[Objective] Through the discussion of diurnal changes of photosynthesis of Flaveria bidentis at the seedling stage under different soil moisture conditions,photosynthetic physiological basis of Flaveria bidentis to ad...[Objective] Through the discussion of diurnal changes of photosynthesis of Flaveria bidentis at the seedling stage under different soil moisture conditions,photosynthetic physiological basis of Flaveria bidentis to adjust to drought stress is investigated in order to provide a theoretical basis for prevention of further invasion. [Method] The seeds of Flaveria bidentis were planted in plastic buckets laid within all-transparent canopy. It was set with 3 soil moisture treatments,that is,the soil relative water contents （SRWC） were 80% （CK）,60% （T1）,30% （T2） of field maximum moisture capacity. Photosynthetic parameters and diurnal changes of relevant ecological factors of Flaveria bidentis at the seedling stage were measured and the differences between different treatments were compared. [Result] Under CK treatment,the diurnal changing curve of Pn of Flaveria bidentis was basically in a ＂bimodal＂ shape,while under T1 and T2 treatment,Pn was a ＂unimodal＂ curve. At about 11：30 am,CK reaches its first peak value of 31.83 μmol/（m2·s） and its second peak value of 23.34 μmol/（m2·s） appears at 15：30. At 13：30 T1 and T2 have their peak values. The diurnal changes of Tr of Flaveria bidentis leaves in the three treatments are all in a unimodal curve. There are no significant differences between CK and T2 treatments,while the diurnal water use efficiency in T1 treatment is obviously below the ones in CK and T2 treatments. [Conclusion] Drought stress reduces Pn,Tr,Sc and other physiological indices of Flaveria bidentis. The reason why Pn is reduced is due to both stoma and non-stoma factors. Drought stress also postpones the appearance of Pn peak value. Proper drought can efficiently promote water use efficiency of Flaveria bidentis and cause its anti-drought reaction.展开更多
Large amounts ofFlaveria bidentis＇s root culturing solution were obtained by using DFT （deep flow technique） equipment and these solution which was vacuum concentrated （10, 20 mg mL-~） can have a certain inhibiti...Large amounts ofFlaveria bidentis＇s root culturing solution were obtained by using DFT （deep flow technique） equipment and these solution which was vacuum concentrated （10, 20 mg mL-~） can have a certain inhibition on Triticum aestivum, Cucumis sativus, Raphanus sativus, Amaranthus retroflexus, Setaria viridis, Chenopodium album, Echinochloa crusgalli and Chloris virgata. This outcome suggested some active compounds in the root exudates ofFIaveria bidentis can inhibit the germination, seedling elongation and root length. The dichloromethane extract of root exudates was identificated by GC-MS, and 29 kinds of compounds, including esters, hydrocarbons, ketones, thiazole, amines, etc. were obtained and the phthalate n-octyl ester, phthalate 2-ethylhexyl ester were proved to be allelochemicals. The culturing solution of root exudates was separated through the resin column and silica gel column and a component inhibiting seedling height, root length and fresh weight of wheat was got. There were 6 kinds of organic compounds in this component including dioctyl phthalate, 1,2-phthalate, mono（2-ethylhexyl） ester by GC-MS.展开更多
In order to understand the composition and structure of herbicidal active substance from the root of Flaveria bidentis （L.） Kuntze, the isolation and structural identification were researched in this paper. The crud...In order to understand the composition and structure of herbicidal active substance from the root of Flaveria bidentis （L.） Kuntze, the isolation and structural identification were researched in this paper. The crude extract from the root ofF. bidentis （L.） Kuntze was extracted by petroleum ether, ethyl acetate, and water saturation of n-butyl alcohol, respectively, and the extraction fluid was separated by using the method of TLC, then the main fraction was separated by HPLC, and the structure of the herbicidal active substance was analyzed by LC-MS, elemental analysis and ~H-NMR. The results showed that the petroleum extraction had the strongest herbicidal activity, and the purple blue stripe separated by TLC had the strongest effect on Digitaria sanguinalis. The herbicidal active substance was identified as ct-terthienyl according to the data of LC-MS, elemental analysis and 1H-NMR.展开更多
Arbuscular mycorrhizal fungi(AMF)and Bacillus play a crucial role in promoting the growth and defense of exotic plants,and their interaction may further enhance plant invasions.Soil nitrogen level is an important fact...Arbuscular mycorrhizal fungi(AMF)and Bacillus play a crucial role in promoting the growth and defense of exotic plants,and their interaction may further enhance plant invasions.Soil nitrogen level is an important factor that affects the interaction.However,the effect of the interaction on the growth and defensive ability of exotic plants under different nitrogen levels remains unclear.In this study,a pot experiment was conducted using Rhizoglomus intraradices(RI)and Bacillus megaterium(BM),one of the dominant AMF and Bacillus in the rhizosphere of Flaveria bidentis,with three soil nitrogen levels(0,3.75 and 7.5 g m^(−2))and four inoculation treatments(uninoculated,inoculation with RI,inoculation with BM and co-inoculated with RI and BM).Significant correlations were observed between microbial inoculations and indicators of plant growth and defense across varying soil nitrogen levels.Co-inoculation notably enhanced both plant growth and defense compared to single inoculations,especially under the nitrogen concentration of 3.75 g m^(−2).Specifically,compared to single inoculation,co-inoculation increased the biomass of F.bidentis by 8.27%and 16.4%,as well as the flavonoids concentration by 21.89%-30.95%and phenolic acids concentration by 54.22%-60.93%,respectively.These enhancements in growth and defensive compound production likely promote the competitive ability of F.bidentis and its resistance to biotic and abiotic stresses,thereby contributing to its successful invasion.展开更多
The effect of exotic plants on Bacillus diversity in the rhizosphere and the role of Bacilli in exotic or native plant species remain poorly understood.Flaveria bidentis is an invasive grass in China.Setaria viridis i...The effect of exotic plants on Bacillus diversity in the rhizosphere and the role of Bacilli in exotic or native plant species remain poorly understood.Flaveria bidentis is an invasive grass in China.Setaria viridis is a native grass and occurs in areas invaded by F.bidentis.Our objectives were(i)to examine the differences in the Bacillus communities between F.bidentis and S.viridis rhizospheres soil,and(ii)to compare the effects of Bacilli from F.bidentis and S.viridis rhizospheres on the competitiveness of the invasive species.Flaveria bidentis monoculture,mixture of F.bidentis and S.viridis and S.viridis monoculture were designed in the field experiment.Bacillus diversity in their rhizosphere was analyzed using 16S rRNA.One of the dominant Bacilli in the rhizosphere soil of F.bidentis was selected to test its effect on the competitive growth of F.bidentis in a greenhouse experiment.Bacillus diversity differed in F.bidentis and S.viridis rhizosphere.Brevibacterium frigoritolerans was the dominant Bacilli in the rhizosphere of both F.bidentis and S.viridis;however,its relative abundance in the F.bidentis rhizosphere was much higher than that in the S.viridis rhizosphere.In addition,B.frigoritolerans in the F.bidentis rhizosphere enhanced the growth of the plant compared with that of S.viridis by improving the nitrogen and phosphorus levels.This study showed that F.bidentis invasion influenced Bacillus communities,especially B.frigoritolerans,which,in turn,facilitated F.bidentis growth by increasing the levels of available nitrogen and phosphorus.展开更多
C_(4) photosynthesis evolved from ancestral C_(3) photosynthesis by recruiting pre-existing genes to fulfill new functions.The enzymes and transporters required for the C_(4) metabolic pathway have been intensively st...C_(4) photosynthesis evolved from ancestral C_(3) photosynthesis by recruiting pre-existing genes to fulfill new functions.The enzymes and transporters required for the C_(4) metabolic pathway have been intensively studied and well documented;however,the transcription factors(TFs)that regulate these C_(4) metabolic genes are not yet well understood.In particular,how the TF regulatory network of C_(4) metabolic genes was rewired during the evolutionary process is unclear.Here,we constructed gene regulatory networks(GRNs)for four closely evolutionarily related species from the genus Flaveria,which represent four different evolutionary stages of C_(4) photosynthesis:C_(3)(F.robusta),type Ⅰ C_(3)-C_(4)(F.sonorensis),type Ⅱ C_(3)-C_(4)(F.ramosissima),and C_(4)(F.trinervia).Our results show that more than half of the co-regulatory relationships between TFs and core C_(4) metabolic genes are species specific.The counterparts of the C_(4) genes in C_(3) species were already co-regulated with photosynthesis-related genes,whereas the required TFs for C_(4) photosynthesis were recruited later.The TFs involved in C_(4) photosynthesis were widely recruited in the type Ⅰ C_(3)-C_(4) species;nevertheless,type Ⅱ C_(3)-C_(4) species showed a divergent GRN from C_(4) species.In line with these findings,a ^(13)CO_(2) pulse-labeling experiment showed that the CO_(2) initially fixed into C_(4) acid was not directly released to the Calvin–Benson–Bassham cycle in the type Ⅱ C_(3)-C_(4) species.Therefore,our study uncovered dynamic changes in C_(4) genes and TF co-regulation during the evolutionary process;furthermore,we showed that the metabolic pathway of the type Ⅱ C_(3)-C_(4) species F.ramosissima represents an alternative evolutionary solution to the ammonia imbalance in C_(3)-C_(4) intermediate species.展开更多
基金Supported by Research upon Prevention and Control of New Invasive PlantFlaveria bidentis(200803022)~~
文摘[Objective] Through the discussion of diurnal changes of photosynthesis of Flaveria bidentis at the seedling stage under different soil moisture conditions,photosynthetic physiological basis of Flaveria bidentis to adjust to drought stress is investigated in order to provide a theoretical basis for prevention of further invasion. [Method] The seeds of Flaveria bidentis were planted in plastic buckets laid within all-transparent canopy. It was set with 3 soil moisture treatments,that is,the soil relative water contents （SRWC） were 80% （CK）,60% （T1）,30% （T2） of field maximum moisture capacity. Photosynthetic parameters and diurnal changes of relevant ecological factors of Flaveria bidentis at the seedling stage were measured and the differences between different treatments were compared. [Result] Under CK treatment,the diurnal changing curve of Pn of Flaveria bidentis was basically in a ＂bimodal＂ shape,while under T1 and T2 treatment,Pn was a ＂unimodal＂ curve. At about 11：30 am,CK reaches its first peak value of 31.83 μmol/（m2·s） and its second peak value of 23.34 μmol/（m2·s） appears at 15：30. At 13：30 T1 and T2 have their peak values. The diurnal changes of Tr of Flaveria bidentis leaves in the three treatments are all in a unimodal curve. There are no significant differences between CK and T2 treatments,while the diurnal water use efficiency in T1 treatment is obviously below the ones in CK and T2 treatments. [Conclusion] Drought stress reduces Pn,Tr,Sc and other physiological indices of Flaveria bidentis. The reason why Pn is reduced is due to both stoma and non-stoma factors. Drought stress also postpones the appearance of Pn peak value. Proper drought can efficiently promote water use efficiency of Flaveria bidentis and cause its anti-drought reaction.
基金supported by the Natural Science Foundation of Hebei Province,China(C2013204115)the Science and Technology Support of Hebei Province,China(C20121124001)
文摘Large amounts ofFlaveria bidentis＇s root culturing solution were obtained by using DFT （deep flow technique） equipment and these solution which was vacuum concentrated （10, 20 mg mL-~） can have a certain inhibition on Triticum aestivum, Cucumis sativus, Raphanus sativus, Amaranthus retroflexus, Setaria viridis, Chenopodium album, Echinochloa crusgalli and Chloris virgata. This outcome suggested some active compounds in the root exudates ofFIaveria bidentis can inhibit the germination, seedling elongation and root length. The dichloromethane extract of root exudates was identificated by GC-MS, and 29 kinds of compounds, including esters, hydrocarbons, ketones, thiazole, amines, etc. were obtained and the phthalate n-octyl ester, phthalate 2-ethylhexyl ester were proved to be allelochemicals. The culturing solution of root exudates was separated through the resin column and silica gel column and a component inhibiting seedling height, root length and fresh weight of wheat was got. There were 6 kinds of organic compounds in this component including dioctyl phthalate, 1,2-phthalate, mono（2-ethylhexyl） ester by GC-MS.
基金the National Natural Science Foundation of China(31171877)
文摘In order to understand the composition and structure of herbicidal active substance from the root of Flaveria bidentis （L.） Kuntze, the isolation and structural identification were researched in this paper. The crude extract from the root ofF. bidentis （L.） Kuntze was extracted by petroleum ether, ethyl acetate, and water saturation of n-butyl alcohol, respectively, and the extraction fluid was separated by using the method of TLC, then the main fraction was separated by HPLC, and the structure of the herbicidal active substance was analyzed by LC-MS, elemental analysis and ~H-NMR. The results showed that the petroleum extraction had the strongest herbicidal activity, and the purple blue stripe separated by TLC had the strongest effect on Digitaria sanguinalis. The herbicidal active substance was identified as ct-terthienyl according to the data of LC-MS, elemental analysis and 1H-NMR.
基金supported by the National Key Research and Development Program of China(2022YFC2601100)the National Natural Science Foundation of China(grant nos.31972343 and 32272562)the Hebei Natural Science Foundation(grant no.C2022201032).
文摘Arbuscular mycorrhizal fungi(AMF)and Bacillus play a crucial role in promoting the growth and defense of exotic plants,and their interaction may further enhance plant invasions.Soil nitrogen level is an important factor that affects the interaction.However,the effect of the interaction on the growth and defensive ability of exotic plants under different nitrogen levels remains unclear.In this study,a pot experiment was conducted using Rhizoglomus intraradices(RI)and Bacillus megaterium(BM),one of the dominant AMF and Bacillus in the rhizosphere of Flaveria bidentis,with three soil nitrogen levels(0,3.75 and 7.5 g m^(−2))and four inoculation treatments(uninoculated,inoculation with RI,inoculation with BM and co-inoculated with RI and BM).Significant correlations were observed between microbial inoculations and indicators of plant growth and defense across varying soil nitrogen levels.Co-inoculation notably enhanced both plant growth and defense compared to single inoculations,especially under the nitrogen concentration of 3.75 g m^(−2).Specifically,compared to single inoculation,co-inoculation increased the biomass of F.bidentis by 8.27%and 16.4%,as well as the flavonoids concentration by 21.89%-30.95%and phenolic acids concentration by 54.22%-60.93%,respectively.These enhancements in growth and defensive compound production likely promote the competitive ability of F.bidentis and its resistance to biotic and abiotic stresses,thereby contributing to its successful invasion.
基金funded by the National Natural Science Foundation of China(31972343)Hebei National Natural Science Foundation(C2019201059)College of Life Science,Institute of Life Science and Green Development,Hebei University.
文摘The effect of exotic plants on Bacillus diversity in the rhizosphere and the role of Bacilli in exotic or native plant species remain poorly understood.Flaveria bidentis is an invasive grass in China.Setaria viridis is a native grass and occurs in areas invaded by F.bidentis.Our objectives were(i)to examine the differences in the Bacillus communities between F.bidentis and S.viridis rhizospheres soil,and(ii)to compare the effects of Bacilli from F.bidentis and S.viridis rhizospheres on the competitiveness of the invasive species.Flaveria bidentis monoculture,mixture of F.bidentis and S.viridis and S.viridis monoculture were designed in the field experiment.Bacillus diversity in their rhizosphere was analyzed using 16S rRNA.One of the dominant Bacilli in the rhizosphere soil of F.bidentis was selected to test its effect on the competitive growth of F.bidentis in a greenhouse experiment.Bacillus diversity differed in F.bidentis and S.viridis rhizosphere.Brevibacterium frigoritolerans was the dominant Bacilli in the rhizosphere of both F.bidentis and S.viridis;however,its relative abundance in the F.bidentis rhizosphere was much higher than that in the S.viridis rhizosphere.In addition,B.frigoritolerans in the F.bidentis rhizosphere enhanced the growth of the plant compared with that of S.viridis by improving the nitrogen and phosphorus levels.This study showed that F.bidentis invasion influenced Bacillus communities,especially B.frigoritolerans,which,in turn,facilitated F.bidentis growth by increasing the levels of available nitrogen and phosphorus.
基金supported by the Strategic Priority Research Program of the General Project of the Chinese Academy of Sciences(grant no.XDB27020105)by the National Research and Development Program of the Ministry of Science and Technology of the People’s Republic of China,MSTC(2019YFA0904600).
文摘C_(4) photosynthesis evolved from ancestral C_(3) photosynthesis by recruiting pre-existing genes to fulfill new functions.The enzymes and transporters required for the C_(4) metabolic pathway have been intensively studied and well documented;however,the transcription factors(TFs)that regulate these C_(4) metabolic genes are not yet well understood.In particular,how the TF regulatory network of C_(4) metabolic genes was rewired during the evolutionary process is unclear.Here,we constructed gene regulatory networks(GRNs)for four closely evolutionarily related species from the genus Flaveria,which represent four different evolutionary stages of C_(4) photosynthesis:C_(3)(F.robusta),type Ⅰ C_(3)-C_(4)(F.sonorensis),type Ⅱ C_(3)-C_(4)(F.ramosissima),and C_(4)(F.trinervia).Our results show that more than half of the co-regulatory relationships between TFs and core C_(4) metabolic genes are species specific.The counterparts of the C_(4) genes in C_(3) species were already co-regulated with photosynthesis-related genes,whereas the required TFs for C_(4) photosynthesis were recruited later.The TFs involved in C_(4) photosynthesis were widely recruited in the type Ⅰ C_(3)-C_(4) species;nevertheless,type Ⅱ C_(3)-C_(4) species showed a divergent GRN from C_(4) species.In line with these findings,a ^(13)CO_(2) pulse-labeling experiment showed that the CO_(2) initially fixed into C_(4) acid was not directly released to the Calvin–Benson–Bassham cycle in the type Ⅱ C_(3)-C_(4) species.Therefore,our study uncovered dynamic changes in C_(4) genes and TF co-regulation during the evolutionary process;furthermore,we showed that the metabolic pathway of the type Ⅱ C_(3)-C_(4) species F.ramosissima represents an alternative evolutionary solution to the ammonia imbalance in C_(3)-C_(4) intermediate species.
