During the boll formation stage,cotton bolls exhibit the lowest expression of Bacillus thuringiensis(Bt)insecticidal proteins.Resistance to insects varies notably among different organs,which poses challenges for cont...During the boll formation stage,cotton bolls exhibit the lowest expression of Bacillus thuringiensis(Bt)insecticidal proteins.Resistance to insects varies notably among different organs,which poses challenges for controlling cotton bollworms.Consequently,an experimental strategy was designed in the 2020-2021 cotton growing season to coordinate the enhancement of protein synthesis and the attenuation of degradation.Two Bt cultivars of Gossypium hirsutum,namely the hybrid Sikang 3 and the conventional Sikang 1,were used as test materials.Three treatments were applied at the peak flowering period:CK(the control),T1(amino acids),and T2(amino acids and EDTA).The results show that,in comparison to the CK group,the Bt protein contents were significantly increased in both cotton bolls and their subtending leaves under the T1 and T2 treatments.The maximum levels of increase observed were 67.5%in cotton bolls and 21.7%in leaves.Moreover,the disparity in Bt protein content between cotton bolls and their subtending leaves notably decreased by 31.2%.Correlation analysis suggested that the primary physiological mechanisms for augmenting Bt protein content involve increased protein synthesis and reduced protein catabolism,which are independent of Bt gene expression levels.Stepwise regression and path analysis revealed that elevating the soluble protein content and transaminase activity,while reducing the catabolic enzyme activities,are instrumental in enhancing the Bt protein content.Consequently,the coordinated application of amino acids and EDTA emerges as a strategy that can improve the overall resistance of Bt cotton and mitigate the spatiotemporal variations in Bt toxin concentrations in both cotton bolls and leaves.展开更多
Understanding physiological responses in saline agriculture may facilitate wheat breeding programs.Based on a screening test,the Ningmai-14(NM-14)and Yangmai-23(YM-23)wheat cultivars were selected for further experime...Understanding physiological responses in saline agriculture may facilitate wheat breeding programs.Based on a screening test,the Ningmai-14(NM-14)and Yangmai-23(YM-23)wheat cultivars were selected for further experiments to understand the underlying salinity tolerance mechanism.This study investigated the effects of five salinity levels such as Control(CK)=0(without NaCl stress),S1=0.20%,S2=0.25%,S3=0.30%and S4=0.35%of NaCl concentrations of soil on wheat plants.The results showed that increased salinity concentration reduced the growth and yield of wheat cultivars(NM-14 and YM-23).However,YM-23(12.7%)yielded more than NM-14 at maximum salinity stress.The higher salinity(S4)increased the concentration of Na^(+)(4.3 to 5.8-fold)and P contents(2.5 to 2.2-fold),while reducing the average concentrations of K^(+),Cu,and K^(+)/Na^(+)ratio.The higher salinity(S4)reduced the spikelet length by 21.35%(followed by grain spike−1),and the starch content by 18.81%.In the YM-23 cultivar,higher salinity increased superoxide dismutase(SOD),total antioxidant capacity(TAC),and amylase.Compared to NM-14,induced expression of TaYUC2,6,and TaGA13ox,20ox genes were recorded in YM-23.Similarly,in YM-23 the stress-specific genes such as TaHSP70,90 were enhanced whereas,TaSOS1,2 were suppressed.Overall,our study revealed that salt tolerant cultivars modulate hormonal and antioxidant activities,thus maintaining high growth.展开更多
Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluate...Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluated the effect of K on fiber elongation using two cotton cultivars,Simian 3 and Siza 3,grown in well-watered and drought-stressed conditions.Potassium fertilizer(K2O)was applied 0,150,or 300 kg ha?1 in each growing condition.Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation(Vmax,mmday?1).The application of K alleviated the droughtinduced fiber length reduction by increasing Vmax.At 10 and 15 days post-anthesis(DPA),drought significantly reduced osmotic potential(OP)and increased K+and malate contents at all K rates,relative to well-watered conditions,which was associated with increased activities of phosphoenolpyruvate carboxylase(PEPC),V-ATPase,PPase,and PM H+-ATPase in cotton fiber.However,the relative contribution of K+and malate to OP declined under drought in comparison with well-watered condition.Compared with control without K,K application decreased OP and increased the accumulation of osmolytes(K+,malate and soluble sugar)as well as the activities of related enzymes in fiber irrespective of water treatments.Moreover,K application increased osmotic adjustment during drought,and improved the contribution of K+and malate to OP,especially under drought stress.This study showed that drought decreased fiber length by reducing Vmax,and K application ameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells.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
The fleshy taproot of radish is an important storage organ determining its yield and quality.Taproot thickening is a complex developmental process in radish.However,the molecular mechanisms governing this process rema...The fleshy taproot of radish is an important storage organ determining its yield and quality.Taproot thickening is a complex developmental process in radish.However,the molecular mechanisms governing this process remain unclear at the proteome level.In this study,a comparative proteomic analysis was performed to analyze the proteome changes at three developmental stages of taproot thickening using iTRAQ approach.In total,1862 differentially expressed proteins(DEPs)were identified from 6342 high-confidence proteins,among which 256 up-regulated proteins displayed overlapped accumulation in S1(pre-cortex splitting stage)vs.S2(cortex splitting stage)and S1 vs.S3(expanding stage)pairs,whereas 122 up-regulated proteins displayed overlapped accumulation in S1 vs.S3 and S2 vs.S3 pairs.Gene Ontology(GO)and pathway enrichment analysis showed that these DEPs were mainly involved in several processes such as“starch and sucrose metabolism”,“plant hormone signal transduction”,and“biosynthesis of secondary metabolites”.A high concordance existed between iTRAQ and RT-qPCR at the mRNA expression levels.Furthermore,association analysis showed that 187,181,and 96 DEPs were matched with their corresponding differentially expressed genes(DEGs)in S1 vs.S2,S1 vs.S3,and S2 vs.S3 comparison,respectively.Notably,several functional proteins including cell division cycle 5-like protein(CDC5),expansin B1(EXPB1),and xyloglucan endotransglucosylase/hydrolase protein 24(XTH24)were responsible for cell division and expansion during radish taproot thickening process.These results could facilitate a better understanding of the molecular mechanism underlying taproot thickening,and provide valuable information for the identification of critical genes/proteins responsible for taproot thickening in root vegetable crops.展开更多
Dense planting could be a feasible method for reducing nitrogen(N) application rates without compromising rice grain yield in northeast and central China. It is still unclear whether reduced N application with dense p...Dense planting could be a feasible method for reducing nitrogen(N) application rates without compromising rice grain yield in northeast and central China. It is still unclear whether reduced N application with dense planting(RNDP) can achieve higher rice yield and N use efficiency(NUE) in Jiangsu, east China. Three japonica inbred rice(JI) and three indica hybrid rice(IH) cultivars were grown in a field experiment. Their grain yield, NUE, and related traits were compared under two cultivation treatments:conventional high-yielding practice(CHYP) and RNDP. JI showed similar yields under the two treatments,while IH showed lower yield under RNDP than under CHYP, and the partial factor productivity of N and N use efficiency for grain yield increased(P < 0.05) in both JI and IH under RNDP. Compared with CHYP,RNDP reduced spikelets per panicle but increased panicles per m2 and filled-kernel percentage of JI and IH, and JI's kernel weight was increased(P < 0.05) under RNDP. Shoot biomass weight and nonstructural carbohydrate(NSC) content in the stem at heading and maturity of JI and IH were reduced under RNDP, while harvest index and NSC remobilization reserve were increased(P < 0.05) under RNDP, especially for JI. Our results suggest that RNDP could achieve a higher rice grain yield and NUE, particularly for JI, a dominant rice cultivar type in Jiangsu. For JI, the increased panicles per m2, sink-filling efficiency, harvest index, and NSC remobilization after heading under RNDP contributed to a grain yield similar to that under CHYP.展开更多
The dragonfly wing, which consists of veins and membrane, is of biological hierarchical material. We observed the cross-sections of longitudinal veins and membrane using Environmental Scanning Electron Microscopy (E...The dragonfly wing, which consists of veins and membrane, is of biological hierarchical material. We observed the cross-sections of longitudinal veins and membrane using Environmental Scanning Electron Microscopy (ESEM). Based on the experiments and previous studies, we described the longitudinal vein and the membrane in terms of two hierarchical levels of organization of composite materials at the micro- and nano-scales. The longitudinal vein of dragonfly wing has a complex sandwich structure with two chitinous shells and a protein layer, and it is considered as the first hierarchical level of the vein. Moreover, the chitinous shells are concentric multilayered structures. Clusters of nano-fibrils grow along the circumferential orientation embedded into the protein layer. It is considered as the second level of the hierarchy. Similarly, the upper and lower epidermises of membrane constitute the first hierarchical level of organization in micro scale. Similar to the vein shell, the membrane epidermises were found to be a paralleled multilayered structure, defined as the second hierarchical level of the membrane. Combining with the mechanical behavior analysis of the dragonfly wing, we concluded that the growth orientation of the hierarchical structure of the longitudinal vein and membrane is relevant to its biomechanical behavior.展开更多
The configurations of dragonfly wings, including the corrugations of the chordwise cross-section, the microstructure of the longitudinal veins and membrane, were comprehensively investigated using the Environmental Sc...The configurations of dragonfly wings, including the corrugations of the chordwise cross-section, the microstructure of the longitudinal veins and membrane, were comprehensively investigated using the Environmental Scanning Electron Microscopy (ESEM). Based on the experimental results reported previously, the multi-scale and multi-dimensional models with different structural features of dragonfly wing were created, and the biological dynamic behaviors of wing models were discussed through the Finite Element Method (FEM). The results demonstrate that the effects of different structural features on dynamic behaviors of dragonfly wing such as natural frequency/modal, bending/torsional deformation, reaction force/torque are very significant. The corrugations of dragonfly wing along the chordwise can observably improve the flapping frequency because of the greater structural stiffness of wings. In updated model, the novel sandwich microstrueture of the longitudinal veins re- markably improves the torsional deformation of dragonfly wing while it has a little effect on the flapping frequency and bending deformation. These integrated structural features can adjust the deformation of wing oneself, therefore the flow field around the wings can be controlled adaptively. The fact is that the flights of dragonfly wing with sandwich microstructure of longitudinal veins are more efficient and intelligent.展开更多
Aims mycorrhizas play key roles in important ecosystem processes and functions.Carbon(C),nitrogen(N)and phosphorus(P)concentrations and their ratios are very important foliar traits and their cycling constrains most e...Aims mycorrhizas play key roles in important ecosystem processes and functions.Carbon(C),nitrogen(N)and phosphorus(P)concentrations and their ratios are very important foliar traits and their cycling constrains most ecosystem processes.thus,this study addresses the influence of mycorrhizal strategies on these foliar nutrients and their response to climate change.Methods a new database was established including mycorrhizal types and leaf C_(mass),N_(mass),P_(mass),C:N and N:P of each plant species based on He et al.[(2008)leaf nitrogen:Phosphorus stoichiometry across Chinese grassland biomes.oecologia 155:301-10].the predomi-nant type of mycorrhizal association of each plant species was classified according to the published literature and our own obser-vations.We analyzed leaf C_(mass),N_(mass),P_(mass),C:N and N:P among 112 plant species in 316 samples of ascertained mycorrhizal type in the major grassland biomes of China.Important Findingsthe results show highly significant variation among different myc-orrhizal strategy types for foliar C_(mass),N_(mass) and N:P.the highest foliar C_(mass) was observed in ectotrophic mycorrhiza(ECM)type(469.8mg g1)followed by that in arbuscular mycorrhiza(AM)type(443.884 mg g1)and nonmycorrhizal(NM)type(434.0 mg g^(-1)).The foliar N concentration was significantly higher in NM type(31.0mg g^(-1)).However,the AM type had the greater C:N value(19)than the other types although less variation in C_(mass) and N:P among abuscular types on AM strategy was observed.Foliar traits showed significant variation in response to precipita-tion(mean growing season and annual precipitation(GSP and MAP))and temperature(mean growing season and annual tem-peratures(GST and MAT))depending on different mycorrhizal strategies and arbuscular types.When the responses of all folia parameters to precipitation and temperature were compared,the influence of GSP on leaf traits was greater than the influence of GST.展开更多
In order to explore the influence of arbuscular mycorrhizal(AM)fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem,rhizosphere soils were coll...In order to explore the influence of arbuscular mycorrhizal(AM)fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem,rhizosphere soils were collected from eight different poisonous plants in degraded grasslands and one from pasture grass in non-degraded grasslands(CK).The collected soils were used as inocula to assess the influence of indigenous AM fungi on the growth of two typical pasture grass species,Elymus nutans and Poa pratensis,in a bioassay experiment.Five growth parameters and two AM parameters were determined.The mycorrhizal responsiveness and the importance value were calculated.Significant differences between the eight poisonous plants and CK were observed.Compared to CK,rhizosphere soil from the eight poisonous plants had lower AM fungal spore densities.The growth of E.nutans and P.pratensis seedlings was depressed with the inoculation from poisonous plants rhizosphere soil.This study demonstrated that the presence of poisonous plants with grassland degradation altered inherent AM fungal community abundance,and could exert inhibition effects on the growth of pasture grasses.It may attribute to discover the important role of rhizosphere soil of different poisonous plants to AM fungal community on the Alpine meadow.展开更多
The microstructure of the main longitudinal veins of the dragonfly wing and the aerodynamic behaviors of the wing were investigated in this paper. The microstructure of longitudinal vein presents two circumferential c...The microstructure of the main longitudinal veins of the dragonfly wing and the aerodynamic behaviors of the wing were investigated in this paper. The microstructure of longitudinal vein presents two circumferential chitin layers and a protein-fiber soft layer. The dragonfly wing is corrugated due to the spatial arrangement of longitudinal veins. It was found that the corru- gation angle could significantly influence the lift/drag ratio across a range of attack angles by the wind tunnel experiments. The results of the finite element analysis indicate that the protein soft layer of vein facilitates the change of the corrugation angle by allowing substantial relative twisting deformation between two neighboring veins, which is not possible in veins without a soft sandwich layer.展开更多
基金supported by the National Natural Science Foundation of China(31901462 and 31671613)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJA210005)+1 种基金the China Scholarship Council(202308320440)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX22_3508)。
文摘During the boll formation stage,cotton bolls exhibit the lowest expression of Bacillus thuringiensis(Bt)insecticidal proteins.Resistance to insects varies notably among different organs,which poses challenges for controlling cotton bollworms.Consequently,an experimental strategy was designed in the 2020-2021 cotton growing season to coordinate the enhancement of protein synthesis and the attenuation of degradation.Two Bt cultivars of Gossypium hirsutum,namely the hybrid Sikang 3 and the conventional Sikang 1,were used as test materials.Three treatments were applied at the peak flowering period:CK(the control),T1(amino acids),and T2(amino acids and EDTA).The results show that,in comparison to the CK group,the Bt protein contents were significantly increased in both cotton bolls and their subtending leaves under the T1 and T2 treatments.The maximum levels of increase observed were 67.5%in cotton bolls and 21.7%in leaves.Moreover,the disparity in Bt protein content between cotton bolls and their subtending leaves notably decreased by 31.2%.Correlation analysis suggested that the primary physiological mechanisms for augmenting Bt protein content involve increased protein synthesis and reduced protein catabolism,which are independent of Bt gene expression levels.Stepwise regression and path analysis revealed that elevating the soluble protein content and transaminase activity,while reducing the catabolic enzyme activities,are instrumental in enhancing the Bt protein content.Consequently,the coordinated application of amino acids and EDTA emerges as a strategy that can improve the overall resistance of Bt cotton and mitigate the spatiotemporal variations in Bt toxin concentrations in both cotton bolls and leaves.
基金the National Natural Science Foundation of China(32101817)Jiangsu Agriculture Science and this work was funded by the National Natural Science Foundation of China(32101817)+3 种基金Jiangsu Agriculture Science and Technology Innovation Fund(CX(21)3111)the Natural Science Foundation of the Jiangsu Higher Education Institutions(21KJD210001)the Scientific and Technological Innovation Fund of Carbon Emissions Peak and Neutrality of Jiangsu Provincial Department of Science and Technology(BE2022304)the project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)for their financial support.
文摘Understanding physiological responses in saline agriculture may facilitate wheat breeding programs.Based on a screening test,the Ningmai-14(NM-14)and Yangmai-23(YM-23)wheat cultivars were selected for further experiments to understand the underlying salinity tolerance mechanism.This study investigated the effects of five salinity levels such as Control(CK)=0(without NaCl stress),S1=0.20%,S2=0.25%,S3=0.30%and S4=0.35%of NaCl concentrations of soil on wheat plants.The results showed that increased salinity concentration reduced the growth and yield of wheat cultivars(NM-14 and YM-23).However,YM-23(12.7%)yielded more than NM-14 at maximum salinity stress.The higher salinity(S4)increased the concentration of Na^(+)(4.3 to 5.8-fold)and P contents(2.5 to 2.2-fold),while reducing the average concentrations of K^(+),Cu,and K^(+)/Na^(+)ratio.The higher salinity(S4)reduced the spikelet length by 21.35%(followed by grain spike−1),and the starch content by 18.81%.In the YM-23 cultivar,higher salinity increased superoxide dismutase(SOD),total antioxidant capacity(TAC),and amylase.Compared to NM-14,induced expression of TaYUC2,6,and TaGA13ox,20ox genes were recorded in YM-23.Similarly,in YM-23 the stress-specific genes such as TaHSP70,90 were enhanced whereas,TaSOS1,2 were suppressed.Overall,our study revealed that salt tolerant cultivars modulate hormonal and antioxidant activities,thus maintaining high growth.
基金financial support from the National Key Research and Development Program of China (2018YFD1000900)Jiangsu Collaborative Innovation Center for Modern Crop Production (JCIC-MCP)Jiangsu Overseas Research and Training Program for University Prominent Young and Middle-aged Teachers and President (2016), China
文摘Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluated the effect of K on fiber elongation using two cotton cultivars,Simian 3 and Siza 3,grown in well-watered and drought-stressed conditions.Potassium fertilizer(K2O)was applied 0,150,or 300 kg ha?1 in each growing condition.Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation(Vmax,mmday?1).The application of K alleviated the droughtinduced fiber length reduction by increasing Vmax.At 10 and 15 days post-anthesis(DPA),drought significantly reduced osmotic potential(OP)and increased K+and malate contents at all K rates,relative to well-watered conditions,which was associated with increased activities of phosphoenolpyruvate carboxylase(PEPC),V-ATPase,PPase,and PM H+-ATPase in cotton fiber.However,the relative contribution of K+and malate to OP declined under drought in comparison with well-watered condition.Compared with control without K,K application decreased OP and increased the accumulation of osmolytes(K+,malate and soluble sugar)as well as the activities of related enzymes in fiber irrespective of water treatments.Moreover,K application increased osmotic adjustment during drought,and improved the contribution of K+and malate to OP,especially under drought stress.This study showed that drought decreased fiber length by reducing Vmax,and K application ameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells.
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.
基金This work was in part supported by grants from National Key Technology R&D Program of China(2017YFD0101803,2017YFD0101806)Key Technology R&D Program of Jiangsu Province(BE2016379)+2 种基金the Jiangsu Agricultural Science and Technology Innovation Fund[CX(16)1012]the Fundamental Research Funds for the Central Universities(KJQN201656,KJQN201734)Project of Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,MOA,China(IVF201706).
文摘The fleshy taproot of radish is an important storage organ determining its yield and quality.Taproot thickening is a complex developmental process in radish.However,the molecular mechanisms governing this process remain unclear at the proteome level.In this study,a comparative proteomic analysis was performed to analyze the proteome changes at three developmental stages of taproot thickening using iTRAQ approach.In total,1862 differentially expressed proteins(DEPs)were identified from 6342 high-confidence proteins,among which 256 up-regulated proteins displayed overlapped accumulation in S1(pre-cortex splitting stage)vs.S2(cortex splitting stage)and S1 vs.S3(expanding stage)pairs,whereas 122 up-regulated proteins displayed overlapped accumulation in S1 vs.S3 and S2 vs.S3 pairs.Gene Ontology(GO)and pathway enrichment analysis showed that these DEPs were mainly involved in several processes such as“starch and sucrose metabolism”,“plant hormone signal transduction”,and“biosynthesis of secondary metabolites”.A high concordance existed between iTRAQ and RT-qPCR at the mRNA expression levels.Furthermore,association analysis showed that 187,181,and 96 DEPs were matched with their corresponding differentially expressed genes(DEGs)in S1 vs.S2,S1 vs.S3,and S2 vs.S3 comparison,respectively.Notably,several functional proteins including cell division cycle 5-like protein(CDC5),expansin B1(EXPB1),and xyloglucan endotransglucosylase/hydrolase protein 24(XTH24)were responsible for cell division and expansion during radish taproot thickening process.These results could facilitate a better understanding of the molecular mechanism underlying taproot thickening,and provide valuable information for the identification of critical genes/proteins responsible for taproot thickening in root vegetable crops.
基金financed by the National Natural Science Foundation of China(31901448)the Key Research and Development Program of Jiangsu(BE2019343)+4 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJB210004)China Postdoctoral Science Foundation(2020M671628,2020M671629)Jiangsu Postdoctoral Science Foundation(2020Z061)the Guizhou Science and Technology Department(20161148)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Dense planting could be a feasible method for reducing nitrogen(N) application rates without compromising rice grain yield in northeast and central China. It is still unclear whether reduced N application with dense planting(RNDP) can achieve higher rice yield and N use efficiency(NUE) in Jiangsu, east China. Three japonica inbred rice(JI) and three indica hybrid rice(IH) cultivars were grown in a field experiment. Their grain yield, NUE, and related traits were compared under two cultivation treatments:conventional high-yielding practice(CHYP) and RNDP. JI showed similar yields under the two treatments,while IH showed lower yield under RNDP than under CHYP, and the partial factor productivity of N and N use efficiency for grain yield increased(P < 0.05) in both JI and IH under RNDP. Compared with CHYP,RNDP reduced spikelets per panicle but increased panicles per m2 and filled-kernel percentage of JI and IH, and JI's kernel weight was increased(P < 0.05) under RNDP. Shoot biomass weight and nonstructural carbohydrate(NSC) content in the stem at heading and maturity of JI and IH were reduced under RNDP, while harvest index and NSC remobilization reserve were increased(P < 0.05) under RNDP, especially for JI. Our results suggest that RNDP could achieve a higher rice grain yield and NUE, particularly for JI, a dominant rice cultivar type in Jiangsu. For JI, the increased panicles per m2, sink-filling efficiency, harvest index, and NSC remobilization after heading under RNDP contributed to a grain yield similar to that under CHYP.
文摘The dragonfly wing, which consists of veins and membrane, is of biological hierarchical material. We observed the cross-sections of longitudinal veins and membrane using Environmental Scanning Electron Microscopy (ESEM). Based on the experiments and previous studies, we described the longitudinal vein and the membrane in terms of two hierarchical levels of organization of composite materials at the micro- and nano-scales. The longitudinal vein of dragonfly wing has a complex sandwich structure with two chitinous shells and a protein layer, and it is considered as the first hierarchical level of the vein. Moreover, the chitinous shells are concentric multilayered structures. Clusters of nano-fibrils grow along the circumferential orientation embedded into the protein layer. It is considered as the second level of the hierarchy. Similarly, the upper and lower epidermises of membrane constitute the first hierarchical level of organization in micro scale. Similar to the vein shell, the membrane epidermises were found to be a paralleled multilayered structure, defined as the second hierarchical level of the membrane. Combining with the mechanical behavior analysis of the dragonfly wing, we concluded that the growth orientation of the hierarchical structure of the longitudinal vein and membrane is relevant to its biomechanical behavior.
文摘The configurations of dragonfly wings, including the corrugations of the chordwise cross-section, the microstructure of the longitudinal veins and membrane, were comprehensively investigated using the Environmental Scanning Electron Microscopy (ESEM). Based on the experimental results reported previously, the multi-scale and multi-dimensional models with different structural features of dragonfly wing were created, and the biological dynamic behaviors of wing models were discussed through the Finite Element Method (FEM). The results demonstrate that the effects of different structural features on dynamic behaviors of dragonfly wing such as natural frequency/modal, bending/torsional deformation, reaction force/torque are very significant. The corrugations of dragonfly wing along the chordwise can observably improve the flapping frequency because of the greater structural stiffness of wings. In updated model, the novel sandwich microstrueture of the longitudinal veins re- markably improves the torsional deformation of dragonfly wing while it has a little effect on the flapping frequency and bending deformation. These integrated structural features can adjust the deformation of wing oneself, therefore the flow field around the wings can be controlled adaptively. The fact is that the flights of dragonfly wing with sandwich microstructure of longitudinal veins are more efficient and intelligent.
基金National Natural Science Foundation of China(grant 40971150)the Chinese Postdoctoral Science Foundation(20090450004,20103018)+1 种基金the open fund of Laboratory for Earth Surface Processes,Ministry of Education(2011004)the Science Foundation Fostering Innovative Ability of Henan University of Science and Technology(2009CZ0006).
文摘Aims mycorrhizas play key roles in important ecosystem processes and functions.Carbon(C),nitrogen(N)and phosphorus(P)concentrations and their ratios are very important foliar traits and their cycling constrains most ecosystem processes.thus,this study addresses the influence of mycorrhizal strategies on these foliar nutrients and their response to climate change.Methods a new database was established including mycorrhizal types and leaf C_(mass),N_(mass),P_(mass),C:N and N:P of each plant species based on He et al.[(2008)leaf nitrogen:Phosphorus stoichiometry across Chinese grassland biomes.oecologia 155:301-10].the predomi-nant type of mycorrhizal association of each plant species was classified according to the published literature and our own obser-vations.We analyzed leaf C_(mass),N_(mass),P_(mass),C:N and N:P among 112 plant species in 316 samples of ascertained mycorrhizal type in the major grassland biomes of China.Important Findingsthe results show highly significant variation among different myc-orrhizal strategy types for foliar C_(mass),N_(mass) and N:P.the highest foliar C_(mass) was observed in ectotrophic mycorrhiza(ECM)type(469.8mg g1)followed by that in arbuscular mycorrhiza(AM)type(443.884 mg g1)and nonmycorrhizal(NM)type(434.0 mg g^(-1)).The foliar N concentration was significantly higher in NM type(31.0mg g^(-1)).However,the AM type had the greater C:N value(19)than the other types although less variation in C_(mass) and N:P among abuscular types on AM strategy was observed.Foliar traits showed significant variation in response to precipita-tion(mean growing season and annual precipitation(GSP and MAP))and temperature(mean growing season and annual tem-peratures(GST and MAT))depending on different mycorrhizal strategies and arbuscular types.When the responses of all folia parameters to precipitation and temperature were compared,the influence of GSP on leaf traits was greater than the influence of GST.
基金TThis study was supported by National Natural Science Foundation of China(31270558)Natural Science Foundation of Shanghai(18ZR1425400)the Research Funds for the Introduction of Talents of Shanghai Science and Technology Museum.
文摘In order to explore the influence of arbuscular mycorrhizal(AM)fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem,rhizosphere soils were collected from eight different poisonous plants in degraded grasslands and one from pasture grass in non-degraded grasslands(CK).The collected soils were used as inocula to assess the influence of indigenous AM fungi on the growth of two typical pasture grass species,Elymus nutans and Poa pratensis,in a bioassay experiment.Five growth parameters and two AM parameters were determined.The mycorrhizal responsiveness and the importance value were calculated.Significant differences between the eight poisonous plants and CK were observed.Compared to CK,rhizosphere soil from the eight poisonous plants had lower AM fungal spore densities.The growth of E.nutans and P.pratensis seedlings was depressed with the inoculation from poisonous plants rhizosphere soil.This study demonstrated that the presence of poisonous plants with grassland degradation altered inherent AM fungal community abundance,and could exert inhibition effects on the growth of pasture grasses.It may attribute to discover the important role of rhizosphere soil of different poisonous plants to AM fungal community on the Alpine meadow.
基金The authors would like to acknowledge the projects supported by the National Natural Science Foundation of China (Grants No: 11272173, 11572170).
文摘The microstructure of the main longitudinal veins of the dragonfly wing and the aerodynamic behaviors of the wing were investigated in this paper. The microstructure of longitudinal vein presents two circumferential chitin layers and a protein-fiber soft layer. The dragonfly wing is corrugated due to the spatial arrangement of longitudinal veins. It was found that the corru- gation angle could significantly influence the lift/drag ratio across a range of attack angles by the wind tunnel experiments. The results of the finite element analysis indicate that the protein soft layer of vein facilitates the change of the corrugation angle by allowing substantial relative twisting deformation between two neighboring veins, which is not possible in veins without a soft sandwich layer.