Abstract Few plants can survive and grow equally well in salty and salt-free substrates (i.e., habitat-indifferent halophytes). Such plants provide a good opportunity to understand physiological and biochemical mechanisms underlying salinity tolerance. In this study, we investigated the environmental salinity impacts on several physiological and biochemical features of Suaeda vermiculata, a habitat-indifferent halophyte. Samples of different organs were collected from S. vermiculata from both a highly saline marsh habitat (HSMH) and non-salty gravel plain (NSGP) for the determination of the following physiological and bio-chemical features: chlorophyll and carotenoids, proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2), antioxidant enzymes (Catalase, CAT; guaiacol peroxidase, GPX; Ascorbate peroxidase, APX) activities. Elemental compositions in soil and plant samples from both habitats were also assessed. Results showed that plants from HSMH had significantly lower values of chlorophyll a, b, carotenoids and leaf biomass, compared to those from NSGP. Roots from HSMH attained higher levels of antioxidant enzymes (CAT, GPX, APX) and lower values of reactive oxygen species (MDA and H2O2), indicating that the enzymes are more likely scavenging the reactive oxygen species (ROS). The enzyme activities and ROS levels were much lower in the shoots of both HSMH and NSGP than in roots. Accumulation of sodium was higher in leaves and shoots than roots of S. vermiculata. This study indicates that Suaeda vermiculata is a salt tolerant plant with adaptations to different environments through down-regulation of different biochemical and physiological features to avoid oxidative stress.

中文翻译：

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旱盐植物 Suaeda vermiculata 在其超干旱环境中对盐度的生理反应

摘要 很少有植物能够在含盐和无盐基质（即与栖息地无关的盐生植物）中同样良好地生存和生长。这些植物提供了一个很好的机会来了解耐盐性背后的生理和生化机制。在这项研究中，我们调查了环境盐度对 Suaeda vermiculata（一种与栖息地无关的盐生植物）的几个生理和生化特征的影响。从高盐度沼泽栖息地 (HSMH) 和无盐砾石平原 (NSGP) 的 S. vermiculata 中收集不同器官的样本，用于测定以下生理和生化特征：叶绿素和类胡萝卜素、脯氨酸、丙二醛（ MDA)、过氧化氢 (H2O2)、抗氧化酶（过氧化氢酶，CAT；愈创木酚过氧化物酶，GPX；抗坏血酸过氧化物酶，APX）活性。还评估了来自两个栖息地的土壤和植物样本中的元素组成。结果表明，与来自 NSGP 的植物相比，来自 HSMH 的植物具有显着较低的叶绿素 a、b、类胡萝卜素和叶片生物量的值。HSMH 的根获得了较高水平的抗氧化酶（CAT、GPX、APX）和较低的活性氧（MDA 和 H2O2）值，表明这些酶更有可能清除活性氧（ROS）。HSMH 和 NSGP 的枝条中的酶活性和 ROS 水平远低于根。叶片和枝条中钠的积累高于S. vermiculata 的根。