Prospecting Endophytic Bacteria Endowed With Plant Growth Promoting Potential Isolated From Camellia sinensis

Endophytes are well-acknowledged inoculants to promote plant growth, and extensive research has been done in different plants. However, there is a lacuna about the endophytes associated with tea clones and their benefit to promote plant growth. The present study focuses on isolating and characterizing the beneficial endophytic bacteria (EnB) prevalent in commercially important tea clones cultivated in North Eastern India as plant growth promoters. Diversity of culturable EnB microbiome, in vitro traits for plant growth promotion (PGP), and applicability of potent isolates as bioinoculant for in vivo PGP abilities have been assessed in the present study. A total of 106 EnB identified as members of phyla Proteobacteria, Firmicutes, and Actinobacteria were related to 22 different genera and six major clusters. Regarding PGP traits, the percentage of isolates positive for the production of indole acetic acid, phosphate solubilization, nitrogen fixation siderophore, ammonia, and 1-aminocyclopropane-1-carboxylic acid deaminase production were 86.8, 28.3, 78.3, 30.2, 95.3, and 87.7, respectively. In total, 34.0, 52.8, and 17.0% of EnB showed notable production of hydrolytic enzymes like cellulase, protease, and amylase, respectively. Additionally, based on the bonitur score, the top two isolates K96 identified as Stenotrophomonas sp. and M45 identified as Pseudomonas sp. were evaluated for biofilm formation, motility, and in vivo plant growth promoting activity. Results suggested strong biofilm formation and motility in K96 and M45 which may attribute to the colonization of the strains in the plants. Further in vivo plant growth promotion experiment suggested sturdy efficacy of the K96 and M45 as plant growth promoters in nursery condition in commercial tea clones Tocklai vegetative (TV) TV22 and TV26. Thus, this study emphasizes the opportunity of commercialization of the selected isolates for sustainable development of tea and other crops.

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Isolation and selection of plant growth-promoting bacteria associated with sugarcane

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632016v4639526 ◽

2016 ◽

Vol 46 (2) ◽

pp. 149-158 ◽

Cited By ~ 19

Author(s):

Ariana Alves Rodrigues ◽

Marcus Vinicius Forzani ◽

Renan de Souza Soares ◽

Sergio Tadeu Sibov ◽

José Daniel Gonçalves Vieira

Keyword(s):

Plant Growth ◽

Growth Promotion ◽

Vital Role ◽

Plant Growth Promoting Bacteria ◽

Biotic And Abiotic Stress ◽

Phosphate Solubilizers ◽

Chitinase A ◽

Plant Growth Promoting ◽

Promote Plant Growth ◽

Growth Promoting

ABSTRACT Microorganisms play a vital role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study aimed at isolating and characterizing plant growth-promoting bacteria associated with sugarcane, as well as assessing their ability to promote plant growth. Endophytic bacteria from leaf, stem, root and rhizosphere were isolated from the RB 867515 commercial sugarcane variety and screened for indole acetic acid (IAA) production, ability to solubilize phosphate, fix nitrogen and produce hydrogen cyanide (HCN), ammonia and the enzymes pectinase, cellulase and chitinase. A total of 136 bacteria were isolated, with 83 of them presenting some plant growth mechanism: 47 % phosphate solubilizers, 26 % nitrogen fixers and 57 % producing IAA, 0.7 % HCN and chitinase, 45 % ammonia, 30 % cellulose and 8 % pectinase. The seven best isolates were tested for their ability to promote plant growth in maize. The isolates tested for plant growth promotion belong to the Enterobacteriaceae family and the Klebsiella, Enterobacter and Pantoea genera. Five isolates promoted plant growth in greenhouse experiments, showing potential as biofertilizers.

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Characterization of bacterial endophytes from the roots of native and cultivated Brazil nut trees (Bertholletia excelsa)

Acta Amazonica ◽

10.1590/1809-4392201804831 ◽

2019 ◽

Vol 49 (4) ◽

pp. 257-267

Author(s):

Patrícia Bombonati CHALITA ◽

Eliane do Nascimento Cunha FARIAS ◽

Ismaele Breckenfeld da COSTA ◽

Brenda Ferreira SOUSA ◽

Marco Antônio Oliveira dos SANTOS ◽

...

Keyword(s):

Plant Growth ◽

Plant Growth Promotion ◽

Endophytic Bacteria ◽

Growth Promotion ◽

Nifh Gene ◽

Aluminum Phosphate ◽

Brazil Nut ◽

Indole Compounds ◽

Plant Growth Promoting ◽

Growth Promoting

ABSTRACT Brazil nut is a very important nontimber forest product in the Amazon region. Propagation of this tree still represents a challenge due to slow and uneven seed germination. In this context, plant growth-promoting bacteria can facilitate the process of propagation. The aims of this study were to isolate and characterize endophytic bacteria from the roots of Brazil nut trees in native terra firme forest and cultivation areas in northern Brazil, and to identify mechanisms by which bacteria act in plant growth promotion. Overall, 90 bacterial isolates were obtained from the roots of Brazil nut trees in monoculture, agroforestry and native forest areas by using different semisolid media. The isolates were characterized by sequencing the 16S rRNA gene. Plant growth-promoting characteristics were evaluated by the presence of the nifH gene, aluminum phosphate solubilization and the production of indole compounds. The isolates were affiliated with 18 genera belonging to 5 different classes (α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Bacilli and Actinobacteria). The genus Bacillus was predominant in the forest and monoculture areas. Fourteen isolates presented the nifH gene. Most of the bacteria were able to solubilize aluminum phosphate and synthetize indole compounds. The results indicated high diversity of endophytic bacteria present among the roots of Brazil nut trees, mainly in the agroforestry area, which could be related to soil attributes. Among the 90 isolates, the 22 that presented the best results regarding plant growth promotion traits were good candidates for testing in seedling production of Brazil nut trees.

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Plant growth promoting endophyte Burkholderia contaminans NZ antagonizes phytopathogen Macrophomina phaseolina through melanin synthesis and pyrrolnitrin inhibition

PLoS ONE ◽

10.1371/journal.pone.0257863 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0257863

Author(s):

Nazia R. Zaman ◽

Umar F. Chowdhury ◽

Rifath N. Reza ◽

Farhana T. Chowdhury ◽

Mrinmoy Sarker ◽

...

Keyword(s):

Plant Growth ◽

Growth Promotion ◽

Genome Mining ◽

Gene Clusters ◽

Macrophomina Phaseolina ◽

Melanin Synthesis ◽

Burkholderia Contaminans ◽

Plant Growth Promoting ◽

Growth Promoting

The endophytic bacterium Burkholderia contaminans NZ was isolated from jute, which is an important fiber-producing plant. This bacterium exhibits significant growth promotion activity in in vivo pot experiments, and like other plant growth-promoting (PGP) bacteria fixes nitrogen, produces indole acetic acid (IAA), siderophore, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. B. contaminans NZ is considered to exert a promising growth inhibitory effect on Macrophomina phaseolina, a phytopathogen responsible for infecting hundreds of crops worldwide. This study aimed to identify the possibility of B. contaminans NZ as a safe biocontrol agent and assess its effectiveness in suppressing phytopathogenic fungi, especially M. phaseolina. Co-culture of M. phaseolina with B. contaminans NZ on both solid and liquid media revealed appreciable growth suppression of M. phaseolina and its chromogenic aberration in liquid culture. Genome mining of B. contaminans NZ using NaPDoS and antiSMASH revealed gene clusters that displayed 100% similarity for cytotoxic and antifungal substances, such as pyrrolnitrin. GC-MS analysis of B. contaminans NZ culture extracts revealed various bioactive compounds, including catechol; 9,10-dihydro-12’-hydroxy-2’-methyl-5’-(phenylmethyl)- ergotaman 3’,6’,18-trione; 2,3-dihydro-3,5- dihydroxy-6-methyl-4H-pyran-4-one; 1-(1,6-Dioxooctadecyl)- pyrrolidine; 9-Octadecenamide; and 2- methoxy- phenol. These compounds reportedly exhibit tyrosinase inhibitory, antifungal, and antibiotic activities. Using a more targeted approach, an RP-HPLC purified fraction was analyzed by LC-MS, confirming the existence of pyrrolnitrin in the B. contaminans NZ extract. Secondary metabolites, such as catechol and ergotaman, have been predicted to inhibit melanin synthesis in M. phaseolina. Thus, B. contaminans NZ appears to inhibit phytopathogens by apparently impairing melanin synthesis and other potential biochemical pathways, exhibiting considerable fungistatic activity.

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Enhancement of verticillium wilt resistance in tomato transplants by in vitro co-culture of seedlings with a plant growth promoting rhizobacterium (Pseudomonas sp. strain PsJN)

Canadian Journal of Microbiology ◽

10.1139/w98-017 ◽

1998 ◽

Vol 44 (6) ◽

pp. 528-536 ◽

Cited By ~ 67

Author(s):

V K Sharma ◽

J Nowak

Keyword(s):

Plant Growth ◽

Verticillium Wilt ◽

Plant Growth Promotion ◽

Growth Promotion ◽

Disease Suppression ◽

Pseudomonas Sp ◽

Plant Growth Promoting ◽

Growth Promoting

The potential utilization of a plant growth promoting rhizobacterium, Pseudomonas sp. strain PsJN, to enhance the resistance of tomato transplants to verticillium wilt was investigated. Plant growth and disease development were tested on the disease-susceptible cultivar Bonny Best after Verticillium dahliae infection of tissue culture plantlets bacterized in vitro (by co-culturing with the bacterium) and seedlings bacterized in vivo (after 3 weeks growth in the greenhouse). Significant differences in both disease suppression and plant growth were obtained between in vitro bacterized and nonbacterized (control) plants. The degree of protection afforded by in vitro bacterization depended on the inoculum density of V. dahliae; the best and worst protection occurred at the lowest (103 conidia ·mL-1) and highest (106 conidia ·mL-1) levels, respectively. In contrast, the in vivo bacterized tomatoes did not show plant growth promotion when compared to the nonbacterized control plants. When challenged with Verticillium, significant growth differences between in vivo bacterized plants (26.8% for shoot height) and nonbacterized controls were only seen at the 3rd week after inoculation. Compared with the in vitro inoculation, there was no delay in the verticillium wilt symptom expression, even at the lowest concentration of V. dahliae, by in vivo PsJN inoculation. These results suggest that endophytic colonization of tomato tissues is required for the Verticillium-resistance responses. Plant growth promotion preceeds the disease-resistance responses and may depend on the colonization thresholds and subsequent sensitization of hosts.Key words: Pseudomonas sp., plant growth promoting rhizobacterium, Verticillium dahliae, tomato, colonization, plant growth promotion, disease suppression.

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Sterile fungi from zoysiagrass rhizosphere as plant growth promoters in spring wheat

Canadian Journal of Microbiology ◽

10.1139/m94-101 ◽

1994 ◽

Vol 40 (8) ◽

pp. 637-644 ◽

Cited By ~ 46

Author(s):

Manchanahally B. Shivanna ◽

Manchanahally S. Meera ◽

Mitsuro Hyakumachi

Keyword(s):

Plant Growth ◽

Yield Components ◽

Growth Promotion ◽

Wheat Variety ◽

Field Conditions ◽

Growth Promoters ◽

Wheat Varieties ◽

Trichoderma Species ◽

Plant Growth Promoting ◽

Growth Promoting

Eleven out of 18 sterile fungal isolates and an isolate each of Penicillium sp. and Trichoderma sp. from the zoysiagrass rhizosphere were effective in enhancing the growth of two wheat varieties in greenhouse conditions. They enhanced the top length and top dry biomass of plants significantly and induced the plants to produce long earheads and more seeds. Notable among isolates were GS6-1, GS6-2, GS7-3, GS7-4, GS8-6, GS10-1, GS10-2, and GU23-3, which enhanced the growth by several times, resulting in a conspicuous growth promotion effect that differed depending on the variety. Penicillium and Trichoderma species were less effective than sterile isolates in enhancing growth. Seven of the 11 effective sterile isolates from the zoysiagrass rhizosphere (as determined under greenhouse conditions) and a wheat rhizosphere isolate (K-17) were further tested under field conditions. Most of the isolates except K-17 enhanced the growth of one variety, whereas a few isolates enhanced the growth of the other variety. However, at least four isolates each increased yields of both varieties. Isolate GS6-1, which was very effective under greenhouse conditions in promoting overall growth, was less effective under field conditions; however, the yield components were not affected. The efficiency of the plant growth promoting isolates depended upon the wheat variety and soil nutrient conditions in addition to their inherent growth promotion abilities.Key words: plant growth promoting fungi (PGPF), sterile fungi, wheat growth promotion, yield components.

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Endophytic bacteria associated with rice roots from suboptimal land as plant growth promoters

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d220153 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Nur Prihatiningsih ◽

HERU ADI DJATMIKO ◽

PUJI LESTARI

Keyword(s):

Plant Growth ◽

Plant Height ◽

Incubation Period ◽

Infection Rate ◽

Endophytic Bacteria ◽

Plant Protection ◽

Growth Promoters ◽

Rice Roots ◽

Plant Growth Promoters ◽

Promote Plant Growth

Abstract. Prihatiningsih N, Djatmiko HA, Lestari P. 2021. Endophytic bacteria associated with rice roots from suboptimal land as plant growth promoters. Biodiversitas 22: 432-437. Endophytic bacteria directly promoted plant growth and undirectly control the pathogens. This research was aimed to evaluate endophytic bacteria associated with rice root and their activity to promote plant growth and to control rice diseases. The study was conducted at the Laboratorium of Plant Protection and experimental farm Faculty of Agriculture Jenderal Soedirman University, from April to August 2020. The endophytic bacterial from suboptimal land were evaluated for promoting plant growth with soaking seed before seedling and spraying them at 10, 20, and 30 days after transplanting. The experiment was arranged with six replications and four treatments namely control (untreated endophytic bacteria) SM1 (endophytic bacteria isolate from Somagede); SB1 and SB3 (from Sumbang). Xanthomonas oyzae pv. oryzae was nature inoculation because the experiment location is in the endemic category of bacterial leaf blight. The variables observed were the plant growth components i.e plant height, number of tillers, number of panicles, incubation period, disease intensity, infection rate and effectiveness control. The result of this research shows that endophytic bacteria from Somagede (SM1) is the best to enhance plant height and number of tillers, and suppress disease intensity, and delay of incubation period.

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Rhizobacteria Associated with a Native Solanaceae Promote Plant Growth and Decrease the Effects of Fusariumoxysporum in Tomato

Agronomy ◽

10.3390/agronomy11030579 ◽

2021 ◽

Vol 11 (3) ◽

pp. 579

Author(s):

Carmen Sanjuana Delgado-Ramírez ◽

Rufina Hernández-Martínez ◽

Edgardo Sepúlveda

Keyword(s):

Plant Growth ◽

Fusarium Wilt ◽

Growth Promotion ◽

Plant Growth Promoting Rhizobacteria ◽

Positive Effects ◽

Alternative Approach ◽

Plant Growth Promoting ◽

Promote Plant Growth ◽

Growth Promoting

Plant growth-promoting rhizobacteria are often utilized to improve crop health and productivity. Nevertheless, their positive effects can be hindered if they fail to withstand the environmental and ecological conditions of the regions where they are applied. An alternative approach to circumvent this problem is a tailored selection of bacteria for specific agricultural systems. In this work, we evaluated the plant growth promoting and pathogen inhibition activity of rhizobacteria obtained from the rhizosphere of Mariola (Solanum hindsianum), an endemic shrub from Baja California. Eight strains were capable of inhibiting Fusarium oxysporum in vitro, and thirteen strains were found to possess three or more plant-growth-promotion traits. Molecular identification of these strains, using 16 s rRNA partial sequences, identified them as belonging to the genera Arthrobacter, Bacillus, Paenibacillus, Pseudomonas, and Streptomyces. Finally, the effect of selected plant growth-promoting rhizobacteria (PGPR) strains on the growth and suppression of Fusarium wilt in tomato was evaluated. Results showed that these strains improved tomato plants growth under greenhouse conditions and reduced Fusarium wilt effects, as reflected in several variables such as length and weight of roots and stem. This work highlights the potential of native plants related to regionally important crops as a valuable source of beneficial bacteria.

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ENDOPHYTIC BACTERIA USED AS BIOINOCULANTS IN MICROPROPAGATED BANANA SEEDLINGS

Revista Brasileira de Fruticultura ◽

10.1590/0100-29452017324 ◽

2017 ◽

Vol 39 (2) ◽

Author(s):

GLEIKA LARISSE OLIVEIRA DORASIO DE SOUZA ◽

DEIVISSON FERREIRA DA SILVA ◽

SILVIA NIETSCHE ◽

ADELICA APARECIDA XAVIER ◽

MARLON CRISTIAN TOLEDO PEREIRA

Keyword(s):

Plant Growth ◽

Endophytic Bacteria ◽

Plant Growth Promoting Bacteria ◽

Bacillus Sp ◽

Microbial Inoculants ◽

Plant Growth Promoting ◽

Promote Plant Growth ◽

Growth Promoting ◽

Indole 3 Acetic Acid

ABSTRACT The use of bio-fertilizers and microbial inoculants that promote plant growth and increased yield has been accepted as an alternative to reduce the use of chemical fertilizers. The objective of the present study was to evaluate the effect of plant growth promoting bacteria inoculation on growth and quality of micropropagated banana seedlings ‘Prata Anã’. The experimental design was completely randomized, with four replications and the treatments consisted of 24 isolates of endophytic bacteria. The isolates EB-50 (Bacillus sp.) and EB-133 (Bacillus amyloliquefaciens) characterized as diazotrophic, the EB-51 (Bacillus pumilus) indicate for inorganic phosphate solubilization and EB-55(Bacillus subtilis) and EB-40 (Bacillus sp.) indole-3-acetic acid producers have provided significant increases for length, pseudostem diameter, fresh masses and dry masses in ‘Prata Anã’ micropropagated banana seedlings.

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Silencing of Phytopathogen Communication by the Halotolerant PGPR Staphylococcus Equorum Strain EN21

Microorganisms ◽

10.3390/microorganisms8010042 ◽

2019 ◽

Vol 8 (1) ◽

pp. 42

Author(s):

Clara Vega ◽

Miguel Rodríguez ◽

Inmaculada Llamas ◽

Victoria Béjar ◽

Inmaculada Sampedro

Keyword(s):

Plant Growth ◽

Pseudomonas Syringae ◽

Plant Growth Promotion ◽

Crop Production ◽

Growth Promotion ◽

Signal Molecules ◽

Staphylococcus Equorum ◽

Plant Growth Promoting ◽

Growth Promoting

Increasing world food demand together with soil erosion and indiscriminate use of chemical fertilization highlight the need to adopt sustainable crop production strategies. In this context, a combination of plant growth-promoting rhizobacteria (PGPR) and pathogen management represents a sustainable and efficient alternative. Though little studied, halophilic and halotolerant PGPR could be a beneficial plant growth promotion strategy for saline and non-saline soils. The virulence of many bacterial phytopathogens is regulated by quorum sensing (QS) systems. Quorum quenching (QQ) involves the enzymatic degradation of phytopathogen-generated signal molecules, mainly N-acyl homoserine lactones (AHLs). In this study, we investigate plant growth-promoting (PGP) activity and the capacity of the halotolerant bacterium Staphylococcus equorum strain EN21 to attenuate phytopathogens virulence through QQ. We used biopriming and in vivo tomato plant experiments to analyse the PGP activity of strain EN21. AHL inactivation was observed to reduce Pseudomonas syringae pv. tomato infections in tomato and Arabidopsis plants. Our study of Dickeya solani, Pectobacterium carotovorum subsp. carotovorum and Erwinia amylovora bacteria in potato tubers, carrots and pears, respectively, also demonstrated the effectiveness of QS interruption by EN21. Overall, this study highlights the potential of strain S. equorum EN21 in plant growth promotion and QQ-driven bacterial phytopathogen biocontrol.

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Photoperiod regulates elicitation of growth promotion but not induced resistance by plant growth-promoting rhizobacteria

Canadian Journal of Microbiology ◽

10.1139/w06-114 ◽

2007 ◽

Vol 53 (2) ◽

pp. 159-167 ◽

Cited By ~ 52

Author(s):

J.W. Kloepper ◽

A. Gutiérrez-Estrada ◽

J.A. McInroy

Keyword(s):

Plant Growth ◽

Induced Resistance ◽

Growth Promotion ◽

Plant Growth Promoting Rhizobacteria ◽

Systemic Resistance ◽

Plant Growth Promoting ◽

Promote Plant Growth ◽

Growth Promoting ◽

Leachate Quality ◽

Shoot Mass

For several years, we have noticed that plant growth-promoting rhizobacteria (PGPR), which consistently promote plant growth in greenhouse tests during spring, summer, and fall, fail to elicit plant growth promotion during the midwinter under ambient light conditions. This report tests the hypothesis that photoperiod regulates elicitation of growth promotion and induced systemic resistance (ISR) by PGPR. A commercially available formulation of PGPR strains Bacillus subtilis GB03 and Bacillus amyloliquefaciens IN937a (BioYield®) was used to grow tomato and pepper transplants under short-day (8 h of light) (SD) and long-day (12 h of light) (LD) conditions. Results of many experiments indicated that under LD conditions, BioYield consistently elicited significant increases in root and shoot mass as well as in several parameters of root architecture. However, under SD conditions, such increases were not elicited. Differential root colonization of plants grown under LD and SD conditions and changes in leachate quality partially account for these results. BioYield elicited ISR in tomato and pepper under both LD and SD conditions, indicating that although growth promotion was not elicited under SD conditions, induced resistance was. Overall, the results indicate that PGPR-mediated growth promotion is regulated by photoperiod, while ISR is not.

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