Trade-off between cadmium tolerance and relative growth rate in 10 grass species
Trade-off between cadmium tolerance and relative growth rate in 10 grass species
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DOI：
10.1016/j.envexpbot.2007.10.019
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发表时间：
2008-05
影响因子：
5.7
通讯作者：
S. Sabreen;S. Sugiyama
中科院分区：
文献类型：
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作者：
S. Sabreen;S. Sugiyama
不同植物对重金属的积累和耐受性存在较大差异。本研究比较了不同镉处理（0、5、10和50μM）条件下水培生长的10种C3grass对镉胁迫的响应差异。植物茎部干质量对Cd处理的响应（抗性）分为回避（茎部Cd浓度对Cd处理的响应）和耐受（茎部干质量对茎部Cd浓度的响应）。在最佳生长条件下，测定了植株的相对生长率（RGR）和叶片结构特性。在抗性、避害性和耐受性方面存在较大差异。避免和耐受分别归因于总Cd抗性。抗性和耐受性与RGR、叶片含水量（LW）、比叶面积（SLA）、叶片伸长率（LER）和叶长（LL）呈负相关，而叶片干物质浓度（LMDC）和核DNA含量与抗性和耐受性呈正相关。这些结果表明了生长速度和对Cd胁迫的耐受性之间的权衡。Ca/Mg比值较高的物种对镉胁迫的回避程度较低（r= - 0.943***），表明Ca2+的摄取受到抑制，形成了对镉胁迫的回避。
Plant species exhibit great differences in heavy metal accumulation and tolerance. In this study we compared interspecific differences in responses to Cadmium (Cd) stress among 10 C3grass species by growing hydroponically under the conditions of different Cd treatments (0, 5, 10 and 50μM). Responses of plant shoot dry mass to Cd treatments (resistance) were separated into avoidance (the response of shoot Cd concentration to Cd treatments) and tolerance (the response of shoot dry mass to shoot Cd concentration). The relative growth rate (RGR) and leaf structural properties of plants were measured under optimum growth condition. There were large differences in resistance, avoidance and tolerance among the species. Avoidance and tolerance were attributed independently to total Cd resistance. Resistance and tolerance were correlated negatively with RGR, leaf water content (LW), specific leaf area (SLA), leaf elongation rate (LER), and leaf length (LL), but the leaf dry matter concentration (LMDC), and nuclear DNA content showed a positive correlation with resistance and tolerance. These results indicate a trade-off between growth rate and tolerance to Cd stress. Species with higher Ca/Mg ratios showed low avoidance (r=−0.943***), suggesting uptake inhibition by Ca2+to develop avoidance against Cd stress.