Biocontrol potential of saline- or alkaline-tolerant Trichoderma asperellum mutants against three pathogenic fungi under saline or alkaline stress conditions

Abstract

Salinity and alkalinity are major abiotic stresses that limit growth and development of poplar. We investigated biocontrol potential of saline- and alkaline-tolerant mutants of Trichoderma asperellum to mediate the effects of salinity or alkalinity stresses on Populus davidiana×P. alba var. pyramidalis (PdPap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using an Agrobacterium tumefaciens mediated transformation system; this process yielded sixty five positive transformants (T1-T65). The salinity tolerant mutant, T59, grew in Potato Dextrose Agar (PDA) containing up to 10% (1709.40mM) NaCl. Under NaCl-rich conditions, T59 was most effective in inhibiting Alternaria alternata (52.00%). The alkalinity tolerant mutants, T3 and T5, grew in PDA containing up to 0.4% (47.62mM) NaHCO. The ability of the T3 and T5 mutants to inhibit Fusarium oxysporum declined as NaHCO concentrations increased. NaHCO tolerance of the PdPap seedlings improved following treatment with the spores of the WT, T3, and T5 strains. The salinity tolerant mutant (T59) and two alkalinity tolerant mutants (T3 and T5) generated in this study can be applied to decrease the incidence of pathogenic fungi infection under saline or alkaline stress.

Isolation, Identification and Enzymatic Activity of Halotolerant and Halophilic Fungi from the Great Sebkha of Oran in Northwestern of Algeria

“…Several studies have been conducted on the search for halotolerant strains of Trichoderma spp. that could be used as biological control agents under salt stress because of the use of saline water for irrigation in agriculture in arid zone [31,65,66]. This is the first isolation of T. gamsii in Algeria.…”

Biocontrol Potential of Salt-Tolerant Trichoderma and Hypocrea Isolates for the Management of Tomato Root Rot Under Saline Environment

“…However, fungicidal resistance among pathogens, pollution of ground water and food, residual toxicity, health hazards, and oncogenic threats have alarmed researchers for searching alternative and effective methods (Solanki et al 2011). Use of salinity-tolerant biocontrol agents alone or in combination could be the best alternative (Gal-Hemed et al 2011;Rawat et al 2013;Guo et al 2018). Among various microbe-derived biopesticides deployed for crop disease management in stressed environment, antagonistic species of Trichoderma and Hypocrea genus are ranked at the top among all the biological control agents employed to contain fungal plant pathogens including R. solani (Srivastava et al 2012;Solanki et al 2011;Mastouri et al 2010;Montealegre et al 2010).…”

Metagenomic analysis of cucumber rhizospheric microbiome provides insights into NaHCO3 stress mitigation by Rheinheimera pacifica NYJ

“…Under the stress of NaHCO 3 , inoculation of Enterobacter aerogenes LJL-5 and Pseudomonas aeruginosa LJL-13 increases alfalfa yield and quality [14]. Application of Trichoderma asperellum decreases the infection incidence of pathogenic fungi and alleviates NaHCO 3 stress in poplar [15]. To the best of our knowledge, it has not been reported that PGPR would mitigate the stress of NaHCO 3 in plants by changing the microbial community composition and structure in plant rhizosphere.…”

“…Among these, 669 enriched and 1296 depleted species were identified. The top 10 NaHCO 3 -responsive genera with highest number of species were Streptomyces (81), Pseudomonas (70), Bacillus(22), Rhizobium(22), Rhodococcus(19), Bradyrhizobium(17), Mycobacterium(17), Micromonospora(15), Pseudoalteromonas(14), and Sphingomonas(14). Based on the 16S rRNA amplicon sequencing, the genera Pseudomonas, Rhizobium, Bradyrhizobium, Mycobacterium, and Sphingomonas were still in response to NaHCO 3 tress (Additional file 4:Table S5).…”