Symbiotic microbiomes of Sphagnum have been confirmed to play a fundamental role in carbon and nitrogen cycles, however, little is known about microbiomes associated with other bryophytes in subtropical peatland ecosy...Symbiotic microbiomes of Sphagnum have been confirmed to play a fundamental role in carbon and nitrogen cycles, however, little is known about microbiomes associated with other bryophytes in subtropical peatland ecosystems. To explore the differences in community structure, metabolic potential and interaction relationship of bacterial microbiomes associated with different bryophytes species, the gametophytes of three bryophyte species(Sphagnum palustre, Aulacomnium androgynum, and Polytrichum commune) and their underlying peat sediments were collected from the subtropical Dajiuhu Peatland and subjected to Illumina high-throughout sequencing of 16S r RNA gene. Results showed that bacterial diversity was lowest in S. palustre, the dominant moss species, among the three moss species investigated in Dajiuhu Peatland. Bacterial communities from bryophytes clearly separated with those from sediments as indicated by both phylogenetic and taxonomical approaches. Linear discriminant analysis effect size(LEf Se) identified 30 and 36 indicator taxa in mosses and peat sediments. Bacteroidetes, Verrucomicrobia and Thermoleophilia significantly enriched in S. palustre, A. androgynum and P. commune, Chloroflexi, Proteobacteria and Acidobacteria subgroup 6 was indicator taxa for corresponding underlying sediments, respectively. Despite of these differences in compositions, bacterial functional structures were similar among all bryophytes, such as abundant aerobic heterotrophs, rare nitrifiers and denitrifiers. This phenomenon was also observed among the underlying sediments. Network analysis indicated that Proteobacteria and Acidobacteria located in the center of network and exerted strong interactions to other taxa. The sub-network of bacterial communities in sediments was more connected and microbial groups were more competitive than those in bryophytes subnetwork. Our results offer new insight into the community structure, ecological function and interaction pattern of bacterial microbiomes in the Dajiuhu Peatland across different habitats.展开更多
This research adds to the literature studying the effects of outward foreign direct investment(OF DI)on domestic innovation performance and the moderating effect of a technology gap between host and home countries.New...This research adds to the literature studying the effects of outward foreign direct investment(OF DI)on domestic innovation performance and the moderating effect of a technology gap between host and home countries.New definitions of observed technology gap and expected technology'gap are proposed.An observed technology gap captures the existing differences in technology level between establishments,regions or countries.An expected technology'gap is an indication of the effort of imitating and learning from technology leaders.The corresponding measures and effects of observed and expected technology gaps on OFDI-induced reverse technology spillover are analyzed.OFDI in developed countries promotes innovation performance.However,OFDI in emerging markets hampers innovation performance.It is also found that regions with a wider observed technology^gap and a narrower expected technology gap can benefit more from OFDI.展开更多
To investigate the vertical variation of microbial functional groups particular nitrogen fixers and ammonia oxidizers, sediment samples from a 155 cm deep peat profile were collected from the acidic Dajiuhu Peatland a...To investigate the vertical variation of microbial functional groups particular nitrogen fixers and ammonia oxidizers, sediment samples from a 155 cm deep peat profile were collected from the acidic Dajiuhu Peatland and subsequently subjected to clone library construction and quantification. Results showed that nifH gene abundance varied between 105–108 copies per gram dry sediment and reduced gradually with depth. The abundances of ammonia oxidizing archaea(AOA) and ammonia oxidizing bacteria(AOB) abundance were generally comparable in each sample. More AOA was observed with a depth ?55 cm, whereas AOB was more abundant with a depth >55 cm. Phylogenetically nifH could be divided into 94 OTUs which mainly affiliated with ?-Proteobacteria. AOA were affiliated with Nitrosotalea from Group 1.1 a associated(nearly 90%) and Nitrososphaera from Group I.1 b. All AOB belonged to Nitrosospira. Notably, DJH11 with the depth of 50–55 cm was observed to have the highest abundance and the highest diversity of nitrogen fixers and ammonia oxidizers among all the samples. Pearson's correlation analysis showed a positive relationship between water content and p H with the nifH gene abundance. Our results offer the first insight about the microbial community composition and diversity involved in nitrogen cycles in the Dajiuhu Peatland.展开更多
基金jointly supported by National Natural Science Foundation of China (No. 41572325)China University of Geosciences (Wuhan) (Nos. CUGCJ1703 and CUGQY1922)。
文摘Symbiotic microbiomes of Sphagnum have been confirmed to play a fundamental role in carbon and nitrogen cycles, however, little is known about microbiomes associated with other bryophytes in subtropical peatland ecosystems. To explore the differences in community structure, metabolic potential and interaction relationship of bacterial microbiomes associated with different bryophytes species, the gametophytes of three bryophyte species(Sphagnum palustre, Aulacomnium androgynum, and Polytrichum commune) and their underlying peat sediments were collected from the subtropical Dajiuhu Peatland and subjected to Illumina high-throughout sequencing of 16S r RNA gene. Results showed that bacterial diversity was lowest in S. palustre, the dominant moss species, among the three moss species investigated in Dajiuhu Peatland. Bacterial communities from bryophytes clearly separated with those from sediments as indicated by both phylogenetic and taxonomical approaches. Linear discriminant analysis effect size(LEf Se) identified 30 and 36 indicator taxa in mosses and peat sediments. Bacteroidetes, Verrucomicrobia and Thermoleophilia significantly enriched in S. palustre, A. androgynum and P. commune, Chloroflexi, Proteobacteria and Acidobacteria subgroup 6 was indicator taxa for corresponding underlying sediments, respectively. Despite of these differences in compositions, bacterial functional structures were similar among all bryophytes, such as abundant aerobic heterotrophs, rare nitrifiers and denitrifiers. This phenomenon was also observed among the underlying sediments. Network analysis indicated that Proteobacteria and Acidobacteria located in the center of network and exerted strong interactions to other taxa. The sub-network of bacterial communities in sediments was more connected and microbial groups were more competitive than those in bryophytes subnetwork. Our results offer new insight into the community structure, ecological function and interaction pattern of bacterial microbiomes in the Dajiuhu Peatland across different habitats.
基金the National Natural Science Foundation of China(Nos.71172213 and 71572188).
文摘This research adds to the literature studying the effects of outward foreign direct investment(OF DI)on domestic innovation performance and the moderating effect of a technology gap between host and home countries.New definitions of observed technology gap and expected technology'gap are proposed.An observed technology gap captures the existing differences in technology level between establishments,regions or countries.An expected technology'gap is an indication of the effort of imitating and learning from technology leaders.The corresponding measures and effects of observed and expected technology gaps on OFDI-induced reverse technology spillover are analyzed.OFDI in developed countries promotes innovation performance.However,OFDI in emerging markets hampers innovation performance.It is also found that regions with a wider observed technology^gap and a narrower expected technology gap can benefit more from OFDI.
基金supported by the National Natural Science Foundation of China (No. 41572325)
文摘To investigate the vertical variation of microbial functional groups particular nitrogen fixers and ammonia oxidizers, sediment samples from a 155 cm deep peat profile were collected from the acidic Dajiuhu Peatland and subsequently subjected to clone library construction and quantification. Results showed that nifH gene abundance varied between 105–108 copies per gram dry sediment and reduced gradually with depth. The abundances of ammonia oxidizing archaea(AOA) and ammonia oxidizing bacteria(AOB) abundance were generally comparable in each sample. More AOA was observed with a depth ?55 cm, whereas AOB was more abundant with a depth >55 cm. Phylogenetically nifH could be divided into 94 OTUs which mainly affiliated with ?-Proteobacteria. AOA were affiliated with Nitrosotalea from Group 1.1 a associated(nearly 90%) and Nitrososphaera from Group I.1 b. All AOB belonged to Nitrosospira. Notably, DJH11 with the depth of 50–55 cm was observed to have the highest abundance and the highest diversity of nitrogen fixers and ammonia oxidizers among all the samples. Pearson's correlation analysis showed a positive relationship between water content and p H with the nifH gene abundance. Our results offer the first insight about the microbial community composition and diversity involved in nitrogen cycles in the Dajiuhu Peatland.
