Fungus Gibberella Fujikuroi Research Articles

Gibberellin biosynthesis, its roles in plant physiology and abiotic stress responses

Gibberellins (GAs) are a group of phytohormones that significantly impact plant growth and development processes, including seed germination, stem elongation, and fruit development. These diterpenoid acids are influenced by environmental factors such as light and temperature, which can alter their concentration and activity. Initially discovered in the 1920s in the fungus Gibberella fujikuroi, over 136 GAs have been identified in various plants, fungi, and bacteria. A particularly active form of gibberellin, GA3, is widely used in agriculture to promote cell elongation, induce the grow of seedless fruits and improve crop yields. The synthesis and regulation of gibberellins in plants involve complex biosynthetic pathways that integrate both endogenous and environmental signals. Additionally, GAs play a role in stress response, helping plants adapt to challenging conditions like salinity and water scarcity. Research continues to explore the biotechnological applications of GAs, including their use in floriculture, fruit production, and improving plant resilience under stress conditions, making them essential for sustainable agriculture.

Production of Gibberellic Acid by Solid-State Fermentation Using Wastes from Rice Processing and Brewing Industry.

Gibberellic acid (GA3) is a natural hormone present in some plants used in agricultural formulations as a growth regulator. Currently, its production on an industrial scale is performed by submerged fermentation using the fungus Gibberella fujikuroi, which is associated with low yields, leaving the purification stages with high costs. An alternative is solid-state fermentation (SSF), which makes it possible to obtain higher concentrations of product using low-cost substrates, such as agroindustrial by-products. This research investigated the use of raw rice bran (RRB) and barley malt residue (BMR) as substrates for GA3 production by the fungus Gibberella fujikuroi. Through two statistical designs, the effect of moisture (50 to 70 wt.%) and medium composition (RRB content between 30 and 70 wt.% to a mass ratio between RRB and BMR) was first evaluated. Using the best conditions previously obtained, the effect of adding glucose (carbon source, between 0 and 80g·L-1) and ammonium nitrate-NH4NO3-(nitrogen source, between 0 and 5g·L-1) on GA3 productivity was analyzed. The best yield was obtained using 30 wt.% RRB and 70 wt.% BMR for a medium with 70 wt.% of moisture after 7days of process. It was also found that higher concentrations of NH4NO3 favor the GA3 formation for intermediate values of glucose content (40g·L-1). Finally, a kinetic investigation showed an increasing behavior in the GA3 production (10.1g·kg of substrate-1 was obtained), with a peak on the seventh day and subsequent tendency to stabilization.

Biosynthesis and beneficial effects of microbial gibberellins on crops for sustainable agriculture.

Soil microbes promote plant growth through several mechanisms such as secretion of chemical compounds including plant growth hormones. Among the phytohormones, auxins, ethylene, cytokinins, abscisic acid and gibberellins are the best understood compounds. Gibberellins were first isolated in 1935 from the fungus Gibberella fujikuroi and are synthesized by several soil microbes. The effect of gibberellins on plant growth and development has been studied, as has the biosynthesis pathways, enzymes, genes and their regulation. This review revisits the history of gibberellin research highlighting microbial gibberellins and their effects on plant health with an emphasis on the early discoveries and current advances that can find vital applications in agricultural practices.

Microbial transformation of pseudoprotodioscin by Gibberella fujikuroi

Three new (6, 9, and 12) and nine known steroidal saponins were obtained from the fermentation broth of pseudoprotodioscin (PPD) incubated with a fungus Gibberella fujikuroi CGMCC 3.4663. Structures of the metabolites were elucidated by 1-D (1H, 13C), 2-D (HMBC, HSQC, NOESY) NMR, and HR-MS analyses. The biotransformation pathway of pseudoprotodioscin by Gibberella fujikuroi CGMCC 3.4663 was proposed. Compounds 1–11 were tested in vitro for their cytotoxic activities against two human cancer cell lines (HepG2 and Hela). Compounds 1, 6, 9, and 10 exhibited cytotoxic activity against HepG2 cells. Compound 10 exhibited cytotoxicity to Hela cells.

Biotransformation of geranylated- and acetylated-phloroglucinols by Gibberella fujikuroi into molecules with increased antifungal activity against Botrytis cinerea

Terpenylated phenols possess interesting biological activities. These properties vary mainly according to the type of terpene associated and the degree of oxidation of the molecule. The search for new active molecules for application in different areas of knowledge includes the structural modification of these through ecological methodologies, such as biotransformation. The aims of this study were the biotransformation of geranylated- and acetylated-phloroglucinol by the fungus Gibberella fujikuroi and the evaluation of the antifungal activity of the derivatives. Five major derivatives were identified after biotransformation, highlighting the formation of specific monoacetylated products. In vitro antifungal activity assays against the phytopathogenic fungus Botrytis cinerea indicated that deacetylated derivatives possess higher activity compared to the precursor molecule. In other biotransformation reactions, a relationship between the release of the alkyl chain from the aromatic ring with a decrease of the antifungal activity, was observed. The in vivo tests in infected tomato plants with B. cinerea confirmed the antifungal activity of the derivatives observed in in vitro experiments.

A Century of Gibberellin Research.

Gibberellin research has its origins in Japan in the 19th century, when a disease of rice was shown to be due to a fungal infection. The symptoms of the disease including overgrowth of the seedling and sterility were later shown to be due to secretions of the fungus Gibberella fujikuroi (now reclassified as Fusarium fujikuroi), from which the name gibberellin was derived for the active component. The profound effect of gibberellins on plant growth and development, particularly growth recovery in dwarf mutants and induction of bolting and flowering in some rosette species, prompted speculation that these fungal metabolites were endogenous plant growth regulators and this was confirmed by chemical characterisation in the late 1950s. Gibberellins are now known to be present in vascular plants, and some fungal and bacterial species. The biosynthesis of gibberellins in plants and the fungus has been largely resolved in terms of the pathways, enzymes, genes and their regulation. The proposal that gibberellins act in plants by removing growth limitation was confirmed by the demonstration that they induce the degradation of the growth-inhibiting DELLA proteins. The mechanism by which this is achieved was clarified by the identification of the gibberellin receptor from rice in 2005. Current research on gibberellin action is focussed particularly on the function of DELLA proteins as regulators of gene expression. This review traces the history of gibberellin research with emphasis on the early discoveries that enabled the more recent advances in this field.

Agricultural welsh onion waste as a source of gibberellic acid

The obtention of gibberellic acid from the branches of the Welsh onion, as an option to the conventional gaining from the fungus Gibberella fujikuroi and as an alternative to give some value to this agricultural waste was evaluated. A extract was obtained from the branches and by thin layer chromatography and by comparison with a commercial pattern, the presence of gibberellic acid was evidenced. A ultraviolet spectrophotometry revealed that the concentration of gibberellic acid correspond to a 2.70% of the dry Welsh onion.To evaluate the biological effect of the extract, three groups of peas plants were arranged, including a control, treated with the commercial pattern of the Gibberellic acid. The results showed that the onion branch extract increased the length of plant's stem in a 47%, the foliage in a 67% but had no effect on the main root's elongation compared to the control. In studies with groups of lettuce seeds, arranged in similar ways than the peas plants but with 39 individuals per group, it was found that the extract promotes the seed's germination in 28% more, compared to the control. All the biological tests performed with the onion's extract presented similar behavior to those treated with the gibberellic acid pattern, presenting no differences in the variance analysis ANOVA and Turkey test (p < 0.05). It was concluded that it is possible to obtain a crude extract with the presence of gibberellic acid from this agricultural waste.

A SVM Gray-Box Model for a Solid Substrate Fermentation Process

Gray-Box models (GBM) which combine a priori knowledge of a process –e.g. first principle equationswith a black-box modeling technique are useful when some parameters of the first-principle model – normally time-variant parameters like the specific kinetics of some bioprocessescannot be easily determined. In this case the black-box part of the GBM can be used to model the influence of input and state variables on the evolution of those parameters. The most commonly used black-box technique for GBM is Artificial Neural Networks (ANN). However Support Vector Machine (SVM) has shown its usefulness by improving over the performance of different supervised learning methods, either as classification models or as regression models. In this paper, a kind of SVM –the Least-Square Support Vector Machine (LS-SVM)are used to develop a GBM for a solid-substrate fermentation (SSF) batch process, the growth of the filamentous fungus Gibberella fujikuroi. SSF are well known as low water consumption processes, therefore reducing liquid effluent treatment costs. They can also use agricultural wastes as substrates. Although these advantages lack of adequate models attempts to better exploit SSF processes at an industrial level. The aim of the present work is then to build a GBM to simultaneously estimate the specific growth kinetics and the specific production kinetics. Good results confirm that SVM can be effectively used for developing GBM for SSF processes.

Antifungal depsidone metabolites from Cordyceps dipterigena, an endophytic fungus antagonistic to the phytopathogen Gibberella fujikuroi

Among thirty four endophytic fungal strains screened for in vitro antagonism, the endophytic fungus Cordyceps dipterigena was found to strongly inhibit mycelial growth of the plant pathogenic fungus Gibberella fujikuroi. Two new depsidone metabolites, cordycepsidone A (1) and cordycepsidone B (2), were isolated from the PDA culture extract of C. dipterigena and identified as being responsible for the antifungal activity. Elucidation of their chemical structures was carried out using 1D and 2D NMR spectroscopy in combination with IR and MS spectroscopic data. Cordycepsidone A displayed strong and dose-dependent antifungal activity against the plant pathogenic fungus G. fujikuroi. The isolates were inactive in bioassays for malaria (Plasmodium falciparum), leishmaniasis (Leishmania donovani), Chagas‘s disease (Trypanosoma cruzi), and cytotoxicity at 10μg/mL. The compounds were also found to be inactive against several bacterial strains at 50μg/mL.

New stereoisomeric derivatives of jasmonic acid generated by biotransformation with the fungus Gibberella fujikuroi affect the viability of human cancer cells

Background: Several studies have shown that (-)-Jasmonic acid, (+)-7-iso-Jasmonic acid and its methyl ester, methyl jasmonate, have anti-cancer activity in vitro and in vivo , exhibiting selective cytotoxicity towards cancer cells. The degree of activity of these molecules is strongly related to their stereochemistry. The biotransformation of known compounds, natural or synthesized, related to interesting biological activities, generates new molecules displaying new improved properties compared with the original ones, increasing its value and providing new more effective products. Therefore, based on the above rationales and observations, in this work a biotransformation protocol to modify the chemical structure of the plant hormone jasmonic acid by using the fungus Gibberella fujikuroi was established. Results: The three jasmonic acid derivatives obtained, 3(S)-Hydroxy-2(R)-(2Z-pentenyl)-cyclopentane-1(R)-acetic acid (1), 3(R)-Hydroxy-2(R)-(2Z-pentenyl)-cyclopentane-1(R)-acetic acid (2), 3-Hydroxy-2(S)-(2Z-pentenyl)-cyclopentane-1(S)-acetic acid (3), were tested for cell-growth inhibition activity towards the human cancer epithelial cell line, the oral squamous carcinoma cells (KB). The results obtained show that jasmonic acid derivatives (1-3) are active on human cancer cells examined in different concentration ranges, with IC 50 value less than of 25 µM. The compound 3, with the same molecular structure of compounds 1 and 2, but with different stereochemistry, was more active confirming that the activity of jasmonate compounds is related to their stereochemistry and to substituents in the cyclopentane ring. In this study, we also tested the potential proapoptotic activity of compound 3, and our data suggest that it, as other jasmonate compounds, is able to trigger apoptotic death in cancer cells. This event may be correlated at an elevation of reactive oxygen species (ROS). Administration of N-acetylcysteine (NAC) prevented compound 3 cytotoxicity. Conclusions: This work shows for the by first time the production of hydroxylated derivatives of JA by biotransformation. The activity observed of these compounds in cancer cells is higher than the observed with JA and is strongly related to its stereochemistry.

Biotransformation of 7α-hydroxy- and 7-oxo- ent-atis-16-ene derivatives by the fungus Gibberella fujikuroi

The microbiological transformation of 7α,19-dihydroxy- ent-atis-16-ene by the fungus Gibberella fujikuroi gave 19-hydroxy-7-oxo- ent-atis-16-ene, 13( R),19-dihydroxy-7-oxo- ent-atis-16-ene, 7α,11β,19-trihydroxy- ent-atis-16-ene and 7α,16β,19-trihydroxy- ent-atis-16-ene, while the incubation of 19-hydroxy-7-oxo- ent-atis-16-ene afforded 13( R),19-dihydroxy-7-oxo- ent-atis-16-ene and 16β,17-dihydroxy-7-oxo- ent-atisan-19-al. The biotransformation of 7-oxo- ent-atis-16-en-19-oic acid gave 6β-hydroxy-7-oxo- ent-atis-16-en-19-oic acid, 6β,16β,17-trihydroxy-7-oxo-19- nor- ent-atis-4(18)-ene and 3β,7α-dihydroxy-6-oxo- ent-atis-16-en-19-oic acid.

Preparation of an in-house reference material containing fumonisins in Thai rice and matrix extension of the analytical method for Japanese rice.

Mycotoxin contamination in rice is less reported, compared to that in wheat or maize, however, some Fusarium fungi occasionally infect rice in the paddy field. Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which often ruins maize. Rice adherent fungus Gibberella fujikuroi is taxonomically near to F. verticillioides, and there are sporadic reports of fumonisin contamination in rice from Asia, Europe and the United States. Therefore, there exists the potential risk of fumonisin contamination in rice as well as the need for the validated analytical method for fumonisins in rice. Although both natural and spiked reference materials are available for some Fusarium mycotoxins in matrices of wheat and maize, there are no reference materials for Fusarium mycotoxins in rice. In this study, we have developed a method for the preparation of a reference material containing fumonisins in Thai rice. A ShakeMaster grinding machine was used for the preparation of a mixed material of blank Thai rice and F. verticillioides-infected Thai rice. The homogeneity of the mixed material was confirmed by one-way analysis of variance, which led this material to serve as an in-house reference material. Using this reference material, several procedures to extract fumonisins from Thai rice were compared. Accordingly, we proved the applicability of an effective extraction procedure for the determination of fumonisins in Japanese rice.

Microbiological transformation of an ent-pimaradiene hydrocarbon by Gibberella fujikuroi

The hydrocarbon 9,13- epi- ent-pimara-7,15-diene has been obtained from its 18-hydroxy derivative by treatment with Ph 3/CCl 4 and subsequent reduction with tri- n-butyltin hydride. The incubation of this diterpene with the fungus Gibberella fujikuroi afforded 1α,9α-dihydroxy-7α,8α-epoxy-13- epi- ent-pimara-15-ene. The main difference between the biotransformation of the hydrocarbon and that of the corresponding 18-alcohol is that in the former, the rearrangement of the epoxy group to give 7-oxo-derivatives was not observed. However, the sequence of reactions 7α,8α-epoxidation, hydroxylation at C-9α and subsequent C-1α hydroxylation occurred in both biotransformations.

Limited surveillance of fumonisins in brown rice and wheat harvested in Japan.

Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which is a major contaminant of corn. However, there are sporadic reports of fumonisin contamination in wheat worldwide. The rice adherent fungus Gibberella fujikuroi is taxonomically closely related to F. verticillioides. Therefore, the potential risk of fumonisin contamination in rice and wheat is significant. Previously, a sensitive detection method utilizing liquid chromatography with tandem electrospray mass spectrometry (LC-ESI-MS-MS) was developed for the determination of fumonisins in brown rice. In the present study, the incidence of fumonisins in brown rice and wheat harvested in Japan was investigated using LC-ESI-MS-MS. Forty-eight rice samples and 47 wheat samples were screened and analyzed for the major B-type fumonisins: fumonisin B1 (FB1) and fumonisin B2 (FB2). About 1 kg of rice or wheat seed was divided into three subsamples, and 10 g from each subsample was used for the analysis. The limits of detection were 0.012 and 0.011 mg/kg for FBt and FB2, respectively, in rice samples and 0.010 and 0.008 mg/kg for FB1 and FB2, respectively, in wheat samples. The mean (standard deviation) recoveries of FB1 spiked at 0.50 mg/kg into toxin-free rice and wheat samples were 77.6 (4.2)% and 84.5 (3.1)%, respectively. One of the wheat samples was positive for FBt with a value greater than the limit of detection,but no fumonisin was found in any of the rice samples. This is the first report of fumonisins detected in Japanese wheat.

DELLAs Control Plant Immune Responses by Modulating the Balance of Jasmonic Acid and Salicylic Acid Signaling

In Arabidopsis, the flagellin-derived peptide flg22 elevates antibacterial resistance [1] and inhibits growth [2] upon perception via the leucine-rich repeat receptor-like kinase Flagellin-Sensitive 2 (FLS2) [3]. DELLA proteins are plant growth repressors whose degradation is promoted by the phytohormone gibberellin [4]. Here, we show that DELLA stabilization contributes to flg22-induced growth inhibition. In addition, we show that DELLAs promote susceptibility to virulent biotrophs and resistance to necrotrophs, partly by altering the relative strength of salicylic acid and jasmonic acid (JA) signaling. A quadruple-DELLA mutant (which lacks four out of the five Arabidopsis DELLA proteins [5]) was partially insensitive to gene induction by Methyl-Jasmonate (MeJA), whereas the constitutively active dominant DELLA mutant gai[6] was sensitized for JA-responsive gene induction, implicating DELLAs in JA-signaling and/or perception. Accordingly, the elevated resistance of gai to the necrotrophic fungus Alternaria brassicicola and susceptibility to the hemibiotroph Pseudomonas syringae pv. tomato strain DC3000 (Pto DC3000) was attenuated in the JA-insensitive coi1-16 mutant [7]. These findings suggest an explanation for why the necrotrophic fungus Gibberella fujikuroi, causal agent of the foolish-seedling disease of rice, makes gibberellin.

Kinetic of the gibberellic acid and bikaverin production in an airlift bioreactor

A mathematical description of the principal kinetics involved in gibberellic acid and bikaverin production in an airlift bioreactor was attained using a non-structured model. Growth, dextrose and nitrogen consumption, and gibberellic acid and bikaverin production kinetics were considered for this purpose. Experimental data were obtained from submerged batch fermentation of the fungus Gibberella fujikuroi (CDBB H-984) and were fitted to three different sigmoidal models: 2- and 3-parameter Gompertz models and a logistic model. The most appropriate model was determined by means of an F test using growth kinetic fitting. The 2-parameter Gompertz model was found to be the most suitable and was used for both dextrose and nitrogen consumption, and gibberellic acid and bikaverin production fitting. A sensitivity analysis was performed to determine the effect of the parameters in the global model. The parameters of the 2-parameter Gompertz model were transformed in order to give them a biological meaning.

Natural occurrence of Gibberella fujikuroi and its potential for control of the woolly aphid Ceratovacuna lanigera (Homoptera: Aphididae) in Indian sugarcane plantations

Studies were conducted to determine the natural occurrence of entomopathogenic fungi and their potential for utilisation in biological control of the woolly aphid (Ceratovacuna lanigera Zehntner) in Indian sugarcane plantations. A fungus Gibberella fujikuroi (Sawada) Wr. (Synonym: Fusarium verticillioides (Sacc.) Nirenberg, Synonym: Fusarium moniliforme (Sheld.) emend. Snyd. and Hans.) was found to be a promising biocontrol agent. It was further characterised and its field performance was studied. Reductions of aphid populations up to 60% were observed when the fungus was applied as two sprays at a week interval in the field.

The microbiological transformation of 7α-hydroxy- ent-kaur-16-ene derivatives by Gibberella fujikuroi

The biotransformation of 7α-hydroxy- ent-kaur-16-ene ( epi-candol A) by the fungus Gibberella fujikuroi gave 7α,16α,17-trihydroxy- ent-kaur-16-ene and a seco-ring B derivative, fujenoic acid, whilst the incubation of candicandiol (7α,18-dihydroxy- ent-kaur-16-ene) and canditriol (7α,15α,18-trihydroxy- ent-kaur-16-ene) afforded 7α,18,19-trihydroxy- ent-kaur-16-ene and 7α,11β,15α,18-tetrahydroxy- ent-kaur-16-ene, respectively. The presence of a 7α-hydroxyl group in epi-candol A avoids its biotransformation along the biosynthetic pathway of gibberellins, and directs it to the seco-ring B acids route. The 15α-hydroxyl group in canditriol inhibits oxidation at C-19 and direct hydroxylation at C-11(β). The formation of fujenoic acid, from 7α-hydroxy- ent-kaur-16-ene, probably occurs via 7α-hydroxykaurenoic acid and 7-oxokaurenoic acid, with subsequent hydroxylation at the C-6(β) position.

Heterothallism in Cordyceps takaomontana

Perithecium formation of an entomopathogenic fungus Cordyceps takaomontana was promoted by treating the mycelia with cell wall-degrading enzymes and PEG 4000. Perithecia were formed in the mixed culture of both mating-type strains MAT1 and MAT2, and not in the culture of MAT1 or MAT2 alone. The MAT1 strains did not possess a mating-type gene MAT1-1-3, but could produce perithecia. These results strongly suggested that C. takaomontana is heterothallic, and does not need MAT1-1-3 for the perithecium formation. MAT1-1-3 was also not found in another entomopathogenic fungus Cordyceps militaris. On the other hand, phytopathogenic fungi Balansia sp., Claviceps purpurea and Epichloë typhina possessed MAT1-1-3. The structures of mating-type locus MAT1-1 of these phytopathogenic fungi in the family Clavicipitaceae were similar to that of a phytopathogenic fungus Gibberella fujikuroi in the family Nectriaceae, which is closely related to Clavicipitaceae. These results suggested that phytopathogen might be more ancestral group than entomopathogen in Clavicipitaceae, and that MAT1-1-3 might be lost in the course of the host shift from plants to insects.

Biotransformation of 7-oxo- ent-kaur-16-ene derivatives by Gibberella fujikuroi

The microbiological transformation of 7-oxo- ent-kaur-16-ene by the fungus Gibberella fujikuroi gave fujenoic acid as the main compound, whilst the incubation of 18-hydroxy-7-oxo- ent-kaur-16-ene and 3α,18-dihydroxy-7-oxo- ent-kaur-16-ene afforded the corresponding 6β-hydroxy-derivatives. These facts indicate that the formation of fujenoic acid in this biotransformation should occur via a 7-oxo-6β-hydroxy derivative. In the three biotransformations, an 11β-hydroxylation was also produced, in low yield, indicating that a 7-oxo-group also directs hydroxylation at C-11.