Plant Ecophysiology, Institute for Environmental Biology, Utrecht University 3584CH, Utrecht, The Netherlands.
Plant Physiol. 2013 Nov;163(3):1277-92. doi: 10.1104/pp.113.222588. Epub 2013 Sep 27.
Complete submergence represses photosynthesis and aerobic respiration, causing rapid mortality in most terrestrial plants. However, some plants have evolved traits allowing them to survive prolonged flooding, such as species of the genus Rorippa, close relatives of Arabidopsis (Arabidopsis thaliana). We studied plant survival, changes in carbohydrate and metabolite concentrations, and transcriptome responses to submergence of two species, Rorippa sylvestris and Rorippa amphibia. We exploited the close relationship between Rorippa species and the model species Arabidopsis by using Arabidopsis GeneChip microarrays for whole-genome transcript profiling of roots of young plants exposed to a 24-h submergence treatment or air. A probe mask was used based on hybridization of genomic DNA of both species to the arrays, so that weak probe signals due to Rorippa species/Arabidopsis mismatches were removed. Furthermore, we compared Rorippa species microarray results with those obtained for roots of submerged Arabidopsis plants. Both Rorippa species could tolerate deep submergence, with R. sylvestris surviving much longer than R. amphibia. Submergence resulted in the induction of genes involved in glycolysis and fermentation and the repression of many energy-consuming pathways, similar to the low-oxygen and submergence response of Arabidopsis and rice (Oryza sativa). The qualitative responses of both Rorippa species to submergence appeared roughly similar but differed quantitatively. Notably, glycolysis and fermentation genes and a gene encoding sucrose synthase were more strongly induced in the less tolerant R. amphibia than in R. sylvestris. A comparison with Arabidopsis microarray studies on submerged roots revealed some interesting differences and potential tolerance-related genes in Rorippa species.
完全浸没会抑制光合作用和有氧呼吸，导致大多数陆生植物迅速死亡。然而，一些植物已经进化出了能够在长时间浸泡中存活的特征，例如毛果芸香属（Rorippa）的一些物种，它们是拟南芥（Arabidopsis thaliana）的近亲。我们研究了两种植物（Rorippa sylvestris 和 Rorippa amphibia）在淹没条件下的植物存活、碳水化合物和代谢物浓度变化以及转录组响应。我们利用 Rorippa 物种与模式物种拟南芥之间的密切关系，使用拟南芥基因芯片微阵列对暴露于 24 小时淹没处理或空气的幼苗根进行全基因组转录谱分析。探针掩模是基于两个物种的基因组 DNA 与芯片的杂交来设计的，因此，由于 Rorippa 物种/拟南芥不匹配导致的弱探针信号被去除。此外，我们将 Rorippa 物种的微阵列结果与淹没条件下拟南芥根的结果进行了比较。两种 Rorippa 物种都能耐受深淹，其中 R. sylvestris 的存活时间比 R. amphibia 长得多。淹没导致参与糖酵解和发酵的基因的诱导，以及许多耗能途径的抑制，与拟南芥和水稻（Oryza sativa）的低氧和淹没响应相似。两种 Rorippa 物种对淹没的定性响应大致相似，但在数量上有所不同。值得注意的是，在耐受力较低的 R. amphibia 中，糖酵解和发酵基因以及编码蔗糖合酶的基因的诱导更为强烈，而在 R. sylvestris 中则较弱。与拟南芥对淹没根的微阵列研究进行比较，揭示了 Rorippa 物种中一些有趣的差异和潜在的耐受力相关基因。
