Abstract Climacoptera crassa is an annual halophyte species with great potential for use in the urban landscape. This study was performed to determine C. crassa tolerance to salinity and heavy metal stresses and to compare the plant associated mechanisms to counteract these stresses. For this purpose, the plant seedlings were exposed separately to various concentrations of NaCl (0–700 mM) or heavy metals cadmium (Cd) and lead (Pb) (0–2 mM). Our results indicated that C. crassa seedlings were able to survive at 700 mM NaCl. However, the optimum growth of seedlings was observed at 500 mM salinity. Plant in non-saline condition also displayed a normal growth. C. crassa seedlings were able to tolerate all levels of Pb, whereas their growth was inhibited at Cd concentrations exceeding 0.1 mM. The results also indicated that the increase in salinity levels in the culture medium was paralleled with the enhancement in proline, peroxide and sugar content in seedlings. A comparatively similar trend was observed when seedlings exposed to heavy metal stresses, although, the plant responses were more intense in this condition. These data suggest that osmolyte adjustment beside antioxidative enzyme activation account for the high salt tolerance of this species. Similarly, it was revealed that C. crassa uses the same mechanisms to cope with the excessive amount of heavy metals in culture medium. Therefore, it can be speculated that C. crassa benefits from its halophytic nature to tackle metal ion stresses. The present study clearly suggests that C. crassa is a highly tolerant taxon to salinity that can also survive the presence of low to moderate amount of Cd and Pb at seedling stage.

中文翻译：

---

盐生植物 Climacoptera crassa 在体外条件下对盐度和重金属胁迫的形态生理反应

摘要 Climacoptera crassa 是一年生盐生植物，在城市景观中具有巨大的应用潜力。进行这项研究是为了确定 C. crassa 对盐度和重金属胁迫的耐受性，并比较植物相关机制来抵消这些胁迫。为此，将植物幼苗分别暴露于不同浓度的 NaCl (0-700 mM) 或重金属镉 (Cd) 和铅 (Pb) (0-2 mM)。我们的结果表明 C. crassa 幼苗能够在 700 mM NaCl 下存活。然而，在 500 mM 盐度下观察到幼苗的最佳生长。在无盐条件下的植物也表现出正常的生长。C. crassa 幼苗能够耐受所有水平的 Pb，而其生长在 Cd 浓度超过 0.1 mM 时受到抑制。结果还表明，培养基中盐度水平的增加与幼苗中脯氨酸、过氧化物和糖含量的增加是平行的。当幼苗暴露于重金属胁迫时，观察到了一个相对相似的趋势，尽管在这种情况下植物的反应更加强烈。这些数据表明，除了抗氧化酶激活外，渗透剂调节也是该物种高耐盐性的原因。同样，发现 C. crassa 使用相同的机制来应对培养基中过量的重金属。因此，可以推测 C. crassa 受益于其盐生性质来解决金属离子应力。本研究清楚地表明，C.