Research Center for Molecular and Developmental Biology, Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
Plant Cell Environ. 2011 Jan;34(1):52-64. doi: 10.1111/j.1365-3040.2010.02225.x. Epub 2010 Oct 4.
With global climate change, abnormally low temperatures have affected the world's rice production. Many genes have been shown to be essential for molecular improvement of rice cold-tolerance traits. However, less is known about the molecular cellular mechanism of their response to cold stress. Here, we investigated OsRAN2 involved in regulation of cell division during cold stress in rice. Expression of OsRAN2 was increased under cold treatment, but not during salt and drought stress. The mean root mitotic index was closely related to the expression level of OsRAN2. Knockdown transgenic rice lines showed an aberrant organization of spindles during mitosis and stunted growth during development. Overexpression of OsRAN2 enhanced cold tolerance in rice. The transgenic rice overexpressing OsRAN2 showed maintained cell division, decreased proportion of cells with intranuclear tubulin and formation of a normal nuclear envelope under the cold condition. Our study suggests a mechanism for OsRAN2 in regulating cold resistance in rice by maintaining cell division through promoting the normal export of intranuclear tubulin at the end of mitosis. This insight could help improve the cold-tolerance trait in rice.
随着全球气候变化，异常低温已经影响了世界范围内的水稻产量。许多基因已被证明对于水稻耐寒性性状的分子改良至关重要。然而，对于它们应对冷胁迫的分子细胞机制却知之甚少。在这里，我们研究了在水稻中参与调控细胞分裂的 OsRAN2。OsRAN2 的表达在冷处理下增加，但在盐和干旱胁迫下没有增加。平均根有丝分裂指数与 OsRAN2 的表达水平密切相关。敲低转基因水稻品系在有丝分裂过程中表现出纺锤体的异常组织，并且在发育过程中生长受阻。过表达 OsRAN2 增强了水稻的耐寒性。过表达 OsRAN2 的转基因水稻在低温条件下保持了细胞分裂，减少了核内微管的比例，形成了正常的核膜。我们的研究表明，OsRAN2 通过在有丝分裂末期促进核内微管的正常输出来维持细胞分裂，从而在水稻中调节抗寒性的机制。这一见解有助于提高水稻的耐寒性性状。
