Rapid and tissue-specific changes in ABA and in growth rate in response to salinity in barley leaves
Rapid and tissue-specific changes in ABA and in growth rate in response to salinity in barley leaves
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DOI：
10.1093/jxb/erh117
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发表时间：
2004-05-01
影响因子：
6.9
通讯作者：
Kudoyarova, G
中科院分区：
文献类型：
--
作者：
Fricke, W;Akhiyarova, G;Kudoyarova, G
向大麦植物的根培养基中加入100 mM NaCl导致生长中的第三叶迅速停止伸长，随后在接下来的一小时内突然恢复生长。的想法，恢复生长之前，并介导的快速和组织特异性的变化，阿坝浓度和蒸腾作用的变化进行了测试。叶片伸长速度连续记录使用线性可变位移传感器（LVDT），阿坝测定免疫测定，蒸腾和气孔导度测定重量法和孔隙度，分别。在10分钟内加入盐，阿坝增加6倍，在叶伸长区的远端部分，在近端部分，阿坝积累延迟。在生长叶片的一部分，出现阿坝增加了3倍，并保持在随后的20分钟内升高。这之前的蒸腾作用和气孔导度，这反过来，正好与生长恢复下降。盐胁迫20小时后，阿坝浓度恢复到胁迫前的水平。叶片伸长速率仍呈下降趋势。它的结论是，NaCl导致阿坝的快速增加，在蒸腾部分的生长叶片。这导致蒸腾作用的减少。因此，木质部水势预计将上升。当木质部和生长区外围细胞之间的水势梯度有利于后者再次吸水时，叶伸长恢复。结果表明，阿坝在不同的叶区引起不同的反应，都旨在促进叶片生长的恢复。
The addition of 100 mM NaCl to the root medium of barley plants caused the rapid cessation of elongation of the growing leaf three, followed by a sudden resumption of growth during the following hour. The idea that resumption of growth is preceded and mediated by rapid and tissue-specific changes in ABA concentration and by changes in transpiration was tested. Leaf elongation velocity was recorded continuously using linear variable displacement transducers (LVDT), ABA was determined by immunoassay, and transpiration and stomatal conductivity were measured gravimetrically and by porometry, respectively. Within 10 min following addition of salt, ABA increased 6-fold in the distal portion of the leaf elongation zone; in the proximal portion, ABA accumulated with a delay. In the portion of the growing blade that had emerged ABA increased 3-fold and remained elevated during the following 20 min. This preceded a decrease in transpiration and stomatal conductivity, which, in turn, coincided with growth resumption. Twenty hours following the addition of salt, the ABA concentrations had returned to the level before stress. Leaf elongation velocity was still reduced. It is concluded that NaCl causes a rapid increase in ABA in the transpiring portion of the growing leaf. This leads to a decrease in transpiration. As a result, xylem water potential is expected to rise. The moment that the water potential gradient between the xylem and the peripheral cells in the growth zone favours water uptake again into the latter, leaf elongation resumes. The results suggest that ABA causes different responses in different leaf regions, all aimed at promoting the resumption of leaf growth.