Objective:To develop a camelid single-domain antibody (SdAb) recognizing linear B-cell epitopes in glutamate dehydrogenase of Clostridium difficile(CD-GDH), and to apply it in Western blot and ELISA. Methods:Purified recombinant CD-GDH was used as bait to screen phage-displayed camelid SdAb library and obtain positive clones. Then those clones were confirmed by Western blot, and their variable domain of heavy chain of heavy chain antibody(VHH) nucleotide sequence were determined. The VHH sequence was synthesized after codon optimization and cloned into the expression vector pET28a. The SdAb was then expressed and purified, and its ability to detect CD-GDH protein in multiple assays was further explored.Results:Six positive clones were obtained, among which clone GA4 was chosen for recombinant expression in Escherichia coli and further purification. The purified GA4 binded well with CD-GDH with a Kd value of 3 nmol/L. In Western blot and ELISA, GA4 was proven to be able to selectively detect both recombinant and endogenous CD-GDH. Conclusions:A camelid SdAb targeting a linear B-cell epitope in CD-GDH is successfully developed, which provides a very useful tool for detecting CD-GDH.

Objective To analyze the spatial distribution patterns of the potential suitable habitats for Cremastrae Pseudobulbus Pleiones Pseudobulbus,including Cremastra appendiculata(D.Don)Makino,Pleione bulbocodioides(Franch.)Rolfe and Pleione yunnanensis Rolfe under current climatic conditions,and the factors influencing the spatial differentiation of their habitats.Methods Based on the maximum entropy(MaxEnt)model,a species distribution model was established using the screened species distribution data and environmental variable data.The factor detection and interaction detection of geographical detector were applied to quantify the factors influencing the spatial differentiation of the suitable areas.By overlaying the suitable areas with land cover types,the distribution characteristics of forest land and arable land in the potential suitable areas were quantified.Results Under the current climatic scenario,environmental variables such as solar radiation intensity,precipitation and temperature were closely related to the spatial distribution of Cremastrae Pseudobulbus Pleiones Pseudobulbus.The potential suitable areas for Cremastra appendiculata(D.Don)Makino,Pleione bulbocodioides(Franch.)Rolfe and Pleione yunnanensis Rolfe were 2.20×106 km2,2.75×106 km2 and 7.22×105 km2,respectively.Considering land cover types,the actual possible suitable areas for Cremastra appendiculata(D.Don)Makino,Pleione bulbocodioides(Franch.)Rolfe and Pleione yunnanensis Rolfe were 1.86×106 km2,2.20×106 km2 and 5.77×105 km2,respectively.Among these,the area of forest land was 1.17×106 km2,1.34×106 km2 and 3.67×105 km2,respectively,and the area of arable land was 6.95×105 km2,8.64×105 km2 and 2.10×105 km2,respectively.Conclusion This study can provide a basis for the protection and sustainable utilization of wild resources of the original plant materials of Cremastrae Pseudobulbus Pleiones Pseudobulbus.

Objective To investigate the spatial distribution pattern of the suitable habitats for Codonopsis pilosula(Franch.)Nannf.and the factors influencing the spatial differentiation of its habitat under current climatic conditions in China.Methods Based on maximum entropy(MaxEnt)model,a species distribution model was established with filtered species occurrence data and environmental variable data.The geographical detector was applied to quantify the factors influencing the spatial differentiation of the suitable areas,employing both factor detection and interaction detection functionalities.Additionally,an overlay analysis with land cover types was conducted to quantify the distribution characteristics of arable land and forest land within the potential suitable areas for Codonopsis pilosula(Franch.)Nannf..Results Based on the contribution rate of environmental factors and the Jackknife method,average solar radiation intensity in December,precipitation in July,and highest temperature in December were identified as key environmental factors affecting the suitability of Codonopsis pilosula(Franch.)Nannf.habitats,which were further validated by the geographical detector.The total suitable area for Codonopsis pilosula(Franch.)Nannf.in China under current climatic conditions was approximately 4.46×106 km2,with the areas of high,moderate,and low suitability being 1.08×106 km2,1.70×106 km2,and 1.68×106 km2,respectively.After overlaying with arable and forest lands,the potentially suitable total forest area for Codonopsis pilosula(Franch.)Nannf.was 1.55×106 km2,and the arable land area was 1.63×106 km2.Conclusion This study provides reference for the optimization of cultivation areas for Codonopsis pilosula(Franch.)Nannf.and the conservation of its wild resources.

Objective To analyze the spatial distribution pattern of the potential suitable habitats for Cordyceps under current climatic conditions in China based on space characteristics and biological traits;To explore the key environmental factors affecting the spatial differentiation of its habitats.Methods The Maximum Entropy model was utilized as a predictive tool to synthesize the distribution data of Cordyceps and its associated species Polygonum viviparum and Polygonum macrophyllum,along with environmental variable data.Factor detectors and interaction detectors of geographic detectors were used to conduct geographic exploration of spatial differentiation factors in the suitable habitats of Cordyceps.Furthermore,by overlaying the potential suitable habitats of Cordyceps with surface cover types and the suitable areas of Polygonum viviparum and Polygonum macrophyllum,the specific distribution range of the potential suitable habitats for Cordyceps was refined.Results Under the current climatic conditions,altitude,the precipitation amount of the warmest season,the highest temperature in February,and the precipitation in July are the key environmental factors influencing the distribution of Cordyceps.The potential suitable habitats for Cordyceps reaches 1.18×106 km2,and considering surface cover types,the actual potential suitable habitats for Cordyceps is 7.33×105 km2.Taking into account the associated relationships between species,the actual potential suitable habitats for Cordyceps is 7.27×105 km2.Conclusion The results of this study can reflect the ecological needs of Cordyceps,promote its sustainable utilization of resources,and provide reference for maintaining biodiversity and ecosystem integrity.

Objective To investigate the geographical distribution patterns and influencing factors of suitable habitats for the desert medicinal plant Cynomorium songaricum Rupr under current climatic conditions;To provide a basis for its resource conservation and sustainable utilization.Methods The MaxEnt model was used to analyze potential suitable habitats for Cynomorium songaricum Rupr.Geographical Detector model was used to identify key environmental factors affecting habitat suitability.Surface cover data were overlaid to assess the distribution of sandy and Gobi regions within suitable habitats,enabling a quantitative evaluation of actual potential suitable areas.Results Model predictions indicated a total suitable habitat area of approximately 2.98×106 km2,representing 30.99%of China's mainland area.Highly suitable habitats are concentrated in desert and Gobi regions of Gansu,Xinjiang,Inner Mongolia,Qinghai and Ningxia.Among climatic factors,precipitation of the coldest quarter(bio19),solar radiation in August(srad8),and mean temperature of the coldest quarter(bio11)significantly influence Cynomorium songaricum Rupr distribution.The interaction between temperature and solar radiation intensity exhibited the highest explanatory power for habitat distribution patterns(q=0.82).Overlay analysis with surface cover data estimated the actual potential suitable area at approximately 9.70×105 km2,with sandy regions comprising 5.73×105 km2 and Gobi regions 3.98×105 km2.Conclusion By integrating multi-source data and modeling approaches,this study delineates the potential suitable habitats for Cynomorium songaricum Rupr across China and evaluates the spatial distribution characteristics and influencing factors of suitable habitats in Cynomorium songaricum Rupr.These findings offer a foundation for conserving wild Cynomorium songaricum Rupr resources,optimizing ecological planting regions,and promoting sustainable industry development.

Objective To analyze the spatial distribution pattern of potential suitable habitats and the influencing factors of habitat spatial differentiation of Gastrodiae Rhizoma under current climate conditions.Methods Based on 137 distribution records of Gastrodiae Rhizoma sourced from the Global Biodiversity Information Facility and 104 environmental variables acquired from the WorldClim dataset,a predictive model for the potential suitable habitat of Gastrodiae Rhizoma was developed using the MaxEnt model.The geodetector was applied to quantitatively analyze the environmental factors influencing the spatial heterogeneity of the suitable habitats.Subsequently,an overlay analysis with land cover types was conducted to obtain the distribution characteristics of forest land and cultivated land in the potential suitable habitats.Results Under current climate conditions,key environmental factors affecting the distribution of Gastrodiae Rhizoma included precipitation in July,average temperature in the coldest quarter,precipitation in the warmest quarter,water vapor pressure in September,altitude,and solar radiation in December.The potential geographical distribution range of Gastrodiae Rhizoma was 1.64×106 km2.Considering land cover types,the actual potential suitable area for Gastrodiae Rhizoma was 1.33×106 km2,of which the forest land area was 8.56×105 km2 and the cultivated land area was 4.74×105 km2.The highly suitable forest areas were mainly located within the provinces of Guizhou,Sichuan,Shaanxi,Hubei,Hunan and Gansu.The cultivated land suitable areas are mainly located within the provinces of Guizhou,Sichuan,Yunnan,Shaanxi and Hubei.Conclusion The highly suitable habitats of Gastrodiae Rhizoma are mainly located in provinces such as Guizhou,Sichuan,Shaanxi and Hubei,and are affected by factors such as solar radiation,water vapor pressure,temperature and precipitation.The research results can provide reference for the protection of wild Gastrodiae Rhizoma resources,artificial nurturing and optimal selection of ecological planting areas.

Objective To analyze the spatial distribution pattern of the potential suitable habitats for the Tibetan medicinal plant Sinopodophyllum hexandrum under current climatic conditions and the factors influencing the spatial differentiation of the habitats.Methods Based on the maximum entropy model,a species distribution model was established using selected species distribution data and environmental variable data.The geographic detector and the interaction detector were applied to quantify the factors affecting the spatial differentiation of the suitable area.By overlaying the suitable area with land cover types,the distribution characteristics of potential arable land and forest land within the potential suitable area were quantified.Results Under the current climatic conditions,altitude,precipitation in July,precipitation during the warmest season,water vapor pressure in June,precipitation in December,and the highest temperature in February are the key environmental factors affecting the distribution of Sinopodophyllum hexandrum.Under the current climatic conditions,the potential geographical distribution range of Sinopodophyllum hexandrum covers an area of 1.30×106 km2.Considering land cover types,the actual suitable area for Sinopodophyllum hexandrum is 6.13×105 km2,including 4.25×105 km2 of forest land and 1.88×105 km2 of arable land.The highly suitable forest areas are mainly distributed in the Aba Tibetan and Qiang Autonomous Prefecture,Ganzi Tibetan Autonomous Prefecture of Sichuan Province,Diqing Tibetan Autonomous Prefecture,Nujiang Lisu Autonomous Prefecture of Yunnan Province and Linzhi City within the Tibet Autonomous Region.The highly suitable arable land areas are mainly distributed in the Linxia Hui Autonomous Prefecture,Dingxi City,Tianshui City,and Longnan City of Gansu Province,with sporadic belt-like distributions in Sichuan Province,Yunnan Province and the Tibet Autonomous Region.Conclusion The study can provide evidence for the protection of wild Sinopodophyllum hexandrum resources and the selection of optimal planting areas.

Objective To analyze the spatial distribution pattern of potential suitable habitats and the influencing factors of habitat spatial differentiation of Gastrodiae Rhizoma under current climate conditions.Methods Based on 137 distribution records of Gastrodiae Rhizoma sourced from the Global Biodiversity Information Facility and 104 environmental variables acquired from the WorldClim dataset,a predictive model for the potential suitable habitat of Gastrodiae Rhizoma was developed using the MaxEnt model.The geodetector was applied to quantitatively analyze the environmental factors influencing the spatial heterogeneity of the suitable habitats.Subsequently,an overlay analysis with land cover types was conducted to obtain the distribution characteristics of forest land and cultivated land in the potential suitable habitats.Results Under current climate conditions,key environmental factors affecting the distribution of Gastrodiae Rhizoma included precipitation in July,average temperature in the coldest quarter,precipitation in the warmest quarter,water vapor pressure in September,altitude,and solar radiation in December.The potential geographical distribution range of Gastrodiae Rhizoma was 1.64×106 km2.Considering land cover types,the actual potential suitable area for Gastrodiae Rhizoma was 1.33×106 km2,of which the forest land area was 8.56×105 km2 and the cultivated land area was 4.74×105 km2.The highly suitable forest areas were mainly located within the provinces of Guizhou,Sichuan,Shaanxi,Hubei,Hunan and Gansu.The cultivated land suitable areas are mainly located within the provinces of Guizhou,Sichuan,Yunnan,Shaanxi and Hubei.Conclusion The highly suitable habitats of Gastrodiae Rhizoma are mainly located in provinces such as Guizhou,Sichuan,Shaanxi and Hubei,and are affected by factors such as solar radiation,water vapor pressure,temperature and precipitation.The research results can provide reference for the protection of wild Gastrodiae Rhizoma resources,artificial nurturing and optimal selection of ecological planting areas.

Objective To analyze the spatial distribution pattern of the potential suitable habitats for the Tibetan medicinal plant Sinopodophyllum hexandrum under current climatic conditions and the factors influencing the spatial differentiation of the habitats.Methods Based on the maximum entropy model,a species distribution model was established using selected species distribution data and environmental variable data.The geographic detector and the interaction detector were applied to quantify the factors affecting the spatial differentiation of the suitable area.By overlaying the suitable area with land cover types,the distribution characteristics of potential arable land and forest land within the potential suitable area were quantified.Results Under the current climatic conditions,altitude,precipitation in July,precipitation during the warmest season,water vapor pressure in June,precipitation in December,and the highest temperature in February are the key environmental factors affecting the distribution of Sinopodophyllum hexandrum.Under the current climatic conditions,the potential geographical distribution range of Sinopodophyllum hexandrum covers an area of 1.30×106 km2.Considering land cover types,the actual suitable area for Sinopodophyllum hexandrum is 6.13×105 km2,including 4.25×105 km2 of forest land and 1.88×105 km2 of arable land.The highly suitable forest areas are mainly distributed in the Aba Tibetan and Qiang Autonomous Prefecture,Ganzi Tibetan Autonomous Prefecture of Sichuan Province,Diqing Tibetan Autonomous Prefecture,Nujiang Lisu Autonomous Prefecture of Yunnan Province and Linzhi City within the Tibet Autonomous Region.The highly suitable arable land areas are mainly distributed in the Linxia Hui Autonomous Prefecture,Dingxi City,Tianshui City,and Longnan City of Gansu Province,with sporadic belt-like distributions in Sichuan Province,Yunnan Province and the Tibet Autonomous Region.Conclusion The study can provide evidence for the protection of wild Sinopodophyllum hexandrum resources and the selection of optimal planting areas.

Objective To analyze the spatial distribution patterns of the potential suitable habitats for Cremastrae Pseudobulbus Pleiones Pseudobulbus,including Cremastra appendiculata(D.Don)Makino,Pleione bulbocodioides(Franch.)Rolfe and Pleione yunnanensis Rolfe under current climatic conditions,and the factors influencing the spatial differentiation of their habitats.Methods Based on the maximum entropy(MaxEnt)model,a species distribution model was established using the screened species distribution data and environmental variable data.The factor detection and interaction detection of geographical detector were applied to quantify the factors influencing the spatial differentiation of the suitable areas.By overlaying the suitable areas with land cover types,the distribution characteristics of forest land and arable land in the potential suitable areas were quantified.Results Under the current climatic scenario,environmental variables such as solar radiation intensity,precipitation and temperature were closely related to the spatial distribution of Cremastrae Pseudobulbus Pleiones Pseudobulbus.The potential suitable areas for Cremastra appendiculata(D.Don)Makino,Pleione bulbocodioides(Franch.)Rolfe and Pleione yunnanensis Rolfe were 2.20×106 km2,2.75×106 km2 and 7.22×105 km2,respectively.Considering land cover types,the actual possible suitable areas for Cremastra appendiculata(D.Don)Makino,Pleione bulbocodioides(Franch.)Rolfe and Pleione yunnanensis Rolfe were 1.86×106 km2,2.20×106 km2 and 5.77×105 km2,respectively.Among these,the area of forest land was 1.17×106 km2,1.34×106 km2 and 3.67×105 km2,respectively,and the area of arable land was 6.95×105 km2,8.64×105 km2 and 2.10×105 km2,respectively.Conclusion This study can provide a basis for the protection and sustainable utilization of wild resources of the original plant materials of Cremastrae Pseudobulbus Pleiones Pseudobulbus.