This work aimed to evaluate the antagonist effect of Trichoderma viride against Fusarium oxysporum and its ability to promote growth and resistance defence of oil palm. The antagonistic effect of T. viride was tested by paired culture, cellophane plate, and micro-atmosphere methods. In the nursery, 30-day-old oil palm plants were inoculated with T. viride, and 30 days after growing, the roots of plants were infected with the spores of Fusarium oxysporum. Ninety days after infection, plants were harvested, and a series of morphological (height, fresh root and shoot) and biochemical changes (total chlorophyll, phenol compounds, soluble proteins and oxidative enzymes), which are considered to be part of the plant defence response, were evaluated. Results showed that, in dual culture, T. viride significantly reduced mycelial growth of Fusarium oxysporum and released non-volatile and volatile compounds that inhibited the pathogen. In the nursery, there was a significant reduction in disease impact (severity index and incidence) in oil palm inoculated with T. viride and infected with Fusarium oxysporum. A significant increase in plant root and shoot fresh weights, as well as chlorophyll, soluble proteins, and phenol content, was noticed in comparison with non-inoculated control plants. A significant increase in peroxidase, polyphenol oxidase, and phenylalanine ammonia lyase activities was recorded in inoculated and infected plants, compared to control. There was a significant and positive correlation between disease incidence and the activity of these oxidative enzymes. These findings suggest that these compounds play a vital role in plant defence. T. viride could serve as a biological agent to manage vascular wilt in oil palm. However, analysis of its effects on mass production and field application is needed.

• Klíčová slova
• Fusarium oxyporum elaeidis f. sp. elaeidis, Trichoderma viride, Biochemical defense, Oil palm, Oxidative enzymes,
• Publikační typ
• časopisecké články MeSH

Present study was aimed to develop an efficient microbial consortium for combating Alternaria blight disease in cumin. The research involved isolating biocontrol agents against Alternaria burnsii, characterizing their biocontrol and growth promotion traits, and assessing compatibility. A pot experiment was conducted during rabi season of 2022-2023 to evaluate the bioefficacy of four biocontrol agents (1F, 16B, 31B, and 223B) individually and in consortium, focusing on disease severity, plant growth promotion, and defense responses in cumin challenged with A. burnsii. Microbial isolates 1F, 16B, 31B, and 223B significantly inhibited A. burnsii growth in dual plate assays (~ 86%), displaying promising biocontrol and plant growth promotion activities. They were identified as Trichoderma afroharzianum 1F, Aneurinibacillus aneurinilyticus 16B, Pseudomonas lalkuanensis 31B, and Bacillus licheniformis 223B, respectively. The excellent compatibility was observed among all selected biocontrol agents. Cumin plants treated with consortia of 1F + 16B + 31B + 223B showed least percent disease index (32.47%) and highest percent disease control (64.87%). Consortia of biocontrol agents significantly enhanced production of secondary metabolites (total phenol, flavonoids, antioxidant, and tannin) and activation of antioxidant-defense enzymes (POX, PPOX, CAT, SOD, PAL, and TAL) compared to individual biocontrol treatment and infected control. Moreover, consortium treatments effectively reduced electrolyte leakage over the individual biocontrol agent and infected control treatment. The four-microbe consortium significantly enhanced chlorophyll (154%), carotenoid content (88%), plant height (78.77%), dry weight (72.81%), and seed yield (104%) compared to infected control. Based on these findings, this environmentally friendly four-microbe consortium may be recommended for managing Alternaria blight in cumin.

• Klíčová slova
• Alternaria burnsii, Antioxidant-defense enzymes, Consortia of biocontrol agents, Electrolyte leakage, Secondary metabolites,
• MeSH
• Alternaria * růst a vývoj   fyziologie   MeSH
• biologická ochrana MeSH
• Cuminum * mikrobiologie   imunologie   růst a vývoj   MeSH
• mikrobiální společenstva * MeSH
• nemoci rostlin * mikrobiologie   prevence a kontrola   imunologie   MeSH
• odolnost vůči nemocem MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologická ochrana MeSH

Plant growth-promoting rhizobacteria (PGPR) have emerged as key players in sustainable agriculture due to their ability to enhance plant growth, nutrient uptake, and disease resistance. A significant aspect of PGPR is the emission of volatile organic compounds (VOCs), which serve as signaling molecules that influence various physiological processes in plants. This review article explores the complex interactions between rhizobacterial VOCs and soil health, focusing particularly on their role in nutrient cycling within agricultural ecosystems. By investigating the mechanism of production and release of VOCs by rhizobacteria, along with impacts on soil properties and microbial communities. We aim to highlight the potential of rhizobacterial volatile organic compounds (VOCs) for sustainable agricultural management. Additionally, we discuss the role of rhizobacterial VOCs in promoting root growth, nutrient uptake, and enhancing nutrient cycling processes. By providing insights into these mechanisms, this review offers tailored strategies for exploring the potential of rhizobacterial VOCs to optimize nutrient availability, enhance soil fertility, and address environmental challenges in agriculture. Exploring the potential of rhizobacterial VOCs presents an opportunity to establish sustainable and resilient agricultural systems that significantly enhance global food security and promote environmental stewardship.

• Klíčová slova
• Agricultural sustainability, Nutrient cycling, Plant-microbe interactions, Rhizobacterial VOCs, Soil health,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.

• Klíčová slova
• Ceratobasidium sp., Fusarium culmorum, Microdochium bolleyi, Rhizoctonia-like fungi, Serendipita indica, Tulasnella sp., biocontrol, endophyte,
• Publikační typ
• časopisecké články MeSH

Nitrilases participate in the nitrile metabolism in microbes and plants. They are widely used to produce carboxylic acids from nitriles. Nitrilases were described in bacteria, Ascomycota and plants. However, they remain unexplored in Basidiomycota. Yet more than 200 putative nitrilases are found in this division via GenBank. The majority of them occur in the subdivision Agaricomycotina. In this work, we analyzed their sequences and classified them into phylogenetic clades. Members of clade 1 (61 proteins) and 2 (25 proteins) are similar to plant nitrilases and nitrilases from Ascomycota, respectively, with sequence identities of around 50%. The searches also identified five putative cyanide hydratases (CynHs). Representatives of clade 1 and 2 (NitTv1 from Trametes versicolor and NitAg from Armillaria gallica, respectively) and a putative CynH (NitSh from Stereum hirsutum) were overproduced in Escherichia coli. The substrates of NitTv1 were fumaronitrile, 3-phenylpropionitrile, β-cyano-l-alanine and 4-cyanopyridine, and those of NitSh were hydrogen cyanide (HCN), 2-cyanopyridine, fumaronitrile and benzonitrile. NitAg only exhibited activities for HCN and fumaronitrile. The substrate specificities of these nitrilases were largely in accordance with substrate docking in their homology models. The phylogenetic distribution of each type of nitrilase was determined for the first time.

• Klíčová slova
• Agaricomycotina, Basidiomycota, cyanide hydratase, homology modeling, nitrilase, nitrile, overproduction, phylogenetic distribution, substrate docking, substrate specificity,
• MeSH
• aminohydrolasy chemie   genetika   metabolismus   MeSH
• Basidiomycota klasifikace   enzymologie   genetika   MeSH
• fumaráty metabolismus   MeSH
• fungální proteiny chemie   genetika   metabolismus   MeSH
• fylogeneze MeSH
• kyanovodík metabolismus   MeSH
• pyridiny metabolismus   MeSH
• simulace molekulového dockingu MeSH
• substrátová specifita MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminohydrolasy MeSH
• fumaráty MeSH
• fumaronitrile MeSH Prohlížeč
• fungální proteiny MeSH
• kyanovodík MeSH
• nitrilase MeSH Prohlížeč
• pyridiny MeSH