Bacterial secretion systems contribute to rapid tissue decay in button mushroom soft rot disease.

Potato is one of the most important food crops in the world. Cultivation of potatoes is an important segment of the agriculture and economy as a whole in Ukraine. Bacterial diseases such as ring rot caused by Clavibacter sepedonicus, as well as soft rot and blackleg caused by Pectobacterium atrosepticum evoke tremendous losses of the potato crop. Stored seed tubers are the main source of accumulating pathogens in latent form. In addition, potato crop yield and quality are significantly affected by weather conditions. Along with affecting potatoes directly, meteorological factors such as air temperature and humidity can also impact tuber infestation with bacterial pathogens. The aim of the study was to monitor the prevalence of bacterial ring rot pathogen C. sepedonicus and soft rot pathogen P. atrosepticum in potato tubers on the territory of Ukraine in 2020 and 2021 years and assess its association with different weather conditions. Methods. Potato seed lots from newly harvested crops in eight regions of Ukraine (Odesa, Kyiv, Donetsk, Kherson, Cherkasy, Mykolaiv, Dnipropetrovsk, and Zhytomyr regions) without visual symptoms of diseases were used for the experiments. The detection of C. sepedonicus and P. atrosepticum was conducted by the immunochemical method DAS ELISA. Basal meteorological data (the sum of precipitation (mm/month) and average air temperature (°C) were obtained from the local meteorological stations. The amplitude of air temperature and the sum of precipitation during potato planting, growing, and harvesting seasons, as well as Sielianinov’s hydrothermal coefficient (K) were additionally calculated. The Spearman correlation coefficient was used for the analysis of the correlation between pathogen prevalence and weather parameters. Results. Both ring rot pathogen C. sepedonicus and soft rot pathogen P. atrosepticum were detected in potato lots from all surveyed regions, but the prevalence of latent infestation varied between 2020 and 2021. In 2020, the highest soft rot pathogen prevalence values were registered for Mykolaiv, Kyiv, and Cherkasy regions (21.7, 10.5, and 10% respectively), where high rainfall levels in May and June were observed. In 2021, potato planting, growing, and harvesting seasons were marked by significantly higher precipitation levels, as compared to 2020, in all regions. Average occurrence values for P. atrosepticum in potato lots were 1.7 times higher than that in 2020. The highest prevalence (40%) was observed in the Donetsk region with extremely high air humidity during the potato growing period. Strong positive correlation (r = 0.721) was found between soft rot pathogen prevalence and K coefficients during the potato growing season, as well as between P. atrosepticum prevalence and the sum of precipitation during planting and early growing seasons. Prevalence of ring rot pathogen didn’t differ significantly in 2020 and 2021. The highest C. sepedonicus prevalence was observed in 2020 in the Kyiv region (18.9%), and in 2021 — in the Donetsk region (20%). A moderate positive correlation (r = 0.591) was found between pathogen prevalence and air temperature during planting and early growing season. Conclusions. Weather factors such as air temperature and humidity over the planting and early growing potato season can influence progeny tuber infestation with P. atrosepticum and C. sepedonicus. Knowledge of the effect of the changing weather conditions on the susceptibility of potato varieties with different genetic features to infestation with soft rot and ring rot pathogens warrants future investigation since it is crucially important for developing measures for disease control by potato producers.

Bacterial soft rot disease is one of the most destructive diseases of vegetables worldwide causing huge economic losses in the field, in transit and in storage or during marketing. Potato is one of the most globally important crops its yield is badly affected by soft rot disease. It is primarily caused by Pectobacteriaceae family and Pectobacterium carotovorum is one of the most devastating plant pathogens that causes soft rot disease. Soft rot disease has a wide range of hosts of vegetable crops and ornamental plant. The effected tissue of the host becomes soft and slimy without much discoloration and bad smell. Several strategies have been developed to control potato soft rot. The use of natural plant products such as plant extracts and green synthesized silver nanoparticles has emerged as being promising alternative and safe way than the synthetic chemicals to control soft rot disease. This review discusses potato soft rot disease and the controlling measures through presenting an overview of the results of studies done on this disease.

Soft rot diseases cause crop losses all over the world. These losses can have large economic impacts and threaten international food security. Soft rot bacterial pathogens produce pectolytic enzymes that attack the pectin around plant cells resulting in smelly, wet, and mushy tissue maceration. Once symptoms are visible, the crop cannot be used or consumed in any way. A wide range of vegetables, fruits, and ornamental flowers can be affected by soft rot disease. The plant themselves have defense strategies to protect against invaders, but plant pathogens have their own strategies to evade the host immune system. The most common soft rot agents are Pectobacterium and Dickeya species. Recently, another plant pathogen, Erwinia persicina, has been described as a soft rot agent, but a detailed analysis of this pathogen has not been conducted. Here, we provide the first genomic analysis of Erwinia persicina and the first investigation into the biological role of a phenolic acid decarboxylase gene found in Erwinia persicina. Erwinia persicina shares traits with both common soft rot agents and other Erwinia species, while having unique characteristics of its own. The putative phenolic acid decarboxylase gene confers the ability to utilize phenolic acids, including caffeic acid and p-coumaric acid, when cloned into Escherichia coli LMG194 cells. The phenolic acid decarboxylase has the potential to be a novel pathogenicity factor for soft rot pathogens. Future researchers could leverage these results into in-field diagnostic tools, targets for novel control measures. While it is important to understand how plant pathogens persist in the plant environment, interact with their plant hosts, and cause disease, it is also important, as researchers and instructors, to understand how students learn scientific concepts to effectively teach future scientists and an informed public. Science education research aims to investigate all factors that contribute or impact student learning including student attitudes and motivations, the classroom environment, or the type of instruction received. When comparing different learning strategies, it is important to be able to accurately measure student learning of specific concepts. Concept inventories are multiple-choice assessments that are rigorously tested to evaluate student understanding and pinpoint student misconceptions. We provide an examination into classroom environment, specifically, how seat position can impact student performance, as well as, the development of the Mutations Criterion Reference Assessment (MuCRA) and an investigation into the misconceptions students hold about mutations. Students that sit in the back of a large introductory biology course performed worse and attended less. When accounting for the lowered attendance in a mediation model, the negative effects of sitting the back were more associated with attendance than seat position. The MuCRA was found to be a valid and reliable instrument that contained distractor options that correctly pinpointed common misconceptions. Student misconceptions about mutations persisted across years in college (1st-4th year), but did not persist across levels of biology experience (introductory to advanced). More interaction with biology concepts changes how students select their responses on the assessment. This research has implications for evaluating teaching strategies, providing instructor resources to measure student learning and misconceptions, and insight into how the classroom environment can impact student performance.

In October 2021, soft rot disease seriously affected radish crop in Dangjin, Chungcheongnam-do, Korea. The infected radishes were stunted and turned dark green, with yellowish leaf foliage. A slimy, wet, and decayed pith region was observed in the infected roots. The bacterial strain KNUB-03-21 was isolated from infected roots. The biochemical and morphological characteristics of the isolate were similar to those of Pectobacterium brasiliense. Phylogenetic analysis based on the sequences of the 16S rRNA region and the concatenated DNA polymerase III subunit tau (dnaX), leucine-tRNA ligase (leuS), and recombinase subunit A (recA) genes confirmed that the isolate is a novel strain of P. brasiliense. Artificial inoculation of radish with P. brasiliense KNUB-03-21 resulted in soft rot symptoms similar to those observed in infected radish in the field; subsequently, P. brasiliense KNUB-03-21 was reisolated and reidentified. To our knowledge, this is the first report of P. brasiliense as a causal pathogen of radish soft rot in Korea.

Amorphophallus species are one of the main economic crops in the mountainous areas of southwest China. However, soft rot disease ( Pectobacterium carotovorum ssp. carotovorum ) is devastating for this crop. This study explored the Amorphophallus resistance mechanism against soft rot disease by analyzing transcriptome data using a weighted gene coexpression network analysis. The RNA sequencing of plants infected for 0, 12, 24, and 48 hours produced a total of 52.25 Gb of clean reads. A total of 29,096 genes were divided into 34 modules. Six modules of interest with the highest correlation with the target traits were selected to elucidate the resistance genes and pathways. The selected modules were enriched in the α-linolenic acid metabolism, phenylpropane biosynthesis, plant hormone signal transduction, and plant pathogen interaction pathways. Ultimately, AmBGLU , AmCAML , AmCDPK , AmLOX , and AmRBOHD were identified as genes of interest in the four significantly related metabolic pathways for real-time fluorescence quantitative polymerase chain reaction verification. The determination of salicylic acid (SA) and jasmonic acid (JA) in Amorphophallus muelleri and Amorphophallus konjac that suffered from soft rot disease showed that SA and JA were involved in the A. muelleri and A. konjac defense response against soft rot disease. Methyl jasmonate treatment delayed the onset of A. konjac soft rot disease. This study provides a reference for the interaction between Amorphophallus species and soft rot disease and the breeding of broad-spectrum and specific Amorphophallus cultivars that are resistant to soft rot disease.

White button mushroom (Agaricus bisporus) disrupts androgen receptor signaling in human prostate cancer cells and patient-derived xenograft

Soft rot disease of Amorphorallus konjac, an important and potentially destructive corms disease, is caused by Pectobacterium species. Now, the conventional methods of controlling the disease include the breeding variety and the chemical control, but the effects are uncomfortable. The aim of this study was to screen antagonistic bacteria for soft rot disease and optimize its fermentation conditions. The antagonistic bacterium (strain C12) confirmed Bacillus subtilis by the identification of Biolog system and analysis of 16S rDNA gene sequence. Antimicrobial spectrum of the strain C12 was determined by growth rate method, which could restrain the growth of 12 pathogens. The fermentation conditions of the strain C12 were studied by using the single-factor method. The optimal fermentation conditions for antagonistic bacteria were as follow: Medium initial pH 7.0, the fermentation temperature 31°C, the quantity of medium 50 mL in a 250 mL flask, the inoculation volume 2.5%, the incubation time 22 h and the rotation speed 180 rpm, the glucose as carbon source and yeast as nitrogen source. The fermentation liquor of the strain C12 was twice than the streptomycin in control effect of pot experiment. The research provides reference for controlling soft rot disease of A. konjac. The findings suggested that the strain C12 could be exploited as a biocontrol agent for soft rot pathogens.   Key words: Soft rot disease, antagonistic bacteria, characterization, fermentation condition, optimization.

Button mushroom (Agaricus bisporus) is the predominant mushroom species cultivated around the world. In the button mushroom cultivation, casing soil is one of the main substrate inducing emergence of mushrooms but presence of Trichoderma aggressivum f. aggressivum (causal agent of green mould disease) in casing soil causes devastating yield losses. However, little is known about management of the green mould in button mushroom cultivation. The aim of this study was to examine efficacy of several disinfectants and heat treatments against T. aggressivum f. aggressivum in casing soil and mushroom yield. In this respect, by considering yield (total amount of sporophores) values, in vivo experiments were separately set up according to randomized block design with three replications. As a result, compared to controls, disinfectants [hydrogen peroxide (H202), formaldehyde (CH2O), sodium hypochlorite (NaOCl) and hypochlorous acid (HOCl)] and heat treatments (60, 90 and 120 °C) significantly (P˂0.01) increased mushroom yields up to 18.74 and 24.06% in the treated plots, respectively. Biological efficiency values ranged from 87.16 to 105.72% in the disinfectant treatments, while they varied from 93.15 to 95.68% in the heat treatments. However, applications of the disinfectants at high doses had negative influence on growth of A. bisporus. The overall results suggest that the tested disinfectants and heat treatments may significantly increase button mushroom yield by suppressing development of T. aggressivum f. aggressivum in casing soil. The present study not only reveals management practices that can be used against the green mould in the in vivo but also presents new knowledge for mushroom industry.

The citrus industry is of significant global economic importance but faces substantial postharvest losses from soft rot disease. While chemical fungicides are commonly used for control, their application has raised concerns about pathogen resistance and environmental hazards. This concern underscores the urgent need for safe and sustainable alternatives. The current research focused on isolation and identification of primary pathogen responsible for soft rot in mandarin (Citrus unshiu Marc) and evaluated the efficacy of the antagonistic yeast Debaryomyces nepalensis as a biological control agent. A fungal pathogen was isolated from diseased citrus fruits, identified as Aspergillus niger through morphological and molecular analyses, and its soft rot pathogenicity was confirmed by inoculation experiments, leading to 100% disease incidence within nine days. The biocontrol efficacy of a D. nepalensis and a commercial agent ('LvKangWei') containing Bacillus amyloliquefaciens was tested against A. niger-induced soft rot. Both treatment with 'LvKangWei' and D. nepalensis significantly reduced disease severity, with a control efficacy of 31.54% and 22.98% respectively at 15days post-inoculation. The research extends the study of effect of the yeast biocontrol agents that was associated with the induction of host defense responses, as evidenced by a significant increase in CAT, POD, and SOD activity and the maintenance of total sugar content compared to infected control fruit. Our findings demonstrate that D. nepalensis is an effective biocontrol agent against A. niger-induced soft rot in mandarin.

Head soft rot is the major disease of broccoli caused by Pseudomonas fluorescens and Pectobacterium carotovorum (formerly Erwinia carotovora). However, in the present work, Pseudomonas sp. was isolated along with Pantoea agglomerans and Serratia liquefaciens, from broccoli heads with disease symptoms. Different phytopathogenic assays confirmed the ability of the isolated Serratia liquefaciens strain to produce soft rot disease in stems and florets of broccoli. This study also investigated the effect of an amaranth cystatin (AhCPI) on the growth of these three bacterial pathogens and on the development of soft rot symptoms in broccoli. AhCPI significantly reduced the severity of head soft rot symptoms caused by Pseudomonas sp., and S. liquefaciens in vitro. Bacterial growth inhibition increased with the increase in AhCPI concentration. In the same way, it was demonstrated that the application of AhCPI (10 or 20 μM) on florets of broccoli with soft rot symptoms significantly reduced the severity of disease caused by S. liquefaciens or Pseudomonas sp. Our results suggest that S. liquefaciens can produce head soft rot in florets of broccoli and AhCPI could be a new sustainable alternative for the control of head soft rot disease in broccoli.

Identification and characterization of Pantoea eucalypti as the causative agent of soft rot disease in Chinese chive (Allium tuberosum Rottler ex Sprengle) in China☆

Nonalcoholic fatty liver disease (NAFLD) includes various hepatic pathologies ranging from hepatic steatosis to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Estrogen provides a protective effect on the development of NAFLD in women. Therefore, postmenopausal women have a higher risk of developing NAFLD. Hepatic steatosis is an early stage of fatty liver disease. Steatosis can develop to the aggressive stages (nonalcoholic steatohepatitis, fibrosis and cirrhosis). Currently, there is no specific drug to prevent/treat these liver diseases. In this study, we found that white button mushroom (WBM), Agaricus Bisporus, has protective effects against liver steatosis in ovariectomized (OVX) mice (a model of postmenopausal women). OVX mice were fed a high fat diet supplemented with WBM powder. We found that dietary WBM intake significantly lowered liver weight and hepatic injury markers in OVX mice. Pathological examination of liver tissue showed less fat accumulation in the livers of mice on WBM diet; moreover, these animals had improved glucose clearance ability. Microarray analysis revealed that genes related to the fatty acid biosynthesis pathway, particularly the genes for fatty acid synthetase (Fas) and fatty acid elongase 6 (Elovl6), were down-regulated in the liver of mushroom-fed mice. In vitro mechanistic studies using the HepG2 cell line showed that down-regulation of the expression of FAS and ELOVL6 by WBM extract was through inhibition of Liver X receptor (LXR) signaling and its downstream transcriptional factor SREBP1c. These results suggest that WBM is protective against hepatic steatosis and NAFLD in OVX mice as a model for postmenopausal women.

Films were fabricated using the button mushroom (Agaricus bisporus) sourced high molecular weight chitosan with or without potato starch using the casting method. Glycerol was used as the plasticizer. Chitosan content in the film-forming solution (FFS) was varied (0.5, 0.75 and 1.0% w/v of FFS) while potato starch (1.0% of FFS) and glycerol (25% of the total solid content in the solution) contents were not varied. The control sample contained only chitosan (1.0% of the FFS) and glycerol. The effect of increasing the content of chitosan on the rheological properties of FFS and the properties of the films were investigated. The FFS's shear viscosity and shear modulus (elastic and viscous components) increased with increasing chitosan content. Morphological examination revealed that the films exhibited a compact structure devoid of large pores and cracks. Surface roughness captured with an atomic force microscope was reduced (19-6 nm) with increasing content of chitosan in the film. The films exhibited two hydrated crystalline phases at 9 and 20o. Light transmittance and glossiness of the films were enhanced with increasing chitosan content. FTIR analysis indicated the increasing availability of reactive sites with the increasing content of chitosan leading to an enhanced hydrogen bonds network and increased cohesion of the film structure. This may be the reason for improved mechanical properties and reduced water vapour permeability of the films with increasing chitosan content.

Drying process compared to others remains a promising method of food preserving technology. So, this work aimed to investigate drying kinetics of button mushroom (Agaricus bisporus) treated by microwave, convective dryer and electric oven within consideration of different power density levels of 3.5, 5 and 7.5 W.g-1. Furthermore, five mathematical drying models were statistically analysed to simulate drying kinetics fitted to the obtained experimental moisture ratio results. The obtained results indicated that, increasing of power densities led to rapidly drying consuming low time. The shortest drying time of mushrooms having initial moisture content (d.b.) of 809% was provided with microwave treatment, whereas drying time decreased (at the above mentioned power density levels, respectively) by 77.7, 85.7 and 84%, comparing to convective dryer, whilst 91.6, 94.4 and 94%, comparing to oven. Page, Modified Page (I) and Modified Page (II) models appeared most expressed best description of the experimental drying results.

Ginger is one of the major cash crops of Sikkim and being an organic state, maintaining sustainability in ginger cultivation is a challenge especially in the changing climate scenario. Soft rot caused by <i>Pythium aphanidermatum</i> is a major problem in ginger cultivation and the disease has resulted into reduction in the acreage under the crop in this Himalayan state. Conventional exhaustive organic inputs, self renewable organic inputs like plant growth-promoting rhizobacteria (PGPR) were tested against the soft rot incidence in ginger for two consecutive years. Two local varieties, namely, Bhaise and Majouley were used with conventional organic inputs and PGPR, alone and in combinations. The disease causing organism was challenge inoculated. The disease symptoms were assessed by visual scoring. In addition, growth and yield parameters were recorded. The results revealed that PGPR along with the other organic inputs have a significant effect on disease suppression in addition to promoting the growth and yield parameters like plant height, number of leaves, number of tillers, leaf area and yield per plant. The information generated can act as a readily available environmentally safe method for the management of soft rot in ginger through organic means.