Fusaric acid instigates the invasion of banana by Fusarium oxysporum f. sp. cubense TR4

CITATION: Liu, S. et al. 2020. Fusaric acid instigates the invasion of banana by Fusarium oxysporum f. sp. cubense TR4. New Phytologist, 225:913–929, doi:10.1111/nph.16193.The original publication is available at https://nph.onlinelibrary.wiley.comFusaric acid (FSA) is a phytotoxin produced by several Fusarium species and has been associated with plant disease development, although its role is still not well understood. Mutation of key genes in the FSA biosynthetic gene (FUB) cluster in Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) reduced the FSA production, and resulted in decreased disease symptoms and reduced fungal biomass in the host banana plants. When pretreated with FSA, both banana leaves and pseudostems exhibited increased sensitivity to Foc TR4 invasion. Banana embryogenic cell suspensions (ECSs) treated with FSA exhibited a lower rate of O2 uptake, loss of mitochondrial membrane potential, increased reactive oxygen species (ROS) accumulation, and greater nuclear condensation and cell death. Consistently, transcriptomic analysis of FSA-treated ECSs showed that FSA may induce plant cell death through regulating the expression of genes involved in mitochondrial functions. The results herein demonstrated that the FSA from Foc TR4 functions as a positive virulence factor and acts at the early stage of the disease development before the appearance of the fungal hyphae in the infected tissues.https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.16193Publisher's versio

RNA Sequencing Reveals that Endoplasmic Reticulum Stress and Disruption of Membrane Integrity Underlie Dimethyl Trisulfide Toxicity against Fusarium oxysporum f. sp. cubense Tropical Race 4

Fusarium wilt of banana, a destructive disease that affects banana production, is caused by Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4). In a previous study, we confirmed the strong inhibitory effects of Chinese leek (Allium tuberosum) on the incidence of this disease. Sulfur compounds are the primary antifungal constituents of Chinese leek. Among these, dimethyl trisulfide (DT) was the most abundant and exhibited the strongest inhibition of Foc TR4 growth and development. In the present study, the global gene expression profiles of Foc TR4 isolates treated with DT at 4,000-folds dilution (concentration of 1/4,000, v/v) for 1.5, 6, and 12 h were investigated by using RNA sequencing. The expression patterns of 15 DEGs were validated based on quantitative real-time PCR (qRT-PCR) assay. Untreated sample presented 2,556, 1,691, and 1,150 differentially expressed genes (DEGs) at 1.5, 6, and 12 h after the onset of the experiment, respectively, whereas DT-treated isolates presented 2,823, 3,546, and 6,197 DEGs. Based on Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, DEGs involved in endoplasmic reticulum (ER), glycosylation, and steroid biosynthesis were significantly inhibited by DT exposure. The similar expressional patterns of 15 DEGs between RNA-seq and qRT-PCR assays indicated the reliability of the RNA-seq data. In conclusion, ER stress related to glycosylation inhibition and damage to cell membrane integrity might contribute to the toxicity of DT against Foc TR4. As the results presented here evidenced changes in gene expression associated with DT exposure, which might be used to develop new approaches for controlling FWB

Complete chloroplast genome of Rhus chinensis by de novo sequencing

Rhus chinensis is an important economic species, which could provide raw materials for pharmaceutical and industrial dyes. This is the first report of R. chinensis chloroplast genomes by de novo sequencing. The results showed that the length of R. chinensis was 159,082 bp. The length of LSC and SSC was 85,394 bp and 18,663 bp, respectively. The genomes contained 126 genes, including 88 protein encoding genes, eight rRNA, and 30 tRNA genes. The clustering results showed that Anacardiaceae were closest to R. chinensis, followed by Aceraceae and Anacardiaceae

Complete chloroplast genome of Zingiber mioga by de novo sequencing

Zingiber mioga (Thunb.) Rosc. (Zingiber mioga) is an important edible species, which also has important medical and natural pigment value. This article is firstly reported the Zingiber mioga’s chloroplast genomes which detect by de novo sequencing. The results showed that the length sequence of Zingiber mioga’s chloroplast genome was 163,541 bp, and the length of LSC, SSC, and two IR regions was 88,035, 15,886, and 29,810 bp, respectively. Zingiber mioga’s chloroplast genome was encoded 135 genes involving 10 rRNA, 38 tRNA, and 87 protein-coding genes. After phylogenetic and cluster analysis, the Zingiber were closest approach to Zingiber mioga, followed by Kaempferia, Curcuma, Hedychium, and Roscoea

Complete chloroplast genome of Alternanthera philoxeroides by de novo sequencing

Alternanthera philoxeroides (Mart.) Griseb. (Alternanthera philoxeroides) is an important herbage species, which could provide high-quality feed for livestock and poultry breeding. This paper is the first to report the A. philoxeroides’s chloroplast genomes, which were detected by de novo sequencing. The results showed that the length of A. philoxeroides’ chloroplast genome sequence was 152,255 bp, including a large single-copy (LSC) region (84,670 bp), a small single-copy (SSC) region (17,343 bp), and two inverted repeat (IR) regions (25,121 bp). Alternanthera philoxeroides’ chloroplast genome encoded 132 genes including 8 rRNA, 38 tRNA, and 86 protein-coding genes. After phylogenetic and cluster analysis, A. philoxeroides was closest to Amaranthaceae, and the relationship between Amaranthus and Achyranthes was closest

Genome-Wide Identification and Expression Analysis of GA2ox, GA3ox, and GA20ox Are Related to Gibberellin Oxidase Genes in Grape (Vitis vinifera L.)

Gibberellin (GAs) plays the important role in the regulation of grape developmental and growth processes. The bioinformatics analysis confirmed the differential expression of GA2, GA3, and GA20 gibberellin oxidase genes (VvGA2oxs, VvGA3oxs, and VvGA20oxs) in the grape genome, and laid a theoretical basis for exploring its role in grape. Based on the Arabidopsis GA2oxs, GA3oxs, and GA20oxs genes already reported, the VvGA2oxs, VvGA3oxs, and VvGA20oxs genes in the grape genome were identified using the BLAST software in the grape genome database. Bioinformatics analysis was performed using software such as DNAMAN v.5.0, Clustalx, MapGene2Chrom, MEME, GSDS v.2.0, ExPASy, DNAsp v.5.0, and MEGA v.7.0. Chip expression profiles were generated using grape Affymetrix GeneChip 16K and Grape eFP Browser gene chip data in PLEXdb. The expression of VvGA2oxs, VvGA3oxs, and VvGA20oxs gene families in stress was examined by qRT-PCR (Quantitative real-time-PCR). There are 24 GAoxs genes identified with the grape genome that can be classified into seven subgroups based on a phylogenetic tree, gene structures, and conserved Motifs in our research. The gene family has higher codon preference, while selectivity is negative selection of codon bias and selective stress was analyzed. The expression profiles indicated that the most of VvGAox genes were highly expressed under different time lengths of ABA (Abscisic Acid) treatment, NaCl, PEG and 5 °C. Tissue expression analysis showed that the expression levels of VvGA2oxs and VvGA20oxs in different tissues at different developmental stages of grapes were relatively higher than that of VvGA3oxs. Last but not least, qRT-PCR (Real-time fluorescent quantitative PCR) was used to determine the relative expression of the GAoxs gene family under the treatment of GA3 (gibberellin 3) and uniconazole, which can find that some VvGA2oxs was upregulated under GA3 treatment. Simultaneously, some VvGA3oxs and VvGA20oxs were upregulated under uniconazole treatment. In a nutshell, the GA2ox gene mainly functions to inactivate biologically active GAs, while GA20ox mainly degrades C20 gibberellins, and GA3ox is mainly composed of biologically active GAs. The comprehensive analysis of the three classes of VvGAoxs would provide a basis for understanding the evolution and function of the VvGAox gene family in a grape plant

Contamination of bananas with beauvericin and fusaric acid produced by Fusarium oxysporum f. sp. cubense

CITATION: Li, C. et al. 2013. Contamination of bananas with beauvericin and fusaric acid produced by Fusarium oxysporum f. sp. cubense. PLoS ONE, 8(7): e70226, doi:10.1371/journal.pone.0070226.The original publication is available from: http://journals.plos.orgBackground Fusarium wilt, caused by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases of banana. Toxins produced by Foc have been proposed to play an important role during the pathogenic process. The objectives of this study were to investigate the contamination of banana with toxins produced by Foc, and to elucidate their role in pathogenesis. Methodology/Principal Findings Twenty isolates of Foc representing races 1 and 4 were isolated from diseased bananas in five Chinese provinces. Two toxins were consistently associated with Foc, fusaric acid (FA) and beauvericin (BEA). Cytotoxicity of the two toxins on banana protoplast was determined using the Alamar Blue assay. The virulence of 20 Foc isolates was further tested by inoculating tissue culture banana plantlets, and the contents of toxins determined in banana roots, pseudostems and leaves. Virulence of Foc isolates correlated well with toxin deposition in the host plant. To determine the natural occurrence of the two toxins in banana plants with Fusarium wilt symptoms, samples were collected before harvest from the pseudostems, fruit and leaves from 10 Pisang Awak ‘Guangfen #1’ and 10 Cavendish ‘Brazilian’ plants. Fusaric acid and BEA were detected in all the tissues, including the fruits. Conclusions/Signficance The current study provides the first investigation of toxins produced by Foc in banana. The toxins produced by Foc, and their levels of contamination of banana fruits, however, were too low to be of concern to human and animal health. Rather, these toxins appear to contribute to the pathogenicity of the fungus during infection of banana plants.http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0070226Publisher's versio

HPLC-ESI-MS map of the secondary metabolites from <i>Fusarium oxysporum</i> f.sp. <i>Cubense.</i>

<p>A: [M+H]⁺ map of <i>Foc</i> Race 1; B. [M+H]⁺ map of <i>Foc</i> Race 4.</p

Toxicity analysis of different concentration of BEA and FA on protoplast at 72

<p> <b>h.</b> The scale bar is 100 µm.</p