Characterization of salt tolerance in poplar

在胡杨属中，胡杨的耐盐性突出，但生长缓慢。盐胁迫导致木材结构的解剖变化。由于耐盐程度与年龄有关，因此该模型为研究年龄相关功能以及结构适应压力提供了可能性。本研究的目的是比较耐盐乔木胡杨与盐敏感乔木白杨的特性。由于我们发现盐处理也会影响根的分化并触发H2O2的产生，我们的工作假设是盐度通过干扰细胞氧化还原状态和/或影响离子稳态来诱导分化的变化。我们计划分析H2O2产生与盐诱导茎解剖变化的关系。对杨树形成层中与氧化剂形成和发育变化相关的盐分诱导基因进行转录谱分析。在耐盐环境下，离子稳态是很重要的。我们从胡杨中克隆了两个不同的Na+/H+反转运蛋白的cdna。这些反转运蛋白将在基因和蛋白质水平上进行表征，并将它们的表达与盐胁迫下形成层中亚细胞定位和Na+/K+浓度的变化进行比较。

In the genus Populus, P. euphratica is outstanding with respect to its salt tolerance but also for its slow growth. Salt stress leads to anatomical changes in wood structure. Since the degree of salt tolerance is furthermore age-dependent, this model offers the possibility to study age-related functions as well as structural adaptation to stress. The goal of this proposal is to characterize the salt tolerant tree Populus euphratica in comparison with the salt sensitive Populus x canescens. Since we found that salt treatment also affected the differentiation of roots and triggered production of H2O2, our working hypothesis is that salinity induces changes in differentiation via disturbance of the cellular redox state and/or effects on ion homeostasis. We plan to analyze H2O2 production in relation to salt-induced changes in stem anatomy. Transcriptional profiling of salinity-induced genes of the cambium in relation to oxidant formation and developmental changes in poplar will be performed. In the context of salt tolerance ion homeostasis is important. We have cloned two cDNAs coding for different putative Na+/H+ antiporters from P. euphratica. These antiporters will be characterized at the gene and protein level and their expression will be compared with changes in the subcellular localisation and concentration of Na+/K+ in the cambium under salt stress in relation to tree age.