Nitrification intensity and ammonia-oxidizing bacteria and archaea in different wetland plant rhizosphere soils

In order to explore the nitrogen removal process in constructed wetlands(CW s),the moisture,ammonia nitrogen(NH4+-N),nitrate nitrogen(NO3"-N)and nitrification intensity in three wetland plant rhizosphere soils(Acorns calamus,Typha orientalis,Iris pseudacorus)were investigated at a relatively normal temperature range of15to25The relative abundance of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)were also achieved using fluorescence in situ hybridization(FISH).It is found that T.orientalis achieves the highest nitrification intensity of2.03m g(h?kg)while the second is I.pseudacorrs(1.74m g/(h?kg)),and followed by A.calamus(1.65m g/(h?kg))throughout the experiment.FISH reveals that the abundance of bacteria(1010g_1wet soil)is higher than that of archaea(109g_1wet soil),and AOBare the dominant bacteria in the ammonia oxidation process.The abundance of AOB in te rhizosphere soils from high to low T.orientalis(1.88x1010g"1),I pseudacorus(1.23x1010g1),A.calamus(5.07x109g"1)while the abundance of AOA from high to low ae I.pseudacorus(4.00x109g1),A.calamus(3.52x109g"1),T.orientalis(3.48x109g"1).The study provides valuable evidence of plant selection for nitrogen removal in CWs.

Different responses of soil fauna gut and plant rhizosphere microbiomes to manure applications

Microbial attributes were compared between soil fauna gut and plant rhizosphere.•Manure applications decreased or increased gut or rhizosphere bacterial diversity.•Stochastic or deterministic processes drove gut or rhizosphere bacterial assembly.•Manure applications increased bacterial network complexity of gut and rhizosphere.Diverse microbes inhabit animals and plants,helping their hosts perform multiple functions in agricultural ecosystems.However,the responses of soil fauna gut and plant rhizosphere microbiomes to livestock manure applications are still not well understood.Here we fed Protaetia brevitarsis larvae(PBL)with chicken manure and collected their frass.The frass and manure were applied as fertilizers to lettuce pots.We then compared the changes of microbial diversity,community assembly,and potential functions between the gut group(i.e.,all PBL gut and frass samples)and the rhizosphere group(i.e.,all rhizosphere soil samples).We revealed that manure applications(i.e.,feeding or fertilization)decreased bacterial diversity in the gut group but increased that in the rhizosphere group.Particularly,the proportions of Bacilli in the gut group and Gammaproteobacteria in the rhizosphere group were increased(up to a maximum of 33.8%and 20.4%,respectively)after manure applications.Stochastic and deterministic processes dominated community assembly in the gut and rhizosphere microbiomes,respectively.Manure applications increased the microbial co-occurrence network complexity of both the gut and rhizosphere groups.Moreover,the proportions of functional taxa associated with human/animal pathogens in the gut group and carbon/nitrogen cycling in the rhizosphere group were enhanced(up to 2.6-fold and 24.6-fold,respectively).Our findings illustrate the different responses of microbial diversity,community assembly,and potential functions in soil fauna gut and plant rhizosphere to manure applications.The results could enhance our knowledge on the reasonable utilization of animal and plant microbiomes in agricultural management.

Assessing bacterial communities in the rhizosphere of 8-year-old genetically modified poplar(Populus spp.)

Microbe communities in rhizosphere ecosystems are important for plant health but there is limited knowledge of them in the rhizospheres of genetically modified（GM） plants, especial for tree species. We used the amplitude sequencing method to analyze the V4 regions of the 16 S r RNA gene to identify changes in bacterial diversity and community structure in two GM lines（D520 and D521）, one non-genetically modified（nonGM） line and in uncultivated soil. After chimera filtering,468.133 sequences in the domain Bacteria remained. There were ten dominant taxonomic groups（with [1 % of all sequences） across the samples. 241 of 551 genera（representing a ratio of 97.33 %） were common to all samples.A Venn diagram showed that 1.926 operational taxonomic units（OTUs） were shared by all samples. We found a specific change, a reduction in Chloroflexi, in the microorganisms in the rhizosphere soil planted with poplars. Taken together, the results showed few statistical differences in the bacterial diversity and community structure between the GM line and non-GM line, this suggests that there was no or very limited impact of this genetic modification on the bacterial communities in the rhizosphere.

Looking forward to the Future to Meet the Challenge: Research for Rhizosphere Microbes and Mocrobiome of Medicinal Plants

Molecular biology covers a wide scope of problems related to molecular and cell biology including structural and functional genomics, transcriptomics, proteomics, bio- informatics, and biomedicines. Molecular biology is the study of molecular underpinnings of the processes of replication, transcription, translation, and cell function. The central dogma of molecular biology where genetic material is transcribed into RNA and then translated into proteins, despite being oversimplified, still provides a good starting point for understanding the field. The picture has been revised in light of emerging novel roles for RNA. Increasingly many other areas of biology focus on molecules, either directly or indirectly studying the interactions in their own right. The techniques and methods of molecular biology, such as molecular cloning, polymerase chain reaction, gel electrophoresis, macromolecule blotting and probing, microarray and so on, have been applied in biomedicine and herbal medicines.