Trichoderma aureoviride URM 5158 and Trichoderma hamatum URM 6656 are Biocontrol Agents that act against Cassava Root rot through different Mechanisms

Abstract

Trichoderma has been used to manage a large number of pathogens, but there is a gap in the mechanisms used by these biocontrol agents regarding the physiological response of cassava plants (Manihot esculenta) when it is subjected to cassava root rot. The aims of this study were to investigate the antagonist activity of ten Trichoderma isolates against Fusarium solani on potato dextrose Agar (PDA), to quantify the chitinase production, to select and test in vivo the best isolate from each experiment and to assess the physiological response of cassava to the production of oxidative enzyme complex production (ascorbate peroxidase, catalase, peroxidase and polyphenol oxidase). All Trichoderma isolates have shown competitive capability against F. solani, and Trichoderma hamatum URM 6656 showed the highest inhibition of pathogen growth (88.91%). All isolates have shown chitinase activity, but Trichoderma aureoviride URM 5158 produced the highest amount of chitinase. T. hamatum URM 6656 and T. aureoviride URM 5158 were selected to be applied in vivo. The two Trichoderma strains reduced 64 and 60% of the disease severity in the shoot and 82 and 84% in the root. Cassava plants infected with Trichoderma have shown the highest peroxidase and ascorbate peroxidase production. Our results have indicated that T. aureoviride URM 5158 is an effective biocontrol agent against cassava root rot caused by F. solani, because it presented competitive antagonist capability in vitro, the highest chitinase production, and reduced the cassava root rot severity. The application of T. aureoviride has led to the maximum enzyme activity of reactive oxygen species group in cassava plants.

Fungal Root Microbiome from Healthy and Brittle Leaf Diseased Date Palm Trees (Phoenix dactylifera L.) Reveals a Hidden Untapped Arsenal of Antibacterial and Broad Spectrum Antifungal Secondary Metabolites

“…This finding suggests that mechanisms other than the production of secondary metabolites account for the remaining 50% of the antifungal activity observed by living endophytes. We speculate that this could be related to the presence of alternative biocontrol strategies such as the production of chitinases for example that are known to inhibit the growth of fungal phytopathogens ( Da Silva et al, 2016 ). However, more detailed research work is required to confirm this hypothesis.…”

Microbial Biomass and Enzymatic Activities in Sandy Soil Cultivated With Lettuce Inoculated With Plant Growth Promoters

“…Sacc. and Scytalidium lignicola Pesante (SILVA et al, 2016). The bacterial isolate selected was Pseudomonas UAGF 14 from the collection of microbial cultures of the Microbial Genetics and Biotechnology Laboratory of the Universidade Federal Rural de Pernambuco -UFRPE.…”

“…These microorganisms may also influence the availability of micronutrients by solubilization, chelation and soil reactions (ADAK et al, 2016). Fungus of the Trichoderma genus has been studied by producing a series of extracellular enzymes (HARMAN et al, 2004), such as chitinases, lipases, proteases and glucanases, capable of degrading fungal cell walls (SILVA et al, 2016). These enzymes also act in the decomposition of plant residues as well as in the inhibition of pathogens, interfering with the development of plants (SHANMUGAIAH et al, 2009).…”

WITHDRAWN: Transcriptome Sequencing of Trichoderma Koningiopsis Strain Tk1 to Identify and Analyze Differential Gene Expression Patterns

“…For instance, the enzymes β-1,3-glucanase and protease were produced when T. harzianum mycelia were transferred from a medium containing glucose as the sole carbon source to medium containing cell walls of Botrytis cinerea [12]. Silva et al [13] reported that 10 different chitinase producing Trichoderma strains varied in their enzyme activity, with higher chitinase activity resulting in a stronger inhibitory effect towards the pathogen.…”