•ASA reduced fusarium rot severity and NEO distribution in muskmelon fruits inoculated with F. sulphureum.•ASA increased the generation of O2.− and H2O2 by activating plant membrane NOX.•ASA enhanced ...antioxidant enzymes’ activity of POD, CAT and SOD and ascorbate-glutathione cycle.•ASA improved gene expressions involved in ROS metabolism.
Major losses in the harvested muskmelon fruit can be attributed to decay fungi. Fusarium sulphureum is the major causal agent of fusarium rot in muskmelon, which in turn, not only causes quality deterioration but also leads to neosolaniol (NEO) contamination. Therefore, new strategies to manage muskmelon postharvest decay and decrease NEO production are of paramount importance. Acetylsalicylic acid (ASA), a derivative of salicylic acid (SA), is a putative endogenous signal molecular and can induce resistance against decay fungi in postharvest fruit and vegetable. To investigate the mechanism of induced resistance by ASA treatment against fusarium rot of muskmelon, the fruit was treated with ASA, followed by the inoculation with F. sulphureum. Results showed that the reduction of fusarium rot severity and the suppression of NEO accumulation were linked with the elevation of ROS metabolism. ASA treatment enhanced ROS accumulation and induced the enzymatic activities and up-regulated gene expressions involved in ROS metabolism. Taken together, the present study provides substantial evidence which ASA induced resistance against F. sulphureum in muskmelon fruit to control the fusarium rot development.
Mycotoxins are secondary metabolites produced by pathogenic fungi that colonize fruits and vegetables either during harvesting or during storage. Mycotoxin contamination in fruits and vegetables has ...been a major problem worldwide, which poses a serious threat to human and animal health through the food chain. This review systematically describes the major mycotoxigenic fungi and the produced mycotoxins in fruits and vegetables, analyzes recent mycotoxin detection technologies including chromatography coupled with detector (i.e., mass, ultraviolet, fluorescence, etc.) technology, electrochemical biosensors technology and immunological techniques, as well as summarizes the degradation and detoxification technologies of mycotoxins in fruits and vegetables, including physical, chemical and biological methods. The future prospect is also proposed to provide an overview and suggestions for future mycotoxin research directions.
•EGTA significantly influenced StNOXB in T-2 toxin-treated slices.•EGTA significantly influenced NOX activity on plant membrane and production of O2− and H2O2.•POD, CAT and SOD and ...ascorbate-glutathione cycle were markedly affected by Ca2+.•Ca2+ affects ROS metabolism and the activity of the antioxidant systems in tuber slices.
T-2 toxin at low concentrations can induce ROS accumulation and modulate host resistance in plants. NOX plays crucial roles in ROS production and is regulated by Ca2+via direct binding to EF-hand motifs. In this study, the effect of EGTA (Ca2+ chelating agent) on the expression and enzymatic activity of NOX, as well as the activities and corresponding gene expressions involved in ROS metabolism and cell membrane integrity, were investigated in treated slices. Results indicated that EGTA treatment significantly affected gene expression and activity of NOX, and reduced ROS accumulation and cell membrane integrity and the enzymatic activities and gene expression involved in ROS metabolism when exposed to treatment. The addition of exogenous Ca2+ restored the initial relative transcript abundance, ROS accumulation and their activities. Results suggest that Ca2+ affected by EGTA plays a crucial role in NOX activity regulation, ultimately affecting ROS metabolism in slices induced by T-2 toxin.
Radix Astragali (RA) is the root of Astragalus membranaceus var. mongholicus (Bunge) P.K. Hsiao. In order to determine targeted and effective methods for treating mold infections in fresh RA, ...pathogenic fungi were isolated and identified using morphology and molecular biology techniques, and factors affecting the growth of the pathogenic fungi, such as temperature, pH, light, and carbon and nitrogen sources, were analyzed. Changes in the main active ingredients of RA, such as carbohydrates, flavonoids, and saponins, were detected before and after infection with pathogenic fungi. The results showed that Penicillium polonicum, Trichothecium roseum, and Fusarium equiseti were the main pathogens causing postharvest disease in fresh RA. The optimum growth temperature for the three pathogens was 25 °C; P. polonicum was able to grow at an alkaline pH of 8–9, while T. roseum and F. equiseti grew better and had higher levels of sporulation under acidic conditions with pH values of 5–6. Different carbon and nitrogen sources had different effects on mycelium growth and sporulation. Darkness was favorable for the growth and sporulation of the three pathogens. Compared with healthy RA, the total carbohydrate, flavonoid, and saponin contents of the RA samples infected with the three fungi decreased. This study provides a theoretical basis for the scientific and precise control of RA postharvest disease during storage by targeting different pathogens and their growth conditions.
is an important postharvest pathogen of pomaceous fruit and a causal agent of blue mold or soft rot. In this study, we investigated the effect of ambient pH on growth, ultrastructure alteration, and ...pathogenicity of
, as well as accumulation of patulin and expression of genes involved in patulin biosynthesis. Under different pH, the fungus was routinely cultured and collected for growth, pathogenicity, patulin production, and gene expression studies using transmission electron microscopy, apple inoculation, HPLC, and RT-qPCR methods. Different ambient pH had significant impact on expression of genes and growth factors involved in patulin biosynthesis. Under same range of pH, gene expression profile, growth factors, and patulin accumulation (in vivo and in vitro) all showed similar changing trends. A well-developed cell was observed in addition to upregulation of genes at pH between pH 5.0 and 7.0, while the opposite was observed when pH was too basic (8.5) or too acid (2.5). Additionally, ambient pH had direct or indirect influence on expression of
, and
. These findings will help in understanding the effect of ambient pH on growth, pathogenicity, and patulin production and support the development of successful methods for combating
infection on apple fruits.
The jujube is one of the most popular fruits in China because of its delicious taste and high nutritional value. It has a long history of usage as an important food or traditional medicine. However, ...the jujube is easily infected by fungi, which causes economic losses and threatens human health. When the jujube was infected by
(H1), the changes in nutritional qualities were determined, such as the content of total acid, vitamin C, reducing sugar, etc. In addition, the ability of
(H1) to produce ochratoxin A (OTA) in different inoculation times and culture media was evaluated, and the content of OTA in jujubes was also analyzed. After jujubes were infected by A.
(H1), the total acid, and vitamin C contents increased, while the total phenol content decreased, and the reducing sugar content increased after an initial decrease. Although
(H1) infection caused the jujubes to rot and affected its quality, OTA had not been detected. This research provides a theoretical foundation for maximizing edible safety and evaluating the losses caused by fungal disease in jujubes.
A simple and sensitive label-free impedimetric aptasensor for rapid determination of ochratoxin A (OTA) has been developed, which was based on the combination between thiolated aptamer and gold ...nanoparticles by layer-by-layer self-assembly. Because of the interaction between aptamer and OTA, the relative normalized electron-transfer resistance (ΔR
) values obtained by electrochemical impedance spectroscopy (EIS) was proportional to the concentration of OTA and showed a good linear relationship from 0.1 to 10.0 ng/mL, with a lower detection limit (0.030 ng/mL) than one-step thiolated DNA aptasensor. The established method was successfully applied to detect and analyze OTA in table wine and grape juice, and the recovery was 90.56%⁻104.21% when PVP effective removed of phenolic substances. The label-free impedimetric aptasensor was used for rapid detection and quantitation of OTA in the inoculated grapes with the
(H1), and the production of OTA (62.4 μg/kg, 20 μg/kg) far exceeded the maximum levels of 2 μg/kg after inoculation for three days. The developed method exhibited a good specificity, high sensitivity, time-efficient, and it could be applied to detect the OTA concentration in grape and its commodities.
•ASA inhibited the growth of Fusarium sulphureum.•ASA disturbed the morphological and major cellular changes of F. sulphureum.•ASA reduced Fusarium rot development in muskmelon fruits inoculated with ...F. sulphureum.•ASA reduced neosolaniol accumulation in inoculated muskmelon fruits.•ASA down-regulated Tri genes expressions involved in trichothecenes biosynthesis.
Fusarium rot of muskmelon is a common and frequently-occurring postharvest disease, which leads to quality deterioration and neosolaniol (NEO) contamination. New strategies to control postharvest decay and reduce NEO contamination are of paramount importance. The effects of acetylsalicylic acid (ASA) treatment on the growth of Fusarium sulphureum in vitro, and Fusarium rot development and NEO accumulation in fruits inoculated with F. sulphureum in vivo were investigated. The results showed that ASA inhibited the growth of F. sulphureum, evident morphological and major cellular changes were observed under the microscope. In vivo testing showed that 3.2 mg/mL ASA significantly suppressed Fusarium rot development and NEO accumulation after 6 and 8 d of pathogen inoculation. Meanwhile, Tri gene expressions involved in NEO biosynthesis were down-regulated after treatment. Taken together, ASA treatment not only reduced Fusarium rot development by inhibiting the growth of F. sulphureum, but decreased NEO accumulation by suppressing NEO biosynthesis pathway.
is an important Chinese herbal medicine. However, fresh
is prone to decay during storage due to microorganism infections, seriously affecting the medicinal value and even causing mycotoxin ...accumulation. Therefore, it is necessary to study the pathogens present and develop efficient control strategies to mitigate their detrimental effects on the herbs during storage. In this study, fresh
was collected from Min County in Gansu Province, China. The natural disease symptoms were observed during different storage stages, and the pathogens causing
postharvest decay were isolated from the infected fresh
. Morphological and molecular identification were performed, and pathogenicity was tested using Koch's postulates. In addition, the control of ozone was examined against the isolates and mycotoxin accumulation. The results indicated that the naturally occurring symptom increased progressively with the extension of storage time. The mucor rot caused by
was first observed on day 7, followed by root rot caused by
on day 14. Blue mold disease caused by
was detected as the most serious postharvest disease on day 28. Pink rot disease caused by
was observed on day 56. Moreover, ozone treatment significantly decreased the development of postharvest disease and inhibited the accumulations of patulin, deoxynivalenol, 15-Acetyl-deoxynivalenol, and HT-2 toxin.
Apple blue mold is a significant postharvest disease caused by Penicillium expansum. pH modification in colonized tissues leads to the production of organic substances, the modulation of enzymes, and ...then increases fungal pathogenicity. This study evaluated Penicillium expansum-inoculated apple fruits’ quality responding to pH treatments ranging from 2.5 to 8.5 and analyzed the reactive oxygen species (ROS) metabolism modulation in inoculated apple fruits at the same pH. The results showed that the fruit quality of the firmness, total soluble solids, and titratable acid displayed a quick loss at pHs 5.0 and 7.0, compared with 2.5 and 8.5. Similarly, higher disease incidence was observed at pHs 5.0 and 7.0. Apple fruits infected with P. expansum at pHs 2.5 and 8.5 had less content of O2•−, H2O2, and malondialdehyde (MDA); lower enzymatic activity of NADPH oxidase (NOX); and greater cell membrane integrity than those at pHs 5.0 and 7.0. The analysis of the antioxidant enzymatic activities showed upregulation of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) at pHs 2.5 and 8.5 compared with those at pHs 5.0 and 7.0. Similar trends were shown in ascorbic acid and glutathione. These results support the hypothesis that inoculated apple fruits at pHs 2.5 and 8.5 improve resistance to P. expansum by modulating ROS metabolism, compared with pHs 5.0 and 7.0.
PDF
