Major water absorption region of roots, water flow resistance and their effects on water uptake in soil-root system, the role of plant aquaporins and ABA in water uptake by roots, and the recovery of water absorption ...Major water absorption region of roots, water flow resistance and their effects on water uptake in soil-root system, the role of plant aquaporins and ABA in water uptake by roots, and the recovery of water absorption by roots after rewetting were discussed. Fig 1,Ref展开更多
Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes...Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes from rice. Based on the similarity of the amino acid sequences they encoded, these rice PIP genes were classified into two groups and designated as OsPIP1-1 to OsPIP1-3 and OsPIP2-1 to OsPIP2-7 following the nomenclature of PIP genes in maize. Quantitative RT-PCR analysis identified three root-specific and one leaf-specific OsPIP genes. Furthermore, the expression profile of each OsPIP gene in response to salt, drought and ABA treatment was examined in detail. Analysis on transgenic plants over-expressing of either OsPIP1 （OsPIP1-1） or OsPIP2 （OsPIP2-2） in wild-type Arabidopsis, showed enhanced tolerance to salt （100 mM of NaCl） and drought （200 mM ofmannitol）, but not to salt treatment of higher concentration （150 mM of NaCl）. Taken together, these data suggest a distinct role of each OsPIP gene in response to different stresses, and should add a new layer to the understanding of the physiological function of rice PIP genes.展开更多
Aquaporins are small integral membrane proteins that selectively transport water and some small solutes in mammals, plants and lower organisms. Continued studies of the aquaporins are providing detailed tissue localiz...Aquaporins are small integral membrane proteins that selectively transport water and some small solutes in mammals, plants and lower organisms. Continued studies of the aquaporins are providing detailed tissue localization and the important physiological roles of aquaporins in urinary, respiratory, digestive and nervous systems. Based on the importance of aquaporin studies in the field of structural chemistry in biomembranes, American scientist Peter Agre won the 2003 Chemistry Nobel Prize for the discovery of water channels.展开更多
Background Although some studies have reported that aquaporin-4 （AQP4） plays an important role in the brain edema after traumatic brain injury （TBI）, little is known about the AQP4 expression in the early stage of...Background Although some studies have reported that aquaporin-4 （AQP4） plays an important role in the brain edema after traumatic brain injury （TBI）, little is known about the AQP4 expression in the early stage of TBI, or about the correlation between the structural damage to the blood-brain barrier （BBB） and angioedema. The aim of this project was to investigate the relationship between AQP4 expression and damage to the BBB at early stages of TBI. Methods One hundred and twenty healthy adult Wistar rats were randomly divided into two groups： sham operation group （SO） and TBI group. The TBI group was divided into five sub-groups according to the different time intervals： 1, 3, 6, 12, and 24 hours. The brains of the animals were taken out at different time points after TBI to measure brain water content. The cerebral edema and BBB changes in structure were examined with an optical microscopy （OM） and transmission electron microscopy （TEM）, and the IgG content and AQP4 protein expression in traumatic brain tissue were determined by means of immunohistochemistry and Western blotting. The data were analyzed with SPSS 13.0 statistical software. Results In the SO group, tissue was negative for IgG, and there were no abnormalities in brain water content or AQP4 expression. In the TBI group, brain water content significantly increased at 6 hours and peaked at 24 hours following injury. IgG expression significantly increased from 1 to 6 hours following injury, and remained at a high level at 24 hours. Pathological observation revealed BBB damage at 1 hour following injury. Angioedema appeared at 1 hour, was gradually aggravated, and became obvious at 6 hours. Intracellular edema occurred at 3 hours, with the presence of large glial cell bodies and mitochondrial swelling. These phenomena were aggravated with time and became obvious at 12 hours. In addition, microglial proliferation was visible at 24 hours. AQP4 protein expression were reduced at 1 hour, lowest at 6 hours, and began to increase a展开更多
文摘Major water absorption region of roots, water flow resistance and their effects on water uptake in soil-root system, the role of plant aquaporins and ABA in water uptake by roots, and the recovery of water absorption by roots after rewetting were discussed. Fig 1,Ref
文摘Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes from rice. Based on the similarity of the amino acid sequences they encoded, these rice PIP genes were classified into two groups and designated as OsPIP1-1 to OsPIP1-3 and OsPIP2-1 to OsPIP2-7 following the nomenclature of PIP genes in maize. Quantitative RT-PCR analysis identified three root-specific and one leaf-specific OsPIP genes. Furthermore, the expression profile of each OsPIP gene in response to salt, drought and ABA treatment was examined in detail. Analysis on transgenic plants over-expressing of either OsPIP1 （OsPIP1-1） or OsPIP2 （OsPIP2-2） in wild-type Arabidopsis, showed enhanced tolerance to salt （100 mM of NaCl） and drought （200 mM ofmannitol）, but not to salt treatment of higher concentration （150 mM of NaCl）. Taken together, these data suggest a distinct role of each OsPIP gene in response to different stresses, and should add a new layer to the understanding of the physiological function of rice PIP genes.
文摘Aquaporins are small integral membrane proteins that selectively transport water and some small solutes in mammals, plants and lower organisms. Continued studies of the aquaporins are providing detailed tissue localization and the important physiological roles of aquaporins in urinary, respiratory, digestive and nervous systems. Based on the importance of aquaporin studies in the field of structural chemistry in biomembranes, American scientist Peter Agre won the 2003 Chemistry Nobel Prize for the discovery of water channels.
基金This project was supported by the National Natural Science Foundation of China （No. 81160181） and the International Cooperation Project of Hainan Province （No. Qiongke （2012） 65）.Acknowledgments： We thank XIA Qing-jie from the Department of Molecular Genetics, Institute of Neurological Disease and Translation Neuroscience Center, West China Hospital, Sichuan University, China for help with molecular biology experiments.
文摘Background Although some studies have reported that aquaporin-4 （AQP4） plays an important role in the brain edema after traumatic brain injury （TBI）, little is known about the AQP4 expression in the early stage of TBI, or about the correlation between the structural damage to the blood-brain barrier （BBB） and angioedema. The aim of this project was to investigate the relationship between AQP4 expression and damage to the BBB at early stages of TBI. Methods One hundred and twenty healthy adult Wistar rats were randomly divided into two groups： sham operation group （SO） and TBI group. The TBI group was divided into five sub-groups according to the different time intervals： 1, 3, 6, 12, and 24 hours. The brains of the animals were taken out at different time points after TBI to measure brain water content. The cerebral edema and BBB changes in structure were examined with an optical microscopy （OM） and transmission electron microscopy （TEM）, and the IgG content and AQP4 protein expression in traumatic brain tissue were determined by means of immunohistochemistry and Western blotting. The data were analyzed with SPSS 13.0 statistical software. Results In the SO group, tissue was negative for IgG, and there were no abnormalities in brain water content or AQP4 expression. In the TBI group, brain water content significantly increased at 6 hours and peaked at 24 hours following injury. IgG expression significantly increased from 1 to 6 hours following injury, and remained at a high level at 24 hours. Pathological observation revealed BBB damage at 1 hour following injury. Angioedema appeared at 1 hour, was gradually aggravated, and became obvious at 6 hours. Intracellular edema occurred at 3 hours, with the presence of large glial cell bodies and mitochondrial swelling. These phenomena were aggravated with time and became obvious at 12 hours. In addition, microglial proliferation was visible at 24 hours. AQP4 protein expression were reduced at 1 hour, lowest at 6 hours, and began to increase a
