Fusarium Wilt In Plants Research Articles

Controlled synthesis and computational analysis of gold nanostars for the treatment of Fusarium oxysporum.

Fusarium oxysporum (F. oxysporum) is linked to the widespread fusarium wilt in plants affecting the quality and yield of food crops. Management of fusarium wilt by synthetic fertilizers poses safety concerns. Safer-by-design nanomaterials synthesized with a greener approach can meet the needs of commercial antifungal drug resistance. Herein, a simple aqueous reduction method has been adopted for the synthesis of anisotropic gold nanostars (AuNSs) using quercetin-para aminobenzoic acid (QPABA) as both a reducing and stabilizing agent at room temperature for the treatment of F. oxysporum. QPABA was used to control the growth of Au3+ star-shaped nanoparticles at increasing concentrations in the ratio of 2 : 1 (QPABA : Au3+ ions) respectively. Transmission electron microscopy (TEM) analysis of the as-prepared gold nanoparticles confirmed the formation of nanostars with sizes of 40 ± 2 nm. The formation of anisotropic gold nanoparticles was evaluated by UV-vis characterizations which showed longitudinal surface plasmon modes at 540 and 800 nm. The gold nanoparticles exhibit excellent antifungal activity against F. oxysporum with the minimum inhibitory concentration (MIC) of 100 μg mL-1 using an agar well-diffusion assay. AuNSs proved to be efficacious in controlling F. oxysporum, as shown in the SEM analysis with a disintegrated cell membrane upon treatment. Computational analysis was performed to determine the specific binding sites on the QPABA ligand for gold ion interactions using the DFT B3LYP method, with a 6-31+G(d) basis set. Results showed that the interaction between Au3+ and QPABA at the 4 and 3 positions yielded the highest stability and formation of gold nanostars. The results suggest that the synthesized AuNSs act as a promising antifungal agent with great potential in treating frequent fungal infections that affect agricultural production.

Target of rapamycin controls hyphal growth and pathogenicity through FoTIP4 in Fusarium oxysporum.

Fusarium oxysporum is the causal agent of the devastating Fusarium wilt by invading and colonizing the vascular system in various plants, resulting in substantial economic losses worldwide. Target of rapamycin (TOR) is a central regulator that controls intracellular metabolism, cell growth, and stress responses in eukaryotes, but little is known about TOR signalling in F. oxysporum. In this study, we identified conserved FoTOR signalling pathway components including FoTORC1 and FoTORC2. Pharmacological assays showed that F. oxysporum is hypersensitive to rapamycin in the presence of FoFKBP12 while the deletion mutant strain ΔFofkbp12 is insensitive to rapamycin. Transcriptomic data indicated that FoTOR signalling controls multiple metabolic processes including ribosome biogenesis and cell wall‐degrading enzymes (CWDEs). Genetic analysis revealed that FoTOR1 interacting protein 4 (FoTIP4) acts as a new component of FoTOR signalling to regulate hyphal growth and pathogenicity of F. oxysporum. Importantly, transcript levels of genes associated with ribosome biogenesis and CWDEs were dramatically downregulated in the ΔFotip4 mutant strain. Electrophoretic mobility shift assays showed that FoTIP4 can bind to the promoters of ribosome biogenesis‐ and CWDE‐related genes to positively regulate the expression of these genes. These results suggest that FoTOR signalling plays central roles in regulating hyphal growth and pathogenicity of F. oxysporum and provide new insights into FoTOR1 as a target for controlling and preventing Fusarium wilt in plants.

In vitro antifungal activity of lime peels extract (Citrus aurantifolia (Cristm.) Swingle.) against Fusarium oxysporum Schlecht. em. Snyd. & Hans.

Fusarium wilt in plants is caused by Fusarium oxysporum. Fusarium wilt disease prevention using synthetic fungicides cause various problems in the environment and human health, it is necessary to change to natural fungicides like lime peels. This study was conducted to determine the percentage of antifungal activity at the optimum concentration of ethanol extract of lime peel (Citrus aurantifolia) to inhibit the growth of Fusarium oxysporum. Lime peel extract was obtained from the maceration process using 96% ethanol solvent. Antifungal activity test uses a food poisoning method with mycelium diameter parameters that grow on the media. The concentration of ethanol extract of lime peels tested was 0%, 15%, 30%, 45%, and 60%, and the positive control used was synthetic antracol fungicide 0.3%. The results showed the optimum concentration of ethanol extract of lime peel to inhibit the growth of Fusarium oxysporum was a concentration of 15% with a percentage of antifungal activity is 56.34%. This is because the concentration is the lowest concentration that can inhibit the growth of Fusarium oxysporum with a strong level of activity.

GhABP19, a Novel Germin-Like Protein From Gossypium hirsutum, Plays an Important Role in the Regulation of Resistance to Verticillium and Fusarium Wilt Pathogens.

Germin-like proteins (GLPs) are water-soluble plant glycoproteins belonging to the cupin superfamily. The important role of GLPs in plant responses against various abiotic and biotic stresses, especially pathogens, is well validated. However, little is known about cotton GLPs in relation to fungal pathogens. Here, a novel GLP gene was isolated from Gossypium hirsutum and designated as GhABP19. The expression of GhABP19 was upregulated in cotton plants inoculated with Verticillium dahliae and Fusarium oxysporum and in response to treatment with jasmonic acid (JA) but was suppressed in response to salicylic acid treatment. A relatively small transient increase in GhABP19 was seen in H2O2 treated samples. The three-dimensional structure prediction of the GhABP19 protein indicated that the protein has three histidine and one glutamate residues responsible for metal ion binding and superoxide dismutase (SOD) activity. Purified recombinant GhABP19 exhibits SOD activity and could inhibit growth of V. dahliae, F. oxysporum, Rhizoctonia solani, Botrytis cinerea, and Valsa mali in vitro. To further verify the role of GhABP19 in fungal resistance, GhABP19-overexpressing Arabidopsis plants and GhABP19-silenced cotton plants were developed. GhABP19-transgenic Arabidopsis lines showed much stronger resistance to V. dahliae and F. oxysporum infection than control (empty vector) plants did. On the contrary, silencing of GhABP19 in cotton conferred enhanced susceptibility to fungal pathogens, which resulted in necrosis and wilt on leaves and vascular discoloration in GhABP19-silenced cotton plants. The H2O2 content and endogenous SOD activity were affected by GhABP19 expression levels in Arabidopsis and cotton plants after inoculation with V. dahliae and F. oxysporum, respectively. Furthermore, GhABP19 overexpression or silencing resulted in activation or suppression of JA-mediated signaling, respectively. Thus, GhABP19 plays important roles in the regulation of resistance to verticillium and fusarium wilt in plants. These modulatory roles were exerted by its SOD activity and ability to activate the JA pathway. All results suggest that GhABP19 was involved in plant disease resistance.

New foci of strawberry Fusarium wilt in Huelva (Spain) and susceptibility of the most commonly used cultivars

Abstract Strawberry Fusarium wilt is becoming an important disease after methyl bromide banning. In southwestern Spain, this disease was previously detected in a soilless culture system and several years later only one isolation was reported from plant cultivated in soil. This study reports the appearance of new foci of strawberry Fusarium wilt in plants cultivated on soils and evaluates the susceptibility of nine of the most commonly grown cultivars in this zone. Fungal isolates were obtained from diseased strawberry plants in the nineteen new foci showing an increase of incidence and geographic range of this disease. These isolates were morphologically and molecularly characterized as Fusarium oxysporum . Fofra amplicons were not obtained and only eight isolates amplified for Fusarium transcription factor 1 . Pathogenicity of six selected isolates as well as a Fusarium oxysporum f. sp. fragariae culture from Japan were tested using by inoculating cultivar ‘Splendor’. All the Spanish isolates were found to be pathogenic. As a follow-up study, nine strawberry cultivars were inoculated with the Japanese isolate and a mixture of three Spanish isolates. The least susceptible cultivars to the Spanish isolates were ‘Rociera FNM’, ‘San Andreas’, ‘Camarosa’, ‘Sabrina’ and ‘Sabrosa Candonga’. Cultivar susceptibility was different with respect to Japanese isolate.