Brown Rot Research Articles

Significance of Gnomoniopsis smithogilvyi as kernel rot of sweet chestnut in Turkey

AbstractChestnut nut rots caused by fungi, especially by Gnomoniopsis smithogilvyi, showed a significant increase not only in Turkey but also in the other chestnut‐producing countries. In this study, the prevalence of chestnut kernel rot was determined by using 800 fruits collected from eight significant chestnut‐growing provinces of Turkey located in the Black Sea, Marmara, and Aegean Regions. Six types of kernel rot symptoms were determined from the necrotic nuts, brown rot being the most common accounting for 62% of the necrotic nuts. Along with G. smithogilvyi, seven additional fungal species Colletotrichum fioriniae, C. godetiae, Cryphonectria parasitica, Diplodina agrifoliae, Fusarium concentricum, Fusarium tricinctum, and Trichothecium roseum were found to be associated with kernel rot. In addition, some other ubiquitous fungi such as Penicillium spp. were detected. All the pathogenic fungi were identified through a combination of morphological traits and phylogenetic analysis involving partial internal transcribed spacer (ITS) sequences, as well as tef1 and tub2 loci sequences. The most frequently isolated fungus was G. smithogilvyi, and it was found at 98, 31, 10, and 1 of the necrotic kernels out of 291 showing brown rot, brown to black rot, cream colour decay, and white rot symptoms, respectively. It was not found from the kernels showing green rot and greenly‐blue rot symptoms. G. smithogilvyi was prevalent in six of eight chestnut‐growing locations in Turkey. Based on the findings, G. smithogilvyi was shown to be the main fungal agent of brown kernel rot of chestnuts, and some of the other fungi obtained from the kernels were shown to contribute kernel rots of chestnuts.

A type VI secretion system effector TseG of Pantoea ananatis is involved in virulence and antibacterial activity.

The type VI secretion system (T6SS) of many gram-negative bacteria injects toxic effectors into adjacent cells to manipulate host cells during pathogenesis or to kill competing bacteria. However, the identification and function of the T6SS effectors remains only partly known. Pantoea ananatis, a gram-negative bacterium, is commonly found in various plants and natural environments, including water and soil. In the current study, genomic analysis of P. ananatis DZ-12 causing brown stalk rot on maize demonstrated that it carries three T6SS gene clusters, namely, T6SS-1, T6SS-2, and T6SS-3. Interestingly, only T6SS-1 secretion systems are involved in pathogenicity and bacterial competition. The study also investigated the T6SS-1 system in detail and identified an unknown T6SS-1-secreted effector TseG by using the upstream T6SS effector chaperone TecG containing a conserved domain of DUF2169. TseG can directly interact with the chaperone TecG for delivery and with a downstream immunity protein TsiG for protection from its toxicity. TseG, highly conserved in the Pantoea genus, is involved in virulence in maize, potato, and onion. Additionally, P. ananatis uses TseG to target Escherichia coli, gaining a competitive advantage. This study provides the first report on the T6SS-1-secreted effector from P. ananatis, thereby enriching our understanding of the various types and functions of type VI effector proteins.

Turmeric Plant Leaf Oversight, Diagnosis and Recommendation for Control of Diseases by Raspberry Pi 4 and Pi Camera System

In the agriculture industry, disease identification is vital. As a rhizomatous crop, turmeric is widely recognized for its therapeutic use. It is vital to keep an eye on these crops. The most common diseases that affect turmeric leaves are leaf spots, leaf blotch, brown rot, dry rot, and leaf blight. The research creates a hardware system that enables early disease diagnosis and prevention before it affects the entire crop, resulting in high-quality agricultural production. Using k-means image segmentation, a database of various leaf pictures will be generated and handled. Pi camera interfaced with Raspberry Pi 4 hardware will be used to capture images of infected plants and will be used for further processing and analysis. Pesticides or insecticides will be recommended to farmers according to the status of plant disease through the use of friendly communication like WhatsApp or SMS.

Trunk Injection Delivery of Biocontrol Strains of Trichoderma spp. Effectively Suppresses Nut Rot by Gnomoniopsis castaneae in Chestnut (Castanea sativa Mill.).

Gnomoniopsis castaneae is responsible for brown or chalky nut rot in sweet chestnut (Castanea sativa), causing heavy reductions in nut production. Controlling it is challenging, due to its inconspicuous infections, erratic colonization of host tissues and endophytic lifestyle. Fungicides are not applicable because they are prohibited in chestnut forests and strongly discouraged in fruit chestnut groves. Trichoderma species are safe and wide-spectrum biocontrol agents (BCAs), with a variety of beneficial effects in plant protection. This study tested selected strains of T. viride, T. harzianum and T. atroviride for their ability to suppress G. castaneae. Field experiments were conducted in four chestnut groves (two test plots plus two controls) at two sites with a different microclimate. As the size of the trees were a major drawback for uniform and effective treatments, the Trichoderma strains were delivered directly by trunk injection, using the BITE® (Blade for Infusion in TrEes) endotherapic tool. The BCA application, repeated twice in two subsequent years, significantly reduced nut rot incidence, with a more marked, presumably cumulative, effect in the second year. Our data showed the tested Trichoderma strains retain great potential for the biological control of G. castaneae in chestnut groves. The exploitation of Trichoderma spp. as biopesticides is a novelty in the forestry sector and proves the benefits of these microbes in plant disease protection.

Global Transcriptome Analysis of the Peach (Prunus persica) in the Interaction System of Fruit-Chitosan-Monilinia fructicola.

The peach (Prunus persica L.) is one of the most important stone-fruit crops worldwide. Nevertheless, successful peach fruit production is seriously reduced by losses due to Monilinia fructicola the causal agent of brown rot. Chitosan has a broad spectrum of antimicrobial properties and may also act as an elicitor that activate defense responses in plants. As little is known about the elicitation potential of chitosan in peach fruits and its impact at their transcriptional-level profiles, the aim of this study was to uncover using RNA-seq the induced responses regulated by the action of chitosan in fruit-chitosan-M. fructicola interaction. Samples were obtained from fruits treated with chitosan or inoculated with M. fructicola, as well from fruits pre-treated with chitosan and thereafter inoculated with the fungus. Chitosan was found to delay the postharvest decay of fruits, and expression profiles showed that its defense-priming effects were mainly evident after the pathogen challenge, driven particularly by modulations of differentially expressed genes (DEGs) related to cell-wall modifications, pathogen perception, and signal transduction, preventing the spread of fungus. In contrast, as the compatible interaction of fruits with M. fructicola was challenged, a shift towards defense responses was triggered with a delay, which was insufficient to limit fungal expansion, whereas DEGs involved in particular processes have facilitated early pathogen colonization. Physiological indicators of peach fruits were also measured. Additionally, expression profiles of particular M. fructicola genes highlight the direct antimicrobial activity of chitosan against the fungus. Overall, the results clarify the possible mechanisms of chitosan-mediated tolerance to M. fructicola and set new foundations for the potential employment of chitosan in the control of brown rot in peaches.

Decay resistance of southern pine wood containing varying amounts of resin against Fomitopsis ostreiformis (Berk.) T. Hatt.

Abstract Resin production in wood tissues is a regular feature of pine wood species, including southern pine. High resin contents of southern pine wood may increase wood resistance against decay fungi. The current study investigated the effect of resin contents in southern pine wood on decay resistance by exposing non-extracted heartwood, mixed wood (sapwood + heartwood), and sapwood blocks with varying resin content to brown rot, Fomitopsis ostreiformis in a laboratory decay test. Matching blocks of each wood type were successively extracted in a Soxhlet using three solvents to determine resin content and were exposed to decay fungus in parallel. Results showed that mass losses in non-extracted heartwood and mixed wood depended on resin content levels, and very shallow or no mass losses were observed in blocks containing more than 31 % resin content. Sapwood experienced high mass losses, but the presence of resinous extractives significantly increased the decay resistance. All solvent-extracted blocks experienced high mass loss (53–55 %). Scanning electron microscopy showed that penetration of brown rot hyphae and cell damage depended on the resin contents of blocks. Most of the identified compounds through GC-MS belonged to oleoresins, among which monoterpene hydrocarbons, oxygenated monoterpenoids, and sesquiterpenes were more abundant in heartwood than sapwood.

Screening of Antagonistic Bacillus against Brown Rot in Dendrocalamus latiflorus and Preparation of Applying Bacterial Suspension.

The aim of this study was to isolate biocontrol bacteria that could antagonize brown rot of Dendrocalamus latiflorus, optimize the culture conditions, and develop an effective biocontrol preparation for brown rot of D. latiflorus. This study isolated a bacterium with an antagonistic effect on bamboo brown rot from healthy D. latiflorus rhizosphere soil. Morphology, molecular biology, and physiological biochemistry methods identified it as Bacillus siamensis. The following culturing media and conditions improved the inhibition effect of B. siamensis: the best culturing media were 2% sucrose, 1.5% yeast extract, and 0.7% potassium chloride; the optimal culturing time, temperature, pH, and inoculation amount were 48 h, 30℃, 6, and 20%. The optimum formula of the applying bacterial suspension was 14% sodium dodecyl benzene sulfonate emulsifier, 4% Na2HPO4·2H2O, 0.3% hydroxypropyl methylcellulose thickener, and 20% B. siamensis. The pot experiment results showed the control effect of applying bacterial suspension, diluted 1,000 times is still better than that of 24% fenbuconazole suspension. The applying bacterial suspension enables reliable control of brown rot in D. latiflorus.

Effect of co-cultivation of white and brown rot species on basidiome production, lignocelluloytic enzyme activity and dye decolourisation

The aim of this work was studying the impact of co-cultivating two mushroom species: a white (Pleurotus albidus CLA 45) and a brown rot one (Laetiporus sulphureus BAFC 205) in substrates based on poplar or pine sawdust, on their lignocellulolytic enzyme production, yield values and basidiomes properties. Laetiporus sulphureus only developed basidiome primordia, but P. albidus monoculture and co-culture in pine sawdust achieved biological efficiencies of up to 50–55 %. Co-cultivation on diverse substrates rendered varied enzyme titers. Laccase and Manganese peroxidase titers were highest in pine co-culture and P. albidus poplar monoculture, respectively. Enzymatic extracts obtained from spent poplar substrate of dual cultures displayed potential for treating non-sterile textile-coloured effluents, achieving 35 % decolourisation after 120 h. The knowledge available on the effects of co-culture of white and brown rot fungi is still limited. This study represents an initial exploration of the interaction between them within intensive cultivation conditions.

Reevaluation of Sensitivity of Monilinia fructicola Isolates to the DMI Fungicide Propiconazole in the Southeastern United States and Investigation of the Genetic Element Mona.

Sterol demethylation inhibitor (DMI) fungicides continue to be essential components for the control of brown rot of peach caused by Monilinia fructicola in the United States and worldwide. In the southeastern United States, resistance to DMIs had been associated with overexpression of the cytochrome P450 14α-demethylase gene MfCYP51 as well as the genetic element Mona, a 65 bp in length nucleotide sequence located upstream of MfCYP51 in resistant isolates. About 20 years after the first survey, we reevaluated sensitivity of M. fructicola from South Carolina and Georgia to propiconazole and also evaluated isolates from Alabama for the first time. A total of 238 M. fructicola isolates were collected from various commercial and two experimental orchards, and sensitivity to propiconazole was determined based on a discriminatory dose of 0.3 μg/ml. Results indicated 16.2, 89.2, and 72.4% of isolates from Alabama, Georgia, and South Carolina, respectively, were resistant to propiconazole. The detection of resistance in Alabama is the first report for the state. All resistant isolates contained Mona, but it was absent from most sensitive isolates. It was unclear if the resistance frequency had increased in South Carolina and Georgia. However, the resistance levels (as assessed by the isolate frequency in discriminatory dose-based relative growth categories) did not change notably, and no evidence of other resistance genotypes was found. Analysis of the upstream MfCYP51 gene region in the resistant isolate CF010 revealed an insertion sequence described for the first time in this report. Our study suggests that current fungicide spray programs have been effective against increasing resistance levels in populations of M. fructicola and suppressing development of new resistant genotypes of the pathogen.

Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Citrus limetta Peels Extract and Their Antibacterial Activity Against Brown and Soft Rot Pathogens and Antioxidant Potential

Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Citrus limetta Peels Extract and Their Antibacterial Activity Against Brown and Soft Rot Pathogens and Antioxidant Potential

Insights into the functional role of Actinomycetia in promoting plant growth and biocontrol in tea (Camellia sinensis) plants.

Tea, a highly aromatic and globally consumed beverage, is derived from the aqueous infusion of dried leaves of Camellia sinensis (L.) O. Kuntze. Northeast India, encompassing an expansive geographical area between 24° and 27°N latitude and 88° and 95°E longitude, is a significant tea-producing region covering approximately 312,210 hectares. Despite its prominence, this region faces persistent challenges owing to a conducive climate that harbors the prevalence of pests, fungal pathogens, and weeds, necessitating agrochemicals. Helopeltis theivora, Oligonychus coffeae, and Biston suppressaria are prominent among the tea pests in this region. Concurrently, tea plants encounter fungal infections such as blister blight, brown root rot, and Fusarium dieback. The growing demand for safer tea production and the need to reduce pesticide and fertilizer usage has spurred interest in exploring biological control methods. This review focuses on Actinomycetia, which potentially safeguards plants from diseases and pest infestations by producing many bioactive substances. Actinomycetia, which resides in the tea rhizosphere and internal plant tissues, can produce antagonistic secondary metabolites and extracellular enzymes while promoting plant growth. Harnessing the biocontrol potential of Actinomycetia offers a promising solution to enhance tea production, while minimizing reliance on harmful agrochemicals, contributing to a more environmentally conscious and economically viable tea cultivation system.

Taxonomic study and diversity of Postia s.lat. in Swat, Pakistan: addition of five brown rot Polypores to the country.

Brown rot Polypores are ecologically significant as they play a crucial role in maintaining the carbon cycle and contribute to humus formation in forest ecosystems through their lignocellulose degradation ability. It is important to note that some species can significantly impact timber, potentially causing decay in economically valuable wood. Many Asian countries including Pakistan are still under the exploratory phase and have undocumented species diversity in Polypore fungi. In the current study, collections representing five different species belonging to two families, Postiaceae and Adustoporiaceae, were subjected to detailed morphoanatomical and molecular analyses. A combined matrix of two gene datasets (ITS and nrLSU) was analyzed using three different phylogenetic methods viz. Maximum Parsimony (MP), Maximum Likelihood (ML), and Bayesian inference (BI). Our study presents descriptions of five previously undocumented brown rot Polypore species from the country including Fuscopostia fragilis (Fr.) B.K. Cui, L.L. Shen & Y.C. Dai, Amaropostia stiptica (Pers.) B.K. Cui, L.L. Shen & Y.C. Dai, Cyanosporus piceicola B.K. Cui, L.L. Shen & Y.C. Dai, Spongiporus balsameus (Peck) A. David, Rhodonia placenta (Fr.) Niemelä, K.H. Larss. & Schigel. Regarding the molecular data, nodes of our subject sequences were substantially supported and fell under their respective species clades with high ML bootstrap values (≥ 95), MP bootstrap ≥ 74 and BI probabilities ≥ 0.98. Findings of the study will not only contribute to our understanding of local Polypores species diversity but also enhance knowledge of geographical distribution in global context.

Degradation of reburied archaeological wood piles after preservative treatment for twenty years

This study investigated the degradation mechanism and microbial communities of a reburied stone-fixed wooden pile (SP) after being excavated and treated with pentachlorophenol/polyethylene glycol (PCP/PEG) preservatives for a 20-year period at the Jin Zhongdu Watergate Heritage Cultural Site. High-throughput sequencing (HTS) techniques were combined with scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectrum analysis, and quantitative chemical analyses. A foundation wooden pile (FP) forming the watergate supports, which has been in service for nearly 870 years at the site, was also examined. The results showed that preservatives still partially remained in the SP after burial. More abundant and richer microbial communities were found in the SP (including brown rot, soft rot, white rot fungi and bacteria) due to the hydrophilic PEG providing more favorable habitats for microbial. Therefore, it was indicated that the PCP had gradually lost its antibacterial function. Although brown rot fungi had not been detected using HTS, typical morphological characteristics were observed in the FP using SEM, thereby the characteristics of brown rot fungi were the results of previous decay. The absence of brown rot may have been attributed the competition among wood rot fungi.

Study on the control effect and physiological mechanism of Wickerhamomyces anomalus on primary postharvest diseases of peach fruit

Brown rot, aspergillosis and soft rot are the primary diseases of postharvest peach fruit. Our study aimed to investigate the biocontrol effect of Wickerhamomyces anomalus on the primary postharvest diseases of peach fruit and to explore its underlying physiological mechanism. The findings demonstrated that W. anomalus had an obvious inhibitory effect on Monilinia fructicola, Aspergillus niger and Rhizopus stolonifer. At the same time, W. anomalus can grow stably on the wound and surface of peach fruit at 25 °C and 4 °C and can form biofilm. W. anomalus increased the activity of resistance-related enzymes such as PPO, POD, GLU and the content of secondary metabolites such as total phenols, flavonoids and lignin in peach. Furthermore, the application of W. anomalus led to a reduced MDA level in peach fruit and increased activity of the active oxygen-scavenging enzyme system. This increase involved various antioxidant defense enzymes such as SOD and CAT, as well as ascorbic acid-glutathione (AsA-GSH) enzymes, including APX, GPX, GR, DHAR, and MDHAR. Our findings demonstrate that W. anomalus exerts its biocontrol effect by growing rapidly, competing with pathogens for nutrition and space, and enhancing the disease resistance and antioxidative capabilities of the peach fruit.

The volatile components from Bacillus cereus N4 can restrain brown rot of peach fruit by inhibiting sporulation of Monilinia fructicola and inducing disease resistance

Brown rot caused by Monilinia fructicola is one major disease in harvested peach fruit. Natural volatile compounds (VOCs) produced by antagonistic microorganisms have good biocontrol effects on postharvest fungal diseases. The present study showed the VOCs of Bacillus cereus N4 isolated from the orchard soil could significantly inhibit the sporulation and mycelial growth of M. fructicola. The expression levels of MfRGS2, MfRGS3 and MfLTF2α, which are unfavorable to the sporulation of M. fructicola were significantly induced by the VOCs of B. cereus N4. Moreover, the expression levels of MfRGS1, MfRGS4, MfREG1, MfPPOA and MfOPT1, which are beneficial to the sporulation of M. fructicola were markedly repressed. After fumigated with the VOCs of B. cereus N4 then inoculated with M. fructicola, peach fruit exhibited markedly lower disease incidence and lesion diameter than the control. Moreover, the activity of CHI and the expression level of PpCHI and PpPR1 of the fruit were significantly improved. 3-methyl-1-butanol, s-methyl butanethioate and 2-methyl-2-(methylthio)propane were the main antifungal substances in the VOCs of B. cereus N4 identified by gas chromatograph-mass spectrometer (GC-MS). Overall, the study provides natural candidates antibacterial agent from a biocontrol agent B. cereus N4 to restrain brown rot of peach fruit caused by M. fructicola.

Streptomyces rapamycinicus HCD1–10: An effective biocontrol actinomycetes against postharvest Chinese flat peach brown rot caused by Monilinia fructicola

Monilinia spp. causing brown rot are fungal pathogens producing severe losses in worldwide stone fruit production, with high economic relevance (M€ 1.7/year). There are three main fungal species: Monilinia laxa, M. fructigena and M. fructicola. The pathogen infects aerial parts of host plants with a variety of symptoms, including blighting of blossoms, cankers on woody tissues and rotting of fruits, although the prevalent fruit losses are in the postharvest phase. Fungicide sprays in pre- and postharvest periods are usually used to control Monilinia spp. but, in Europe, no fungicide fruit treatments are allowed after harvest. Many studies conducted in recent years have defined three main research fields within the alternative methods for postharvest brown rot control: (1) biological control sensu strictum with microbial antagonists; (2) use of natural bioactive compounds; and (3) use of physicochemical methods. Although the reviewed results have reported a significant reduction of pesticide use, a multidisciplinary approach is recommended in the future, where biological products will be combined with low-risk chemical fungicides, natural antimicrobial substances and other physical means for an integrated strategy to control brown rot.

Virus induced gene silencing confirms oligogenic inheritance of brown stem rot resistance in soybean.

Brown Stem Rot (BSR), caused by the soil borne fungal pathogen Phialophora gregata, can reduce soybean yields by as much as 38%. Previous allelism studies identified three Resistant to brown stem Rot genes (Rbs1, Rbs2, and Rbs3), all mapping to large, overlapping regions on soybean chromosome 16. However, recent fine-mapping and genome wide association studies (GWAS) suggest Rbs1, Rbs2, and Rbs3 are alleles of a single Rbs locus. To address this conflict, we characterized the Rbs locus using the Williams82 reference genome (Wm82.a4.v1). We identified 120 Receptor-Like Proteins (RLPs), with hallmarks of disease resistance receptor-like proteins (RLPs), which formed five distinct clusters. We developed virus induced gene silencing (VIGS) constructs to target each of the clusters, hypothesizing that silencing the correct RLP cluster would result in a loss of resistance phenotype. The VIGS constructs were tested against P. gregata resistant genotypes L78-4094 (Rbs1), PI 437833 (Rbs2), or PI 437970 (Rbs3), infected with P. gregata or mock infected. No loss of resistance phenotype was observed. We then developed VIGS constructs targeting two RLP clusters with a single construct. Construct B1a/B2 silenced P. gregata resistance in L78-4094, confirming at least two genes confer Rbs1-mediated resistance to P. gregata. Failure of B1a/B2 to silence resistance in PI 437833 and PI 437970 suggests additional genes confer BSR resistance in these lines. To identify differentially expressed genes (DEGs) responding to silencing, we conducted RNA-seq of leaf, stem and root samples from B1a/B2 and empty vector control plants infected with P. gregata or mock infected. B1a/B2 silencing induced DEGs associated with cell wall biogenesis, lipid oxidation, the unfolded protein response and iron homeostasis and repressed numerous DEGs involved in defense and defense signaling. These findings will improve integration of Rbs resistance into elite germplasm and provide novel insights into fungal disease resistance.

Correction: First report of bacterial brown root rot in pea sprouts (Pisum sativum L.) caused by a Pseudomonas species

Correction: First report of bacterial brown root rot in pea sprouts (Pisum sativum L.) caused by a Pseudomonas species

A Review on Natural Extractives as Protective Agent against Decay on Wood and Bamboo Products

This study examined plant extracts from leaves, bark, bole, roots, flowers, and fruits. Plant metabolites and derivatives inhibit brown, white, and soft rot, which decomposes wood and bamboo. The metabolites and derivatives found in plant extracts serve as a protective measure against the biodeterioration of wood and bamboo. The effectiveness of the plant depends on the toxicity of its extract. Plant extracts contain volatile compounds with antifungal properties. Mineral salts such as aluminium and copper sulphates, as well as MUF, impede the process of alcohol evaporation. Plant extract is a more effective and environmentally friendly treatment for bamboo and wood.

Epoxy-Acrylic Polymer In-Situ Filling Cell Lumen and Bonding Cell Wall for Wood Reinforcement and Stabilization.

Under a global carbon-neutralizing environment, renewable wood is a viable alternative to non-renewable resources due to its abundance and high specific strength. However, fast-growing wood is hard to be applied extensively due to low mechanical strength and poor dimensional stability and durability. In this study, epoxy-acrylic resin-modified wood was prepared by forming a functional monomer system with three monomers [glycidyl methacrylate (GMA), maleic anhydride (MAN), and polyethylene glycol-200-dimethylacrylic acid (PEGDMA)] and filling into the wood cell cavity. The results showed that in the case of an optimal monomer system of nGMA:nPEGDMA = 20:1 and an optimal MAN dosage of 6%, the conversion rate of monomers reached 98.01%, the cell cavity was evenly filled by the polymer, with the cell wall chemically bonded. Thus, a bonding strength of as high as 1.13 MPa, a bending strength of 112.6 MPa and an impact toughness of 74.85 KJ/m2 were applied to the modified wood, which presented excellent dimensional stability (720 h water absorption: 26%, and volume expansion ratio: 5.04%) and rot resistance (loss rates from white rot and brown rot: 3.05% and 0.67%). Additionally, polymer-modified wood also exhibited excellent wear resistance and heat stability. This study reports a novel approach for building new environmentally friendly wood with high strength and toughness and good structural stability and durability.