In plant immunity,the mutually antagonistic hormones salicylic acid(SA)and jasmonic acid(JA)are implicated in resistance to biotrophic and necrotrophic pathogens,respectively.Promoters that can respond to both SA and ...In plant immunity,the mutually antagonistic hormones salicylic acid(SA)and jasmonic acid(JA)are implicated in resistance to biotrophic and necrotrophic pathogens,respectively.Promoters that can respond to both SA and JA signals are urgently needed to engineer plants with enhanced resistance to a broad spectrum of pathogens.However,few natural pathogen-inducible promoters are available for this purpose.To address this problem,we have developed a strategy to synthesize dual SA-and JA-responsive promoters by combining SA-and JA-responsive cis elements based on the interaction between their cognate transacting factors.The resulting promoters respond rapidly and strongly to both SA and Methyl Jasmonate(MeJA),as well as different types of phytopathogens.When such a synthetic promoter was used to control expression of an antimicrobial peptide,transgenic plants displayed enhanced resistance to a diverse range of biotrophic,necrotrophic,and hemi-biotrophic pathogens.A dual-inducible promoter responsive to the antagonistic signals auxin and cytokinin was generated in a similar manner,confirming that our strategy can be used for the design of other biotically or abiotically inducible systems.展开更多
Although doping with growth hormone （GH） is banned, there is anecdotal evidence that it is widely abused. GH is reportedly used often in combination with anabolic steroids at high doses for several months. Developme...Although doping with growth hormone （GH） is banned, there is anecdotal evidence that it is widely abused. GH is reportedly used often in combination with anabolic steroids at high doses for several months. Development of a robust test for GH has been challenging because recombinant human 22 kDa （22K） GH used in doping is indistinguishable analytically from endogenous GH and there are wide physiological fluctuations in circulating GH concentrations. One approach to GH testing is based on measurement of different circulating GH isoforms using immunoassays that differentiate between 22K and other GH isoforms. Administration of 22K GH results in a change in its abundance relative to other endogenous pituitary GH isoforms. The differential isoform method has been implemented; however, its utility is limited because of the short window of opportunity of detection. The second approach, which will extend the window of opportunity of detection, is based on the detection of increased levels of circulating GH-responsive proteins, such as insulin-like growth factor （IGF） axis and collagen peptides. Age and gender are the major determinants of variability for IGF-I and the collagen markers; therefore, a test based on these markers must take age into account for men and women. Extensive data is now available that validates the GH- responsive marker approach and implementation is now largely dependent on establishing an assured supply of standardized assays. Future directions will include more widespread implementation of both approaches by the World Anti-Doping Agency, possible use of other platforms for measurement and an athlete＇s passport to establish individual reference levels for biological parameters such as GH-responsive markers. Novel approaches include gene expression and proteomic profiling.展开更多
基金supported by the National Natural Science Foundation of China(31071463)Chongqing Foundation for leaders of disciplines in science(cstc2014kjcxljrc005)the Chongqing Research Program of Basic Research and Frontier Technology(cstc2017jcyjB0316).
文摘In plant immunity,the mutually antagonistic hormones salicylic acid(SA)and jasmonic acid(JA)are implicated in resistance to biotrophic and necrotrophic pathogens,respectively.Promoters that can respond to both SA and JA signals are urgently needed to engineer plants with enhanced resistance to a broad spectrum of pathogens.However,few natural pathogen-inducible promoters are available for this purpose.To address this problem,we have developed a strategy to synthesize dual SA-and JA-responsive promoters by combining SA-and JA-responsive cis elements based on the interaction between their cognate transacting factors.The resulting promoters respond rapidly and strongly to both SA and Methyl Jasmonate(MeJA),as well as different types of phytopathogens.When such a synthetic promoter was used to control expression of an antimicrobial peptide,transgenic plants displayed enhanced resistance to a diverse range of biotrophic,necrotrophic,and hemi-biotrophic pathogens.A dual-inducible promoter responsive to the antagonistic signals auxin and cytokinin was generated in a similar manner,confirming that our strategy can be used for the design of other biotically or abiotically inducible systems.
文摘Although doping with growth hormone （GH） is banned, there is anecdotal evidence that it is widely abused. GH is reportedly used often in combination with anabolic steroids at high doses for several months. Development of a robust test for GH has been challenging because recombinant human 22 kDa （22K） GH used in doping is indistinguishable analytically from endogenous GH and there are wide physiological fluctuations in circulating GH concentrations. One approach to GH testing is based on measurement of different circulating GH isoforms using immunoassays that differentiate between 22K and other GH isoforms. Administration of 22K GH results in a change in its abundance relative to other endogenous pituitary GH isoforms. The differential isoform method has been implemented; however, its utility is limited because of the short window of opportunity of detection. The second approach, which will extend the window of opportunity of detection, is based on the detection of increased levels of circulating GH-responsive proteins, such as insulin-like growth factor （IGF） axis and collagen peptides. Age and gender are the major determinants of variability for IGF-I and the collagen markers; therefore, a test based on these markers must take age into account for men and women. Extensive data is now available that validates the GH- responsive marker approach and implementation is now largely dependent on establishing an assured supply of standardized assays. Future directions will include more widespread implementation of both approaches by the World Anti-Doping Agency, possible use of other platforms for measurement and an athlete＇s passport to establish individual reference levels for biological parameters such as GH-responsive markers. Novel approaches include gene expression and proteomic profiling.
