Leaf-to-Whole Plant Spread Bioassay for Pepper and Ralstonia solanacearum Interaction Determines Inheritance of Resistance to Bacterial Wilt for Further Breeding.

Bacterial wilt (BW) disease from Ralstonia solanacearum is a serious disease and causes severe yield losses in chili peppers worldwide. Resistant cultivar breeding is the most effective in controlling BW. Thus, a simple and reliable evaluation method is required to assess disease severity and to investigate the inheritance of resistance for further breeding programs. Here, we developed a reliable leaf-to-whole plant spread bioassay for evaluating BW disease and then, using this, determined the inheritance of resistance to R. solanacearum in peppers. Capsicum annuum 'MC4' displayed a completely resistant response with fewer disease symptoms, a low level of bacterial cell growth, and significant up-regulations of defense genes in infected leaves compared to those in susceptible 'Subicho'. We also observed the spreading of wilt symptoms from the leaves to the whole susceptible plant, which denotes the normal BW wilt symptoms, similar to the drenching method. Through this, we optimized the evaluation method of the resistance to BW. Additionally, we performed genetic analysis for resistance inheritance. The parents, F1 and 90 F2 progenies, were evaluated, and the two major complementary genes involved in the BW resistance trait were confirmed. These could provide an accurate evaluation to improve resistant pepper breeding efficiency against BW.

Comprehensive transcriptome resource for response to phytohormone-induced signaling in Capsicum annuum L.

OBJECTIVES: Phytohormones are small signaling molecules with crucial roles in plant growth, development, and environmental adaptation to biotic and abiotic stress responses. Despite several previously published molecular studies focused on plant hormones, our understanding of the transcriptome induced by phytohormones remains unclear, especially in major crops. Here, we aimed to provide transcriptome dataset using RNA sequencing for phytohormone-induced signaling in plant. DATA DESCRIPTION: We used high-throughput RNA sequencing profiling to investigate the pepper plant response to treatment with four major phytohormones (salicylic acid, jasmonic acid, ethylene, and abscisic acid). This dataset yielded 78 samples containing three biological replicates per six different time points for each treatment and the control, constituting 187.8 Gb of transcriptome data (2.4 Gb of each sample). This comprehensive parallel transcriptome data provides valuable information for understanding the relationships and molecular networks that regulate the expression of phytohormone-related genes involved in plant developments and environmental stress adaptation.

Anti­inflammatory activity of 3,5,6,7,3',4'­hexamethoxyflavone via repression of the NF­κB and MAPK signaling pathways in LPS­stimulated RAW264.7 cells.

Citrus peel has been used as a Traditional medicine in Asia to treat coughs, asthma and bronchial disorders. Therefore, the anti­inflammatory effects of 3,5,6,7,3',4'­hexamethoxyflavone (quercetogetin, QUE) isolated from Citrus unshiu peel were investigated in lipopolysaccharide (LPS)­induced RAW 264.7 macrophage cells. The results showed that QUE repressed the production of prostaglandin E2 and nitric oxide by suppressing LPS­induced expression of cyclooxygenase­2 and inducible nitric oxide synthase. It also suppressed the production of interleukin (IL)­6, IL­1ß, and tumor necrosis factor­α cytokines, and decreased the nuclear translocation of NF­κB by interrupting the phosphorylation of NF­κB inhibitor α in macrophage cells. Based on the finding that QUE inhibited the phosphorylation of ERK protein expression in LPS­induced RAW264.7 cells, it was confirmed that inhibition of inflammatory responses by QUE was mediated via the ERK pathway. Therefore, this study suggests that QUE has strong anti­inflammatory effects, making it a promising compound for use as a therapeutic agent in treating inflammatory lung diseases, such as emphysema.

Transcriptome profiling of abiotic responses to heat, cold, salt, and osmotic stress of Capsicum annuum L.

Peppers (Capsicum annuum L.), belonging to the Solanaceae family, are one of the most economically important crops globally. Like other crops, peppers are threatened by diverse environmental conditions due to different pathogens and abiotic stresses. High-quality reference genomes with massive datasets of transcriptomes from various conditions can provide clues to preferred agronomic traits for breeding. However, few global gene expression profiling datasets have been published to examine the environmental stress-resistant mechanisms in peppers. In this study, we report the RNA-seq analyses of peppers treated with heat, cold, salinity, and osmotic stress at six different time points. RNA-seq libraries from 78 RNA samples containing three biological replicates per time point for each of the abiotic stresses and a mock control were constructed. A total of 204.68 Gb of transcriptome data were verified by differentially expressed genes and gene ontology enrichment analysis. Analyses of the transcriptome data in this study will provide useful information for basic studies of various stimuli to facilitate the development of stress-resistant pepper cultivars.

Whole genome and global gene expression analyses of the model mushroom Flammulina velutipes reveal a high capacity for lignocellulose degradation.

Flammulina velutipes is a fungus with health and medicinal benefits that has been used for consumption and cultivation in East Asia. F. velutipes is also known to degrade lignocellulose and produce ethanol. The overlapping interests of mushroom production and wood bioconversion make F. velutipes an attractive new model for fungal wood related studies. Here, we present the complete sequence of the F. velutipes genome. This is the first sequenced genome for a commercially produced edible mushroom that also degrades wood. The 35.6-Mb genome contained 12,218 predicted protein-encoding genes and 287 tRNA genes assembled into 11 scaffolds corresponding with the 11 chromosomes of strain KACC42780. The 88.4-kb mitochondrial genome contained 35 genes. Well-developed wood degrading machinery with strong potential for lignin degradation (69 auxiliary activities, formerly FOLymes) and carbohydrate degradation (392 CAZymes), along with 58 alcohol dehydrogenase genes were highly expressed in the mycelium, demonstrating the potential application of this organism to bioethanol production. Thus, the newly uncovered wood degrading capacity and sequential nature of this process in F. velutipes, offer interesting possibilities for more detailed studies on either lignin or (hemi-) cellulose degradation in complex wood substrates. The mutual interest in wood degradation by the mushroom industry and (ligno-)cellulose biomass related industries further increase the significance of F. velutipes as a new model.

A mutation in the Xanthomonas oryzae pv. oryzae wxoD gene affects xanthan production and chemotaxis.

Xanthomonas oryzae pv. oryzae causes bacterial blight in rice (Oryza sativa L.). The effect of a mutation in the wxoD gene, that encodes a putative O-antigen acetylase, on xanthan production as well as bacterial chemotaxis was investigated. The mutation increased xanthan production by 52 %. The mutant strain was non-motile on semi-solid agar swarm plates. In addition, several genes involved in chemotaxis, including the cheW, cheV, cheR, and cheD genes, were down-regulated by a mutation in the wxoD gene. Thus, the mutation in the wxoD gene affects xanthan production as well as bacterial chemotaxis. However, the wxoD gene is not essential for the virulence of X. oryzae.

Next-generation sequencing-based transcriptome analysis of L-lysine-producing Corynebacterium glutamicum ATCC 21300 strain.

In the present study, 151 genes showed a significant change in their expression levels in Corynebacterium glutamicum ATCC 21300 compared with those of C. glutamicum ATCC 13032. Of these 151 genes, 56 genes (2%) were up-regulated and 95 genes (3%) were down-regulated. RNA sequencing analysis also revealed that 11 genes, involved in the L-lysine biosynthetic pathway of C. glutamicum, were up- or down-regulated compared with those of C. glutamicum ATCC 13032. Of the 151 genes, 10 genes were identified to have mutations including SNP (9 genes) and InDel (1 gene). This information will be useful for genome breeding of C. glutamicum to develop an industrial amino acid-producing strain with minimal mutation.

Next-generation sequencing-based genome-wide mutation analysis of L-lysine-producing Corynebacterium glutamicum ATCC 21300 strain.

In order to identify single nucleotide polymorphism and insertion/deletion mutations, we performed whole-genome re-sequencing of the enhanced L-lysine-producing Corynebacterium glutamicum ATCC 21300 strain. In total, 142 single nucleotide polymorphisms and 477 insertion/deletion mutations were identified in the ATCC 21300 strain when compared to 3,434 predicted genes of the wild-type C. glutamicum ATCC 13032 strain. Among them, 110 transitions and 29 transversions of single nucleotide polymorphisms were found from genes of the ATCC 21300 strain. In addition, 11 genes, involved in the L-lysine biosynthetic pathway and central carbohydrate metabolism, contained mutations including single nucleotide polymorphisms and insertions/deletions. Interestingly, RT-PCR analysis of these 11 genes indicated that they were normally expressed in the ATCC 21300 strain. This information of genome-wide gene-associated variations will be useful for genome breeding of C. glutamicum in order to develop an industrial amino acid-producing strain with minimal mutation.