Growth Stage-dependent Bacterial Communities in Soybean Plant Tissues: Methylorubrum Transiently Dominated in the Flowering Stage of the Soybean Shoot.

Plant-associated bacteria are critical for plant growth and health. However, the effects of plant growth stages on the bacterial community remain unclear. Analyses of the microbiome associated with field-grown soybean revealed a marked shift in the bacterial community during the growth stages. The relative abundance of Methylorubrum in the leaf and stem increased from 0.2% to more than 45%, but decreased to approximately 15%, with a peak at the flowering stage at which nitrogen metabolism changed in the soybean plant. These results suggest the significance of a time-series analysis for understanding the relationship between the microbial community and host plant physiology.

Artificial leaf device for solar fuel production.

Solar fuels, such as hydrogen gas produced from water and methanol produced from carbon dioxide reduction by artificial photosynthesis, have received considerable attention. In natural leaves the photosynthetic proteins are well-organized in the thylakoid membrane. To develop an artificial leaf device for solar low-carbon fuel production from CO2, a chlorophyll derivative chlorin-e6 (Chl-e6; photosensitizer), 1-carboxylundecanoyl-1'-methyl-4,4'-bipyrizinium bromide, iodide (CH3V(CH2)9COOH; the electron carrier) and formate dehydrogenase (FDH) (the catalyst) immobilised onto a silica-gel-based thin layer chromatography plate (the Chl-V-FDH device) was investigated. From luminescence spectroscopy measurements, the photoexcited triplet state of Chl-e6 was quenched by the CH3V(CH2)9COOH moiety on the device, indicating the photoinduced electron transfer from the photoexcited triplet state of Chl-e6 to the CH3V(CH2)9COOH moiety. When the CO2-saturated sample solution containing NADPH (the electron donor) was flowed onto the Chl-V-FDH device under visible light irradiation, the formic acid concentration increased with increasing irradiation time.