The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and i...The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and inter-root microbial communities,particularly their impact on organic phosphorus(P)cycling,remain unclear.This study investigated the gene regulation processes involved in inter-root soil phosphorus cycling in wetland plants,specifically Iris tectorum,following inoculation with AMF under varying concentrations of chromium(Cr)stress.Through macro-genome sequencing,we analyzed the composition and structure of the inter-root soil microbial community associated with Iris tectorum under greenhouse pot conditions.The results demonstrated significant changes in the diversity and composition of the inter-root soil microbial community following AMF inoculation,with Proteobacteria,Actinobacteria,Chloroflexi,Acidobacteria,and Bacteroidetes being the dominant taxa.Under Cr stress,species and gene co-occurrence network analysis revealed that AMF promoted the transformation process of organic phosphorus mineralization and facilitated inorganic phosphorus uptake.Additionally,network analysis of functional genes indicated strong aggregation of(pstS,pstA,pstC,TC.PIT,phoR,pp-gppA)genes,which collectively enhanced phosphorus uptake by plants.These findings shed light on the inter-root soil phosphorus cycling process during the co-remediation of Cr-contaminated soil by AMF-Iris tectorum symbiosis,providing valuable theoretical support for the application of AMF-wetland plant symbiosis systems to remediate heavy metal-contaminated soil.展开更多
The invasion of nonnative plants is considered one of the main threats to the structure and function of North American ecosystems. Moreover, they can alter ecosystem processes and reduce biodiversity. In arid and semi...The invasion of nonnative plants is considered one of the main threats to the structure and function of North American ecosystems. Moreover, they can alter ecosystem processes and reduce biodiversity. In arid and semi-arid region of North America, the species of European annual grass Bromus tectorum L. is an outstanding example of these problems, which not only increase the fire density and change the fire regime, but replace native communities. Therefore, there are amount of researches on B. tectorum, including resource acquisition, water use efficiency and growth. Whereas the relevant research on the morphology of diaspore is scare. Diaspores have a fundamental role in seed germination and seedling establishment. Besides, as an important link between different generations, diaspores have a vital significance on individual reproduction and population extension. Hence, dias- pores under selection for studying have an important implication. This study compares differences in seed mor- phology for Bromus tectorum collected from the United States, Kazakhstan, and Xinjiang of China. The following indices of B. tectorum diaspores were analyzed： size, thickness of covering layers, and micromorphological char- acteristics of the base, middle and transition area of diaspores as well as of the awn. Micromorphology of the lemma and the cross-section of the diaspore were observed by scanning electron microscopy. Results showed that thick- ness of the lemma and the palea of diaspores from B. tectorum-infested grasslands in the United States were re- duced （P〈0.05）, likely because of environmental influences. This reduction facilitated the germination of diaspores and lowered the resistance of B. tectorum to adverse environmental conditions. The length of the awn also in- creased significantly （P〈0.05）, which helped in dispersal and anchoring of diaspores. Therefore, B. tectorum adapted ecologically to its new environment in the United States by strengthening its establishment ability. However, the defense capability of B. tectorum decreased. These results fit the evolution of increased competitive ability hy- pothesis （EICA） of invasive species. Analysis of various cells on the lemma revealed that prickle densities and col- lapsed, long epidermal cells were easily influenced by environmental factors such as temperature and moisture because of the physiologic function of these structures on silicon accumulation. However, the form and the position of silica cells, which were not greatly influenced by environmental factors, might be genetically controlled. Studying these structures at the microscopic level helps define the relationship between the diaspore and its environment. This study has a reference value for future studies on B. tectorum.展开更多
The aim of the present study was to investigate the potential allelopathic effects of different concentrations of Zygophyllum album （donor species） aqueous extract （2.5, 5, 7.5 and 10%） on germination percentage, ...The aim of the present study was to investigate the potential allelopathic effects of different concentrations of Zygophyllum album （donor species） aqueous extract （2.5, 5, 7.5 and 10%） on germination percentage, plumule and radicle length ofBromus tectorum （weed） and Triticum aestivum （crop species） under laboratory conditions to have the greatest inhibitory allelopathic effect on the recipient species in mixed culture compared to that pure culture. The germination percentage, plumule and radicle length ofB. tectorum in mixed culture was completely inhibited at the highest concentration of aqueous extracts of the donor species level the exerted weak measures as affected by the highest concentration level of donor in pure culture. This inhibition was markedly in obvious B. tectorum that is more sensitive to tested donor. The domineering effect of aqueous extract of the donor was more prominent on weeds than crop species. The variant response to the allelopathic substance could be related to the species specific growth regulatory effect of allelochemicals and concentration dependent. There is possibility of using these allelochemicals directly or as structural leads for the discovery and development of environment friendly herbicides to control weeds.展开更多
A new C-glycosylflavone,5-hydroxyl-4′,7-dimethoxyflavone-6-C-[0-(α-L-3″-acetylrhamno-pyranosy)-1→2-β-D-glucopyranoside](1),along with five known C-glycosylflavones,5-hydroxy-4′,7-dimethoxyfavone-6-C-[0-(α-L-2′...A new C-glycosylflavone,5-hydroxyl-4′,7-dimethoxyflavone-6-C-[0-(α-L-3″-acetylrhamno-pyranosy)-1→2-β-D-glucopyranoside](1),along with five known C-glycosylflavones,5-hydroxy-4′,7-dimethoxyfavone-6-C-[0-(α-L-2′″-acetylrhamnopyranosy1)-1→2-β-D-glucopyranoside](2),embinin(3),embigenin(4),swertisin(5)and swertiajaponin(6)were isolated from the leaves of Iris tectorum Maxim.Their structures were elucidated on the basis of extensive NM R experiments and spectral methods and their cytotoxic activities against A 549(lung cancer)human cell lines were determined.展开更多
基金supported by 2024 Guizhou Basic Research Plan(Natural Science)Project,China(Foundation of Guizhou science cooperation-ZK[2024]General 490)the National Natural Science Foundation of China(No.31560107).
文摘The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and inter-root microbial communities,particularly their impact on organic phosphorus(P)cycling,remain unclear.This study investigated the gene regulation processes involved in inter-root soil phosphorus cycling in wetland plants,specifically Iris tectorum,following inoculation with AMF under varying concentrations of chromium(Cr)stress.Through macro-genome sequencing,we analyzed the composition and structure of the inter-root soil microbial community associated with Iris tectorum under greenhouse pot conditions.The results demonstrated significant changes in the diversity and composition of the inter-root soil microbial community following AMF inoculation,with Proteobacteria,Actinobacteria,Chloroflexi,Acidobacteria,and Bacteroidetes being the dominant taxa.Under Cr stress,species and gene co-occurrence network analysis revealed that AMF promoted the transformation process of organic phosphorus mineralization and facilitated inorganic phosphorus uptake.Additionally,network analysis of functional genes indicated strong aggregation of(pstS,pstA,pstC,TC.PIT,phoR,pp-gppA)genes,which collectively enhanced phosphorus uptake by plants.These findings shed light on the inter-root soil phosphorus cycling process during the co-remediation of Cr-contaminated soil by AMF-Iris tectorum symbiosis,providing valuable theoretical support for the application of AMF-wetland plant symbiosis systems to remediate heavy metal-contaminated soil.
基金supported by the International Science and Technology Cooperation Program of China (2010DFA92720-06)with partial support to RSN from the US National Science Foundation (1047575) and the Nevada Agricultural Experiment Station
文摘The invasion of nonnative plants is considered one of the main threats to the structure and function of North American ecosystems. Moreover, they can alter ecosystem processes and reduce biodiversity. In arid and semi-arid region of North America, the species of European annual grass Bromus tectorum L. is an outstanding example of these problems, which not only increase the fire density and change the fire regime, but replace native communities. Therefore, there are amount of researches on B. tectorum, including resource acquisition, water use efficiency and growth. Whereas the relevant research on the morphology of diaspore is scare. Diaspores have a fundamental role in seed germination and seedling establishment. Besides, as an important link between different generations, diaspores have a vital significance on individual reproduction and population extension. Hence, dias- pores under selection for studying have an important implication. This study compares differences in seed mor- phology for Bromus tectorum collected from the United States, Kazakhstan, and Xinjiang of China. The following indices of B. tectorum diaspores were analyzed： size, thickness of covering layers, and micromorphological char- acteristics of the base, middle and transition area of diaspores as well as of the awn. Micromorphology of the lemma and the cross-section of the diaspore were observed by scanning electron microscopy. Results showed that thick- ness of the lemma and the palea of diaspores from B. tectorum-infested grasslands in the United States were re- duced （P〈0.05）, likely because of environmental influences. This reduction facilitated the germination of diaspores and lowered the resistance of B. tectorum to adverse environmental conditions. The length of the awn also in- creased significantly （P〈0.05）, which helped in dispersal and anchoring of diaspores. Therefore, B. tectorum adapted ecologically to its new environment in the United States by strengthening its establishment ability. However, the defense capability of B. tectorum decreased. These results fit the evolution of increased competitive ability hy- pothesis （EICA） of invasive species. Analysis of various cells on the lemma revealed that prickle densities and col- lapsed, long epidermal cells were easily influenced by environmental factors such as temperature and moisture because of the physiologic function of these structures on silicon accumulation. However, the form and the position of silica cells, which were not greatly influenced by environmental factors, might be genetically controlled. Studying these structures at the microscopic level helps define the relationship between the diaspore and its environment. This study has a reference value for future studies on B. tectorum.
文摘The aim of the present study was to investigate the potential allelopathic effects of different concentrations of Zygophyllum album （donor species） aqueous extract （2.5, 5, 7.5 and 10%） on germination percentage, plumule and radicle length ofBromus tectorum （weed） and Triticum aestivum （crop species） under laboratory conditions to have the greatest inhibitory allelopathic effect on the recipient species in mixed culture compared to that pure culture. The germination percentage, plumule and radicle length ofB. tectorum in mixed culture was completely inhibited at the highest concentration of aqueous extracts of the donor species level the exerted weak measures as affected by the highest concentration level of donor in pure culture. This inhibition was markedly in obvious B. tectorum that is more sensitive to tested donor. The domineering effect of aqueous extract of the donor was more prominent on weeds than crop species. The variant response to the allelopathic substance could be related to the species specific growth regulatory effect of allelochemicals and concentration dependent. There is possibility of using these allelochemicals directly or as structural leads for the discovery and development of environment friendly herbicides to control weeds.
基金The project supported by the National Natural Science Foundation of China(Grant No.30170103).
文摘A new C-glycosylflavone,5-hydroxyl-4′,7-dimethoxyflavone-6-C-[0-(α-L-3″-acetylrhamno-pyranosy)-1→2-β-D-glucopyranoside](1),along with five known C-glycosylflavones,5-hydroxy-4′,7-dimethoxyfavone-6-C-[0-(α-L-2′″-acetylrhamnopyranosy1)-1→2-β-D-glucopyranoside](2),embinin(3),embigenin(4),swertisin(5)and swertiajaponin(6)were isolated from the leaves of Iris tectorum Maxim.Their structures were elucidated on the basis of extensive NM R experiments and spectral methods and their cytotoxic activities against A 549(lung cancer)human cell lines were determined.
