Frank Wolfgang, Ratnadewi Diah, Reski Ralf
Plant Biotechnology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg, Germany.
Planta. 2005 Jan;220(3):384-94. doi: 10.1007/s00425-004-1351-1. Epub 2004 Aug 18.
In order to determine the degree of tolerance of the moss Physcomitrella patens to different abiotic stress conditions, we examined its tolerance against salt, osmotic and dehydration stress. Compared to other plants like Arabidopsis thaliana, P. patens exhibits a high degree of abiotic stress tolerance, making it a valuable source for the identification of genes effecting the stress adaptation. Plants that had been treated with NaCl tolerated concentrations up to 350 mM. Treatments with sorbitol revealed that plants are able to survive concentrations up to 500 mM. Furthermore, plants that had lost 92% water on a fresh-weight basis were able to recover successfully. For molecular analyses, a P. patens expressed sequence tag (EST) database was searched for cDNA sequences showing homology to stress-associated genes of seed plants and bacteria. 45 novel P. patens genes were identified and subjected to cDNA macroarray analyses to define their expression pattern in response to water deficit. Among the selected cDNAs, we were able to identify a set of genes that is specifically up-regulated upon dehydration. These genes encode proteins exerting their function in maintaining the integrity of the plant cell as well as proteins that are known to be members of signaling networks. The identified genes will serve as molecular markers and potential targets for future functional analyses.
为了确定小立碗藓对不同非生物胁迫条件的耐受程度，我们检测了它对盐胁迫、渗透胁迫和脱水胁迫的耐受性。与拟南芥等其他植物相比，小立碗藓表现出高度的非生物胁迫耐受性，这使其成为鉴定影响胁迫适应性基因的宝贵资源。用氯化钠处理的植株能够耐受高达350 mM的浓度。用山梨醇处理表明植株能够在高达500 mM的浓度下存活。此外，以鲜重计失水92%的植株能够成功恢复。为了进行分子分析，在小立碗藓表达序列标签（EST）数据库中搜索与种子植物和细菌的胁迫相关基因具有同源性的cDNA序列。鉴定出45个新的小立碗藓基因，并对其进行cDNA宏阵列分析以确定它们在缺水情况下的表达模式。在所选的cDNA中，我们能够鉴定出一组在脱水时特异性上调的基因。这些基因编码在维持植物细胞完整性方面发挥作用的蛋白质以及已知是信号网络成员的蛋白质。鉴定出的基因将作为分子标记和未来功能分析的潜在靶点。
