Denitrification of overlying water by microbial electrochemical snorkel

A novel microbial electrochemical snorkel (MES) bioreactor was constructed by inserting an iron rod into the sediment of a simulated natural water body for the first time. Its nitrate removal performance and mechanism were investigated. The DNA high-throughput sequencing analysis indicates that denitrifying bacteria were grown on the iron rod in the overlying solution. The XRD analysis on the oxides formed on the surface of the iron rod indicates that they are goethite and green rust. In the MES system, the green rust on the iron rod can concentrate nitrate and denitrifying bacteria, forming an anaerobic biocathode. The denitrifying bacteria can reduce the nitrate into nitrogen with the electrons moved from the sediment. The nitrate removal efficiency reached 98% in 16 days. This novel MES system showed excellent in-situ nitrate removal performance by moving and concentrating the electrons in sediment and the nitrate in overlying solution in an anaerobic microenvironment. (C) 2015 Elsevier Ltd. All rights reserved.Major Program of the National Natural Science Foundation of China [91434132]; National Natural Science Foundation of China [31570118, 51378020, 21077001]; Shandong Provincial Natural Science Foundation, China [ZR2015CM029]; Program for New Century Excellent Talents in University of Ministry of Education of China [NCET-10-0208]; Collaborative Innovation Center for Regional Environmental QualitySCI(E)[email protected]

Single‐Cell and Spatial Transcriptomics Reveals a Stereoscopic Response of Rice Leaf Cells to Magnaporthe oryzae Infection

Abstract Infection by the fungal pathogen Magnaporthe oryzae elicits dynamic responses in rice. Utilizing an integrated approach of single‐cell and spatial transcriptomics, a 3D response is uncovered within rice leaf cells to M. oryzae infection. A comprehensive rice leaf atlas is constructed from 236 708 single‐cell transcriptomes, revealing heightened expression of immune receptors, namely Pattern Recognition Receptors (PRRs) and Nucleotide‐binding site and leucine‐rich repeat (NLRs) proteins, within vascular tissues. Diterpene phytoalexins biosynthesis genes are dramatically upregulated in procambium cells, leading to an accumulation of these phytoalexins within vascular bundles. Consistent with these findings, microscopic observations confirmed that M. oryzae is prone to target leaf veins for invasion, yet is unable to colonize further within vascular tissues. Following fungal infection, basal defenses are extensively activated in rice cells, as inferred from trajectory analyses. The spatial transcriptomics reveals that rice leaf tissues toward leaf tips display stronger immunity. Characterization of the polarity gene OsHKT9 suggests that potassium transport plays a critical role in resisting M. oryzae infection by expression along the longitudinal axis, where the immunity is stronger toward leaf tip. This work uncovers that there is a cell‐specific and multi‐dimensional (local and longitudinal) immune response to a fungal pathogen infection