASD-treated soil amended with wheat bran plus NT25 compared to ASD-wheat bran or NT25 alone. Rhizoctonia solani populations were significantly reduced by ASD treatment regardless of carbon source, while Trichoderma populations were not affected by ASD treatment with the exception of ASD-mustard greens. The interactions of either Trichoderma isolate and ASD with most carbon sources were additive, while T22 with ASD-molasses and NT25 with ASD–wheat bran interactions were synergistic in reducing disease severity. One interaction, T22 with ASD-chicken manure was antagonistic. Enhancement of ASD efficacy in suppressing soilborne diseases such as Rhizoctonia root rot by additional soil amendment with Trichoderma spp. during the process appears to be dependent on both Trichoderma isolate and ASD carbon source.

scholarly journals Effect of Organic Inputs and Solarization for the Suppression of Rhizoctonia solani in Woody Ornamental Plant Production

Plants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 138 ◽  
Author(s):  
Fulya Baysal-Gurel ◽  
Md Niamul Kabir ◽  
Prabha Liyanapathiranage
Keyword(s):  
Rhizoctonia Solani ◽  
Cover Crops ◽  
Root Rot ◽  
Plant Production ◽  
Soil Solarization ◽  
Plant Weight ◽  
Rhizoctonia Root Rot ◽  
Compost Amendment ◽  
Flowering Cherry ◽  
Mustard Green

Soilborne diseases are the most economically significant problem faced by Southern region nursery producers. The goal of this research was to improve Rhizoctonia root rot disease management through the use of soil solarization alone and in combination with biofumigant cover crops—arugula ‘Astro’ (Eruca vesicaria ssp. sativa), mustard green ‘Amara’ (Brassica carinata), and turnip ‘Purple top forage’ (B. rapa); good quality compost and mustard meal amendment. The experiments were established as on-farm trials in 2016 and 2017 with prevalent Rhizoctonia solani population in propagation beds. All three biofumigant cover crops, arugula ‘Astro’, mustard green ‘Amara’, and turnip ‘Purple top forage’ in combination with solarization were able to reduce the Rhizoctonia root rot in flowering cherry ‘Kwanzan’ plants in nursery propagation beds. Compost amendment increased the flowering cherry rooted cuttings growth (plant weight, root weight, and plant height) compared to other treatments. Soil solarization in combination with cover crops and organic inputs could be used as part of an integrated approach to manage Rhizoctonia root rot in nursery crop propagation beds.

scholarly journals Transcriptomic evidence for involvement of reactive oxygen species in Rhizoctonia solani AG1 IA sclerotia maturation

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5103 ◽  
Author(s):  
Bo Liu ◽  
Haode Wang ◽  
Zhoujie Ma ◽  
Xiaotong Gai ◽  
Yanqiu Sun ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Disease Control ◽  
Rhizoctonia Solani ◽  
Developmental Stages ◽  
Expression Profiles ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Oxidoreductase Activity ◽  
Sclerotial Formation

Rhizoctonia solani AG1 IA is a soil-borne fungal phytopathogen that can significantly harm crops resulting in economic loss. This species overwinters in grass roots and diseased plants, and produces sclerotia that infect future crops. R. solani AG1 IA does not produce spores; therefore, understanding the molecular mechanism of sclerotia formation is important for crop disease control. To identify the genes involved in this process for the development of disease control targets, the transcriptomes of this species were determined at three important developmental stages (mycelium, sclerotial initiation, and sclerotial maturation) using an RNA-sequencing approach. A total of 5,016, 6,433, and 5,004 differentially expressed genes (DEGs) were identified in the sclerotial initiation vs. mycelial, sclerotial maturation vs. mycelial, and sclerotial maturation vs. sclerotial initiation stages, respectively. Moreover, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses showed that these DEGs were enriched in diverse categories, including oxidoreductase activity, carbohydrate metabolic process, and oxidation-reduction processes. A total of 12 DEGs were further verified using reverse transcription quantitative PCR. Among the genes examined, NADPH oxidase 1 (NOX1) and superoxide dismutase (SOD) were highly induced in the stages of sclerotial initiation and maturation. In addition, the highest reactive oxygen species (ROS) production levels were detected during sclerotial initiation, and enzyme activities of NOX1, SOD, and catalase (CAT) matched with the gene expression profiles. To further evaluate the role of ROS in sclerotial formation, R. solani AG1 IA was treated with the CAT inhibitor aminotriazole and H2O2, resulting in the early differentiation of sclerotia. Taken together, this study provides useful information toward understanding the molecular basis of R. solani AG1 IA sclerotial formation and maturation, and identified the important role of ROS in these processes.

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