Plant invasion is one of the factors of global change,threatening ecosystem services and functions.Invasive plants are different in physiological characteristics,which make them have a strong competitive advantage in resource utilization and resistance to environmental stress,hence higher N2O emission.The fluorescence characteristics of chlorophyll are closely related to the photosynthesis efficiency of plants and play an important role in plant growth.Soil microorganisms are essential for plants to absorb and utilize soil nutrients.Understanding how soil microbes affect the chlorophyll fluorescence characteristics of invasive plants under the background of nitrogen deposition is helpful to understand the evolutionary characteristics and invasion mechanisms,to effectively prevent and control invasive plants and reduce it and provides a theoretical basis for the damage to the ecosystem.In this experiment,seeds of Triadica sebifera（T.sebifera）were collected from the introduced（United States）and native（China）range.Soils were collected from the experimental field of T.sebifera,and non-heating greenhouse experiment was conducted in the native range of T.sebifera at Jiangxi Agricultural University,Nanchang.The performed experiments studied the effect of fertilizer,microbial inhibitors（bacteria and fungi）or their interaction on the performance of T.sebifera origin,soil enzyme activities,photosynthesis and N2O emission rates.Full factorial experimental design was employed.The net effects of nitrogen deposition,and soil microbial inhibitors on the growth of T.sebifera seedlings were analyzed by measuring the growth,biomass,morphological characteristics and chlorophyll fluorescence of the T.sebifera seedlings.The effects of different treatment interacted with T.sebifera origin on N2O emission rate were studied.Native and introduced populations of T.sebifera had similar above-and belowground biomass in active（control）soil but soil sterilization decreased them,especially for native populations.Urease activity was higher for native population plants in active soils but an opposite pattern was found in sterilized soil.Belowground biomass specific phosphatase activities were increased by soil sterilization,especially for native populations or when both N and P were added.Nitrogen deposition significantly increased the relative chlorophyll content（SPAD）of T.sebifera,the maximum quantum yield of photosystem II（Fv/Fm）,non-photochemical quenching（NPQ）and half-saturated light intensity（IK）.The invasive T.sebifera has lower SPAD than the native.The combined application of nitrogen deposition and bacterial inhibitors significantly enhanced Fv/Fm,NPQ and IK,and significantly weakened the light energy utilization rateαand SPAD.Bacterial inhibitors slowed down theαof native T.sebifera,and fungal inhibitors promoted the IK of native T.sebifera and inhibited the invasive T.sebifera IK.In the N application treatment,leaf biomass and leaf numbers were significantly increased,and decrease was noted in root biomass and root/shoot ratio than those from the control treatment.Root/shoot was found higher in control for invasive population than those from native population but opposite pattern was found with N application.Bacterial and fungal inhibitor increased the root,leaf,aboveground and total biomass but it was remaining higher in fungal inhibitor than those from any other treatments.Bacterial and fungal inhibitors or their interaction respectively decreased the N2O emission and cumulative rate,higher in control treatment and lower in bacterial interaction fungal inhibitor.In case of T.sebifera origin,higher N2O emission and cumulative rate was noted in invasive than native.Nitrous oxide emissions were positive correlated to temperature or plant traits,while negatively correlated to moisture and leaf area ratio.In conclusion,the dependence of soil enzyme activities on the interactions of soil sterilization,soil fertility and plant population origin suggest that there may have been genetic changes in soil enzyme activities during the invasion process.Because urease and phosphatase showed distinct patterns,T.sebifera may have acquired different strategies for the utilization of soil nitrogen and phosphorus,which likely has implications for understanding and managing invasions.Microbial facilitation and nutrients use efficiency of T.sebifera should be considered for future management under global climate change.Increased nitrogen deposition may interact with soil microorganism impacting the invasion process of T.sebifera.Plant soil feedback process and microbial communities both may affect successful invasion process of T.sebifera.Such as,Nitrogen deposition and fungal inhibitors have a synergistic effect on the chlorophyll fluorescence characteristics of T.sebifera,therefore has strong invasion ability.Microbial dynamics,N availability and increases in temperature may be the main reason of N2O emission,which can be affected by introduced population and may vary to ecosystem type.