Streptomyces-triggered coordination between rhizosphere microbiomes and plant transcriptome enables watermelon Fusarium wilt resistance.

The use of microbial inoculant is a promising strategy to improve plant health, but their efficiency often faces challenges due to difficulties in successful microbial colonization in soil environments. To this end, the application of biostimulation products derived from microbes is expected to resolve these barriers via direct interactions with plants or soil pathogens. However, their effectiveness and mechanisms for promoting plant growth and disease resistance remain elusive. In this study, we showed that root irrigation with the extracts of Streptomyces ahygroscopicus strain 769 (S769) solid fermentation products significantly reduced watermelon Fusarium wilt disease incidence by 30% and increased the plant biomass by 150% at a fruiting stage in a continuous cropping field. S769 treatment led to substantial changes in both bacterial and fungal community compositions, and induced a highly interconnected microbial association network in the rhizosphere. The root transcriptome analysis further suggested that S769 treatment significantly improved the expression of the MAPK signalling pathway, plant hormone signal transduction and plant-pathogen interactions, particular those genes related to PR-1 and ethylene, as well as genes associated with auxin production and reception. Together, our study provides mechanistic and empirical evidences for the biostimulation products benefiting plant health through coordinating plant and rhizosphere microbiome interaction.

Rosmarinic acid ameliorates septic-associated mortality and lung injury in mice via GRP78/IRE1α/JNK pathway.

OBJECTIVES: Acute lung injury (ALI) is the major complication of sepsis, and no effective treatment is available now. Recently, rosmarinic acid (RA), a water-soluble polyphenolic phytochemical, exerts a potential role on ALI with anti-inflammation, and antioxidant properties. However, there is still no evidence on its protective effect on cell apoptosis in sepsis. Here, we investigated the protective effect of RA in septic-associated mortality and lung injury based on apoptosis. METHODS: Male C57BL/6 mice were administered with lipopolysaccharide (LPS) (15 mg/kg, ip) to establish ALI mice model. Preteatment of RA (20 or 40 mg/kg, ip) was performed once daily for five consecutive days. The mortality was monitored for seven days after injection of LPS. KEY FINDINGS: RA (40 mg/kg) significantly decreased mortality and alleviated septic-associated lung injury. Meanwhile, RA significantly reversed LPS induced decrease in serum T-aoc level and superoxide dismutase (SOD) activity, and increase in malondialdehyde (MDA) activity. Furthermore, RA pretreatment significantly inhibited lung cell apoptosis, as well as decreased p53 level in sepsis mice. Finally, the LPS induced activation of GRP78/IRE1α/JNK pathway was suppressed by RA pretreatment. CONCLUSIONS: These findings indicated that RA could be beneficial to septic-associated lung injury through anti-apoptosis effect.

Three new 3,4-seco-cycloartane triterpenes from Gardenia sootepensis.

The plants in the genus Gardenia (Rubiaceae) have long been used as traditional medicines in China. In this study, two new 3,4-seco-cycloartane triterpenes, sootepin J (1) and sootepin K (2), and a novel nor-3,4-seco-cycloartane triterpenes, sootepin L (3), together with two known compounds (4-5), were isolated from the methanolic extract of the leaves and twigs of Gardenia sootepensis. The structures of the new compounds were elucidated by combinations of 1D, 2D NMR experiments and HR-MS data, while the known compounds were identified by comparison of the NMR data with previously published data.

Constituents from the seeds of Brucea javanica with inhibitory activity of Tobacco mosaic virus.

Three new constituents were obtained along with 10 known compounds from the seeds of Brucea javanica. The structures of these compounds were determined based on spectral and chemical evidence. These new compounds included a monoterpenoid glycoside and two sesquiterpenes. Bioactivity screening of these constituents showed that compounds 1, 3, 8, 9, and 13 with obvious activities in inhibiting multiplication of the Tobacco mosaic virus.

[Fleas on small mammals in the surrounding area of Erhai Lake].

OBJECTIVE: To investigate the distribution pattern, species diversity and community structure of fleas on small mammals in the surrounding area of Erhai Lake, and the relationship between fleas and their hosts. METHODS: Different geographical areas surrounding the Erhai Lake in Yunnan were selected as investigated spots. Small mammals were captured with baited cages. The cage-traps were examined and re-baited each morning. All fleas on the hosts were collected and identified. The richness (S), evenness (J'), diversity index (H'), dominance index (C'), total ectoparasite infestation rate (Rpt), total ectoparasite infestation index (Ipt), and constituent ratio (Cr) were used to measure the community structure. RESULTS: Altogether, 3,303 small mammals and 3,243 fleas were collected. From the 21 species of small mammal hosts, 13 species of fleas were identified. In southern area of the Lake, the species richness (21 species of small mammals & 12 species of fleas) was highest among the three selected areas. Seventeen species of small mammals and 8 species of fleas were found in eastern area, and only 13 species of small mammals and 7 species of fleas found in the west. This implied the probable influences of ecological environments on the fleas and their corresponding hosts. The community structure of fleas on small mammals was complex. The species diversity, species composition, community structure and distribution pattern of fleas were simultaneously influenced by the hosts' body surface microenvironment and the macroenvironment (habitat). CONCLUSION: The fleas are commonly distributed in small mammals in the areas and their communities are related to host species and the habitats.

Antiphytoviral activity of bruceine-D from Brucea javanica seeds.

BACKGROUND: Brucea javanica (L.) Merr. is widely distributed throughout the southern parts of China and has been used in traditional medicine to treat a variety of diseases. The objective of the present study was to identify the active antiphytoviral compound in the seeds of B. javanica and evaluate the inhibitory activity of the compound against plant virus. RESULTS: Bioassay-guided fractionation of the most active extract from the seeds led to the isolation of an antiphytoviral compound which was identified as bruceine-D by conventional spectroscopy methods. The compound exhibited significant inhibitory activity against the infection and replication of tobacco mosaic virus (TMV), with IC(50) values of 13.98 and 7.13 mg L(-1) respectively. The compound also showed a strong inhibitory effect on the infectivity of potato virus Y (PVY) and cucumber mosaic virus (CMV). Furthermore, the compound could effectively inhibit systemic TMV infection in the host tobacco plant under glasshouse conditions. CONCLUSION: The results suggested that bruceine-D from Brucea javanica may have the potential to be used as a natural viricide, or a lead compound for new viricides.

Six new triterpenoid saponins from the leaves of Ilex oblonga and their inhibitory activities against TMV replication.

Six new triterpenoid saponins of the ursane types were isolated from the MeOH extract of the leaves of Ilex oblonga. They were oblonganoside A (1), oblonganoside B (2), oblonganoside C (6), oblonganoside D (8), oblonganoside E (9), and oblonganoside F (10), together with three known triterpenoid saponins. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and compound 1 showed appreciable inhibitory activity against TMV replication with EC50 value 0.074 mM.

Anti-tobacco mosaic virus (TMV) triterpenoid saponins from the leaves of Ilex oblonga.

Ten triterpene saponins have been isolated from a MeOH extract of the leaves of Ilex oblonga. In their structures, six new triterpenoid saponins were named as oblonganosides H-M (2, 4, 5, and 8-10). All structures were elucidated on the basis of spectroscopic analysis. Among the triterpenoid saponins, three compounds (7, 8, and 10) showed obvious activities in inhibiting multiplication of the tobacco mosaic virus (TMV).

Structure-activity relationship of triterpenes and triterpenoid glycosides against tobacco mosaic virus.

A new activity of triterpenes and triterpenoid glycosides against phytovirus has been found. Based on the anti-TMV replication activity in vivo, 47 triterpenes and triterpenoid glycosides were screened through the leaf-disk method together with indirect ELISA. Structure-activity relationships were analyzed according to the results of bio-activity screening. Besides, the EC(50) values of those compounds having higher activities were measured.