Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signal...Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology.展开更多
Brassinosteroids （BRs） are a group of naturally-occurring steroidal phytohormones playing fundamental roles during normal plant growth and development. Using a combination of experimental approaches, including analy...Brassinosteroids （BRs） are a group of naturally-occurring steroidal phytohormones playing fundamental roles during normal plant growth and development. Using a combination of experimental approaches, including analytical chemistry, genetics, and biochemistry, the major BR biosynthetic pathway has been largely elucidated. The least-understood knowledge in the BR research field is probably the molecular mechanisms controlling the bioactive levels of BRs in response to various developmental and environmental cues. In this review, we focus our discussion on a recently-proposed, 8-step predominant BR biosynthetic pathway, several newly-identified transcription factors regulating the expression of key enzymes that catalyze BR biosynthesis, and up-to-date information about the mechanisms that plants use to inactivate unnecessary BRs.展开更多
在植物组织培养中 ,对于影响细胞分裂分化的 p H因子 ,人们对其真正的影响未引起足够的重视 .结合文献并通过实验发现 :环境 p H值对胞质 p H值、质膜透性、植物激素作用、生理代谢及培养物的生长和分化都存在不同程度影响 ,是植物组织...在植物组织培养中 ,对于影响细胞分裂分化的 p H因子 ,人们对其真正的影响未引起足够的重视 .结合文献并通过实验发现 :环境 p H值对胞质 p H值、质膜透性、植物激素作用、生理代谢及培养物的生长和分化都存在不同程度影响 ,是植物组织培养中应加以重视的影响因子 .展开更多
Terrestrial plants must cope with drought stress to survive. Under drought stress, plants accumulate the phytohormone abscisic acid （ABA） by increasing its biosynthesis and decreasing its catabolism. However, the re...Terrestrial plants must cope with drought stress to survive. Under drought stress, plants accumulate the phytohormone abscisic acid （ABA） by increasing its biosynthesis and decreasing its catabolism. However, the regulatory pathways controlling ABA catabolism in response to drought remain largely unclear. Here, we report that the flowering repressor SHORT VEGETATIVE PHASE （SVP） is induced by drought stress and associates with the promoter regions of the ABA catabolism pathway genes CYP707A 1, CYP707A3 and AtBG1, causing decreased expression of CYP7OTA 1 and CYP707A3 but enhanced expression ofAtBG1 inArabidopsis leaves. Loss-of-function mutations in CYP707A 1 and CYP707A3 or overexpression of AtBG1 could rescue the drought-hypersensitive phenotype of svp mutant plants by increasing cellular ABA levels. Collectively, our results suggest that SVP is a central regulator of ABA catabolism and that a regulatory pathway involving SVP, CYP707A1/3, and AtBG1 plays a critical role in plant response to water deficit and plant drought resistance.展开更多
With improvements in personnel and vehicular body armor,robust casualty evacuation capabilities,and damage control resuscitation strategies,more combat casualties are surviving to reach higher levels of care throughou...With improvements in personnel and vehicular body armor,robust casualty evacuation capabilities,and damage control resuscitation strategies,more combat casualties are surviving to reach higher levels of care throughout the casualty evacuation system.As such,medical centers are becoming more accustomed to managing the deleterious late consequences of combat trauma related to the dysregulation of the immune system.In this review,we aim to highlight these late consequences and identify areas for future research and therapeutic strategies.Trauma leads to the dysregulation of both the innate and adaptive immune responses,which places the injured at risk for several late consequences,including delayed wound healing,late onset sepsis and infection,multi-organ dysfunction syndrome,and acute respiratory distress syndrome,which are significant for their association with the increased morbidity and mortality of wounded personnel.The mechanisms by which these consequences develop are complex but include an imbalance of the immune system leading to robust inflammatory responses,triggered by the presence of damage associated molecules and other immune-modifying agents following trauma.Treatment strategies to improve outcomes have been difficult to develop as the immunophenotype of injured personnel following trauma is variable,fluid and difficult to determine.As more information regarding the triggers that lead to immune dysfunction following trauma is elucidated,it may be possible to identify the immunophenotype of injured personnel and provide targeted treatments to reduce the late consequences of trauma,which are known to lead to significant morbidity and mortality.展开更多
文摘Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology.
基金supported by grants from the National Natural Science Foundation of China(91117008and90917019)by the Ministry of Science and Technology(2011CB915401)
文摘Brassinosteroids （BRs） are a group of naturally-occurring steroidal phytohormones playing fundamental roles during normal plant growth and development. Using a combination of experimental approaches, including analytical chemistry, genetics, and biochemistry, the major BR biosynthetic pathway has been largely elucidated. The least-understood knowledge in the BR research field is probably the molecular mechanisms controlling the bioactive levels of BRs in response to various developmental and environmental cues. In this review, we focus our discussion on a recently-proposed, 8-step predominant BR biosynthetic pathway, several newly-identified transcription factors regulating the expression of key enzymes that catalyze BR biosynthesis, and up-to-date information about the mechanisms that plants use to inactivate unnecessary BRs.
文摘Terrestrial plants must cope with drought stress to survive. Under drought stress, plants accumulate the phytohormone abscisic acid （ABA） by increasing its biosynthesis and decreasing its catabolism. However, the regulatory pathways controlling ABA catabolism in response to drought remain largely unclear. Here, we report that the flowering repressor SHORT VEGETATIVE PHASE （SVP） is induced by drought stress and associates with the promoter regions of the ABA catabolism pathway genes CYP707A 1, CYP707A3 and AtBG1, causing decreased expression of CYP7OTA 1 and CYP707A3 but enhanced expression ofAtBG1 inArabidopsis leaves. Loss-of-function mutations in CYP707A 1 and CYP707A3 or overexpression of AtBG1 could rescue the drought-hypersensitive phenotype of svp mutant plants by increasing cellular ABA levels. Collectively, our results suggest that SVP is a central regulator of ABA catabolism and that a regulatory pathway involving SVP, CYP707A1/3, and AtBG1 plays a critical role in plant response to water deficit and plant drought resistance.
基金RJS was supported by National Institutes of Health grants,K08-GM117367.
文摘With improvements in personnel and vehicular body armor,robust casualty evacuation capabilities,and damage control resuscitation strategies,more combat casualties are surviving to reach higher levels of care throughout the casualty evacuation system.As such,medical centers are becoming more accustomed to managing the deleterious late consequences of combat trauma related to the dysregulation of the immune system.In this review,we aim to highlight these late consequences and identify areas for future research and therapeutic strategies.Trauma leads to the dysregulation of both the innate and adaptive immune responses,which places the injured at risk for several late consequences,including delayed wound healing,late onset sepsis and infection,multi-organ dysfunction syndrome,and acute respiratory distress syndrome,which are significant for their association with the increased morbidity and mortality of wounded personnel.The mechanisms by which these consequences develop are complex but include an imbalance of the immune system leading to robust inflammatory responses,triggered by the presence of damage associated molecules and other immune-modifying agents following trauma.Treatment strategies to improve outcomes have been difficult to develop as the immunophenotype of injured personnel following trauma is variable,fluid and difficult to determine.As more information regarding the triggers that lead to immune dysfunction following trauma is elucidated,it may be possible to identify the immunophenotype of injured personnel and provide targeted treatments to reduce the late consequences of trauma,which are known to lead to significant morbidity and mortality.
