Garcia A. B., Engler JdA., Iyer S., Gerats T., Van Montagu M., Caplan A. B.
Laboratorium voor Genetica, Departement Genetica, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium (A.B.G., J.d.A.E., T.G., M.V.M., A.B.C.).
Plant Physiol. 1997 Sep;115(1):159-169. doi: 10.1104/pp.115.1.159.
Plants accumulate a number of osmoprotective substances in response to NaCl stress, one of them being proline (Pro). While characterizing some of the changes in solute accumulation in NaCl-stressed rice (Oryza sativa L.), we identified several other potential osmoprotectants. One such substance, trehalose, begins to accumulate in small amounts in roots after 3 d. We performed a series of experiments to compare the effects of Pro and trehalose on ion accumulation to determine whether the two chemicals protect the same physiological processes. We found that Pro either has no effect or, in some cases, exasperates the effect of NaCl on growth inhibition, chlorophyll loss, and induction of a highly sensitive marker for plant stress, the osmotically regulated salT gene. By contrast, low to moderate concentrations of trehalose reduce Na+ accumulation, salT expression, and growth inhibition. Somewhat higher concentrations (10 mM) prevent NaCl-induced loss of chlorophyll in blades, preserve root integrity, and enhance growth. The results of this study indicate that during osmotic stress trehalose or carbohydrates might be more important for rice than Pro.
植物会积累多种渗透保护物质以应对氯化钠胁迫，其中之一是脯氨酸（Pro）。在研究氯化钠胁迫下水稻（Oryza sativa L.）溶质积累的一些变化时，我们鉴定出了其他几种潜在的渗透保护剂。其中一种物质海藻糖，在3天后开始在根部少量积累。我们进行了一系列实验来比较脯氨酸和海藻糖对离子积累的影响，以确定这两种化学物质是否保护相同的生理过程。我们发现脯氨酸要么没有效果，要么在某些情况下会加剧氯化钠对生长抑制、叶绿素损失以及植物胁迫高度敏感标记物——渗透调节的salT基因诱导的影响。相比之下，低至中等浓度的海藻糖可减少钠离子积累、salT表达以及生长抑制。稍高浓度（10 mM）可防止氯化钠诱导的叶片叶绿素损失，保持根系完整性，并促进生长。这项研究的结果表明，在渗透胁迫期间，海藻糖或碳水化合物对水稻可能比脯氨酸更重要。
