Drought is one of the most serious environmental factors that limit the productivity of agricultural crops worldwide. However, the mechanism underlying drought tolerance in plants is unclear. WRKY transcription factor...Drought is one of the most serious environmental factors that limit the productivity of agricultural crops worldwide. However, the mechanism underlying drought tolerance in plants is unclear. WRKY transcription factors are known to function in adaptation to abiotic stresses. By screening a pool of WRKY-associated T-DNA insertion mutants, we isolated a gain-of-function mutant, acquired drought tolerance （adt）, showing improved drought tolerance. Under drought stress conditions, adt accumulated higher levels of ABA than wild-type plants. Stomatal aperture analysis indi- cated that adt was more sensitive to ABA than wild-type plants. Molecular genetic analysis revealed that a T-DNA inser- tion in adt led to activated expression of a WRKY gene that encodes the WRKR57 protein. Constitutive expression of WRKY57 also conferred similar drought tolerance. Consistently with the high ABA content and enhanced drought tol- erance, three stress-responsive genes （RD29A, NCED3, and ABA3） were up-regulated in adt. ChIP assays demonstrated that WRKY57 can directly bind the W-box of RD29A and NCED3 promoter sequences. In addition, during ABA treatment, seed germination and early seedling growth of adt were inhibited, whereas, under high osmotic conditions, adt showed a higher seed germination frequency. In summary, our results suggested that the activated expression of WRKY57 improved drought tolerance of Arabidopsis by elevation of ABA levels. Establishment of the functions of WRKY57 will enable improvement of plant drought tolerance through gene manipulation approaches.展开更多
Anthocyanins, a group of L-phenylalanine （Phe）-derived flavonoids, have been demonstrated to play impor- tant roles in plant stress resistance and interactions between plants and insects. Although the anthocyanin bi...Anthocyanins, a group of L-phenylalanine （Phe）-derived flavonoids, have been demonstrated to play impor- tant roles in plant stress resistance and interactions between plants and insects. Although the anthocyanin biosynthetic pathway and its regulatory mechanisms have been extensively studied, it remains unclear whether the level of Phe supply affects anthocyanin biosynthesis. Here, we investigated the roles of arogenate dehydratases （ADTs）, the key enzymes that catalyze the conversion of arogenate into Phe, in sucrose-induced anthocyanin biosynthesis in Arabidopsis. Genetic analysis showed that all six ADT isoforms function redundantly in anthocyanin biosynthesis but have differential contributions. ADT2 contributes the most to anthocyanin accumulation, followed by ADT1 and ADT3, and ADT4-ADT6. We found that anthocyanin content is positively correlated with the levels of Phe and sucrose-induced ADT transcripts in seedlings. Consistently, addition of Phe to the medium could dramatically increase anthocyanin content in the wild-type plants and rescue the phenotype of the adtl adt3 double mutant regarding the anthocyanin accumulation. Moreover, transgenic plants overexpressing ADT4, which appears to be less sensitive to Phe than overexpression ofADT2, hyperaccumulate Phe and produce elevated level of antho- cyanins. Taken together, our results suggest that the level of Phe is an important regulatory factor for sus- taining anthocyanin biosynthesis.展开更多
Androgen deprivation therapy （ADT） has been associated with a plethora of adverse effects, consistent with the androgen dependency of multiple reproductive and somatic tissues. One such tissue is the hemopoietic sys...Androgen deprivation therapy （ADT） has been associated with a plethora of adverse effects, consistent with the androgen dependency of multiple reproductive and somatic tissues. One such tissue is the hemopoietic system, and one of the most predictable consequences of ADT is the development of anemia. Although anemia caused by ADT is rarely severe, ADT is often given to frail, elderly men with increased susceptibility to anemia due to multiple other causes. ADT-associated anemia may contribute to fatigue and reduced quality of life （QoL） in such men, although this requires further study. While anemia is an independent risk factor of mortality in men with prostate cancer, it is not known whether treatment of ADT-associated anemia alters clinically important outcomes, or whether treatment affects mortality. Awareness of the phenomenon of ADT-induced anemia should avoid unnecessary work-up in mild cases of normocytic normochromic anemia. However, assessment and treatment of more severe anemia may be required. This should be determined on an individual basis. In contrast to the weli-descrihed actions of ADT on erythropoiesis, its effect on other hemopoietic lineages has been less well elucidated. While preclinical studies have found roles for androgens in maturation and differentiated function of neutrophils, lymphocytes and platelets, the implications of these findings for men with prostate cancer receiving ADT require further studies.展开更多
为加速有限元分析流程,提出了一种面向有限元分析的自适应三角网格模型布尔运算方法。将ADT(alternating digital tree)数据结构应用于三角面片的判交计算,提升了布尔运算中三角面片的判交效率;借鉴结合球填充算法和插点/去点算法的网...为加速有限元分析流程,提出了一种面向有限元分析的自适应三角网格模型布尔运算方法。将ADT(alternating digital tree)数据结构应用于三角面片的判交计算,提升了布尔运算中三角面片的判交效率;借鉴结合球填充算法和插点/去点算法的网格重生成方法来重剖分局部区域,保证了算法的效率和生成网格的质量;通过改进的八叉树背景网格来记录和光滑尺寸场,生成了自适应的网格;通过尺寸场合理地控制重剖分区域,使算法效率和生成网格的质量得以很好地平衡。实验结果表明,所提方法可以高效地生成满足有限元分析需求的网格。展开更多
Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent elec...Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent electrocatalytic performance of both activity and stability for methanol oxidation reaction （MOR）. The mass and specific activities of CoPt TONPs is 8 and 6 times higher than that of standard commercial Pt/C, respectively. After accelerated durability test （ADT）, the loss of electrochemical surface area （ECSA） for CoPt TONPs is only 18.5%, which is significantly less than that of commercial Pt/C （68.2%）, indicating that CoPt TONPs possess much better stability than commercial Pt/C in the prolonged operation. The Curie temperature of CoPt TONPs down to 8 nm is as high as 350 K with weak ferromagntism at room temperature （RT）, which is greatly valuable for recycling in the eletrocatalytic applications.展开更多
The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product—Absolute Dynamic Topography (ADT) from AVISO. The accuracy of the ADT data is validated wi...The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product—Absolute Dynamic Topography (ADT) from AVISO. The accuracy of the ADT data is validated with the mooring data from a two-year subantarctic-front experiment. It is demonstrated that the ADT is consistent with in-situ measurements and captures the meso-scale activity of the Antarctic Circumpolar Current (ACC). Stream-coordinate analysis of ADT surface geostrophic flows finds that ACC jets exhibit large spatio-temporal variability and do not correspond to particular streamfunction values. In the circumpolar scope ACC jets display a transient fragmented pattern controlled by topographic features. The poleward shift of jet in streamfunction space, as revealed by a streamwise correlation method, indicates the presence of meridional fluxes of zonal momentum. Such cross-stream eddy fluxes concentrate the broad ACC baroclinic flow into narrow jets. Combined with a recent discovery of gravest empirical mode (GEM) in the thermohaline fields, the study clarifies the interrelationship among front, jet and streamfunction in the Southern Ocean.展开更多
基金This research was supported by the Science Foundation of the Ministry of Agriculture of the Peoples' Republic of China，the Science Foundation of the Chinese Academy of Sciences，the National Natural Science Foundation of China
文摘Drought is one of the most serious environmental factors that limit the productivity of agricultural crops worldwide. However, the mechanism underlying drought tolerance in plants is unclear. WRKY transcription factors are known to function in adaptation to abiotic stresses. By screening a pool of WRKY-associated T-DNA insertion mutants, we isolated a gain-of-function mutant, acquired drought tolerance （adt）, showing improved drought tolerance. Under drought stress conditions, adt accumulated higher levels of ABA than wild-type plants. Stomatal aperture analysis indi- cated that adt was more sensitive to ABA than wild-type plants. Molecular genetic analysis revealed that a T-DNA inser- tion in adt led to activated expression of a WRKY gene that encodes the WRKR57 protein. Constitutive expression of WRKY57 also conferred similar drought tolerance. Consistently with the high ABA content and enhanced drought tol- erance, three stress-responsive genes （RD29A, NCED3, and ABA3） were up-regulated in adt. ChIP assays demonstrated that WRKY57 can directly bind the W-box of RD29A and NCED3 promoter sequences. In addition, during ABA treatment, seed germination and early seedling growth of adt were inhibited, whereas, under high osmotic conditions, adt showed a higher seed germination frequency. In summary, our results suggested that the activated expression of WRKY57 improved drought tolerance of Arabidopsis by elevation of ABA levels. Establishment of the functions of WRKY57 will enable improvement of plant drought tolerance through gene manipulation approaches.
文摘Anthocyanins, a group of L-phenylalanine （Phe）-derived flavonoids, have been demonstrated to play impor- tant roles in plant stress resistance and interactions between plants and insects. Although the anthocyanin biosynthetic pathway and its regulatory mechanisms have been extensively studied, it remains unclear whether the level of Phe supply affects anthocyanin biosynthesis. Here, we investigated the roles of arogenate dehydratases （ADTs）, the key enzymes that catalyze the conversion of arogenate into Phe, in sucrose-induced anthocyanin biosynthesis in Arabidopsis. Genetic analysis showed that all six ADT isoforms function redundantly in anthocyanin biosynthesis but have differential contributions. ADT2 contributes the most to anthocyanin accumulation, followed by ADT1 and ADT3, and ADT4-ADT6. We found that anthocyanin content is positively correlated with the levels of Phe and sucrose-induced ADT transcripts in seedlings. Consistently, addition of Phe to the medium could dramatically increase anthocyanin content in the wild-type plants and rescue the phenotype of the adtl adt3 double mutant regarding the anthocyanin accumulation. Moreover, transgenic plants overexpressing ADT4, which appears to be less sensitive to Phe than overexpression ofADT2, hyperaccumulate Phe and produce elevated level of antho- cyanins. Taken together, our results suggest that the level of Phe is an important regulatory factor for sus- taining anthocyanin biosynthesis.
文摘Androgen deprivation therapy （ADT） has been associated with a plethora of adverse effects, consistent with the androgen dependency of multiple reproductive and somatic tissues. One such tissue is the hemopoietic system, and one of the most predictable consequences of ADT is the development of anemia. Although anemia caused by ADT is rarely severe, ADT is often given to frail, elderly men with increased susceptibility to anemia due to multiple other causes. ADT-associated anemia may contribute to fatigue and reduced quality of life （QoL） in such men, although this requires further study. While anemia is an independent risk factor of mortality in men with prostate cancer, it is not known whether treatment of ADT-associated anemia alters clinically important outcomes, or whether treatment affects mortality. Awareness of the phenomenon of ADT-induced anemia should avoid unnecessary work-up in mild cases of normocytic normochromic anemia. However, assessment and treatment of more severe anemia may be required. This should be determined on an individual basis. In contrast to the weli-descrihed actions of ADT on erythropoiesis, its effect on other hemopoietic lineages has been less well elucidated. While preclinical studies have found roles for androgens in maturation and differentiated function of neutrophils, lymphocytes and platelets, the implications of these findings for men with prostate cancer receiving ADT require further studies.
文摘为加速有限元分析流程,提出了一种面向有限元分析的自适应三角网格模型布尔运算方法。将ADT(alternating digital tree)数据结构应用于三角面片的判交计算,提升了布尔运算中三角面片的判交效率;借鉴结合球填充算法和插点/去点算法的网格重生成方法来重剖分局部区域,保证了算法的效率和生成网格的质量;通过改进的八叉树背景网格来记录和光滑尺寸场,生成了自适应的网格;通过尺寸场合理地控制重剖分区域,使算法效率和生成网格的质量得以很好地平衡。实验结果表明,所提方法可以高效地生成满足有限元分析需求的网格。
基金supported by the National Basic Research Program of China(2015CB921401)the National Instrument Program of China(2012YQ120048)+2 种基金the National Natural Science Foundation of China(51625101,51431009,51471183,51331002,51371015,11274371 and 11674023)the Instrument Development Program of Chinese Academy of Sciences(YZ201345)the Fundamental Research Funds for the Central Universities(FRF-BR-15-009B)
文摘Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent electrocatalytic performance of both activity and stability for methanol oxidation reaction （MOR）. The mass and specific activities of CoPt TONPs is 8 and 6 times higher than that of standard commercial Pt/C, respectively. After accelerated durability test （ADT）, the loss of electrochemical surface area （ECSA） for CoPt TONPs is only 18.5%, which is significantly less than that of commercial Pt/C （68.2%）, indicating that CoPt TONPs possess much better stability than commercial Pt/C in the prolonged operation. The Curie temperature of CoPt TONPs down to 8 nm is as high as 350 K with weak ferromagntism at room temperature （RT）, which is greatly valuable for recycling in the eletrocatalytic applications.
基金Supported by the National Basic Research Program of China (973 Program) (Nos.2006CB403601,2007CB411804)the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX2-YW-Q11-02)the National Natural Sciences Foundation of China (No.40776014)
文摘The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product—Absolute Dynamic Topography (ADT) from AVISO. The accuracy of the ADT data is validated with the mooring data from a two-year subantarctic-front experiment. It is demonstrated that the ADT is consistent with in-situ measurements and captures the meso-scale activity of the Antarctic Circumpolar Current (ACC). Stream-coordinate analysis of ADT surface geostrophic flows finds that ACC jets exhibit large spatio-temporal variability and do not correspond to particular streamfunction values. In the circumpolar scope ACC jets display a transient fragmented pattern controlled by topographic features. The poleward shift of jet in streamfunction space, as revealed by a streamwise correlation method, indicates the presence of meridional fluxes of zonal momentum. Such cross-stream eddy fluxes concentrate the broad ACC baroclinic flow into narrow jets. Combined with a recent discovery of gravest empirical mode (GEM) in the thermohaline fields, the study clarifies the interrelationship among front, jet and streamfunction in the Southern Ocean.
