Dual functionality of Trichoderma: Biocontrol of Sclerotinia sclerotiorum and biostimulant of cotton plants

Authors: SILVA, LUCAS - Embrapa; CAMARGO, RENATO - Embrapa; MASCARIN, GABRIEL - Embrapa; DE OLIVEIRA NUNES, PETERSON SYLVIO - Embrapa; Dunlap, Christopher; BETTIOL, WAGNER - Embrapa

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2022
Publication Date: 10/7/2022
Citation: Silva, L.G., Camargo, R.C., Mascarin, G.M., De Oliveira Nunes, P., Dunlap, C.A., Bettiol, W. 2022. Dual functionality of Trichoderma: Biocontrol of Sclerotinia sclerotiorum and biostimulant of cotton plants. Frontiers in Plant Science. 13. Article 983127. https://doi.org/10.3389/fpls.2022.983127.
DOI: https://doi.org/10.3389/fpls.2022.983127

Interpretive Summary: An ARS researcher from Peoria, IL, collaborated with scientists from Brazil to characterize two isolates of fungi for plant protection applications. The two strains of fungi belong to the genus Trichoderma, which is a common fungus to used to control other fungal plant pathogens. The isolates were tested for their ability to control white rot in cotton plants and for their ability to act as a biostimulant to promote plant growth. The results showed that one of these strains were effective at controlling white rot in cotton, while the second strain was better adapted to serve as a biostimulant. The results suggest Trichoderma strains may be useful in providing multiple benefits for cotton plants. This research will assist growers in reducing the use of synthetic growth promoters and fungicides against white mold in cotton crops.

Technical Abstract: Microbial crop protection products based on Trichoderma have the ability to display multifunctional roles in plant protection, such as; pathogen parasitism, enhance nutrient availability and stimulate plant growth, and these traits can be used to enhance the overall agronomic performance of a variety of crops. In the current study we used these traits for the biocontrol of Sclerotinia sclerotiorum, a key plant pathogen of cotton (Gossypium hirsutum L.), while also using it as a biostimulant to enhance cotton plant growth. The potential of two indigenous Brazilian strains of Trichoderma (T. asperelloides CMAA 1584 and T. lentiforme CMAA 1585) were assessed for their capability of controlling S. sclerotiorum and for the ability of growth promotion in cotton plants. Both strains were able to solubilize mineral phosphorus (CaHPO4), to produce indole-3-acetic acid in vitro, to release volatile organic compounds that impaired the mycelial growth of S. sclerotiorum, and to promote the growth of cotton plants under greenhouse conditions. In dual culture, Trichoderma strains reduced the growth rate and the number of sclerotia of the pathogen. By treating sclerotia with conidial suspensions of these Trichoderma strains incited a strong inhibition on the myceliogenic germination, as a result of the marked parasitism of sclerotia. The parasitism effect over S. sclerotiorum was more aggressive with T. asperelloides CMAA 1584. The positive effect of biostimulants on cotton growth was more pronounced with T. lentiforme CMAA 1585 and showed a higher capacity of phosphate solubilization. Thus, T. asperelloides CMAA 1584 presents high efficiency in controlling S. sclerotiorum, while T. lentiforme CMAA 1585 is more suitable as a biostimulant due to its ability to promote better growth in cotton plants. Overall, these Trichoderma strains may be used in mixture to provide both pathogen control and growth promotion, and will assist growers in reducing the use of synthetic fertilizers and fungicides against white mold in cotton crops.