Split-root solution culture was used to study the promoting effect of lanthanum on rice (Oryza sativa) growth and its physiological mechanisms. Results sho w that low concentration (0.05～1.5 mg·L -1) increases...Split-root solution culture was used to study the promoting effect of lanthanum on rice (Oryza sativa) growth and its physiological mechanisms. Results sho w that low concentration (0.05～1.5 mg·L -1) increases rice yield an d grain numbers. High concentration depresses grain formation (9～30 mg·L -1 ) and root elongation (1.5～30 mg·L -1). No significant influence on str aw dry weight was found over the whole concentration range except the 0.05 mg·L -1 treatment. With the increase of La concentration from 0.05 to 0.75 mg· L -1, catalase (CAT) activity in the first fully expandeing leaves and root s decreases. When La concentration is greater than 0.75 mg·L -1 or less than 9 mg·L -1, it significantly decreases superoxide dismutase activity ( SOD) in the leaves and roots. No significant effects were found on chlorophyll, protein and malondialdehyde (MDA) content. Possible mechanisms of La′s promotin g effect on rice growth and reduction effect of ·O- 2 were discussed.展开更多
Split-root system（SRS） approaches allow the differential treatment of separate and independent root systems, while sharing a common aerial part. As such, SRS is a useful tool for the discrimination of systemic（shoo...Split-root system（SRS） approaches allow the differential treatment of separate and independent root systems, while sharing a common aerial part. As such, SRS is a useful tool for the discrimination of systemic（shoot origin）versus local（root/nodule origin） regulation mechanisms. This type of approach is particularly useful when studying the complex regulatory mechanisms governing the symbiosis established between legumes and Rhizobium bacteria. The current work provides an overview of the main insights gained from the application of SRS approaches to understand how nodule number（nodulation autoregulation） and nitrogen fixation are controlled both under non-stressful conditions and in response to a variety of stresses. Nodule number appears to be mainly controlled at the systemic level through a signal which is produced by nodule/root tissue, translocated to the shoot, and transmitted back to the root system, involving shoot Leu-rich repeat receptor-like kinases. In contrast, both local and systemic mechanisms have been shown to operate for the regulation of nitrogenase activity in nodules. Under drought and heavy metal stress, the regulation is mostly local,whereas the application of exogenous nitrogen seems to exert a regulation of nitrogen fixation both at the local and systemic levels.展开更多
[目的]在三维模型确定与镜下观测一致的骨性标志点,测量辅助单孔分体内镜准确定位并安全减压L_(4)出口神经根的参数。[方法]构建34例L_(4/5)单侧极外侧腰椎间盘突出症患者腰椎CT三维模型,以横突根部下缘与峡部外侧缘的交点(intersection...[目的]在三维模型确定与镜下观测一致的骨性标志点,测量辅助单孔分体内镜准确定位并安全减压L_(4)出口神经根的参数。[方法]构建34例L_(4/5)单侧极外侧腰椎间盘突出症患者腰椎CT三维模型,以横突根部下缘与峡部外侧缘的交点(intersection of the lower margin of the transverse process root with the lateral margin of the isthmus,ITPI)为骨性标志点,分别在ITPI所在的矢状面测量相关指标,并进行男女间、健侧与患侧的比较。[结果]L_(4)出口神经根下缘投影于L_(4/5)椎间隙之上,健侧占比(4/34,11.8%)小于患侧占比(18/34,52.9%),投影于L_(4/5)椎间隙之内,健侧占比(30/34,88.2%)大于患侧占比(12/34,35.3%)。分别测量ITPI至L_(4)出口神经根上缘的垂直距离、L_(4)出口神经根下缘的垂直距离、L_(4)出口神经根后缘的前后水平距离、L_(4)下终板的垂直距离、L_(5)上终板的垂直距离、L_(4)椎弓根下缘的垂直距离;ITPI分别至L_(4)下终板最外侧缘的左右水平距离以及其所在矢状面上L_(4)出口神经根上缘的垂直距离、L_(4)出口神经根下缘的垂直距离、L_(4)下终板的垂直距离、L_(5)上终板的垂直距离;ITPI分别至L_(4)椎弓根内侧壁的左右水平距离、硬脊膜外侧缘的左右水平距离,以上指标男女间、健患侧之间差异均无统计学意义(P>0.05)。各测量指标与年龄、BMI均无显著相关性(P>0.05)。[结论]以L_(4)横突根部下缘与峡部外侧缘交点作为骨性标志点,无需向上探查,只需向外、向下磨除部分骨质即可显露并安全减压L_(4)出口神经根。展开更多
文摘Split-root solution culture was used to study the promoting effect of lanthanum on rice (Oryza sativa) growth and its physiological mechanisms. Results sho w that low concentration (0.05～1.5 mg·L -1) increases rice yield an d grain numbers. High concentration depresses grain formation (9～30 mg·L -1 ) and root elongation (1.5～30 mg·L -1). No significant influence on str aw dry weight was found over the whole concentration range except the 0.05 mg·L -1 treatment. With the increase of La concentration from 0.05 to 0.75 mg· L -1, catalase (CAT) activity in the first fully expandeing leaves and root s decreases. When La concentration is greater than 0.75 mg·L -1 or less than 9 mg·L -1, it significantly decreases superoxide dismutase activity ( SOD) in the leaves and roots. No significant effects were found on chlorophyll, protein and malondialdehyde (MDA) content. Possible mechanisms of La′s promotin g effect on rice growth and reduction effect of ·O- 2 were discussed.
基金partially funded by the Spanish National Research and Development Program (AGL2011-30386-CO2-1 and AGL2011-23738)
文摘Split-root system（SRS） approaches allow the differential treatment of separate and independent root systems, while sharing a common aerial part. As such, SRS is a useful tool for the discrimination of systemic（shoot origin）versus local（root/nodule origin） regulation mechanisms. This type of approach is particularly useful when studying the complex regulatory mechanisms governing the symbiosis established between legumes and Rhizobium bacteria. The current work provides an overview of the main insights gained from the application of SRS approaches to understand how nodule number（nodulation autoregulation） and nitrogen fixation are controlled both under non-stressful conditions and in response to a variety of stresses. Nodule number appears to be mainly controlled at the systemic level through a signal which is produced by nodule/root tissue, translocated to the shoot, and transmitted back to the root system, involving shoot Leu-rich repeat receptor-like kinases. In contrast, both local and systemic mechanisms have been shown to operate for the regulation of nitrogenase activity in nodules. Under drought and heavy metal stress, the regulation is mostly local,whereas the application of exogenous nitrogen seems to exert a regulation of nitrogen fixation both at the local and systemic levels.
文摘[目的]在三维模型确定与镜下观测一致的骨性标志点,测量辅助单孔分体内镜准确定位并安全减压L_(4)出口神经根的参数。[方法]构建34例L_(4/5)单侧极外侧腰椎间盘突出症患者腰椎CT三维模型,以横突根部下缘与峡部外侧缘的交点(intersection of the lower margin of the transverse process root with the lateral margin of the isthmus,ITPI)为骨性标志点,分别在ITPI所在的矢状面测量相关指标,并进行男女间、健侧与患侧的比较。[结果]L_(4)出口神经根下缘投影于L_(4/5)椎间隙之上,健侧占比(4/34,11.8%)小于患侧占比(18/34,52.9%),投影于L_(4/5)椎间隙之内,健侧占比(30/34,88.2%)大于患侧占比(12/34,35.3%)。分别测量ITPI至L_(4)出口神经根上缘的垂直距离、L_(4)出口神经根下缘的垂直距离、L_(4)出口神经根后缘的前后水平距离、L_(4)下终板的垂直距离、L_(5)上终板的垂直距离、L_(4)椎弓根下缘的垂直距离;ITPI分别至L_(4)下终板最外侧缘的左右水平距离以及其所在矢状面上L_(4)出口神经根上缘的垂直距离、L_(4)出口神经根下缘的垂直距离、L_(4)下终板的垂直距离、L_(5)上终板的垂直距离;ITPI分别至L_(4)椎弓根内侧壁的左右水平距离、硬脊膜外侧缘的左右水平距离,以上指标男女间、健患侧之间差异均无统计学意义(P>0.05)。各测量指标与年龄、BMI均无显著相关性(P>0.05)。[结论]以L_(4)横突根部下缘与峡部外侧缘交点作为骨性标志点,无需向上探查,只需向外、向下磨除部分骨质即可显露并安全减压L_(4)出口神经根。
