Over the last few years, it has become evident that reactive oxygen species （ROS） signalling plays an important role in various physiological responses, including pathogen defense and stomatal opening/closure. On th...Over the last few years, it has become evident that reactive oxygen species （ROS） signalling plays an important role in various physiological responses, including pathogen defense and stomatal opening/closure. On the other hand, ROS overproduction is detrimental for proper plant growth and development, indicating that the regulation of an appropriate redox balance is essential for plants. ROS homeostasis in plants involves the mitogen-activated protein kinase （MAPK） pathway consisting of the MAPK kinase kinase MEKK1 and the MAPK MPK4. Phenotypic and molecular analysis revealed that the MAPK kinases MKK1 and MKK2 are part of a cascade, regulating ROS and salicylic acid （SA） accumulation. Gene expression analysis shows that of 32 transcription factors reported to be highly responsive to multiple ROS-inducing conditions, 20 are regulated by the MEKK1, predominantly via the MEKK1-MKK1/2-MPK4 pathway. However, MEKK1 also functions on other as yet unknown pathways and part of the MEKK1-dependent MPK4 responses are regulated independently of MKK1 and MKK2. Overall, this analysis emphasizes the central role of this MAPK cascade in oxidative stress signalling, but also indicates the high level of complexity revealed by this signalling network.展开更多
钙是植物必需的大量元素之一,同时钙离子(Ca^(2+))是细胞信号转导的第二信使。钙依赖蛋白激酶(calcium-dependent protein kinase,CDPK)作为Ca^(2+)的感受器普遍存在于植物和部分原生动物中,是植物特有的一类丝氨酸/苏氨酸型蛋白激酶,...钙是植物必需的大量元素之一,同时钙离子(Ca^(2+))是细胞信号转导的第二信使。钙依赖蛋白激酶(calcium-dependent protein kinase,CDPK)作为Ca^(2+)的感受器普遍存在于植物和部分原生动物中,是植物特有的一类丝氨酸/苏氨酸型蛋白激酶,参与了多种Ca^(2+)介导的信号通路,在植物发育信号和逆境信号转导中具有重要作用。本文概述了钙依赖蛋白激酶在植物体内的分布、结构、底物、功能以及大豆CDPK的研究进展,旨在为今后培育抗逆植物品种提供参考依据。展开更多
应力测试仪广泛应用于移动车辆、大型工程机械等工程装备领域。目前采用有线的方式进行应力测试时,易产生接线复杂、电线断裂、移动测试困难等情况,文章设计了基于无线传输的应力测试仪总体框架,包括信号采集装置和信号接收装置,两个装...应力测试仪广泛应用于移动车辆、大型工程机械等工程装备领域。目前采用有线的方式进行应力测试时,易产生接线复杂、电线断裂、移动测试困难等情况,文章设计了基于无线传输的应力测试仪总体框架,包括信号采集装置和信号接收装置,两个装置之间通过ZigBee进行无线通信。推导了应变片电压信号转化方程,然后设计了供电电源管理模块、信号放大模块、ZigBee无线传输模块电路等关键电路,并采用Arduino UNO R3单片机设计了相应程序,最后,对应力测试仪的结构进行了三维设计和样机加工,并进行了初步测试,验证了设计方案的可行性。展开更多
For many plant species ozone stress has become much more severe in the last decade. The accumulating evidence for the significant effects of ozone pollutant on crop and forest yield situate ozone as one of the most im...For many plant species ozone stress has become much more severe in the last decade. The accumulating evidence for the significant effects of ozone pollutant on crop and forest yield situate ozone as one of the most important environmental stress factors that limits plant productivity worldwide. Today, transcriptomic approaches seem to give the best coverage of genome level responses. Therefore, microarray serves as an invaluable tool for global gene expression analyses, unravelling new information about gene pathways, in-species and cross-species gene expression comparison, and for the characterization of unknown relationships between genes. In this review we summarize the recent progress in the transcriptomics of ozone to demonstrate the benefits that can be harvested from the application of integrative and systematic analytical approaches to study ozone stress response. We focused our consideration on microarray analyses identifying gene networks responsible for response and tolerance to elevated ozone concentration. From these analyses it is now possible to notice how plant ozone defense responses depend on the interplay between many complex signaling pathways and metabolite signals.展开更多
Drought is a major abiotic stress that causes the yearly yield loss of maize, a crop cultured worldwide. Breeding drought-tolerant maize cultivars is a priority requirement of world agriculture. Clade A PP2C phosphata...Drought is a major abiotic stress that causes the yearly yield loss of maize, a crop cultured worldwide. Breeding drought-tolerant maize cultivars is a priority requirement of world agriculture. Clade A PP2C phosphatases （PP2C-A）, which are conserved in most plant species, play important roles in abscisic acid （ABA） signaling and plant drought response. However, natural variations of PP2C-A genes that are directly associated with drought tolerance remain to be elucidated. Here, we conducted a candidate gene association analysis of the ZmPP2C-A gene family in a maize panel consisting of 368 varieties collected worldwide, and identified a drought responsive gene ZmPP2C-AIO that is tightly associated with drought tolerance. We found that the degree of drought tolerance of maize cultivars negatively corre- lates with the expression levels of ZmPP2C-AIO. ZmPP2C-A10, like its Arabidopsis orthologs, interacts with ZmPYL ABA receptors and ZmSnRK2 kinases, suggesting that ZmPP2C-A10 is involved in mediating ABA signaling in maize. Transgenic studies in maize and Arabidopsis confirmed that ZmPP2C-A10 functions as a negative regulator of drought tolerance. Further, a causal natural variation, deletion allele-338, which bears a deletion of ERSE （endoplasmic reticulum stress response element） in the 51-UTR region of ZmPP2C-AIO, was detected. This deletion causes the loss of endoplasmic reticulum （ER） stress-induced expression of ZmPP2C-AIO, leading to increased plant drought tolerance. Our study provides direct evidence linking ER stress signaling with drought tolerance and genetic resources that can be used directly in breeding drought-tolerant maize cultivars.展开更多
Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss...Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss through transpiration. How to reduce water loss and maintain enough CO2 absorption has been an interesting research topic for some time. Simple stomatal opening may elevate CO2 absorption, but, in the meantime, promote the water loss, whereas simple closing of stomatal pores may reduce both water loss and CO2 absorption, resulting in impairment of plant photosynthesis. Both processes are not economical to the plant. As a special rhythmic stomatal movement that usually occurs at smaller stomatal apertures, stomatal oscillation can keep CO2 absorption at a sufficient level and reduce water loss at the same time, suggesting a potential improvement in water use efficiency. Stomatal oscillation is usually found after a sudden change in one environmental factor in relatively constant environments. Many environmental stimuli can induce stomatal oscillation. It appears that, at the physiological level, feedback controls are involved in stomatal oscillation. At the cellular level, possibly two different patterns exist： （i） a quicker responsive pattern; and （ii） a slower response. Both involve water potential changes and water channel regulation, but the mechanisms of regulation of the two patterns are different. Some evidence suggests that the regulation of water channels may play a vital and primary role in stomatal oscillation. The present review summarizes studies on stomatal oscillation and concludes with some discussion regarding the mechanisms of regulation of stomatal oscillation.展开更多
文摘Over the last few years, it has become evident that reactive oxygen species （ROS） signalling plays an important role in various physiological responses, including pathogen defense and stomatal opening/closure. On the other hand, ROS overproduction is detrimental for proper plant growth and development, indicating that the regulation of an appropriate redox balance is essential for plants. ROS homeostasis in plants involves the mitogen-activated protein kinase （MAPK） pathway consisting of the MAPK kinase kinase MEKK1 and the MAPK MPK4. Phenotypic and molecular analysis revealed that the MAPK kinases MKK1 and MKK2 are part of a cascade, regulating ROS and salicylic acid （SA） accumulation. Gene expression analysis shows that of 32 transcription factors reported to be highly responsive to multiple ROS-inducing conditions, 20 are regulated by the MEKK1, predominantly via the MEKK1-MKK1/2-MPK4 pathway. However, MEKK1 also functions on other as yet unknown pathways and part of the MEKK1-dependent MPK4 responses are regulated independently of MKK1 and MKK2. Overall, this analysis emphasizes the central role of this MAPK cascade in oxidative stress signalling, but also indicates the high level of complexity revealed by this signalling network.
文摘钙是植物必需的大量元素之一,同时钙离子(Ca^(2+))是细胞信号转导的第二信使。钙依赖蛋白激酶(calcium-dependent protein kinase,CDPK)作为Ca^(2+)的感受器普遍存在于植物和部分原生动物中,是植物特有的一类丝氨酸/苏氨酸型蛋白激酶,参与了多种Ca^(2+)介导的信号通路,在植物发育信号和逆境信号转导中具有重要作用。本文概述了钙依赖蛋白激酶在植物体内的分布、结构、底物、功能以及大豆CDPK的研究进展,旨在为今后培育抗逆植物品种提供参考依据。
文摘应力测试仪广泛应用于移动车辆、大型工程机械等工程装备领域。目前采用有线的方式进行应力测试时,易产生接线复杂、电线断裂、移动测试困难等情况,文章设计了基于无线传输的应力测试仪总体框架,包括信号采集装置和信号接收装置,两个装置之间通过ZigBee进行无线通信。推导了应变片电压信号转化方程,然后设计了供电电源管理模块、信号放大模块、ZigBee无线传输模块电路等关键电路,并采用Arduino UNO R3单片机设计了相应程序,最后,对应力测试仪的结构进行了三维设计和样机加工,并进行了初步测试,验证了设计方案的可行性。
文摘For many plant species ozone stress has become much more severe in the last decade. The accumulating evidence for the significant effects of ozone pollutant on crop and forest yield situate ozone as one of the most important environmental stress factors that limits plant productivity worldwide. Today, transcriptomic approaches seem to give the best coverage of genome level responses. Therefore, microarray serves as an invaluable tool for global gene expression analyses, unravelling new information about gene pathways, in-species and cross-species gene expression comparison, and for the characterization of unknown relationships between genes. In this review we summarize the recent progress in the transcriptomics of ozone to demonstrate the benefits that can be harvested from the application of integrative and systematic analytical approaches to study ozone stress response. We focused our consideration on microarray analyses identifying gene networks responsible for response and tolerance to elevated ozone concentration. From these analyses it is now possible to notice how plant ozone defense responses depend on the interplay between many complex signaling pathways and metabolite signals.
文摘Drought is a major abiotic stress that causes the yearly yield loss of maize, a crop cultured worldwide. Breeding drought-tolerant maize cultivars is a priority requirement of world agriculture. Clade A PP2C phosphatases （PP2C-A）, which are conserved in most plant species, play important roles in abscisic acid （ABA） signaling and plant drought response. However, natural variations of PP2C-A genes that are directly associated with drought tolerance remain to be elucidated. Here, we conducted a candidate gene association analysis of the ZmPP2C-A gene family in a maize panel consisting of 368 varieties collected worldwide, and identified a drought responsive gene ZmPP2C-AIO that is tightly associated with drought tolerance. We found that the degree of drought tolerance of maize cultivars negatively corre- lates with the expression levels of ZmPP2C-AIO. ZmPP2C-A10, like its Arabidopsis orthologs, interacts with ZmPYL ABA receptors and ZmSnRK2 kinases, suggesting that ZmPP2C-A10 is involved in mediating ABA signaling in maize. Transgenic studies in maize and Arabidopsis confirmed that ZmPP2C-A10 functions as a negative regulator of drought tolerance. Further, a causal natural variation, deletion allele-338, which bears a deletion of ERSE （endoplasmic reticulum stress response element） in the 51-UTR region of ZmPP2C-AIO, was detected. This deletion causes the loss of endoplasmic reticulum （ER） stress-induced expression of ZmPP2C-AIO, leading to increased plant drought tolerance. Our study provides direct evidence linking ER stress signaling with drought tolerance and genetic resources that can be used directly in breeding drought-tolerant maize cultivars.
文摘Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss through transpiration. How to reduce water loss and maintain enough CO2 absorption has been an interesting research topic for some time. Simple stomatal opening may elevate CO2 absorption, but, in the meantime, promote the water loss, whereas simple closing of stomatal pores may reduce both water loss and CO2 absorption, resulting in impairment of plant photosynthesis. Both processes are not economical to the plant. As a special rhythmic stomatal movement that usually occurs at smaller stomatal apertures, stomatal oscillation can keep CO2 absorption at a sufficient level and reduce water loss at the same time, suggesting a potential improvement in water use efficiency. Stomatal oscillation is usually found after a sudden change in one environmental factor in relatively constant environments. Many environmental stimuli can induce stomatal oscillation. It appears that, at the physiological level, feedback controls are involved in stomatal oscillation. At the cellular level, possibly two different patterns exist： （i） a quicker responsive pattern; and （ii） a slower response. Both involve water potential changes and water channel regulation, but the mechanisms of regulation of the two patterns are different. Some evidence suggests that the regulation of water channels may play a vital and primary role in stomatal oscillation. The present review summarizes studies on stomatal oscillation and concludes with some discussion regarding the mechanisms of regulation of stomatal oscillation.
