Author:
Rashad Younes M.,Abdalla Sara A.,Shehata Ahmed S.
Abstract
AbstractFusarium root rot, caused by Fusarium solani (Mart.) Sacc., represents one of the most damaging diseases of maize affecting plant growth and yield. In this study, the antagonistic potential of a non-aflatoxigenic endophytic Aspergillus flavus YRB2, isolated from Thymelaea hirsuta (L.) Endl., was tested against F. solani in vitro. In addition, its biocontrol activity against Fusarium root rot of maize was evaluated under greenhouse conditions. Its impacts on plant molecular, pathological, physiological, and growth levels were also studied. Results obtained revealed a potent antagonistic behavior for A. flavus YRB2 against F. solani in vitro, recording 80% growth inhibition. Seventeen secondary metabolites were detected in the n-hexane extract of A. flavus YRB2 filtered culture broth using GC-MS analysis. Among them, various antifungal secondary metabolites were produced, namely palmitic acid, α-linolenic acid, stearic acid, 2, 4-di-tert-butylphenol, diisobutyl phthalate, and heneicosane. In contrast, HPLC analysis showed that no aflatoxins (B1, B2, G1, and G2) were detected. Under greenhouse conditions, colonization of maize plants with A. flavus YRB2 exhibited a potential biocontrol activity against Fusarium root rot, recording 73.4% reduction in the disease severity. Triggering of transcriptional expression level of the defense-related genes JERF3 (7.2-fold), CHI II (8-fold), and POD (9.1-fold) was reported, indicating the inducing effect on the plant immunity. In addition, an increment in the antioxidant enzymes POD and PPO, and the total phenolic content in maize roots was also observed in response to this treatment. Moreover, a growth-promoting effect was also observed for colonization of maize plants with A. flavus YRB2. Based on the obtained data, we can conclude that A. flavus YRB2 may represent a promising biocontrol and growth-promoting agent for maize plants against Fusarium root rot. Nevertheless, field evaluation is highly requested before the use recommendation.
Funder
City of Scientific Research and Technological Applications
Publisher
Springer Science and Business Media LLC
Subject
Microbiology (medical),Microbiology
Reference60 articles.
1. FAOSTAT (2022). Food and agriculture organization of the United Nations. Available online: http://www.fao.org/faostat/en/#data/QC.
2. Ranum P, Peña-Rosas JP, Garcia-Casal MN. Global maize production, utilization, and consumption. Ann N Y Acad Sci. 2014;1312:105–12. https://doi.org/10.1111/nyas.12396.
3. Rausch KD, Hummel D, Johnson LA, May JB. Wet milling: the basis for corn biorefineries. In: Serna-Saldivar SOBT-C, editor. Corn: chemistry and technology. 3rd ed. Oxford: AACC International Press; 2018. p. 501–35. ISBN 9780128119716.
4. Nyvall RF. Diseases of corn. In: Nyvall RF, editor. Field crop diseases handbook. Boston: Springer US; 1989. p. 91–169. ISBN 978-1-4757-5221-2.
5. Okello PN, Petrović K, Kontz B, Mathew FM. Eight species of Fusarium cause root rot of corn (Zea mays) in South Dakota. Plant Health Prog. 2019;20:38–43. https://doi.org/10.1094/PHP-11-18-0075-RS.