In response to preharvest priming with exogenous methyl jasmonate(MeJA),tea plants adjust their physiological behavior at the molecular level.The whole-organism reconfiguration of aroma formation from the precursor to...In response to preharvest priming with exogenous methyl jasmonate(MeJA),tea plants adjust their physiological behavior at the molecular level.The whole-organism reconfiguration of aroma formation from the precursor to storage is poorly understood.In this study,we performed iTRAQ proteomic analysis and identified 337,246,and 413 differentially expressed proteins in tea leaves primed with MeJA for 12 h,24h,and 48 h,respectively.Furthermore,a total of 266 nonvolatile and 100 volatile differential metabolites were identified by utilizing MS-based metabolomics.A novel approach that incorporated the integration of extended self-organizing map-based dimensionality was applied.The vivid time-scale changes tracing physiological responses in MeJA-primed tea leaves are marked in these maps.Jasmonates responded quickly to the activation of the jasmonic acid pathway in tea leaves,while hydroxyl and glycosyl jasmonates were biosynthesized simultaneously on a massive scale to compensate for the exhausted defense.The levels ofα-linolenic acid,geranyl diphosphate,farnesyl diphosphate,geranylgeranyl diphosphate,and phenylalanine,which are crucial aroma precursors,were found to be significantly changed in MeJA-primed tea leaves.Green leaf volatiles,volatile terpenoids,and volatile phenylpropanoids/benzenoids were spontaneously biosynthesized from responding precursors and subsequently converted to their corresponding glycosidic forms,which can be stably stored in tea leaves.This study elucidated the physiological response of tea leaves primed with exogenous methyl jasmonate and revealed the molecular basis of source and sink changes on tea aroma biosynthesis and catabolism in response to exogenous stimuli.The results significantly enhance our comprehensive understanding of tea plant responses to exogenous treatment and will lead to the development of promising biotechnologies to improve fresh tea leaf quality.展开更多
The increase in wind power penetration has weakened the equivalent inertia of the power system,posing a significant challenge to frequency stability.In this paper,a frequency trajectory planning(FTP)-based frequency r...The increase in wind power penetration has weakened the equivalent inertia of the power system,posing a significant challenge to frequency stability.In this paper,a frequency trajectory planning(FTP)-based frequency regulation(FR)strategy is proposed for permanent magnet synchronous generator-based wind turbines equipped with an energy storage system(ESS)on the DC link.The core idea is that the frequency index provided by the grid code is used to plan a safe frequency trajectory when the system frequency fluctuates.The FR power provided by the ESS is controlled by tracking the planned frequency trajectory to compensate for the unbalanced power in the system,provide inertia support,and ensure the frequency stability of the power grid.The proposed strategy can suppress the frequency fluctuation and optimize the FR power of the ESS.It also effectively circumvents the complex parameter design process of virtual inertia control.The simulation model is established in Matlab/Simulink to verify the effectiveness of the control strategy.展开更多
基金the National Natural Science Foundation of China(31270734)the earmarked fund for China Agricultural Research System(CARS-19)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2014-TRICAAS).
文摘In response to preharvest priming with exogenous methyl jasmonate(MeJA),tea plants adjust their physiological behavior at the molecular level.The whole-organism reconfiguration of aroma formation from the precursor to storage is poorly understood.In this study,we performed iTRAQ proteomic analysis and identified 337,246,and 413 differentially expressed proteins in tea leaves primed with MeJA for 12 h,24h,and 48 h,respectively.Furthermore,a total of 266 nonvolatile and 100 volatile differential metabolites were identified by utilizing MS-based metabolomics.A novel approach that incorporated the integration of extended self-organizing map-based dimensionality was applied.The vivid time-scale changes tracing physiological responses in MeJA-primed tea leaves are marked in these maps.Jasmonates responded quickly to the activation of the jasmonic acid pathway in tea leaves,while hydroxyl and glycosyl jasmonates were biosynthesized simultaneously on a massive scale to compensate for the exhausted defense.The levels ofα-linolenic acid,geranyl diphosphate,farnesyl diphosphate,geranylgeranyl diphosphate,and phenylalanine,which are crucial aroma precursors,were found to be significantly changed in MeJA-primed tea leaves.Green leaf volatiles,volatile terpenoids,and volatile phenylpropanoids/benzenoids were spontaneously biosynthesized from responding precursors and subsequently converted to their corresponding glycosidic forms,which can be stably stored in tea leaves.This study elucidated the physiological response of tea leaves primed with exogenous methyl jasmonate and revealed the molecular basis of source and sink changes on tea aroma biosynthesis and catabolism in response to exogenous stimuli.The results significantly enhance our comprehensive understanding of tea plant responses to exogenous treatment and will lead to the development of promising biotechnologies to improve fresh tea leaf quality.
文摘The increase in wind power penetration has weakened the equivalent inertia of the power system,posing a significant challenge to frequency stability.In this paper,a frequency trajectory planning(FTP)-based frequency regulation(FR)strategy is proposed for permanent magnet synchronous generator-based wind turbines equipped with an energy storage system(ESS)on the DC link.The core idea is that the frequency index provided by the grid code is used to plan a safe frequency trajectory when the system frequency fluctuates.The FR power provided by the ESS is controlled by tracking the planned frequency trajectory to compensate for the unbalanced power in the system,provide inertia support,and ensure the frequency stability of the power grid.The proposed strategy can suppress the frequency fluctuation and optimize the FR power of the ESS.It also effectively circumvents the complex parameter design process of virtual inertia control.The simulation model is established in Matlab/Simulink to verify the effectiveness of the control strategy.
