In order to determine whether hydrogen peroxide （H2O2） generated by polyamlne oxidative degradation Is Involved In the development of lateral roots In soybean, the length and the number of lateral roots, the actlvlt...In order to determine whether hydrogen peroxide （H2O2） generated by polyamlne oxidative degradation Is Involved In the development of lateral roots In soybean, the length and the number of lateral roots, the actlvltlea of polyamlne oxldases and dlamlne oxldases, and the endogenous free polyamlne and H2O2 content were analyzed In soybean （Giycine max （Linn.） Merr.） main roots of 2-d-old seedlings after treatments for 2 d with exogenous β-hydroxyethylhydrazine （an Inhibitor of polyamlne oxldases）, H202, putresclne, cyclohexylamlne （an Inhibitor of spermidine synthase） or N,N＇-dimethylthlourea （a scavenger of hydrogen peroxide）.β-hydroxyethylhydrazlne treatment strongly Inhibited the development of lateral roots In soybean seedlings, reduced the activities of polyamine oxldases and dlamlne oxidases, decreased H2O2 levels, and led to the accumulation of endogenous polyamlnes In the main roots. The inhibitory effect of β-hydroxyethylhydrazlne on root development could be alleviated by exogenously applied 10 μmol/L H2O2 （a major product of polyamlne oxidation）. Treatment with cyclohexylamlne and putresclne promoted root growth slightly, but treatment with cyclohexylamlne plus N,N＇dlmethylthlourea or putresclne plus N,N＇-dlmethylthlourea prevented the development of soybean lateral roots. The effects of these treatments on the development of soybean lateral roots were consistent with the changes In endogenous H2O2 levels. These results suggest that the development of soybean lateral roots Is associated with the oxidative degradation of polyamlnes, and that their products, especially H2O2, are likely to play an Important role In the growth of soybean lateral roots.展开更多
Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of rea...Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species （ROS） that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD （P） H for sperm capacitation. Peroxiredoxins （PRDXs） are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.展开更多
In rice, the Ca^(2+)/calmodulin-dependent protein kinase OsDMI3 is an important positive regulator of abscisic acid (ABA) signaling. In ABA signaling, H_(2)O_(2) is required for ABA-induced activation of OsDMI3, which...In rice, the Ca^(2+)/calmodulin-dependent protein kinase OsDMI3 is an important positive regulator of abscisic acid (ABA) signaling. In ABA signaling, H_(2)O_(2) is required for ABA-induced activation of OsDMI3, which in turn increase H_(2)O_(2) production. However, how OsDMI3 regulates H_(2)O_(2) production in ABA signaling remains unknown. Here we show that OsRbohB is the main NADPH oxidase involved in ABA-induced H_(2)O_(2) production and ABA-mediated physiological responses. OsDMI3 directly interacts with and phosphorylates OsRbohB at Ser-191, which is OsDMI3-mediated site-specific phosphorylation in ABA signaling. Further analyses revealed that OsDMI3-mediated OsRbohB Ser-191 phosphorylation positively regulates the activity of NADPH oxidase and the production of H_(2)O_(2) in ABA signaling, thereby enhancing the sensitivity of seed germination and root growth to ABA and plant tolerance to water stress and oxidative stress. Moreover, we discovered that the OsDMI3-mediated OsRbohB phosphorylation and H_(2)O_(2) production is dependent on the sucrose non-fermenting 1-related protein kinases SAPK8/9/10, which phosphorylate OsRbohB at Ser-140 in ABA signaling. Taken together, these results not only reveal an important regulatory mechanism that directly activates Rboh for ABA-induced H_(2)O_(2) production but also uncover the importance of this regulatory mechanism in ABA signaling.展开更多
基金the Scientific Research Foundation Especially for Doctoral Programs at Chinese Universities （20020307004） and the National Natural Science Foundation of China （30370850 and 30400280）.
文摘In order to determine whether hydrogen peroxide （H2O2） generated by polyamlne oxidative degradation Is Involved In the development of lateral roots In soybean, the length and the number of lateral roots, the actlvltlea of polyamlne oxldases and dlamlne oxldases, and the endogenous free polyamlne and H2O2 content were analyzed In soybean （Giycine max （Linn.） Merr.） main roots of 2-d-old seedlings after treatments for 2 d with exogenous β-hydroxyethylhydrazine （an Inhibitor of polyamlne oxldases）, H202, putresclne, cyclohexylamlne （an Inhibitor of spermidine synthase） or N,N＇-dimethylthlourea （a scavenger of hydrogen peroxide）.β-hydroxyethylhydrazlne treatment strongly Inhibited the development of lateral roots In soybean seedlings, reduced the activities of polyamine oxldases and dlamlne oxidases, decreased H2O2 levels, and led to the accumulation of endogenous polyamlnes In the main roots. The inhibitory effect of β-hydroxyethylhydrazlne on root development could be alleviated by exogenously applied 10 μmol/L H2O2 （a major product of polyamlne oxidation）. Treatment with cyclohexylamlne and putresclne promoted root growth slightly, but treatment with cyclohexylamlne plus N,N＇dlmethylthlourea or putresclne plus N,N＇-dlmethylthlourea prevented the development of soybean lateral roots. The effects of these treatments on the development of soybean lateral roots were consistent with the changes In endogenous H2O2 levels. These results suggest that the development of soybean lateral roots Is associated with the oxidative degradation of polyamlnes, and that their products, especially H2O2, are likely to play an Important role In the growth of soybean lateral roots.
文摘Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species （ROS） that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD （P） H for sperm capacitation. Peroxiredoxins （PRDXs） are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.
基金supported by the National Natural Science Foundation of China(31971824 and 32170316).
文摘In rice, the Ca^(2+)/calmodulin-dependent protein kinase OsDMI3 is an important positive regulator of abscisic acid (ABA) signaling. In ABA signaling, H_(2)O_(2) is required for ABA-induced activation of OsDMI3, which in turn increase H_(2)O_(2) production. However, how OsDMI3 regulates H_(2)O_(2) production in ABA signaling remains unknown. Here we show that OsRbohB is the main NADPH oxidase involved in ABA-induced H_(2)O_(2) production and ABA-mediated physiological responses. OsDMI3 directly interacts with and phosphorylates OsRbohB at Ser-191, which is OsDMI3-mediated site-specific phosphorylation in ABA signaling. Further analyses revealed that OsDMI3-mediated OsRbohB Ser-191 phosphorylation positively regulates the activity of NADPH oxidase and the production of H_(2)O_(2) in ABA signaling, thereby enhancing the sensitivity of seed germination and root growth to ABA and plant tolerance to water stress and oxidative stress. Moreover, we discovered that the OsDMI3-mediated OsRbohB phosphorylation and H_(2)O_(2) production is dependent on the sucrose non-fermenting 1-related protein kinases SAPK8/9/10, which phosphorylate OsRbohB at Ser-140 in ABA signaling. Taken together, these results not only reveal an important regulatory mechanism that directly activates Rboh for ABA-induced H_(2)O_(2) production but also uncover the importance of this regulatory mechanism in ABA signaling.
