Root growth maintenance during water deficits: physiology to functional genomics
Root growth maintenance during water deficits: physiology to functional genomics
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缺水时的根系生长维持：从生理学到功能基因组学
DOI：
10.1093/jxb/erh276
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发表时间：
2004-11-01
影响因子：
6.9
通讯作者：
Nguyen, HT
中科院分区：
文献类型：
--
作者：
Sharp, RE;Poroyko, V;Nguyen, HT
综述了水分亏缺条件下玉米初生根生长维持的机理网络的研究进展。这些包括生长区尺寸的调整，通过渗透调节维持膨压，以及增强细胞壁松弛。激素脱落酸（阿坝）在维持水分亏缺下的根生长的作用也得到了解决。该研究利用了运动学分析，即表征根生长区内细胞扩张的空间和时间模式。这种方法揭示了不同的生长反应，水分亏缺和阿坝缺乏在不同地区的根尖。在顶端3 mm区域中，在严重水分亏缺下，伸长保持在良好的浇水速率下，尽管仅在ABA充足的根中，而距离顶端3-7 mm的区域在良好浇水的根中表现出最大伸长，但在水分亏缺下根的伸长逐渐受到抑制。这些知识极大地促进了参与调节反应的机制的发现。该系统的空间分辨率和迄今为止获得的生理学知识为功能基因组学研究提供了独特而强大的基础。表征水分亏缺诱导的玉米主根生长区内的转录本群体和细胞壁蛋白质谱的变化正在进行中。EST和unigene分析的初步结果，以及浇水和水胁迫的根的提示突出的动力学方法的转录谱的强度。
Progress in understanding the network of mechanisms involved in maize primary root growth maintenance under water deficits is reviewed. These include the adjustment of growth zone dimensions, turgor maintenance by osmotic adjustment, and enhanced cell wall loosening. The role of the hormone abscisic acid (ABA) in maintaining root growth under water deficits is also addressed. The research has taken advantage of kinematic analysis, i.e. characterization of spatial and temporal patterns of cell expansion within the root growth zone. This approach revealed different growth responses to water deficits and ABA deficiency in distinct regions of the root tip. In the apical 3 mm region, elongation is maintained at well-watered rates under severe water deficit, although only in ABA-sufficient roots, whereas the region from 3-7 mm from the apex exhibits maximum elongation in well-watered roots, but progressive inhibition of elongation in roots under water deficit. This knowledge has greatly facilitated discovery of the mechanisms involved in regulating the responses. The spatial resolution with which this system has been characterized and the physiological knowledge gained to date provide a unique and powerful underpinning for functional genomics studies. Characterization of water deficit-induced changes in transcript populations and cell wall protein profiles within the growth zone of the maize primary root is in progress. Initial results from EST and unigene analyses in the tips of well-watered and water-stressed roots highlight the strength of the kinematic approach to transcript profiling.