Purification and in vitro activities of a chitinase-modifying protein from the corn ear rot pathogen Stenocarpella maydis

2019 ◽  
Vol 106 ◽  
pp. 74-80 ◽  
Author(s):  
Todd A. Naumann ◽  
Neil P.J. Price
Keyword(s):  
Ear Rot ◽  
Stenocarpella Maydis

scholarly journals Essential oils on the control of stem and ear rot in maize

2013 ◽  
Vol 43 (11) ◽  
pp. 1945-1951 ◽  
Author(s):  
Glauco Antonio Teixeira ◽  
Eduardo Alves ◽  
Douglas Carvalho Amaral ◽  
José da Cruz Machado ◽  
Fabiano José Perina
Keyword(s):  
Essential Oils ◽  
Thymus Vulgaris ◽  
Environmental Damage ◽  
Syzygium Aromaticum ◽  
Ear Rot ◽  
Maize Production ◽  
Maize Seeds ◽  
Corymbia Citriodora ◽  
Stenocarpella Maydis

Stem and ear rot caused by Stenocarpella maydis are responsible for severe losses in maize production. Treatment of seeds with fungicides may induce environmental damage. Hence, this study aimed to evaluate the effects of essential oils extracted from Cymbopogon winterianus, Thymus vulgaris, Cymbopogon citratus, Corymbia citriodora, Cinnamomum zeylanicum, and Syzygium aromaticum on the development of in vitro S. maydis. In addition, maize seeds were treated with these essential oils to determine their possible mode of action and effects. The oils from S. aromaticum, C. zeylanicum, and T. vulgaris inhibited fungal development at concentrations higher than 0.025%. The oils from S. aromaticum and C. zeylanicum showed seed germination rates of 89.0% and 84.5%, which were higher than that of the control. The oils from S. aromaticum and C. zeylanicum reduced the pathogen incidence in the seeds to 39.0% and 28.0%, respectively. Further, these oils as well as that from T. vulgaris produced lower reduction of maize stand. Scanning electron microscopy examination revealed that essential oils from S. aromaticum and T. vulgaris acted directly on the conidia, impeding germination. The findings suggest that the oils from S. aromaticum, C. zeylanicum, and T. vulgaris are potential alternatives for maize seed treatment in the control of S. maydis.

scholarly journals Allozyme-Specific Modification of a Maize Seed Chitinase by a Protein Secreted by the Fungal Pathogen Stenocarpella maydis

2010 ◽  
Vol 100 (7) ◽  
pp. 645-654 ◽  
Author(s):  
Todd A. Naumann ◽  
Donald T. Wicklow
Keyword(s):  
Inbred Line ◽  
Fungal Pathogen ◽  
Genetic Basis ◽  
Inbred Lines ◽  
Ear Rot ◽  
Maize Seed ◽  
Stalk Rot ◽  
Stenocarpella Maydis ◽  
Commercial Field

Stenocarpella maydis causes both dry-ear rot and stalk rot of maize. Maize inbred lines have varying levels of resistance to ear rot caused by S. maydis. The genetic basis of resistance appears to rely on multiple genetic factors, none of which are known. The commonly used stiff-stalk inbred line B73 has been shown to be strongly susceptible to ear rot caused by S. maydis. Here, we report that the ChitA protein alloform from B73, ChitA-F, encoded by a known allele of the chiA gene, is susceptible to modification by a protein (Stm-cmp) secreted by S. maydis. We also identify a new allele of chiA (from inbred line LH82) which encodes ChitA-S, an alloform of ChitA that is resistant to Stm-cmp modification. Chitinase zymogram analysis of seed from a commercial field showed the presence of both ChitA alloforms in healthy ears, and showed that ChitA-F but not ChitA-S was modified in ears rotted by S. maydis. The ChitA-F protein was purified from inbred line B73 and ChitA-S from LH82. ChitA-F was modified more efficiently than ChitA-S by S. maydis protein extracts in vitro. The chiA gene from LH82 was cloned and sequenced. It is a novel allele that encodes six polymorphisms relative to the known allele from B73. This is the first demonstration that the susceptibility to modification of a fungal targeted plant chitinase differs among inbred lines. These findings suggest that the LH82 chiA allele may be a specific genetic determinant that contributes to resistance to ear rot caused by S. maydis whereas the B73 allele may contribute to susceptibility.

Timing and Efficacy of Fungicide Applications for Diplodia Ear Rot Management in Corn

2015 ◽  
Vol 16 (3) ◽  
pp. 123-131 ◽  
Author(s):  
Martha P. Romero Luna ◽  
Kiersten A. Wise
Keyword(s):  
Fungal Growth ◽  
The United States ◽  
Field Trials ◽  
Individual Growth ◽  
Growth Stages ◽  
Ear Rot ◽  
Management Options ◽  
Vitro Assay ◽  
Stenocarpella Maydis

Diplodia ear rot, a corn (Zea mays L.) disease caused by the fungus Stenocarpella maydis (Berk.) B. Sutton, has been a persistent ear rot across the United States. Management options are currently limited. Field trials conducted under inoculated and non-inoculated conditions were established at two locations in Indiana from 2011 to 2013 to test the fungicides azoxystrobin plus propiconazole and prothioconazole against Diplodia ear rot. Fungicides were applied at three individual growth stages during each year. Fungicides did not consistently reduce Diplodia ear rot compared to non-fungicide-treated controls in any year. Applications also did not consistently increase yield at any timing under inoculated and non-inoculated plots compared with the non-fungicidetreated control. Fungicides were tested in an in vitro assay to determine the effective fungicide concentration at which 50% of mycelial growth or conidial germination of S. maydis was inhibited (EC50). Propiconazole and prothioconazole EC50 values indicated efficacy in reducing fungal growth under controlled conditions; however, current fungicide application methods and plant barriers to fungicide contact with the pathogen may prevent these products from effectively reducing Diplodia ear rot in a field setting. Accepted for publication 23 August 2015. Published 1 September 2015

scholarly journals In Vitro Antagonistic Study of Maize Root Colonizing Fungal Isolates Against Fusarium moniliforme Causing Ear Rot Disease of Maize

2021 ◽  
Vol 11 (2) ◽  
pp. 133-139
Author(s):  
Parimal Mandal ◽  
◽  
Zerald Tiru ◽  
Monalisha Sarkar ◽  
Arka Chakroborty ◽  
...  
Keyword(s):  
Trichoderma Harzianum ◽  
Radial Growth ◽  
Culture Collection ◽  
Maize Root ◽  
Trichoderma Asperellum ◽  
Ear Rot ◽  
Growth Promoters ◽  
Fungal Isolates ◽  
Plant Growth Promoting

In the present study, different root colonizing fungal isolates were isolated from the rhizospheric soil of maize growing areas of Uttar Dinajpur, West Bengal. All the isolates including test pathogen were identified from Indian Type Culture Collection, New Delhi. Plant growth promoting maize root colonizing fungal isolates- Penicillium pinophilum (ITC NO. 11,201.19), Trichoderma harzianum (ITC NO.11,203.19), Trichoderma asperellum (ITC NO. 11,209.19), Aspergillus niger (ITC NO. 11,204.19) and Penicillum purpurogenum (ITC NO. 11,207.19) exhibited antagonistic activities against F. moniliforme (ITC NO. 11,208.19) in vitro. Two antagonistic isolates of T. harzianum and eleven strains of T. asperellum showed antibiosis mechanism for antagonism against F. moniliforme with the range of Percent Inhibition of Radial Growth from 62.41% to 88.57%. Competitive mode of antagonism against test pathogen by the isolates of P. pinophilum, P. purpurogenum and six isolates of A. niger were found. Percent of inhibition of radial growth ranged from 57.14% to 91.42%. In our finding, antagonistic isolates especially Trichoderma harzianum (ITC NO. 11,203.19), Trichoderma asperellum (ITC NO. 11,209.19) strains either single or in combination with rest maize root colonizing strains could be used as potent growth promoters as well as biocontrol (BCA) agents.

Research Note Infection and Ultrastructure of Conidia and Pycnidia of Stenocarpella maydis in Maize

2011 ◽  
Vol 74 (4) ◽  
pp. 676-680
Author(s):  
ZHENGJUN XIA ◽  
HONGYAN WU ◽  
PREMILA N. ACHAR
Keyword(s):  
The United States ◽  
Ear Rot ◽  
Callose Deposition ◽  
Term Survival ◽  
Embryonic Tissues ◽  
Maize Seeds ◽  
Transmission Electron ◽  
Stenocarpella Maydis ◽  
Host Tissues

Stenocarpella maydis is the most prevalent ear rot pathogen of maize (Zea mays) in South Africa, the United States, and other countries. Infection and ultrastructure of propagules of S. maydis in maize were observed by light, scanning, and transmission electron microscopy. Two-celled conidia of S. maydis were found in the tissues of husk and kernels. Mycelia colonized inter- and intracellularly in the host tissues. Pycnidia were found abundantly inside the seed tissues of susceptible cultivars; within a single seed, pycnidia propagated preferentially in embryonic tissues. A pycnidium is composed of morphologically different resting spores mingled with some degraded organelles of the host cell. In this study, various enzymatic activities led to cell wall degradation, lacunae in endosperm tissues, and disrupted organelles in susceptible cultivars. In contrast, callose deposition surrounding fungal hyphae was clearly visible in resistant cultivars. Heavy infection was detected by maceration, even though there was no apparent symptom on the seed coat. The saprophytic nature and structurally different forms of propagules could contribute to a long-term survival of this pathogen in the field and during grain storage. Furthermore, S. maydis might pose a threat of diplodiatoxin intoxication to human and domestic animals when infected maize seeds are consumed.

Diplodia maydis. [Descriptions of Fungi and Bacteria].

1966 ◽  
Author(s):  
B. C. Sutton
Keyword(s):  
United States ◽  
South Africa ◽  
Zea Mays ◽  
South America ◽  
Geographical Distribution ◽  
Ear Rot ◽  
Seedling Blight ◽  
Stalk Rot ◽  
Maize Roots ◽  
Stenocarpella Maydis

Abstract A description is provided for Diplodia maydis[Stenocarpella maydis]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Zea mays. Also on Arundinaria sp. DISEASES: Stalk rot, white ear rot, and seedling blight of maize. Roots may also become infected. GEOGRAPHICAL DISTRIBUTION: Africa (Congo, Kenya, Malawi, Rhodesia, South Africa, Tanzania); Asia (India); Australasia (Australia); Europe (U.S.S.R.), North America (Canada, Mexico, United States); South America (Argentina, Brazil, Colombia).

Characterization of an antifungal soil bacterium and its antagonistic activities againstFusariumspecies

2003 ◽  
Vol 49 (4) ◽  
pp. 253-262 ◽  
Author(s):  
Yiu-Kwok Chan ◽  
Wayne A McCormick ◽  
Keith A Seifert
Keyword(s):  
Bacillus Subtilis ◽  
Culture Filtrate ◽  
Fusarium Species ◽  
Hyphal Growth ◽  
Antagonistic Activity ◽  
Plant Diseases ◽  
Ear Rot ◽  
In Planta ◽  
Head Blight

Bacteria were isolated from a cultivated soil and screened for antagonistic activity against Fusarium graminearum, a predominant agent of ear rot and head blight in cereal crops. Based on its in vitro effectiveness, isolate D1/2 was selected for characterization and identified as a strain of Bacillus subtilis by phenotypic tests and comparative analysis of its 16S ribosomal RNA gene (rDNA) sequence. It inhibited the mycelial growth of a collection of common fungal phytopathogens, including eight Fusarium species, three other ascomycetes, and one basidiomycete. The cell-free culture filtrate of D1/2 at different dilutions was active against macroconidium germination and hyphal growth of F. graminearum, depending on the initial macroconidium density. It induced the formation of swollen hyphal cells in liquid cultures of this fungus grown from macroconidia. A bioassay also demonstrated that D1/2 offered in planta protection against the damping-off disease in alfalfa seedlings caused by F. graminearum, while the type strain of B. subtilis was ineffective. Hence, B. subtilis D1/2 or its culture filtrate has potential application in controlling plant diseases caused by Fusarium.Key words: antifungal activity, Bacillus subtilis, biological control, biopesticide, Fusarium species.

Occurrence of Stenocarpella macrospora Causing Ear Rot in Corn in the United States

2016 ◽  
Vol 17 (2) ◽  
pp. 152-154
Author(s):  
Martha P. Romero Luna ◽  
Carl A. Bradley ◽  
Heather M. Kelly ◽  
Kiersten A. Wise
Keyword(s):  
United States ◽  
South Africa ◽  
South America ◽  
The United States ◽  
Ear Rot ◽  
Stenocarpella Maydis ◽  
The U.S ◽  
Related Fungus

Diplodia ear rot of corn is primarily caused by the fungus Stenocarpella maydis in the United States. Stenocarpella macrospora is a closely related fungus present in the U.S. but primarily associated with Diplodia leaf streak. S. macrospora is recognized as a major ear rot pathogen in South America and South Africa, but has infrequently been associated with ear rot in the U.S. This brief presents the first reports of Diplodia ear rot in Illinois and Tennessee. This is also the first confirmation of S. macrospora causing ear rot in the U.S. in over 60 years. Accepted for publication 19 May 2016. Published 15 June 2016.

Sign in / Sign up

Export Citation Format

Share Document