Growth and Characteristics of Two Different Epichloë sinensis Strains Under Different Cultures

In the present study, two Epichloë sinensis endophyte strains isolated from different Festuca sinensis ecotypes were inoculated on potato dextrose agar (PDA) and potato dextrose broth (PDB) media with or without (control) exogenous additives. After 4weeks of growth, the growth (colony diameter, hyphal diameter, and mycelial biomass) and other characteristics (pH and antioxidant capacity of culture filtrate, mycelial ion contents, and hormone contents) were measured. The results showed that the culture conditions had significant effects (p<0.05) on the hyphal diameter, mycelial biomass, and hormone content of the two strains. The mycelial biomass of the two strains in PDB was significantly higher (p<0.05) than that on PDA. Except for strain 1 with indole-3-acetic acid (IAA) treatment and strain 84F with control and VB1 treatments, the hyphal diameter of the two strains in PDB under the other treatments was significantly higher (p<0.05) than that on PDA. In most cases, the IAA, cytokinins (CTK), abscisic acid (ABA), and gibberlic acid (GA) contents in the mycelia on PDA of the two strains were significantly higher (p<0.05) than those in PDB. The two E. sinensis strains exhibited significantly different performances (p<0.05) under the five treatments. The indices, including colony diameter, mycelial biomass, scavenging ability of superoxide anion radicals and hydroxyl radicals, pH of culture filtrate, ion contents, hyphal diameter, and IAA, CTK, GA, and ABA contents were significantly different (p<0.05) between the two strains, although the performance was inconsistent. Exogenous additives had significant effects (p<0.05) on the performance of the two E. sinensis strains. Indole-3-acetic acid and VB1 treatments significantly promoted (p<0.05) the growth of the two strains on both PDA and PDB. Indole-3-acetic acid treatment also significantly increased the hyphal diameters of the two strains in PDB (p<0.05). Indole-3-acetic acid and VB1 treatments significantly reduced (p<0.05) the antioxidant ability of these two strains in PDB. NaCl and ZnCl2 treatments had significant inhibitory effects (p<0.05) on fungal growth and promotion effects on the antioxidant ability of the two strains. The treatments also had significant effects (p<0.05) on hyphal diameters and ion and hormone contents, although the effects varied with different indices.

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Effect of Ammonia and Indole-3-acetic Acid Producing Endophytic Klebsiella pneumoniae YNA12 as a Bio-Herbicide for Weed Inhibition: Special Reference with Evening Primroses

Plants ◽

10.3390/plants9060761 ◽

2020 ◽

Vol 9 (6) ◽

pp. 761

Author(s):

Sang-Mo Kang ◽

Saqib Bilal ◽

Raheem Shahzad ◽

Yu-Na Kim ◽

Chang-Wook Park ◽

...

Keyword(s):

Acetic Acid ◽

Klebsiella Pneumoniae ◽

Culture Filtrate ◽

Catalase Activity ◽

Endophytic Bacteria ◽

Germination Rate ◽

Herbicidal Activity ◽

Dependent Manner ◽

Evening Primrose ◽

Indole 3 Acetic Acid

Information on the use of endophytic bacteria as a bio-herbicide for the management of weed control in agricultural fields is limited. The current study aimed to isolate endophytic bacteria from evening primroses and to screen them for their bio-herbicidal activity. Two isolated endophytic bacteria (Pantoea dispersa YNA11 and Klebsiella pneumoniae YNA12) were initially screened for citrate utilization and for indole-3-acetic acid (IAA) and catalase production. The preliminary biochemical assessment showed YNA12 as a positive strain. Ammonia, catalase, and IAA in its culture filtrate were quantified. Gas Chromatography/Mass Spectroscopy- Selective Ion Monitoring (GC/MS-SIM) analysis revealed the production of IAA by YNA12 in a time-dependent manner. YNA12 also exhibited significant ammonia-producing potential and catalase activity against hydrogen peroxide. The YNA12 culture filtrate significantly inhibited the germination rate of evening primrose seeds, resulting in a marked reduction in seedling length and biomass compared with those of the control seeds. Moreover, the culture filtrate of YNA12 significantly accelerated the endogenous abscisic acid (ABA) production and catalase activity of evening primrose seedlings. Macronutrient regulation was adversely affected in the seedlings exposed to the culture filtrate of YNA12, leading to inhibition of seed germination. The current results suggest that endophytic YNA12 may be used as a potent bio-herbicidal agent for controlling weed growth and development.

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Effect of Chitosan on Growth and Toxin Production by Alternaria alternata f. sp. lycopersici

HortScience ◽

10.21273/hortsci.32.3.467f ◽

1997 ◽

Vol 32 (3) ◽

pp. 467F-468 ◽

Cited By ~ 7

Author(s):

M.V. Bhaskara Reddy ◽

Essaid Ait Barka ◽

F. Castaigne ◽

Joseph Arul

Keyword(s):

Culture Filtrate ◽

Alternaria Alternata ◽

Electrolyte Leakage ◽

Fungal Growth ◽

Pectin Methylesterase ◽

Toxin Production ◽

Phospholipid Content ◽

Potato Dextrose Broth ◽

Black Mold ◽

Induced Aggregation

The antifungal activity of chitosan, a bioplymer of β-1-4 gluscosamine, against Alternaria alternata, causal agent of black mold of tomato, was investigated. Chitosan was incorporated into potato dextrose broth (PDB) at concentrations of 100, 200, 400, 800, 1600, 3200, and 6400 μg·ml–1, growth and toxin production by the fungus were assessed after a 15-day incubation period. Chitosan significantly affected both growth and toxin production at higher concentrations. However, at lower concentrations, toxin production was affected more than the growth, as evidenced by minimum inhibitory concentrations (MIC) of chitosan derived for toxin production and mycelial growth. Excess sporulation of the fungus was observed in the presence of chitosan, but the spore viability was affected. Chitosan induced aggregation of fungal cells, abnormal shape, excess branching, and hyphal contortion. It also induced leakage of proteins from the fungal cells. The virulence of the toxin in culture filtrate of the fungus from different concentrations of chitosan was assayed by administering on tomato discs. Phospholipid content, electrolyte leakage, xylanase, and pectin methylesterase activity were measured in the culture filtrate administered tomato tissue. Decreased trend in causing electrolyte leakage, phospholipid degradation, and activation of xylanase and pectin methylesterase were observed with increasing concentrations of chitosan. The results showed that chitosan inhibits fungal growth at higher concentrations than toxin production. Further toxin produced at lower concentrations of chitosan was less virulent. Thus chitosan has potential as an antifungal agent.

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Effect of the ectomycorrhizal fungus Hebeloma hiemale on adventitious root formation in derooted Pinus halepensis shoot hypocotyls

Canadian Journal of Botany ◽

10.1139/b90-161 ◽

1990 ◽

Vol 68 (6) ◽

pp. 1265-1270 ◽

Cited By ~ 23

Author(s):

Gilles Gay

Keyword(s):

Acetic Acid ◽

Ectomycorrhizal Fungi ◽

Culture Filtrate ◽

Root Formation ◽

Pinus Halepensis ◽

Hormonal Treatment ◽

Adventitious Root Formation ◽

Ectomycorrhizal Fungus ◽

Indole 3 Acetic Acid

The effect of the ectomycorrhizal fungus Hebeloma hiemale and of its culture filtrate on in vitro rooting of Pinus halepensis derooted shoot hypocotyls was studied in an attempt to determine if ectomycorrhizal fungi could enhance adventitious root formation in gymnosperms. Pinus halepensis hypocotyls did not root in the absence of hormonal treatment, whereas the rooting percentage was 87.3% in the presence of 5 μM indole-3-acetic acid (IAA). In the presence of tryptophan, which is a precursor of IAA, H. hiemale strongly enhanced rooting of hypocotyls cultivated in the absence of any hormonal treatment. In the presence of 0.1 mM tryptophan, the rooting percentage of the inoculated hypocotyls was 96.6%, whereas it was only 7.6% in the absence of the fungus. Hebeloma hiemale culture filtrate obtained in the absence of tryptophan did not contain IAA and did not stimulate rooting of the hypocotyls. In contrast, a culture filtrate obtained in the presence of tryptophan contained IAA; an ethyl acetate extract from this filtrate allowed 100% rooting. Different fractions were isolated by preparative thin-layer chromatography from the IAA-containing filtrate and studied for their effect on rooting. It was demonstrated that IAA was responsible for the rhizogenic activity of H. hiemale. These results suggest that ectomycorrhizal fungi which rapidly metabolize exogenously supplied tryptophan to IAA could be a suitable tool to enhance in vitro rooting of micropropagated gymnosperms. Key words: ectomycorrhizal fungus, indole-3-acetic acid, rooting, shoot hypocotyl, Hebeloma hiemale, Pinus halepensis.

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Phytohormone Production Profiles in Trichoderma Species and Their Relationship to Wheat Plant Responses to Water Stress

Pathogens ◽

10.3390/pathogens10080991 ◽

2021 ◽

Vol 10 (8) ◽

pp. 991

Author(s):

María Illescas ◽

Alberto Pedrero-Méndez ◽

Marcieli Pitorini-Bovolini ◽

Rosa Hermosa ◽

Enrique Monte

Keyword(s):

Water Stress ◽

Antioxidant Activities ◽

Fungal Growth ◽

Acc Deaminase ◽

Wheat Plant ◽

Wheat Root ◽

Plant Responses ◽

Trichoderma Species ◽

Potato Dextrose Broth ◽

Indole 3 Acetic Acid

The production of eight phytohormones by Trichoderma species is described, as well as the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (ACCD) activity, which diverts the ethylene biosynthetic pathway in plants. The use of the Trichoderma strains T. virens T49, T. longibrachiatum T68, T. spirale T75 and T. harzianum T115 served to demonstrate the diverse production of the phytohormones gibberellins (GA) GA1 and GA4, abscisic acid (ABA), salicylic acid (SA), auxin (indole-3-acetic acid: IAA) and the cytokinins (CK) dihydrozeatin (DHZ), isopenteniladenine (iP) and trans-zeatin (tZ) in this genus. Such production is dependent on strain and/or culture medium. These four strains showed different degrees of wheat root colonization. Fresh and dry weights, conductance, H2O2 content and antioxidant activities such as superoxide dismutase, peroxidase and catalase were analyzed, under optimal irrigation and water stress conditions, on 30-days-old wheat plants treated with four-day-old Trichoderma cultures, obtained from potato dextrose broth (PDB) and PDB-tryptophan (Trp). The application of Trichoderma PDB cultures to wheat plants could be linked to the plants’ ability to adapt the antioxidant machinery and to tolerate water stress. Plants treated with PDB cultures of T49 and T115 had the significantly highest weights under water stress. Compared to controls, treatments with strains T68 and T75, with constrained GA1 and GA4 production, resulted in smaller plants regardless of fungal growth medium and irrigation regime.

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