Siderophore isolation and its Biocontrol action against Rice Fungal Pathogens (original) (raw)
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Fifteen rhizobacterial fluorescent pseudomonas isolates obtained from rice in the region of Andhra Pradesh, India In all 10 strains of Pseudomonas fluorescens were selected based on preliminary screening of all these isolates for antifungal activity against rice fungal pathogens (P.oryzae and R.solani)., inhibited the growth of rice fungal pathogens in Fe deficient King's B medium that varied from (3 to 58 % inhibition). Among these Pf 003 strain completely inhibited the mycelial growth of two rice pathogens (P.oryzae and R.solani) both in presence and absence of FeCl 3 which indicated the siderophore mediation along with antifungal metabolites.
World Journal of Microbiology and Biotechnology, 2009
Rice (Oryza sativa) is a staple food in Thailand and, in addition, feeds around one half of the world's population. Therefore, diseases of rice are of special concern. Rice is destroyed by 2 main pathogens, Fusarium oxysporum and Pyricularia oryzae the causative agents of root rot and blast in rice respectively. These pathogens result in low grain yield in Thailand and other Southeast Asian countries. Soil samples were taken from paddy fields in Northern Thailand and bacteria were isolated using the soil dilution plate method on Nutrient agar. Isolation yielded 216 bacterial isolates which were subsequently tested for their siderophore production and effectiveness in inhibiting mycelial growth in vitro of the rice pathogenic fungi; Alternaria sp., Fusarium oxysporum, Pyricularia oryzae and Sclerotium sp., the causal agent of leaf spot, root rot, blast and stem rot in rice. It was found that 23% of the bacteria isolated produced siderophore on solid plating medium and liquid medium, In dual culture technique, the siderophore producing rhizobacteria showed a strong antagonistic effect against the Alternaria (35.4%), Fusarium oxysporum (37.5%), Pyricularia oryzae (31.2%) and Sclerotium sp. (10.4%) strains tested. Streptomyces sp. strain A 130 and Pseudomonas sp. strain MW 2.6 in particular showed a significant higher antagonistic effect against Alternaria sp. while Ochrobactrum anthropi D 5.2 exhibited a good antagonistic effect against F. oxysporum. Bacillus firmus D 4.1 inhibited P. oryzae and Kocuria rhizophila 4(2.1.1) strongly inhibited Sclerotium sp. P. aureofaciens AR 1 was the best siderophore producer overall and secreted hydroxamate type siderophore. This strain exhibits an in vitro antagonistic effect against Alternaria sp., F. oxysporum and P. oryzae. Siderophore production in this isolate was maximal after 15 days and at an optimal temperature of 30°C, yielding 99.96 ± 0.46 lg ml-1 of siderophore. The most effective isolates were identified by biochemical tests and molecular techniques as members of the Genus Bacillus, Pseudomonas and Kocuria including B. firmus D 4.1, P. aureofaciens AR1 and Kocuria rhizophila 4(2.1.1). The study demonstrated antagonistic activity towards the target pathogens discussed and are thus potential agents for biocontrol of soil borne diseases of rice in Thailand and other countries.
2011
Out of 74 isolates, only 29 (39.2%) diazotrophic rhizobacterial isolates showed siderophore production by CAS (chrome azurol S) plate assay. Optimum siderophore production was recorded after 72 h of growth with 2 mM of FeCl 3 at 30 o C temperature in shaking condition in JNFbliquid medium. The amount of siderophore produced by these isolates ranged between 1.45 to 22.22 µg/mg dry weights. 15 (51.7%) isolates were catecholate and 14 (48.3%) were hydroxamate type. TLC analysis of catecholate type siderophores revealed that only 13.8% was exactly similar to 2, 3dihydroxybenzoic acid (DHBA) whereas 86.2 % showed more than one type of siderophores or other catecholate siderophore with varying molecular weights. The siderophore production under 5.0% NaCl stress by Agrobacterium sp. strain BN-2A is the first report.
International Journal of Agriculture, Environment and Biotechnology, 2014
The Pseudomonas fluorescent a major Rhizobacteria encourage the plant growth through producing yellowish green fluroscent siderophore involve in high affinity transport of iron into the cell. The P. fluorescent isolates grow in iron deficient media because of production capacity of siderophore depends on iron content. Fifty nine Pseudomonas fluorescens were isolated in King's B media under 260 nm wavelengths from the rhizosphere and non-rhizospheric soil of cave, forest, fellow land and agriculture field in Chhattisgarh region. The amounts of siderophore produce by P. fluorescent isolates were screen in iron deficient succinate media and most of them were found positive for the production of much siderophores. One of the isolate from Pakhanjore area "P3" produce highest siderophore, which further assessed for plant growth promotion activities of crops rice, urd, mung and arhar. The study showed significantly higher increase in root length over control plants was observed in Rice (68.45%) followed by Urd (40.1%), Mung (33.71%) and Arhar (29.53%). Similarly, significantly higher increase in shoot length over control plants was observed in Rice (68.925%) followed by Urd (43.42%), Mung (39.96%) and Arhar (19.45%). It has been shown that these bacteria competively colonize plant roots and cause the plant statistically significant root and shoot increases by stimulating plant growth and reduce the incidence of plant disease of above mention crops under green house of tray culture conditions. Highlights • There were 59 isolates of pseudomonas fluorescent isolated from rhizosphere and non-rhizospheric soil. • P. fluorescent isolates were screen in iron deficient succinate media for amount of siderophore production. • One of isolate highest siderophore producing further assessed for PGPA. • The study showed significantly higher increase in shoot length and root length by P. fluorescent
2011
The study was made to detect and identify antagonistic bacteria to control Rhizoctonia solani, a causal organism of sheath blight (ShB) disease of rice. Isolation of antagonistic bacteria was done from ShB infected rice leaf collected from the districts of Gazipur, Rajshahi, Bogra and Comilla. Fifty isolates of bacteria were isolated. These isolates were tested for antagonism against ShB pathogen of in PDA medium. Among the isolates of antagonistic bacteria (both fluorescent and non fluorescent), eleven produced more than 15 mm inhibition zone, were selected for this study. Remarkable inhibition zone producing ten isolates were selected to observe their antagonistic behaviour by soaking the sclerotia of Rhizoctonia solani and rice seedlings in different hours into bacterial suspension of 3.84 x 10 7 CFU/ml. Both the in vitro and in vivo rom showed that the sclerotial germination and sheath blight symptom expression were delayed 6-9 days. Soaking of both seedlings and sclerotia with the test bacteria was found most effective to control ShB (38%-100%) than soaking of seedlings alone with bacterial suspension at different hours. However, BanShbFPS5 (2)B, BanShb738(3), BanShb738(2) and BanShb581(1), the four antagonistic bacterial isolates could be applied as biological agent to control sheath blight disease of rice and they could control sheath blight disease development and could delay the epidemics of the disease.
International Journal of Advanced Research, 2020
Rice is a staple crop for a large part of the world population including Vietnam. Although its export is ranged of second place over the world just after Thailand, rice production in Vietnam is challenging by various issues. The most significant is application of agrochemicals, which are not eco-friendly, leading to side effects on the ecosystem and human health. Endophytic bacteria (EB) possess different beneficial traits such as Plant Growth Promoting (PGP) and antagonistic activities against plant pathogens. In this study, a collection of 150 EB strains have been isolated from upland rice roots grown on the mountain-farm in the Tung village, Nam Co commune, Mu Cang Chai district, Yen Bai province, Vietnam. 119/150 isolates showed siderophoreproduction ability including 12 isolates showed the halo orange zone surrounding colonies of 1 – 10 mm in diameter (Dh), considering them as low level of siderophore production, 80 strains exhibited the moderate activity, Dh of 11 – ...
Dynamics, Diversity and Function of Endophytic Siderophore-Producing Bacteria in Rice
Microbial Ecology, 2011
Siderophore production confers to bacteria competitive advantages to colonize plant tissues and to exclude other microorganisms from the same ecological niche. This work shows that the community of endophytic siderophoreproducing bacteria (SPB) associated to Oryza sativa cultivated in Uruguayan soils is dynamic and diverse. These bacteria were present in grains, roots, and leaves, and their density fluctuated between log 10 3.44 and log 10 5.52 cfu g −1 fresh weight (fw) during the plant growth. Less than 10% of the heterotrophic bacteria produced siderophores in roots and leaves of young plants, but most of the heterotrophic bacteria were siderophore-producers in mature plants. According to their amplified restriction DNA ribosomal analysis (ARDRA) pattern, 54 of the 109 endophytic SPB isolated from different plant tissues or growth stages from replicate plots, were unique. Bacteria belonging to the genera Sphingomonas, Pseudomonas, Burkholderia, and Enterobacter alternated during plant growth, but the genus Pantoea was predominant in roots at tillering and in leaves at subsequent stages. Pantoea ananatis was the SPB permanently associated to any of the plant tissues, but the genetic diversity within this speciesrevealed by BOX-PCR fingerprinting-showed that different strains were randomly distributed along time and plant tissue, suggesting that a common trait of the species P. ananatis determined the interaction with the rice plant. Several isolates were stronger IAA producers than Azospirillum brasilense or Herbaspirillum seropedicae. In vitro inhibition assays showed that SPB of the genus Burkholderia were good antagonists of pathogenic fungi and that only one SPB isolate of the genus Pseudomonas was able to inhibit A. brasilense and H. seropedicae. These results denoted that SPB were selected into the rice plant. P. ananatis was the permanent and dominant associated species which was unable to inhibit two of the relevant plant growth-promoting bacteria.
African Journal of Microbiology Research, 2012
A set of 28 Pseudomonas bacterial strains were examined for siderophore production by chrome azurol sulphonate (CAS) assay. Among the 28 strains tested, 14 were found to be siderophore producers. These strains were evaluated for their biocontrol potential against Rhizoctonia solani using various dual culture assays. The role of siderophores in the inhibition of R. solani was confirmed by iron chloride (FeCl 3) experiment. The eight strains that showed best antagonism were found to have the potential of nitrogen fixation, phosphate solubilization, indole acetic acid, hydrolytic enzymes, hydrogen cyanide and antibiotics production. Spectrochemical analysis of siderophores indicated that all the bacterial strains produce catecholate siderophores. Our data demonstrated that bacterial strain Mst 8.2 produces more than one antifungal agents but the siderophore production is the key mechanism involved in the antagonism. Bacterial strains MS-3y, Mst 8.2 and Mst 7.4 were the most effective with more than 70% disease reduction in plant growth of wheat. The complete 16S rRNA gene sequence analysis demonstrated that Mst 8.2 is a Pseudomonas fluorescens strain. In conclusion, Mst 8.2 with its multi-mechanisms of defense has excellent potential to be used as successful biocontrol agent against R. solani root rot disease in wheat.
Siderophore producing Pseudomonas as pathogenic Rhisoctonia solani and Botrytis cinerea antagonists
Pseudomonas aeruginosa, Pseudomonas putida biovar B, Pseudomonas marginalis y Burkholderia cepacia, aisladas de rizosfera y filosfera de plantas de rosa y alstroemeria, identificadas por ensayos bioquímicos y cultivadas en medio King B, mostraron propiedades antagónicas contra los patógenos (se usó medio PDA agar par el cultivo) Rhizoctonia solani y Botrytis cinerea. Estas propiedades coincidieron con la presencia de un sideróforo, sustancia polar con bandas de absorción en 260 nm y 402 nm. Se observó incremento del crecimiento longitudinal de las plantas, medido sobre el tallo central, por influencia de P. putida biovar B, P. aeruginosa y P. marginalis. El crecimiento de rizomas (a: 0.05) fue notorio bajo la influencia de P. marginalis.