A Novel Rhizobium sp. Chiba-1 Strain Exhibits a Host Range for Nodule Symbiosis in Lotus Species.

Rhizobia are soil bacteria that induce the formation of nodules in the roots of leguminous plants for mutualistic establishment. Although the symbiotic mechanism between Lotus japonicus and its major symbiotic rhizobia, Mesorhizobium loti, has been extensively characterized, our understanding of symbiotic mechanisms, such as host specificity and host ranges, remains limited. In the present study, we isolated a novel Rhizobium strain capable of forming nodules on L. burttii from agricultural soil at Iwate prefecture in Japan. We conducted genomic and host range ana-lyses of various Lotus species. The results obtained revealed that the novel isolated Rhizobium sp. Chiba-1 was closely related to R. leguminosarum and had a wide host range that induced nodule development, including L. burttii and several L. japonicus wild-type accessions. However, L. japonicus Gifu exhibited an incompatible nodule phenotype. We also identified the formation of an epidermal infection threads that was dependent on the Lotus species and independent of nodule organ development. In conclusion, this newly isolated Rhizobium strain displays a distinct nodulation phenotype from Lotus species, and the results obtained herein provide novel insights into the functional mechanisms underlying host specificity and host ranges.

Tetrabromobisphenol A and hexabromocyclododecane, brominated flame retardants, trigger endoplasmic reticulum stress and activate necroptosis signaling in PC12 cells.

Tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are brominated flame retardants commonly used in a variety of industrial and consumer products. In this study, we performed RNA sequencing analysis of PC12 cells to clarify the mechanisms by which TBBPA and HBCD induce neurotoxicity. Differential expression analysis demonstrated that 636 and 271 genes were differentially expressed after TBBPA and HBCD treatment, respectively. Gene Ontology (GO) enrichment analysis revealed that genes annotated with the GO term "endoplasmic reticulum unfolded protein response" were upregulated in both TBBPA- and HBCD-treated groups. Furthermore, protein expression of endoplasmic reticulum stress markers, such as HSPA5 and DDIT3, as well as cleaved caspase-3, an apoptosis marker, were induced by TBBPA and HBCD. We also found that the cytotoxicity induced by TBBPA and HBCD was blocked by necrostatin-1, a necroptosis inhibitor, indicating the contribution of necroptosis. Our findings provide new insight into the mechanisms of toxicity induced by these chemicals.

Interactions between pH, reactive species, and cells in plasma-activated water can remove algae.

Lightning strikes cause nitrogen to dissolve in water and form reactive nitrogen and oxygen species, which form natural fertilizers that can be absorbed through plant roots. Such processes during rainstorm events can be simulated by applying plasma to a solution. Plasma-activated water (PAW) has great potential as a source of various dissolved reactive chemical species. Different mixtures of species are produced using different solution compositions. Here, basil seeds were grown in PAW to prevent blooms of Chlorella vulgaris and ion chromatography and UV-vis spectroscopy were used to quantify reactive ions. NO2 -, NO3 -, and H2O2 were found to be key to the antialgal effect. Secondary reactive ions such as peroxynitrite (ONOO-, ONOOH) were also involved. The antialgal effect was strongly related to the pH around the algal cells. Acidification was predominantly caused by the generation of NO2 - and H2O2. After two weeks monitoring basil growth, the antifungal properties were preserved, few reactive oxygen species formed in the plasma zone, and only reactive nitrogen species were transformed into reactive peroxynitrite ions. The pH around the cells was determined using an iridium oxide microelectrode. The PAW antialgal mechanism depended on acidic conditions (pH 2.2, at which peroxynitrite can be generated) under which ONOOH penetrated the algal cell membranes, destroying the cells and preventing growth. This practical and sustainable PAW process allows a surprising amount of fertilizer to be generated with an antialgal effect that could be used in various eco-friendly agricultural processes under ambient conditions.

Indoor gas phase photoactivity of yttrium modified titanate films for fast acetaldehyde oxidation.

Photoactive materials hold structural and catalytic features that make them particularly suitable for environmental applications and in the present work, protonated H3Ti3O7-Y nanofiber-like materials were prepared via the microwave assisted hydrothermal technique. The as-prepared nanofibers exhibited high surface area with titanate structure. The nanofibers, before and after yttrium incorporation, were well-distributed and the fibrous morphology could be observed clearly; as the yttrium loading increased, ribbons and the anatase phase were formed. Practical films of these nanofibers confirmed their likely UV-photoactive properties with 200 ppm of acetaldehyde degradation within 25 min in the presence of 50% of humidity. Activity retention was achieved, keeping stability for 2 consecutive cycles at room temperature. Nowadays, the increase in home office work sets human health at risk, for the exposure to toxic volatile organic compounds and microorganisms such as viruses and bacteria is more frequent indoors. In this context, the synthesized photoactive yttrium-titanate films stand as upcoming practical UV-driven materials for cleaning pollution that concentrated urban activity and indoor environments.