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Genes Apr 2024Black spot, caused by (), poses a serious threat to crucifer production, and knowledge of how plants respond to infection is essential for black spot management. In...
Black spot, caused by (), poses a serious threat to crucifer production, and knowledge of how plants respond to infection is essential for black spot management. In the current study, combined transcriptomic and metabolic analysis was employed to investigate the response to infection in two cabbage ( var. ) genotypes, Bo257 (resistant to ) and Bo190 (susceptible to ). A total of 1100 and 7490 differentially expressed genes were identified in Bo257 (R_mock vs. R_) and Bo190 (S_mock vs. S_), respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that "metabolic pathways", "biosynthesis of secondary metabolites", and "glucosinolate biosynthesis" were the top three enriched KEGG pathways in Bo257, while "metabolic pathways", "biosynthesis of secondary metabolites", and "carbon metabolism" were the top three enriched KEGG pathways in Bo190. Further analysis showed that genes involved in extracellular reactive oxygen species (ROS) production, jasmonic acid signaling pathway, and indolic glucosinolate biosynthesis pathway were differentially expressed in response to infection. Notably, when infected with , genes involved in extracellular ROS production were largely unchanged in Bo257, whereas most of these genes were upregulated in Bo190. Metabolic profiling revealed 24 and 56 differentially accumulated metabolites in Bo257 and Bo190, respectively, with the majority being primary metabolites. Further analysis revealed that dramatic accumulation of succinate was observed in Bo257 and Bo190, which may provide energy for resistance responses against infection via the tricarboxylic acid cycle pathway. Collectively, this study provides comprehensive insights into the -cabbage interactions and helps uncover targets for breeding -resistant varieties in cabbage.
Topics: Alternaria; Brassica; Plant Diseases; Transcriptome; Metabolome; Gene Expression Regulation, Plant; Disease Resistance; Metabolic Networks and Pathways; Gene Expression Profiling; Plant Proteins
PubMed: 38790174
DOI: 10.3390/genes15050545 -
Plant Disease Jul 2023The fungal genus , which causes a variety of crop diseases, is widely distributed in the world. Alternaria leaf blight, caused by , is one of the most common and...
The fungal genus , which causes a variety of crop diseases, is widely distributed in the world. Alternaria leaf blight, caused by , is one of the most common and destructive diseases in carrot. The infection of leads to dramatic decay on both foliage and taproot in severe cases, which results in significant yield losses. In this study, we sequenced and assembled the genome of isolate CALB1, which isolated from the major carrot producing areas of China. A total of 65 contigs were assembled, and the estimated genome size was 34.9 Mb. The draft genome of can be used for comparative genomic analysis of species and provide genetic information for further research on plant-pathogen interactions.
Topics: Alternaria; Daucus carota; Plant Diseases; China
PubMed: 36451305
DOI: 10.1094/PDIS-10-22-2438-A -
Revista Chilena de Infectologia :... Oct 2014
Topics: Alternaria
PubMed: 25491460
DOI: 10.4067/S0716-10182014000500013 -
PloS One 2016Alternaria brown spot is one of the most important diseases of tangerines and their hybrids worldwide. Recently, outbreaks in Mediterranean areas related to susceptible...
Alternaria brown spot is one of the most important diseases of tangerines and their hybrids worldwide. Recently, outbreaks in Mediterranean areas related to susceptible cultivars, refocused attention on the disease. Twenty representatives were selected from a collection of 180 isolates of Alternaria spp. from citrus leaves and fruit. They were characterized along with reference strains of Alternaria spp. Micro- and macroscopic characteristics separated most Alternaria isolates into six morphotypes referable to A. alternata (5) and A. arborescens (1). Phylogenetic analyses, based on endopolygalacturonase (endopg) and internal transcribed spacer (ITS), confirmed this finding. Moreover, a five-gene phylogeny including two anonymous genomics regions (OPA 1-3 and OPA 2-1), and the beta-tubulin gene (ß-tub), produced a further clustering of A. alternata into three clades. This analysis suggested the existence of intra-species molecular variability. Investigated isolates showed different levels of virulence on leaves and fruit. In particular, the pathogenicity on fruit seemed to be correlated with the tissue of isolation and the clade. The toxigenic behavior of Alternaria isolates was also investigated, with tenuazonic acid (TeA) being the most abundant mycotoxin (0.2-20 mg/L). Isolates also synthesized the mycotoxins alternariol (AOH), its derivate alternariol monomethyl ether (AME), and altenuene (ALT), although to a lesser extent. AME production significantly varied among the six morphotypes. The expression of pksJ/pksH, biosynthetic genes of AOH/AME, was not correlated with actual toxin production, but it was significantly different between the two genotypes and among the four clades. Finally, ten isolates proved to express the biosynthetic genes of ACTT1 phytotoxin, and thus to be included in the Alternaria pathotype tangerine. A significant correlation between pathogenicity on leaves and ACTT1 gene expression was recorded. The latter was significantly dependent on geographical origin. The widespread occurrence of Alternaria spp. on citrus fruit and their ability to produce mycotoxins might represent a serious concern for producers and consumers.
Topics: Alternaria; Citrus; Mediterranean Region; Plant Diseases
PubMed: 27636202
DOI: 10.1371/journal.pone.0163255 -
Genes & Genetic Systems Jul 2022Pathogen attacks affect tree health, causing considerable economic losses as well as serious damage to the surrounding environment. Understanding the disease resistance...
Pathogen attacks affect tree health, causing considerable economic losses as well as serious damage to the surrounding environment. Understanding the disease resistance mechanisms of trees is important for tree breeding. In previous studies on birch (Betula platyphylla × B. pendula), we identified a lesion mimic mutant called lmd. We found that reduced expression of BpEIL1 was responsible for the phenotype in lmd. Following cloning, we acquired several BpEIL1 overexpression and suppression lines in birch. In this study, we cloned the BpEIL1 promoter and found that BpEIL1 was primarily expressed in leaves, particularly in veins. We further studied the traits of transgenic lines and the function of BpEIL1 in disease resistance in birch using the BpEIL1 overexpression line OE9, the suppression line SE13 and the non-transgenic line NT. We found that hydrogen peroxide accumulated in SE13 leaves. Ascorbate peroxidase and catalase activity significantly increased in SE13. SE13 was more resistant to the fungal pathogens Alternaria alternata and Rhizoctonia solani than were the OE9 and NT lines. RNA-seq indicated that pathways related to signal transduction, disease resistance and plant immunity were enriched in SE13. BpEIL1 is thus a negative regulatory transcription factor for disease resistance in birch. This study provides a reference for disease resistance of birch and other trees.
Topics: Alternaria; Betula; Disease Resistance; Rhizoctonia
PubMed: 35675986
DOI: 10.1266/ggs.21-00098 -
BMC Microbiology Feb 2019The indolizidine alkaloid-swainsonine is produced by an endophytic fungus Alternaria oxytropis, which was isolated from locoweeds. Swainsonine has many biological...
BACKGROUND
The indolizidine alkaloid-swainsonine is produced by an endophytic fungus Alternaria oxytropis, which was isolated from locoweeds. Swainsonine has many biological activities such as anti-tumorigenic, anti-viral and bacteriostatic. However, the full complement of metabolites produced by Alternaria oxytropis is not known. This study is a chemical analysis of Alternaria oxytropis metabolites, which not only unravels the potential compounds from the fermentation broth but also in which solvent are they extracted, facilitating industrial application.
RESULTS
Alternaria oxytropis isolated from Oxytropis gansuensis was cultured in Czapek's medium for 30d to collect the fermentation broth. The fermentation broth is treated with methanol and then evaporated to dryness to obtain a concentrate of the fermentation broth. The concentrate is added with water for the subsequent fractional extraction with petroleum ether, chloroform, ethyl acetate and n-butanol. Different fractions of the extract were eluted by wet packing and dry loading. The obtained eluate was combined by TLC to detect the same fraction, and then characterized by GC-MS and LC-MS. The results of GC-MS showed that 105 different compounds existed in the petroleum ether, chloroform, and ethyl acetate phases of Alternaria oxytropis fermentation broth. Moreover, the results of LC-MS indicated that the fermentation broth of Alternaria oxytropis contained five alkaloids, 2-hydroxy-indolizidine, retronecine, lentiginosine, swainsonine and swainsonine N-oxide.
CONCLUSIONS
In addition to swainsonine and swainsonine N-oxide, 2-hydroxy-indolizidine, retronecine and lentiginosine were identified as the secondary metabolites of Alternaria oxytropis. Other compounds were also detected including 5,6-dihydroergosterol, eburicol, lanosterol, and L-phenylalanyl-L-proline lactam, which have potential applications as drugs.
Topics: Alkaloids; Alternaria; Astragalus Plant; Chromatography, Liquid; Culture Media; Fermentation; Gas Chromatography-Mass Spectrometry; Industrial Microbiology; Metabolic Networks and Pathways; Tandem Mass Spectrometry
PubMed: 30744547
DOI: 10.1186/s12866-019-1408-8 -
Viruses Nov 2022fungus can cause notable diseases in cereals, ornamental plants, vegetables, and fruits around the world. To date, an increasing number of mycoviruses have been...
fungus can cause notable diseases in cereals, ornamental plants, vegetables, and fruits around the world. To date, an increasing number of mycoviruses have been accurately and successfully identified in this fungus. In this study, we discovered mycoviruses from 78 strains in 6 species of the genus , which were collected from 10 pear production areas using high-throughput sequencing technology. Using the total RNA-seq, we detected the RNA-dependent RNA polymerase of 19 potential viruses and the coat protein of two potential viruses. We successfully confirmed these viruses using reverse transcription polymerase chain reaction with RNA as the template. We identified 12 mycoviruses that were positive-sense single-stranded RNA (+ssRNA) viruses, 5 double-strand RNA (dsRNA) viruses, and 4 negative single-stranded RNA (-ssRNA) viruses. In these viruses, five +ssRNA and four -ssRNA viruses were novel mycoviruses classified into diverse the families . We identified a novel -ssRNA mycovirus isolated from an . strain HB-15 as Alternaria tenuissima negative-stranded RNA virus 2 (AtNSRV2). Additionally, we characterized a novel +ssRNA mycovirus isolated from an . strain SC-8 as Alternaria tenuissima deltaflexivirus 1 (AtDFV1). According to phylogenetic and sequence analyses, we determined that AtNSRV2 was related to the viruses of the genus in the family . We also found that AtDFV1 was related to the virus family . This study is the first to use total RNA sequencing to characterize viruses in spp. These results expand the number of viruses and demonstrate the diversity of these mycoviruses.
Topics: Fungal Viruses; Alternaria; Phylogeny; Genome, Viral; RNA, Viral; RNA Viruses
PubMed: 36423161
DOI: 10.3390/v14112552 -
Scientific Reports Feb 2020Iron is one of the most abundant elements on earth and essential for life. However, Fe ions are rather insoluble and microorganisms such as fungi may use siderophores as...
Iron is one of the most abundant elements on earth and essential for life. However, Fe ions are rather insoluble and microorganisms such as fungi may use siderophores as strong chelators for uptake. In addition, free cytoplasmic iron is rather toxic and intracellular siderophores are used to control the toxicity. Siderophores are also important for iron storage. We studied two siderophore systems in the plant necrotrophic fungus Alternaria alternata and show that the non-ribosomal peptide synthase, Nps2, is required for the biosynthesis of intracellular ferricrocin, whereas Nps6 is needed for the formation of extracellular coprogen and coprogen B. Whereas nps2 was dispensable for growth on iron-depleted medium, nps6 was essential under those conditions. nps2 deletion caused an increase in spore formation and reduced pathogenicity on tomato. Our results suggest that A. alternata employs an external and an internal siderophore system to adapt to low iron conditions.
Topics: Alternaria; Fungal Proteins; Gene Expression Regulation, Fungal; Iron; Peptide Synthases; Siderophores
PubMed: 32107432
DOI: 10.1038/s41598-020-60468-7 -
Toxins Nov 2022mycotoxins including alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), altertoxin-I (ATX-I), tentoxin (TEN), and tenuazonic acid (TeA), are...
mycotoxins including alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), altertoxin-I (ATX-I), tentoxin (TEN), and tenuazonic acid (TeA), are ubiquitous contaminants in agricultural products. A method for the simultaneous determination of these six toxins by ultrahigh performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) with solid phase extraction (SPE) was validated in rice, sesame, tomato, and apple juice matrices. The performance of the method was evaluated in terms of linearity ( > 0.999), the limit of detection (0.04-1.67 μg/kg), the limit of quantification (0.12-5.06 μg/kg), recovery (80.0-114.7%), and precision (<17.7%). The validated method was applied to monitor 152 marketed food samples in South Korea, as well as to investigate the co-occurrence and correlation between toxins. The mean occurrence levels were 2.77 μg/kg for AOH, 4.36 μg/kg for AME, 0.14 μg/kg for ALT, 0.11 μg/kg for ATX-I, 0.43 μg/kg for TEN, and 104.56 μg/kg for TeA. Mean and extreme (95th percentile) daily dietary exposures of South Koreans to toxins were estimated to be 22.93 ng/kg b.w./day and 86.07 ng/kg b.w./day, respectively.
Topics: Humans; Chromatography, Liquid; Alternaria; Tandem Mass Spectrometry; Food, Processed; Food Contamination; Chromatography, High Pressure Liquid; Mycotoxins; Tenuazonic Acid; Lactones
PubMed: 36548721
DOI: 10.3390/toxins14120824 -
Toxins May 2023A total of 181 citrus-based products, including dried fruits, canned fruits, and fruit juices, collected from China and from abroad in 2021 were analyzed for the four...
A total of 181 citrus-based products, including dried fruits, canned fruits, and fruit juices, collected from China and from abroad in 2021 were analyzed for the four toxins (ALTs): alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), and tenuazonic acid (TeA) via ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS). Although the concentrations of the four ALTs varied by product and geographically, TeA was the predominant toxin followed by AOH, AME, and TEN. Products made in China showed higher levels of ALTs than those made abroad. Maximum levels of TeA, AOH, and AME in analyzed domestic samples were 4.9-fold, 1.3-fold, and 1.2-fold, respectively, higher than those in imported products. Furthermore, 83.4% (151/181) of the analyzed citrus-based products were contaminated with at least two or more ALTs. There were significant positive correlations between AOH and AME, AME and TeA, and TeA and TEN in all analyzed samples. More importantly, the solid and the condensed liquid products had higher concentrations of ALTs than the semi-solid product samples, as well as tangerines, pummelos, and grapefruits compared to the other kinds of citrus-based products. In conclusion, co-contamination with ALTs in commercially available Chinese citrus-based products was universal. Extensive and systematic surveillance of ALTs in citrus-based products, both domestic and imported, is required to obtain more scientific data for the determination of the maximum allowable concentrations of ALTs in China.
Topics: Mycotoxins; Alternaria; Citrus; Tandem Mass Spectrometry; Food Contamination; Tenuazonic Acid; China; Lactones
PubMed: 37235359
DOI: 10.3390/toxins15050325