School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583, USA.
Planta. 2013 Jan;237(1):55-64. doi: 10.1007/s00425-012-1740-9. Epub 2012 Sep 15.
The constitutive and drought-induced activities of the Arabidopsis thaliana RD29A and RD29B promoters were monitored in soybean (Glycine max (L.) Merr.] via fusions with the visual marker gene β-glucuronidase (GUS). Physiological responses of soybean plants were monitored over 9 days of water deprivation under greenhouse conditions. Data were used to select appropriate time points to monitor the activities of the respective promoter elements. Qualitative and quantitative assays for GUS expression were conducted in root and leaf tissues, from plants under well-watered and dry-down conditions. Both RD29A and RD29B promoters were significantly activated in soybean plants subjected to dry-down conditions. However, a low level of constitutive promoter activity was also observed in both root and leaves of plants under well-watered conditions. GUS expression was notably higher in roots than in leaves. These observations suggest that the respective drought-responsive regulatory elements present in the RD29X promoters may be useful in controlling targeted transgenes to mitigate abiotic stress in soybean, provided the transgene under control of these promoters does not invoke agronomic penalties with leaky expression when no abiotic stress is imposed.
通过与可视标记基因β-葡萄糖醛酸酶（GUS）融合，监测拟南芥 RD29A 和 RD29B 启动子在大豆（Glycine max（L.）Merr.）中的组成型和干旱诱导活性。在温室条件下，通过 9 天的水分剥夺监测大豆植株的生理反应。数据用于选择合适的时间点来监测各自启动子元件的活性。在根和叶组织中进行了 GUS 表达的定性和定量测定，来自处于充分供水和干旱条件下的植物。在干旱条件下，RD29A 和 RD29B 启动子在大豆植物中均被显著激活。然而，在充分供水条件下的根和叶中也观察到低水平的组成型启动子活性。GUS 表达在根中明显高于叶中。这些观察结果表明，RD29X 启动子中存在的相应干旱响应调节元件可能有助于控制靶向转基因，以减轻大豆中的非生物胁迫，前提是在没有非生物胁迫的情况下，受这些启动子控制的转基因不会因渗漏表达而带来农艺学上的惩罚。
