The complete genome sequence of a novel hypovirus infecting Bipolaris oryzae.

Hypoviruses are positive-sense single-stranded RNA mycovirus that infect filamentous fungi. However, hypoviruses have not been reported in Bipolaris oryzae, an important phytopathogenic fungus in water bamboo and rice. Here, we report the characterization of a novel hypovirus, tentatively named "Bipolaris oryzae hypovirus 1" (BoHV1), isolated from strain ES35 of B. oryzae infecting water bamboo. The complete genome of BoHV1 consists of 13,596 nucleotides and a poly(A) tail at the 3' end. BoHV1 has single open reading frame (ORF) and encodes a putative polyprotein (4,218 amino acids) containing four potential conserved domains for a papain-like protease, a protein of unknown function (DUF3525), RNA-dependent RNA polymerase (RdRp), and helicase. Phylogenetic analysis of the polyprotein, RdRp, and helicase domains suggested that BoHV1 belongs to the genus Hypovirus within the family Hypoviridae. This is the first report of the presence of a hypovirus in the phytopathogenic fungus B. oryzae.

[Phosphate solubilizing characteristics of Talaromyces aurantiacus and its growthpromoting effect on Phyllostachys edulis seedlings]. / ä¸€æ ªé‡‘é»„è“çŠ¶èŒè§£ç£·ç‰¹æ€§åŠå ¶å¯¹æ¯›ç«¹çš„ä¿ƒç”Ÿæ•ˆåº”.

To investigate phosphate-solubilizing characteristics and plant growth-promoting effect of Talaromyces aurantiacus (JXBR04) from Phyllostachys edulis rhizosphere soil, the influence of culture time, carbon sources, nitrogen sources, initial pH, liquid filling volume, and salt ions on phosphate solubilizing ability of strain JXBR04 were examined. The capability to solubilize different types of mineral phosphate was detected using a liquid fermentation method. A pot experiment was conducted to evaluate the effects of strain JXBR04 in promoting the growth of Ph. edulis seedlings. The results showed that strain JXBR04 displayed the highest phosphate-dissolving capacity when the cultivation period was 7 days, the initial pH reached 3.5, the volume of liquid was 1/5 or 2/5, and the NaCl concentration was 0 or 1.0 g·L-1. The phosphate-dissolving ability of the strain was the highest when using sugar as carbon source and yeast powder as nitrogen source. The strain had the greatest ability to solubilize CaHPO4 with 1304.04 mg·L-1, followed by Ca3(PO4)2 and FePO4. We found that available nutrients, leaf, stem, and root phosphorus contents in rhizospheric soil significantly increased in Ph. edulis after 180 days of inoculation with strain JXBR04. In addition, Ph. edulis inoculated with strain JXBR04 had 28.1%, 28.3%, and 51.5% higher ground diameter, seedling height, and biomass accumulation than that without JXBR04, respectively. Our findings suggested that T. aurantiacus has the potential to be applied as environment-friendly biofertilizers in maso bamboo forest in the acid soil in southern China.

Genome editing in Shiraia bambusicola using CRISPR-Cas9 system.

Shiraia bambusicola can produce a type of hypocrellin, which is applied in antibacterial, antitumoral, and antiviral areas. Studies on the hypocrellin pathway have not been confirmed due to the deficiency of suitable genetic methods. We constructed a clustered regularly interspaced short palindromic repeat sequences (CRISPR)/Cas9 system in Shiraia sp. SUPER-H168 and targeted a polyketide synthase (SbaPKS). No hypocrellin production was detected in the ΔSbaPKS mutant. Relative expression levels of SbaPKS and its adjacent genes were extremely down-regulated in the ΔSbaPKS mutant compared to those in the wild strain. Subsequent pathogenicity assays showed that deletion of SbaPKS attenuated virulence on bamboo leaves. In contrast, restored hypocrellin in a SbaPKS overexpression strain generated necrotic lesions on bamboo leaves. These results suggest that SbaPKS is involved in hypocrellin biosynthesis and hypocrellin has an essential role in the virulence of S. bambusicola on bamboo leaves. The CRISPR/Cas9 system in Shiraia sp. will open an avenue for decoding the hypocrellin pathway and genome editing of other filamentous fungi. Strategies that disrupt hypocrellin biosynthesis may reduce the detriment of S. bambusicola.

High-efficiency biosynthesis of hypocrellin A in Shiraia sp. using gamma-ray mutagenesis.

Hypocrellin A (HA), well known as one of the best natural pigments and bioactive agent to treat skin diseases, is further anticipated to play a vital role in photodynamic therapy (PDT) in anticancer and antiviral treatments. In this study, an HA-producing strain ZZZ816 (Shiraia sp.) was isolated from the moso bamboo (Phyllostachys edulis) seeds, and gamma irradiation was used to mutagenize spores of the original strain. After treatment with cobalt-60 gamma ((60)Coγ) with different doses (20, 50, 80, 100, 150, 180, 300, and 500 Gy), the 100 Gy was selected as the optimal condition, which led to 77.2 % lethality of spores and 35 % positive mutant frequency. The extracted compound of the most excellent HA-producing strain (H-4-2) was precisely analyzed by a combination of seven detection methods, and the maximum HA content was shown to reach 2018.3 mg/L. HA production in H-4-2 increased by 414.9 % compared to that of original strain ZZZ816 (392 mg/L) and was significantly higher than all the other industrial HA-producing strains in published reports.

Streptomyces sasae sp. nov., isolated from bamboo (Sasa borealis) rhizosphere soil.

A novel strain of Gram-staining-positive actinobacterium, designated strain JR-39T, was isolated from the rhizosphere soil of bamboo (Sasa borealis) sampled in Damyang, Korea, and its taxonomic position was investigated by a polyphasic approach. The isolate formed flexuous chains of spores that were cylindrical and smooth-surfaced. Strain JR-39T grew at 4­37 °C (optimum 28 °C). The pH range for growth was pH 5­10 (optimum pH 6­8) and the NaCl range for growth was 0­5 % (w/v) with optimum growth at 1 % NaCl. The cell-wall peptidoglycan contained ll-diaminopimelic acid, glutamic acid, alanine and glycine. Whole-cell hydrolysates mainly contained glucose, mannose, ribose and rhamnose. Predominant menaquinones were MK-9 (H6), MK-9 (H8) and MK-9 (H4). The major cellular fatty acids were anteiso-C15 : 0, iso-C16 : 0, iso-C15 : 0 and iso-C14 : 0. The G+C content of the DNA was 72.3 ± 0.34 mol%. Phylogenetic analyses based on 16S rRNA gene sequence analysis indicated that strain JR-39T belonged to the genus Streptomyces, showing the highest sequence similarity to Streptomyces panaciradicis 1MR-8T (99.4 %), Streptomyces capoamus JCM 4734T (98.8 %), Streptomyces galbus DSM 40089T (98.7 %), Streptomyces longwoodensis LMG 20096T (98.7 %), Streptomyces bungoensis NBRC 15711T (98.7 %) and Streptomyces rhizophilus JR-41T (98.7 %). However, DNA­DNA hybridization assays, as well as physiological and biochemical analyses, showed that strain JR-39T could be differentiated from its closest phylogenetic relatives. On the basis of the phenotypic and genotypic characteristics, strain JR-39T represents a novel species for which the name Streptomyces sasae sp. nov. is proposed. The type strain is JR-39T ( = KACC 17182T = NBRC 109809T).

Streptomyces graminifolii sp. nov., isolated from bamboo (Sasa borealis) litter.

The taxonomic position of strain JL-22(T), isolated from litter of a bamboo (Sasa borealis) forest, was determined using a polyphasic approach. The organism had phenotypic and morphological properties consistent with it being a member of the genus Streptomyces. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain JL-22(T) was closely related to Streptomyces prunicolor NRRL B-12281(T) (99.2%), Streptomyces galilaeus JCM 4757(T) (99.0%) and Streptomyces chartreusis NBRC 12753(T) (99.0%). However, the results of DNA-DNA hybridization and physiological and biochemical tests showed that strain JL-22(T) could be differentiated from its closest phylogenetic relatives both genotypically and phenotypically. Based on phenotypic and genotypic data, strain JL-22(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces graminifolii sp. nov. is proposed. The type strain is JL-22(T) ( = KACC 17180(T) = NBRC 109806(T)).

Distribution of lignin-carbohydrate complex in plant kingdom and its functionality as alternative medicine.

Lignin-carbohydrate complexes (LCCs) are major cell wall components formed by the dehydrogenation of three monolignols, p-coumaryl, coniferyl and sinapyl alcohols. Diverse pharmacological activities of LCCs distributed into various plants were summarized. LCCs showed one order higher anti-HIV activity than tannins and flavonoids. Mechanism of anti-HIV activity induction includes the inhibition of HIV adsorption to and penetration into the cells, and inhibition of reverse transcriptase and protease. Limited digestion experiments demonstrated that a phenylpropenoid polymer, but not a sugar moiety, is important for anti-HIV activity. Dehydrogenation polymers of phenylpropenoids without carbohydrate showed higher anti-HIV activity, whereas phenylpropenoid monomers were inactive, suggesting the importance of highly polymerized structure. LCCs inhibited the plaque formation and RNA polymerase activity of influenza virus, and reduced the lethality of virus infection in mice. LCCs inhibited the plaque formation of HSV-1, and oral intake of LCC-vitamin C tablet reduced the symptoms in HSV-1-infected patients. LCCs stimulated the iodination of myeloperoxidase-positive human monocytes, neutrophiles and promyelocytic leukemia that may be involved in the bacterial killing mechanism. LCCs stimulated splenocyte proliferation, and showed both pro- and anti-inflammatory activity in activated macrophage. Preliminary DNA array analysis demonstrated the activation of the signal pathway of chemokine expression via TLR2. The molecular weight, solubility, sterilization method and association with other components during extraction step may produce diverse biological activity of LCCs. Broad and potent anti-viral activity and synergism with vitamin C suggest functionality of LCC as alternative medicine.

Pretreatment of bamboo residues with Coriolus versicolor for enzymatic hydrolysis.

Pretreatment by a white-rot fungus Coriolus versicolor B1 under different conditions and saccharification of bamboo were investigated. The saccharification rate was significantly enhanced and a maximum saccharification rate of 37.0% was achieved after pretreatment. Reducing sugars yield was 223.2 mg/g of bamboo residues, which was 2.34 times that of the raw material. It was feasible to treat bamboo residues with B1 for the saccharification of bamboo.

Clarification of the host substrate of Ascopolyporus and description of Ascopolyporus philodendrus sp. nov.

During a recent collection trip to Barro Colorado Island, Panama, two species belonging to genus Ascopolyporus (Clavicipitaceae, Hypocreales) were collected. Species of Ascopolyporus are epibionts of their bamboo (Poaceae) host and long thought to be biotrophs of their plant hosts. However, based on morphological observations and phylogenetic evidence using large subunit ribosomal DNA data, we propose that genus Ascopolyporus is likely composed of pathogens of scale insects (Coccoideae, Homoptera). Phylogenetic analyses included Ascopolyporus spp. in a clade containing only entomopathogenic clavicipitaceous species (100% posterior probability), and the scale insect pathogen Hyperdermium bertonii was found to share the most recent common ancestor with the Ascopolyporus clade (98% posterior probability). In addition remnants of the scale insect were observed to be embedded within stromata during early stages of stroma development. Ascopolyporus philodendrus sp. nov. was described and distinguished from the type species of the genus, A. polychrous, based on perithecial size, ascus size, plant host substrate and phylogenetic evidence. Furthermore subfamily Clavicipitoideae (Clavicipitaceae) was included and well supported in a single clade (100% posterior probability).