Phosphorus(P)is an essential nutrient for plant growth and reproduction.Plants preferentially absorb P as orthophosphate(Pi),an ion that displays low solubility and that is readily fixed in the soil,making P limita-ti...Phosphorus(P)is an essential nutrient for plant growth and reproduction.Plants preferentially absorb P as orthophosphate(Pi),an ion that displays low solubility and that is readily fixed in the soil,making P limita-tion a condition common to many soils and Pi fertilization an inefficient practice.To cope with Pi limitation,plants have evolved a series of developmental and physiological responses,collectively known as the Pi starvation rescue system(PSR),aimed to improve Pi acquisition and use efficiency(PUE)and protect from Pi-starvation-induced stress.Intensive research has been carried out during the last 20 years to un-ravel the mechanisms underlying the control of the PSR in plants.Here we review the results of this research effort that have led to the identification and characterization of several core Pi starvation signaling components,including sensors,transcription factors,microRNAs(miRNAs)and miRNA inhibitors,kinases,phosphatases,and components of the proteostasis machinery.We also refer to recent results revealing the existence of intricate signaling interplays between Pi and other nutrients and antagonists,N,Fe,Zn,and As,that have changed the initial single-nutrient-centric view to a more integrated view of nutrient homeostasis.Finally,we discuss advances toward improving PUE and future research priorities.展开更多
Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native ...Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.展开更多
Mangroves are one of the most ecologically sensitive ecosystems to global climate change,which have cascading impacts on soil carbon(C),nitrogen(N)and phosphorus(P)cycling.Moreover,mangroves are experiencing increasin...Mangroves are one of the most ecologically sensitive ecosystems to global climate change,which have cascading impacts on soil carbon(C),nitrogen(N)and phosphorus(P)cycling.Moreover,mangroves are experiencing increasing N and P loadings and reduced oxygen availability due to intensified climate change and human activities.However,both direct and interactive effects of these perturbations on microbially mediated soil C,N and P cycling are poorly understood.Here,we simultaneously investigated the effects of N and P loadings and reduced oxygen on microbial biomass,microbial respiration,and extracellular enzyme activities(EEAs)in mangrove soils.We calculated the microbial metabolic quotient(qCO_(2)),which is regarded as a useful inverse metric of microbial C use efficiency(CUE).Our results show that reduced oxygen significantly increases both qCO_(2) and microbial specific EEAs(enzyme activity per unit of microbial biomass)for C-,N-and P-acquisition regardless of N or P loadings.Furthermore,we found that qCO_(2) positively correlated with microbial specific EEAs under reduced oxygen,whereas no clear relationship was detected under ambient oxygen.These results suggest that reduced oxygen increases microbial specific EEAs at the expense of increasing microbial respiration per unit biomass,indicating higher energy cost per unit enzyme production.展开更多
Vesicular-arbuscular mycorrhizal (VAM) fungi have been credited with improving the groWth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. The combined ef...Vesicular-arbuscular mycorrhizal (VAM) fungi have been credited with improving the groWth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. The combined effects of VAM, Zn and P application on the growth and translocation of nutrients in wheat were investigated using a calcareous soil marginal in P and Zn concentrations. Wheat was grown in a growth chamber under various combinations of VAM, P and Zn with measurements done at heading stage and maturity.Vegetative dry matter accumulation was increased by P application and reduced by VAM treatments. Both P and VAM increased grain yield. Zinc concentration and uptake were generally reduced by P addition and VAM infection. There were no antagonistic effects of Zn on P acquisition in the plant. The role of VAM in enhancing the translocation of Zn and P from root to grain would be beneficial to seed setting and yield.展开更多
Toxoplasma gondii is a protozoan of worldwide distribution and the agent of toxoplasmosis.It is estimated that 30%–50%of the world population could be infected with this parasite.Although the infection in immunocompe...Toxoplasma gondii is a protozoan of worldwide distribution and the agent of toxoplasmosis.It is estimated that 30%–50%of the world population could be infected with this parasite.Although the infection in immunocompetent individuals is mostly asymptomatic,the disease in immunosuppressed and pregnant is a risk condition.As a member of the phylum Apicomplexa,T.gondii has an obligatory intracellular lifestyle;therefore,invading a host cell and establishing it inside a parasitophorous vacuole(PV)are mandatories for the survival of this parasite.The construction of a perfect intracellular niche for T.gondii requires the secretion of an arsenal of proteins from unique secretory organelles.These proteins will remodel the vacuolar environment and the host cell organization and functions,allowing the parasite to access essential nutrients and stay“invisible”inside a host cell.In the present review,we will discuss the main steps involved in the PV formation and its differentiation to tissue cyst,focusing mainly on the strategies employed in the acquisition of nutrients and proteins involved in host cell modification.展开更多
The parasitic plant Cistanche deserticola attaches to Haloxylon ammodendron, a perennial shrub with high tolerance to salinity and drought. However, little was known about the parasite-host relation between the two sp...The parasitic plant Cistanche deserticola attaches to Haloxylon ammodendron, a perennial shrub with high tolerance to salinity and drought. However, little was known about the parasite-host relation between the two species. Effects of the parasite on chlorophyll a fluorescence and nutrient accumulation in the host plant （H. am- modendron） were investigated in the Taklimakan Desert. Some photosynthetic parameters of both host and non-host H. ammodendron plants were measured by in vivo chlorophyll a fluorescence technology in the field. The assimilating branches of host and non-host plants were collected and nutrient and inorganic ion contents were analyzed. The results from field experiments showed that the infection of C. deserticola reduced the non-photochemical quenching of the variable chlorophyll fluorescence （NPQ） and the potential maximum quantum yield for primary photochemistry （Fv/Fm） of the host. Compared with non-host plants, the host H. ammodendron had low nutrient, low inorganic ion contents （Na~ and K~） and low K~/Na~ ratios in the assimilating branches. It suggested that C. deserticola infection reduced the nutrient acquisition and caused damage to the photoprotection through thermal dissipation of the energy of the photosystem II in the host, resulting in a decrease in the tolerance to salinity and high radiation. It was concluded that the attachment of the parasite plant （C. deserticola） had negative effects on the growth of its host.展开更多
Round shaped, continuous vertical pores (CVPs) in the soil are typically created by roots and earthworms. CVPs with diameters > 2 mm are abundant in many agricultural soils. We hypothesized that potential effects o...Round shaped, continuous vertical pores (CVPs) in the soil are typically created by roots and earthworms. CVPs with diameters > 2 mm are abundant in many agricultural soils. We hypothesized that potential effects of CVPs on shoot growth of winter wheat (Triticum aestivum L.) increase with: 1) decreasing availability of water and 2) decreasing availability of nutrients in the topsoil. We conducted a microcosm experiment with different irrigation regimes (Irr+/Irr-) and P concentrations (P+/P-), with or without artificially created continuous vertical pores (CVP+/CVP-). Winter wheat was cultivated for 16 weeks. In the bulk soil, presence of CVPs resulted in decreased root length in 20 - 40 cm but increased root length in 40 - 60 cm soil depth. In general, total root length of winter wheat in 20 - 60 cm soil depth was higher when CVPs were present or when P concentrations in the topsoil were elevated. Presence of CVPs generally had a positive effect on shoot dry matter and N uptake of wheat. In columns with high phosphorous concentrations but low soil moisture in the topsoil, presence of CVPs increased shoot dry matter by 66%;in contrast, the beneficial effect of CVPs on shoot dry matter was only 39% in columns with high nutrient concentrations and high soil moisture in the topsoil. In total numbers, however, the effect of CVPs on P uptake into the shoot was more pronounced when P concentrations in the topsoil were elevated. We conclude that CVPs can promote the exploration of the solid soil phase by high root-length densities, but adequate nutrient supply in the topsoil is essential.展开更多
Litter is the crucial carrier of soil nutrition transformation.The influence of arbuscular mycorrhizal(AM)fungi on nutrient acquisition in plants has been widely recognized.However,in nutrient-deficient karst habitat,...Litter is the crucial carrier of soil nutrition transformation.The influence of arbuscular mycorrhizal(AM)fungi on nutrient acquisition in plants has been widely recognized.However,in nutrient-deficient karst habitat,how competitive plants utilize nutrients regulated by AM fungi via litter remain largely unknown.The experimental treatments included the inoculation with or without Glomus etunicatum,the litter addition by the mixed leaves of Broussonetia papyrifera and Carpinus pubescens or no addition,and the competition through the intraspecific competition of B.papyrifera and C.pubescens,respectively,and the interspecific competition mixed both plants.AM fungi differently affected plant on nutrient acquisition,increasing nutrients acquisitions of B.papyrifera in intra-and interspecific competitions while decreasing for C.pubescens.Litter presented opposite influences on N acquisitions of both plants in interspecific competition with AM fungi,being positive for C.pubescens and negative for B.papyrifera,respectively.Under the interaction of AM fungi and litter,nitrogen(N),phosphorus(P)and potassium(K)acquisitions by B.papyrifera and N acquisition by C.pubescens in interspecific competition were all greater than intraspecific competition.In the interspecific competition,the competitive ability of plants on nutrient absorption presented significant species difference,which of B.papyrifera on P and K was significantly increased,while was converse for C.pubescens on K.In conclusion,these results suggest that the interspecific competition presents greater nutrient facilitation compared with intraspecific competition through AM fungi interacting with litter for plants in karst soil.展开更多
Background:The nitrogen isotope natural abundance(δ^(15)N)provides integrated information on ecosystem N dynamics,and carbon isotope natural abundance(δ^(13)C)has been used to infer how water-using processes of plan...Background:The nitrogen isotope natural abundance(δ^(15)N)provides integrated information on ecosystem N dynamics,and carbon isotope natural abundance(δ^(13)C)has been used to infer how water-using processes of plants change in terrestrial ecosystems.However,howδ^(13)C andδ^(15)N abundances in plant life and soils respond to N addition and water availability change is still unclear.Thus,δ^(13)C andδ^(15)N abundances in plant life and soils were used to investigate the effects of long-time(10 years)N addition(+50 kg N·ha^(−1)·yr^(−1)and precipitation reduction(−30%of throughfall)in forest C and N cycling traits in a temperate forest in northern China.Results:We analyzed theδ^(13)C andδ^(15)N values of dominant plant foliage,litterfall,fungal sporophores,roots,and soils in the study.The results showed thatδ^(15)N values of foliage,litterfall,and surface soil layer’s(0–10 cm)total N were significantly increased by N addition,whileδ^(15)N values of fine roots and coarse roots were considerably decreased.Nitrogen addition also significantly increased theδ^(13)C value of fine roots and total N concentration of the surface soil layer compared with the control.The C concentration,δ^(13)C,andδ^(15)N values of foliage andδ^(15)N values of fine roots were significantly increased by precipitation reduction,while N concentration of foliage and litterfall significantly decreased.The combined effects of N addition and precipitation reduction significantly increased theδ^(13)C andδ^(15)N values of foliage as well as theδ^(15)N values of fine roots andδ^(13)C values of litterfall.Furthermore,foliarδ^(15)N values were significantly correlated with foliageδ^(13)C values,surface soilδ^(15)N values,surface soil C concentration,and N concentrations.Nitrogen concentrations andδ^(13)C values of foliage were significantly correlated withδ^(15)N values and N concentrations of fine roots.Conclusions:This indicates that plants increasingly take up the heavier 15N under N addition and the heavier 13C and 15展开更多
Desert ephemeral plants play an important role in desert ecosystem.Soil water availability is considered as the major restrictive factor limiting the growth of ephemeral plants.Moreover,arbuscular mycorrhizal fungi（A...Desert ephemeral plants play an important role in desert ecosystem.Soil water availability is considered as the major restrictive factor limiting the growth of ephemeral plants.Moreover,arbuscular mycorrhizal fungi（AM fungi） are widely reported to improve the growth of desert ephemerals.The present study aimed to test the hypothesis of that AM fungi could alleviate drought stress of desert ephemeral Plantago minuta,and AM fungal functions reduced with the improvement of soil water content.A pot experiment was carried out with three levels of soil water contents（4.5%,9.0%,and 15.8%（w/w））,and three AM inoculation treatments（Glomus mosseae,Glomus etunicatum and non-inoculation）.The results indicate that mycorrhizal colonization rate decreased with the increase of soil water availability.Inoculation improved plant growth and N,P and K acquisition in both shoots and roots regardless water treatments.When comparing the two fungi,plants inoculated with G.mosseae performed better than those inoculated with G.etunicatum in terms of plant growth and nutrient acquisition.These results showed that ameliorative soil water did not suppress arbuscular mycorrhizal fungal functions in improving growth and nutrient acquisition of desert ephemeral Plantago minuta.展开更多
基金the Ministry of Science and Innovation,Spain(grant numbers BIO2017-89530-R and BIO2020-118750RB-100).
文摘Phosphorus(P)is an essential nutrient for plant growth and reproduction.Plants preferentially absorb P as orthophosphate(Pi),an ion that displays low solubility and that is readily fixed in the soil,making P limita-tion a condition common to many soils and Pi fertilization an inefficient practice.To cope with Pi limitation,plants have evolved a series of developmental and physiological responses,collectively known as the Pi starvation rescue system(PSR),aimed to improve Pi acquisition and use efficiency(PUE)and protect from Pi-starvation-induced stress.Intensive research has been carried out during the last 20 years to un-ravel the mechanisms underlying the control of the PSR in plants.Here we review the results of this research effort that have led to the identification and characterization of several core Pi starvation signaling components,including sensors,transcription factors,microRNAs(miRNAs)and miRNA inhibitors,kinases,phosphatases,and components of the proteostasis machinery.We also refer to recent results revealing the existence of intricate signaling interplays between Pi and other nutrients and antagonists,N,Fe,Zn,and As,that have changed the initial single-nutrient-centric view to a more integrated view of nutrient homeostasis.Finally,we discuss advances toward improving PUE and future research priorities.
基金funded by the National Natural Science Foundation of China (32171746,31870522,42077450,32371786)the leading talents of basic research in Henan Province+3 种基金Funding for Characteristic and Backbone Forestry Discipline Group of Henan Provincethe Scientific Research Foundation of Henan Agricultural University (30500854)Research Funds for overseas returnee in Henan Province,Chinasupported by National Key Research and Development Program of China (2019YFE0117000)。
文摘Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native plants.However,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents.Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine max.We measured traits related to root and nodule quantity and activity and mycorrhizal colonization.Compared to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of G.max decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was unaffected.Contribution of N fixation to leaf N content in G.max increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of G.max in the mixed plantings.Increased root quantity and activity,along with a higher mycorrhizal association was observed in X.strumarium in the mixed compared to monoculture.Together,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source.The quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.
基金funding from EU H2020 Marie SkłodowskaCurie Actions(No.839806)Aarhus Universitets Forskningsfond(AUFF-E-2019-7-1)+3 种基金Danish Independent Research Foundation(1127-00015B)Nordic Committee of Agriculture and Food Researchsupported by Natural Environment Research Council(NERC)EAO Doctoral Training Partnership(NE/L002469/1)supported by a Ramon Areces Foundation research Fellowship and BBSRC Discovery Fellowship(BB/S010661/1).
文摘Mangroves are one of the most ecologically sensitive ecosystems to global climate change,which have cascading impacts on soil carbon(C),nitrogen(N)and phosphorus(P)cycling.Moreover,mangroves are experiencing increasing N and P loadings and reduced oxygen availability due to intensified climate change and human activities.However,both direct and interactive effects of these perturbations on microbially mediated soil C,N and P cycling are poorly understood.Here,we simultaneously investigated the effects of N and P loadings and reduced oxygen on microbial biomass,microbial respiration,and extracellular enzyme activities(EEAs)in mangrove soils.We calculated the microbial metabolic quotient(qCO_(2)),which is regarded as a useful inverse metric of microbial C use efficiency(CUE).Our results show that reduced oxygen significantly increases both qCO_(2) and microbial specific EEAs(enzyme activity per unit of microbial biomass)for C-,N-and P-acquisition regardless of N or P loadings.Furthermore,we found that qCO_(2) positively correlated with microbial specific EEAs under reduced oxygen,whereas no clear relationship was detected under ambient oxygen.These results suggest that reduced oxygen increases microbial specific EEAs at the expense of increasing microbial respiration per unit biomass,indicating higher energy cost per unit enzyme production.
文摘Vesicular-arbuscular mycorrhizal (VAM) fungi have been credited with improving the groWth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. The combined effects of VAM, Zn and P application on the growth and translocation of nutrients in wheat were investigated using a calcareous soil marginal in P and Zn concentrations. Wheat was grown in a growth chamber under various combinations of VAM, P and Zn with measurements done at heading stage and maturity.Vegetative dry matter accumulation was increased by P application and reduced by VAM treatments. Both P and VAM increased grain yield. Zinc concentration and uptake were generally reduced by P addition and VAM infection. There were no antagonistic effects of Zn on P acquisition in the plant. The role of VAM in enhancing the translocation of Zn and P from root to grain would be beneficial to seed setting and yield.
文摘Toxoplasma gondii is a protozoan of worldwide distribution and the agent of toxoplasmosis.It is estimated that 30%–50%of the world population could be infected with this parasite.Although the infection in immunocompetent individuals is mostly asymptomatic,the disease in immunosuppressed and pregnant is a risk condition.As a member of the phylum Apicomplexa,T.gondii has an obligatory intracellular lifestyle;therefore,invading a host cell and establishing it inside a parasitophorous vacuole(PV)are mandatories for the survival of this parasite.The construction of a perfect intracellular niche for T.gondii requires the secretion of an arsenal of proteins from unique secretory organelles.These proteins will remodel the vacuolar environment and the host cell organization and functions,allowing the parasite to access essential nutrients and stay“invisible”inside a host cell.In the present review,we will discuss the main steps involved in the PV formation and its differentiation to tissue cyst,focusing mainly on the strategies employed in the acquisition of nutrients and proteins involved in host cell modification.
基金supported by the "Western Light" Talents Training Program of Chinese Academy of Sciences (lhxz200901)
文摘The parasitic plant Cistanche deserticola attaches to Haloxylon ammodendron, a perennial shrub with high tolerance to salinity and drought. However, little was known about the parasite-host relation between the two species. Effects of the parasite on chlorophyll a fluorescence and nutrient accumulation in the host plant （H. am- modendron） were investigated in the Taklimakan Desert. Some photosynthetic parameters of both host and non-host H. ammodendron plants were measured by in vivo chlorophyll a fluorescence technology in the field. The assimilating branches of host and non-host plants were collected and nutrient and inorganic ion contents were analyzed. The results from field experiments showed that the infection of C. deserticola reduced the non-photochemical quenching of the variable chlorophyll fluorescence （NPQ） and the potential maximum quantum yield for primary photochemistry （Fv/Fm） of the host. Compared with non-host plants, the host H. ammodendron had low nutrient, low inorganic ion contents （Na~ and K~） and low K~/Na~ ratios in the assimilating branches. It suggested that C. deserticola infection reduced the nutrient acquisition and caused damage to the photoprotection through thermal dissipation of the energy of the photosystem II in the host, resulting in a decrease in the tolerance to salinity and high radiation. It was concluded that the attachment of the parasite plant （C. deserticola） had negative effects on the growth of its host.
文摘Round shaped, continuous vertical pores (CVPs) in the soil are typically created by roots and earthworms. CVPs with diameters > 2 mm are abundant in many agricultural soils. We hypothesized that potential effects of CVPs on shoot growth of winter wheat (Triticum aestivum L.) increase with: 1) decreasing availability of water and 2) decreasing availability of nutrients in the topsoil. We conducted a microcosm experiment with different irrigation regimes (Irr+/Irr-) and P concentrations (P+/P-), with or without artificially created continuous vertical pores (CVP+/CVP-). Winter wheat was cultivated for 16 weeks. In the bulk soil, presence of CVPs resulted in decreased root length in 20 - 40 cm but increased root length in 40 - 60 cm soil depth. In general, total root length of winter wheat in 20 - 60 cm soil depth was higher when CVPs were present or when P concentrations in the topsoil were elevated. Presence of CVPs generally had a positive effect on shoot dry matter and N uptake of wheat. In columns with high phosphorous concentrations but low soil moisture in the topsoil, presence of CVPs increased shoot dry matter by 66%;in contrast, the beneficial effect of CVPs on shoot dry matter was only 39% in columns with high nutrient concentrations and high soil moisture in the topsoil. In total numbers, however, the effect of CVPs on P uptake into the shoot was more pronounced when P concentrations in the topsoil were elevated. We conclude that CVPs can promote the exploration of the solid soil phase by high root-length densities, but adequate nutrient supply in the topsoil is essential.
基金supported by the National Natural Science Foundation of China(NSFC,31660156,31360106)the First-Class Disciplines Program on Ecology of Guizhou Province(GNYL[2017]007)+2 种基金the Guizhou Hundred-Level Innovative Talents Project(Qian-ke-he platform talents[2020]6004)the Science and Technology Project of Guizhou Province([2021]General-455,[2016]Supporting-2805)the Talent-platform Program of Guizhou Province([2017]5788,[2018]5781).
文摘Litter is the crucial carrier of soil nutrition transformation.The influence of arbuscular mycorrhizal(AM)fungi on nutrient acquisition in plants has been widely recognized.However,in nutrient-deficient karst habitat,how competitive plants utilize nutrients regulated by AM fungi via litter remain largely unknown.The experimental treatments included the inoculation with or without Glomus etunicatum,the litter addition by the mixed leaves of Broussonetia papyrifera and Carpinus pubescens or no addition,and the competition through the intraspecific competition of B.papyrifera and C.pubescens,respectively,and the interspecific competition mixed both plants.AM fungi differently affected plant on nutrient acquisition,increasing nutrients acquisitions of B.papyrifera in intra-and interspecific competitions while decreasing for C.pubescens.Litter presented opposite influences on N acquisitions of both plants in interspecific competition with AM fungi,being positive for C.pubescens and negative for B.papyrifera,respectively.Under the interaction of AM fungi and litter,nitrogen(N),phosphorus(P)and potassium(K)acquisitions by B.papyrifera and N acquisition by C.pubescens in interspecific competition were all greater than intraspecific competition.In the interspecific competition,the competitive ability of plants on nutrient absorption presented significant species difference,which of B.papyrifera on P and K was significantly increased,while was converse for C.pubescens on K.In conclusion,these results suggest that the interspecific competition presents greater nutrient facilitation compared with intraspecific competition through AM fungi interacting with litter for plants in karst soil.
基金from National Natural Science Foundation of China(Grant Nos:41773075,41575137,31370494,31170421).
文摘Background:The nitrogen isotope natural abundance(δ^(15)N)provides integrated information on ecosystem N dynamics,and carbon isotope natural abundance(δ^(13)C)has been used to infer how water-using processes of plants change in terrestrial ecosystems.However,howδ^(13)C andδ^(15)N abundances in plant life and soils respond to N addition and water availability change is still unclear.Thus,δ^(13)C andδ^(15)N abundances in plant life and soils were used to investigate the effects of long-time(10 years)N addition(+50 kg N·ha^(−1)·yr^(−1)and precipitation reduction(−30%of throughfall)in forest C and N cycling traits in a temperate forest in northern China.Results:We analyzed theδ^(13)C andδ^(15)N values of dominant plant foliage,litterfall,fungal sporophores,roots,and soils in the study.The results showed thatδ^(15)N values of foliage,litterfall,and surface soil layer’s(0–10 cm)total N were significantly increased by N addition,whileδ^(15)N values of fine roots and coarse roots were considerably decreased.Nitrogen addition also significantly increased theδ^(13)C value of fine roots and total N concentration of the surface soil layer compared with the control.The C concentration,δ^(13)C,andδ^(15)N values of foliage andδ^(15)N values of fine roots were significantly increased by precipitation reduction,while N concentration of foliage and litterfall significantly decreased.The combined effects of N addition and precipitation reduction significantly increased theδ^(13)C andδ^(15)N values of foliage as well as theδ^(15)N values of fine roots andδ^(13)C values of litterfall.Furthermore,foliarδ^(15)N values were significantly correlated with foliageδ^(13)C values,surface soilδ^(15)N values,surface soil C concentration,and N concentrations.Nitrogen concentrations andδ^(13)C values of foliage were significantly correlated withδ^(15)N values and N concentrations of fine roots.Conclusions:This indicates that plants increasingly take up the heavier 15N under N addition and the heavier 13C and 15
基金funded by the Foundation for University Key Teacher by Henan Educational Committee (2013GGJS070)the National Basic Research Program of China (2014CB954202)+1 种基金the National Natural Science Foundation of China (40971150)the China Scholarship Council (201208410020)
文摘Desert ephemeral plants play an important role in desert ecosystem.Soil water availability is considered as the major restrictive factor limiting the growth of ephemeral plants.Moreover,arbuscular mycorrhizal fungi（AM fungi） are widely reported to improve the growth of desert ephemerals.The present study aimed to test the hypothesis of that AM fungi could alleviate drought stress of desert ephemeral Plantago minuta,and AM fungal functions reduced with the improvement of soil water content.A pot experiment was carried out with three levels of soil water contents（4.5%,9.0%,and 15.8%（w/w））,and three AM inoculation treatments（Glomus mosseae,Glomus etunicatum and non-inoculation）.The results indicate that mycorrhizal colonization rate decreased with the increase of soil water availability.Inoculation improved plant growth and N,P and K acquisition in both shoots and roots regardless water treatments.When comparing the two fungi,plants inoculated with G.mosseae performed better than those inoculated with G.etunicatum in terms of plant growth and nutrient acquisition.These results showed that ameliorative soil water did not suppress arbuscular mycorrhizal fungal functions in improving growth and nutrient acquisition of desert ephemeral Plantago minuta.
