Recent studies have successfully demonstrated high-Tc superconductivity in bilayer nickelate La3Ni2O7.However,research on modulating the structural and transport characteristics of La3Ni2O7 films by applying“chemical...Recent studies have successfully demonstrated high-Tc superconductivity in bilayer nickelate La3Ni2O7.However,research on modulating the structural and transport characteristics of La3Ni2O7 films by applying“chemical”compressive pressure through cation substitution is still limited.Here,we address this issue in the La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,1.5,2.0,and 2.5)thin film samples.It was found that using Nd3+with a smaller radius instead of La3+can reduce the c-axis lattice constant and shift the metal-insulator transition(MIT)temperature TMIT.To probe the origin of the MIT at cryogenic temperatures,experimental measurements of magnetoresistance were conducted,and theoretical analysis was carried out using the Kondo model,Hikami-Larkin-Nagaoka equation,and other methods.The results indicate that as Nd doping rises,the contributions of the Kondo effect and two-dimensional weak localization(WL)first decrease and then increase.The total contribution of WL and the Kondo effect in the mid-doped La_(1.5)Nd_(1.5)Ni_(2)O_(7)sample was the smallest,which to some extent explains the changes in TMIT.The Kondo effect dominates in other La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,2.0,and 2.5)samples.This work demonstrates that cation doping has a significant impact on bilayer nickelates,providing experimental evidence for understanding the physical mechanism of the MIT in bilayer nickelates.展开更多
Ablotlc stresses, such as drought, high salinity, and cold/freezing, lead plants to produce excess reactive oxygen species. Catalase, a unique hydrogen peroxide-scavenging enzyme, plays a very Important role In plants...Ablotlc stresses, such as drought, high salinity, and cold/freezing, lead plants to produce excess reactive oxygen species. Catalase, a unique hydrogen peroxide-scavenging enzyme, plays a very Important role In plants. To characterize the catalase involved In plant response to ablotlc stresses, we constructed a cDNA library from 4℃-treated Festuca arundinacea Schreb seedlings and isolated a catalase gene from this library. The cDNA （FaCat1, 1 735 bp） contained an open reading frame of 1 479 bp. BLAST analysis Indicated that the deduced amino acid sequence showed 96% Identity with that from wheat TaCat1 and 87% Identity with that from maize ZmCat2. Northern blotting analysis showed an obvious Increase of FaCat1 transcripts In leaves In contrast with roots. Time-course analysis of the expression of FaCat1 in F. arundinacea leaves showed that FaCat1 expression was upregulated in cold- and salt-stressed leaves, with the FaCat1 transcripts accumulat-Ing mostly at 4 or 2 h after cold or salt stress, respectively. No significant changes in FaCat1 transcription were observed in dried leaves and inhibition of FaCat1 transcription was found In absclsic acid （ABA）-treated leaves, Indicating that the FaCat1 gene is differentially expressed during cold, high salt, drought, and ABA treatment In F. arundinacea leaves.展开更多
A major objective of quantitative trait locus （QTL） studies is to find genes/markers that can be used in breeding programs via marker assisted selection （MAS）.We surveyed the QTLs for yield and yieldrelated traits...A major objective of quantitative trait locus （QTL） studies is to find genes/markers that can be used in breeding programs via marker assisted selection （MAS）.We surveyed the QTLs for yield and yieldrelated traits and their genomic distributions in common wheat （Triticum aestivum L.） in the available published reports.We then carried out a meta-QTL （MQTL） analysis to identify the major and consistent QTLs for these traits.In total,55 MQTLs were identified,of which 12 significant MQTLs were located on wheat chromosomes 1A,1B,2A,2D,3B,4A,4B,4D and 5A.Our study showed that the genetic control of yield and its components in common wheat involved the important genes such as Rht and Vrn.Furthermore,several significant MQTLs were found in the chromosomal regions corresponding to several rice genomic locations containing important QTLs for yield related traits.Our results demonstrate that meta-QTL analysis is a powerful tool for confirming the major and stable QTLs and refining their chromosomal positions in common wheat,which may be useful for improving the MAS efficiency of yield related traits.展开更多
基金supported by the Natural Science Foundation of Guangdong Province of China(Grant No.2025A1515011071)the National Natural Science Foundation of China(Grant Nos.92065110,11974048,and 12074334)the Beijing Municipal Natural Science Foundation Key Research Topics(Grant No.Z230006)。
文摘Recent studies have successfully demonstrated high-Tc superconductivity in bilayer nickelate La3Ni2O7.However,research on modulating the structural and transport characteristics of La3Ni2O7 films by applying“chemical”compressive pressure through cation substitution is still limited.Here,we address this issue in the La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,1.5,2.0,and 2.5)thin film samples.It was found that using Nd3+with a smaller radius instead of La3+can reduce the c-axis lattice constant and shift the metal-insulator transition(MIT)temperature TMIT.To probe the origin of the MIT at cryogenic temperatures,experimental measurements of magnetoresistance were conducted,and theoretical analysis was carried out using the Kondo model,Hikami-Larkin-Nagaoka equation,and other methods.The results indicate that as Nd doping rises,the contributions of the Kondo effect and two-dimensional weak localization(WL)first decrease and then increase.The total contribution of WL and the Kondo effect in the mid-doped La_(1.5)Nd_(1.5)Ni_(2)O_(7)sample was the smallest,which to some extent explains the changes in TMIT.The Kondo effect dominates in other La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,2.0,and 2.5)samples.This work demonstrates that cation doping has a significant impact on bilayer nickelates,providing experimental evidence for understanding the physical mechanism of the MIT in bilayer nickelates.
文摘Ablotlc stresses, such as drought, high salinity, and cold/freezing, lead plants to produce excess reactive oxygen species. Catalase, a unique hydrogen peroxide-scavenging enzyme, plays a very Important role In plants. To characterize the catalase involved In plant response to ablotlc stresses, we constructed a cDNA library from 4℃-treated Festuca arundinacea Schreb seedlings and isolated a catalase gene from this library. The cDNA （FaCat1, 1 735 bp） contained an open reading frame of 1 479 bp. BLAST analysis Indicated that the deduced amino acid sequence showed 96% Identity with that from wheat TaCat1 and 87% Identity with that from maize ZmCat2. Northern blotting analysis showed an obvious Increase of FaCat1 transcripts In leaves In contrast with roots. Time-course analysis of the expression of FaCat1 in F. arundinacea leaves showed that FaCat1 expression was upregulated in cold- and salt-stressed leaves, with the FaCat1 transcripts accumulat-Ing mostly at 4 or 2 h after cold or salt stress, respectively. No significant changes in FaCat1 transcription were observed in dried leaves and inhibition of FaCat1 transcription was found In absclsic acid （ABA）-treated leaves, Indicating that the FaCat1 gene is differentially expressed during cold, high salt, drought, and ABA treatment In F. arundinacea leaves.
基金supported by the State Key Basic Research and Development Program of China (973 Program)(2009CB118300)the Hi-Tech Research and Development Program of China (863 Program) (2009AA101102)
文摘A major objective of quantitative trait locus （QTL） studies is to find genes/markers that can be used in breeding programs via marker assisted selection （MAS）.We surveyed the QTLs for yield and yieldrelated traits and their genomic distributions in common wheat （Triticum aestivum L.） in the available published reports.We then carried out a meta-QTL （MQTL） analysis to identify the major and consistent QTLs for these traits.In total,55 MQTLs were identified,of which 12 significant MQTLs were located on wheat chromosomes 1A,1B,2A,2D,3B,4A,4B,4D and 5A.Our study showed that the genetic control of yield and its components in common wheat involved the important genes such as Rht and Vrn.Furthermore,several significant MQTLs were found in the chromosomal regions corresponding to several rice genomic locations containing important QTLs for yield related traits.Our results demonstrate that meta-QTL analysis is a powerful tool for confirming the major and stable QTLs and refining their chromosomal positions in common wheat,which may be useful for improving the MAS efficiency of yield related traits.
