Salinity stress is one of the critical environmental drivers of soil organic matter(SOM)decomposition in coastal ecosystems.Although the temperature sensitivity(Q_(10))of SOM decomposition has been widely applied in E...Salinity stress is one of the critical environmental drivers of soil organic matter(SOM)decomposition in coastal ecosystems.Although the temperature sensitivity(Q_(10))of SOM decomposition has been widely applied in Earth system models to forecast carbon processes,the impact of salinity on SOM decomposition by restructuring microbial communities remains uncovered.Here,we conducted a microcosm experiment with soils collected from the coastal salt marsh in the Yellow River Estuary,which is subjected to strong dynamics of salinity due to both tidal flooding and drainage.By setting a gradient of salt solutions,soil salinity was adjusted to simulate salinity stress and soil carbon emission(CO_(2))rate was measured over the period.Results showed that as salinity increased,the estimated decomposition constants based on first-order kinetics gradually decreased at different temperatures.Below the 20‰salinity treatments,which doubled the soil salinity,Q_(10)increased with increasing salinity;but higher salinity constrained the temperature-related response of SOM decomposition by inhibiting microbial growth and carbon metabolisms.Soil bacteria were more sensitive to salinity stress than fungi,which can be inferred from the response of microbial beta-diversity to changing salinity.Among them,the phylotypes assigned to Gammaproteobacteria and Bacilli showed higher salt tolerance,whereas taxa affiliated with Alphaproteobacteria and Bacteroidota were more easily inhibited by the salinity stress.Several fungal taxa belonging to Ascomycota had higher adaptability to the stress.As the substrate was consumed with the incubation,bacterial competition intensified,but the fungal co-occurrence pattern changed weakly during decomposition.Collectively,these findings revealed the threshold effect of salinity on SOM decomposition in coastal salt marshes and emphasized that salt stress plays a key role in carbon sequestration by regulating microbial keystone taxa,metabolisms,and interactions.展开更多
Dear Editor,Microbes play important roles in various symbiotic systems(Douglas,2015;Xing et al.,2017;Zhu and Wu,2016;Xu et al.,2016a).In the symbiosis formed by bark beetles and microbial associates,beetles formed sym...Dear Editor,Microbes play important roles in various symbiotic systems(Douglas,2015;Xing et al.,2017;Zhu and Wu,2016;Xu et al.,2016a).In the symbiosis formed by bark beetles and microbial associates,beetles formed symbiotic relationships with some fungi including mutualistic and antagonistic ones(Cheng et al.,2015;Lu et al.,2016;Scott et al.,2008),and these interactions,indirectly affected by a third or even fourth participator in a community context,may change from antagonistic ones to mutualistic ones.For example,associated bacterial volatiles can alleviate antagonistic展开更多
Plant-associated microbes are critical for plant growth and survival under natural environmental conditions.To date,most plant microbiome studies involving high-throughput amplicon sequencing have focused on the relat...Plant-associated microbes are critical for plant growth and survival under natural environmental conditions.To date,most plant microbiome studies involving high-throughput amplicon sequencing have focused on the relative abundance of microbial taxa.However,this technique does not assess the total microbial load and the abundance of individual microbes relative to the amount of host plant tissues.Here,we report the development of a host-associated quantitative abundance profiling(HA-QAP)method that can accurately examine total microbial load and colonization of individual root microbiome members relative to host plants by the copy-number ratio of microbial marker gene to plant genome.We validate the HAQAP method using mock experiments,perturbation experiments,and metagenomic sequencing.The HA-QAP method eliminates the generation of spurious outputs in the classical method based on microbial relative abundance,and reveals the load of root microbiome to host plants.Using the HA-QAP method,we found that the copy-number ratios of microbial marker genes to plant genome range from 1.07 to 6.61 for bacterial 16S rRNA genes and from 0.40 to 2.26 for fungal internal transcribed spacers in the root microbiome samples from healthy rice and wheat.Furthermore,using HA-QAP we found that an increase in total microbial load represents a key feature of changes in root microbiome of rice plants exposed to drought stress and of wheat plants with root rot disease,which significantly influences patterns of differential taxa and species interaction networks.Given its accuracy and technical feasibility,HA-QAP would facilitate our understanding of genuine interactions between root microbiome and plants.展开更多
基金the Joint Funds of the National Natural Science Foundation of China(U2006215)the China Postdoctoral Science Foundation(2022M720462)。
文摘Salinity stress is one of the critical environmental drivers of soil organic matter(SOM)decomposition in coastal ecosystems.Although the temperature sensitivity(Q_(10))of SOM decomposition has been widely applied in Earth system models to forecast carbon processes,the impact of salinity on SOM decomposition by restructuring microbial communities remains uncovered.Here,we conducted a microcosm experiment with soils collected from the coastal salt marsh in the Yellow River Estuary,which is subjected to strong dynamics of salinity due to both tidal flooding and drainage.By setting a gradient of salt solutions,soil salinity was adjusted to simulate salinity stress and soil carbon emission(CO_(2))rate was measured over the period.Results showed that as salinity increased,the estimated decomposition constants based on first-order kinetics gradually decreased at different temperatures.Below the 20‰salinity treatments,which doubled the soil salinity,Q_(10)increased with increasing salinity;but higher salinity constrained the temperature-related response of SOM decomposition by inhibiting microbial growth and carbon metabolisms.Soil bacteria were more sensitive to salinity stress than fungi,which can be inferred from the response of microbial beta-diversity to changing salinity.Among them,the phylotypes assigned to Gammaproteobacteria and Bacilli showed higher salt tolerance,whereas taxa affiliated with Alphaproteobacteria and Bacteroidota were more easily inhibited by the salinity stress.Several fungal taxa belonging to Ascomycota had higher adaptability to the stress.As the substrate was consumed with the incubation,bacterial competition intensified,but the fungal co-occurrence pattern changed weakly during decomposition.Collectively,these findings revealed the threshold effect of salinity on SOM decomposition in coastal salt marshes and emphasized that salt stress plays a key role in carbon sequestration by regulating microbial keystone taxa,metabolisms,and interactions.
基金supported by Special Fund for Forest Scientific Research in the Public Welfare(201404401)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB11050000)+1 种基金the National Natural Science Foundation of China(31222013)the State Key Laboratory of Integrated Management of Pest Insects and Rodents(ChineseIPM1 712)
文摘Dear Editor,Microbes play important roles in various symbiotic systems(Douglas,2015;Xing et al.,2017;Zhu and Wu,2016;Xu et al.,2016a).In the symbiosis formed by bark beetles and microbial associates,beetles formed symbiotic relationships with some fungi including mutualistic and antagonistic ones(Cheng et al.,2015;Lu et al.,2016;Scott et al.,2008),and these interactions,indirectly affected by a third or even fourth participator in a community context,may change from antagonistic ones to mutualistic ones.For example,associated bacterial volatiles can alleviate antagonistic
基金This work is financially supported by the National Natural Science Foundation of China(grant nos.31772400,31761143017)the National Natural Science Foundation for Young Scientists of China(grant no.31701997)+1 种基金the Key Research Program of the Chinese Academy of Sciences(grant nos.KFZD-SW-112-02-02 and KFZD-SW-219)the Key Research Program of Frontier Sciences,CAS(grant no.QYZDB-SSW-SMC021).
文摘Plant-associated microbes are critical for plant growth and survival under natural environmental conditions.To date,most plant microbiome studies involving high-throughput amplicon sequencing have focused on the relative abundance of microbial taxa.However,this technique does not assess the total microbial load and the abundance of individual microbes relative to the amount of host plant tissues.Here,we report the development of a host-associated quantitative abundance profiling(HA-QAP)method that can accurately examine total microbial load and colonization of individual root microbiome members relative to host plants by the copy-number ratio of microbial marker gene to plant genome.We validate the HAQAP method using mock experiments,perturbation experiments,and metagenomic sequencing.The HA-QAP method eliminates the generation of spurious outputs in the classical method based on microbial relative abundance,and reveals the load of root microbiome to host plants.Using the HA-QAP method,we found that the copy-number ratios of microbial marker genes to plant genome range from 1.07 to 6.61 for bacterial 16S rRNA genes and from 0.40 to 2.26 for fungal internal transcribed spacers in the root microbiome samples from healthy rice and wheat.Furthermore,using HA-QAP we found that an increase in total microbial load represents a key feature of changes in root microbiome of rice plants exposed to drought stress and of wheat plants with root rot disease,which significantly influences patterns of differential taxa and species interaction networks.Given its accuracy and technical feasibility,HA-QAP would facilitate our understanding of genuine interactions between root microbiome and plants.