Background:C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming.Here,we explore how the patterns of abundances of C4 annuals and C4 ...Background:C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming.Here,we explore how the patterns of abundances of C4 annuals and C4 perennials change over space and time.Methods:A total of 280 sites with C4 plants were surveyed in four types of grasslands in 9 years.The relative biomasses of C4 plants(PC4),C4 annuals(PA4),and C4 perennials(PP4)were calculated.Structural equation modeling was used to analyze the drivers of changes in PA4 and PP4.Results:At the regional scale,PA4 on average was 11%(±19%,SD)and PP4 was 13%(±19%,SD).Spatially,C4 annuals dominated the C4 communities within an east–west belt region along 44°N and tended to spread toward northern latitudes(about 0.5°)and higher altitudes in the east mountainous areas.The abundance of C4 annuals decreased,while that of C4 perennials increased.The patterns of C4 annuals and C4 perennials were mainly controlled by temperature,growing season precipitation,and dynamics between the two life forms.Conclusions:C4 annuals exhibited competitive advantages in normal and wet years,while C4 perennials had competitive advantages in dry years.Grazing as a main human disturbance increased C4 annuals,but had no significant effect on C4 perennials.展开更多
Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolera...Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.展开更多
Wetlands play a number of vital roles in the ecosystem, such as serving as nutrient sinks, preventing floods, storing carbon, and filtering water. Encroachment on wetlands has led to substantial economic and environme...Wetlands play a number of vital roles in the ecosystem, such as serving as nutrient sinks, preventing floods, storing carbon, and filtering water. Encroachment on wetlands has led to substantial economic and environmental losses, including water quality degradation, loss of biodiversity and natural habitats, reduced climate mitigation as well as social and health risks. This study evaluated the effect of different land use types on nutrient stock distribution across varying soil depths in Busega wetland. The soil samples were collected in three different land uses (annually cultivated areas, perennially cultivated areas, and the undisturbed wetland area) at three different depths (0 - 10 cm, 10 - 20 cm, and 20 - 30 cm) in 2021. The soil samples were analyzed for physicochemical soil properties including soil texture and nitrogen, phosphorus, calcium, and potassium concentrations. The interaction between land use type and soil depth did not have a significant effect on nutrient distribution. However, our results showed that the main effects of land use type and soil depth influenced nutrient stock distribution across the wetland. Higher nutrient concentrations were observed under perennial cropping system than in both annual cropping system and the undisturbed wetland area. Soils under perennial cropping systems had the highest soil organic matter (1.45%), calcium (2.06 Cmol/Kg) and potassium (0.091 Cmol/Kg) levels. Higher soil organic matter (1.40%), nitrogen (0.22%), calcium (1.74 Cmol/Kg), and potassium (0.07 Cmol/Kg) were found at the mid-soil depth of 10 - 20 cm. Our results show substantial nutrient changes due to agricultural activities in the Busega wetland, suggesting further research is urgently needed to determine if these changes have adverse effects on biodiversity and water quality of the wetland and nearby water resources.展开更多
Over 100 reaches of perennial streams(PS) and non-perennial streams(NPS) were classified based on the Rosgen stream classification. NPS were mainly type B(39%), characterized by moderate entrenchment and low sinuosity...Over 100 reaches of perennial streams(PS) and non-perennial streams(NPS) were classified based on the Rosgen stream classification. NPS were mainly type B(39%), characterized by moderate entrenchment and low sinuosity. The remainder were almost equally split between three different classes, highlighting the morphological diversity of NPS. Fiftynine percent of PS belonged to type C;such streams are slightly entrenched, less sinuous and have a sequential riffle-pool configuration. Surface particles were significantly coarser than the subsurface in both stream types in thalweg and low flow areas, whereas in NPS, this was prominent, showing 4-5 times more armoring than PS. Even though the NPS had a significantly coarser surface sediment layer than PS in thalweg and low flow areas, its subsurface sediment showed similar particle sizes to PS;this is an indication of surface armoring and provision of more infiltration of fine particles in NPS. A two-year return period flow event did not result in a change of the cross-section profiles. In both stream types, the horizontal force required to uproot herbaceous vegetation with unexposed roots under moist conditions manually was higher than the tractive force at high flows;however, at bankfull flows, it was lower. Also, the uprooting force in PS was lower than that of NPS, indicating that NPS banks are more stable, and numerical analyses showed they are stable under the self-weight.展开更多
Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegr...Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.展开更多
《变应性鼻炎及其对哮喘的影响》(Allergic rhinitis and its impact on asthma,ARIA)指南最新修订版(简称ARIA2010版)最近由《Journal of Allergy and Clinical Immunology》杂志全文发表。与旧版ARIA指南使用循证医学的方法不同,ARIA2...《变应性鼻炎及其对哮喘的影响》(Allergic rhinitis and its impact on asthma,ARIA)指南最新修订版(简称ARIA2010版)最近由《Journal of Allergy and Clinical Immunology》杂志全文发表。与旧版ARIA指南使用循证医学的方法不同,ARIA2010版采用推荐、评估、发展和评价分级(Grading of Recommendations,Assessment,Development and Evaluation,GRADE)工作组提出的透明的、系统化的方法修订了临床建议,以提高其实用价值。展开更多
基金supported by the DFG within the DFG research group 536(MAGIM)the National Natural Science Foundation of China(31630010 and 31320103916).
文摘Background:C4 plants have increased substantially during the past several decades in the grasslands of the Mongolian Plateau due to regional warming.Here,we explore how the patterns of abundances of C4 annuals and C4 perennials change over space and time.Methods:A total of 280 sites with C4 plants were surveyed in four types of grasslands in 9 years.The relative biomasses of C4 plants(PC4),C4 annuals(PA4),and C4 perennials(PP4)were calculated.Structural equation modeling was used to analyze the drivers of changes in PA4 and PP4.Results:At the regional scale,PA4 on average was 11%(±19%,SD)and PP4 was 13%(±19%,SD).Spatially,C4 annuals dominated the C4 communities within an east–west belt region along 44°N and tended to spread toward northern latitudes(about 0.5°)and higher altitudes in the east mountainous areas.The abundance of C4 annuals decreased,while that of C4 perennials increased.The patterns of C4 annuals and C4 perennials were mainly controlled by temperature,growing season precipitation,and dynamics between the two life forms.Conclusions:C4 annuals exhibited competitive advantages in normal and wet years,while C4 perennials had competitive advantages in dry years.Grazing as a main human disturbance increased C4 annuals,but had no significant effect on C4 perennials.
基金supported by funding from the National Natural Science Foundation of China(32060593 and 32060474)the Yunnan Provincial Science and Technology Department+4 种基金China(202101AT070021 and 202101AS070001)the Yunnan Provincial Department of Education Science Research Fund ProjectChina(2023J0006)the Graduate Innovation Project of Yunnan UniversityChina(KC-22223012 and ZC-22222760)。
文摘Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.
文摘Wetlands play a number of vital roles in the ecosystem, such as serving as nutrient sinks, preventing floods, storing carbon, and filtering water. Encroachment on wetlands has led to substantial economic and environmental losses, including water quality degradation, loss of biodiversity and natural habitats, reduced climate mitigation as well as social and health risks. This study evaluated the effect of different land use types on nutrient stock distribution across varying soil depths in Busega wetland. The soil samples were collected in three different land uses (annually cultivated areas, perennially cultivated areas, and the undisturbed wetland area) at three different depths (0 - 10 cm, 10 - 20 cm, and 20 - 30 cm) in 2021. The soil samples were analyzed for physicochemical soil properties including soil texture and nitrogen, phosphorus, calcium, and potassium concentrations. The interaction between land use type and soil depth did not have a significant effect on nutrient distribution. However, our results showed that the main effects of land use type and soil depth influenced nutrient stock distribution across the wetland. Higher nutrient concentrations were observed under perennial cropping system than in both annual cropping system and the undisturbed wetland area. Soils under perennial cropping systems had the highest soil organic matter (1.45%), calcium (2.06 Cmol/Kg) and potassium (0.091 Cmol/Kg) levels. Higher soil organic matter (1.40%), nitrogen (0.22%), calcium (1.74 Cmol/Kg), and potassium (0.07 Cmol/Kg) were found at the mid-soil depth of 10 - 20 cm. Our results show substantial nutrient changes due to agricultural activities in the Busega wetland, suggesting further research is urgently needed to determine if these changes have adverse effects on biodiversity and water quality of the wetland and nearby water resources.
文摘Over 100 reaches of perennial streams(PS) and non-perennial streams(NPS) were classified based on the Rosgen stream classification. NPS were mainly type B(39%), characterized by moderate entrenchment and low sinuosity. The remainder were almost equally split between three different classes, highlighting the morphological diversity of NPS. Fiftynine percent of PS belonged to type C;such streams are slightly entrenched, less sinuous and have a sequential riffle-pool configuration. Surface particles were significantly coarser than the subsurface in both stream types in thalweg and low flow areas, whereas in NPS, this was prominent, showing 4-5 times more armoring than PS. Even though the NPS had a significantly coarser surface sediment layer than PS in thalweg and low flow areas, its subsurface sediment showed similar particle sizes to PS;this is an indication of surface armoring and provision of more infiltration of fine particles in NPS. A two-year return period flow event did not result in a change of the cross-section profiles. In both stream types, the horizontal force required to uproot herbaceous vegetation with unexposed roots under moist conditions manually was higher than the tractive force at high flows;however, at bankfull flows, it was lower. Also, the uprooting force in PS was lower than that of NPS, indicating that NPS banks are more stable, and numerical analyses showed they are stable under the self-weight.
基金Supported by National Natural Science Foundation of China(30471274)~~
文摘Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.
文摘《变应性鼻炎及其对哮喘的影响》(Allergic rhinitis and its impact on asthma,ARIA)指南最新修订版(简称ARIA2010版)最近由《Journal of Allergy and Clinical Immunology》杂志全文发表。与旧版ARIA指南使用循证医学的方法不同,ARIA2010版采用推荐、评估、发展和评价分级(Grading of Recommendations,Assessment,Development and Evaluation,GRADE)工作组提出的透明的、系统化的方法修订了临床建议,以提高其实用价值。
