Cadmium re-distribution from pod and root zones and accumulation by peanut (Arachis hypogaea L.)
Cadmium re-distribution from pod and root zones and accumulation by peanut (Arachis hypogaea L.)
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DOI：
10.1007/s11356-015-5348-z
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发表时间：
2015
影响因子：
5.8
通讯作者：
Kairong Wang;Ningning Song;Qiaoqiao Zhao;S. E. A. T. M. van der Zee
中科院分区：
文献类型：
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作者：
Kairong Wang;Ningning Song;Qiaoqiao Zhao;S. E. A. T. M. van der Zee
花生 (ArachishypogaeaL.) 基因型在镉 (Cd) 积累方面可能存在很大差异，但其潜在机制仍不清楚。为了确定不同Cd积累模式花生基因型中Cd重新分配和积累的关键因素，以中国常见的3个花生品种（风花6号、花玉20和花玉23）为对象，进行了分盆土壤试验。将生长培养基分为豆荚区和根区，每个区的镉浓度不同，以确定镉通过不同途径吸收后的重新分布。根据Cd转运效率将花生品种分为两类：（1）高内部Cd转运效率品种（风花6号）和（2）低内部Cd转运效率品种（华玉20和华玉23）。与风花6号相比，低Cd易位品种华玉20和华玉23表现出更高的生物量产量，特别是在茎和叶中，导致金属浓度稀释。结果还表明，当根区施用镉时，根部镉浓度随着土壤中镉浓度的增加而显着增加。然而，不同荚果区Cd处理和对照之间根部Cd浓度没有显着差异，这表明根部吸收而不是荚部吸收是花生根部Cd积累的原因。在豆荚和根区镉暴露处理之间观察到镉分布的显着差异。如果仅考虑额外施用镉，则这三个花生品种显示，豆荚中的籽粒总镉含量高于根区镉暴露。这表明，通过钉和荚壳的吸收可能至少部分地导致了花生品种之间镉的重新分配和积累的变化。植物通过两种途径吸收镉（即分别通过根、通过钉和豆荚）和内部镉易位似乎是决定花生仁中镉积累的重要机制。
Peanut (Arachis hypogaeaL.) genotypes may differ greatly with regard to cadmium (Cd) accumulation, but the underlying mechanisms remain unclear. To determine the key factors that may contribute to Cd re-distribution and accumulation in peanut genotypes with different Cd accumulating patterns, a split-pot soil experiment was conducted with three common Chinese peanut cultivars (Fenghua-6,Huayu-20, andHuayu-23). The growth medium was separated into pod and root zones with varied Cd concentrations in each zone to determine the re-distribution of Cd after it is taken up via different routes. The peanut cultivars were divided into two groups based on Cd translocation efficiency as follows: (1) high internal Cd translocation efficiency cultivar (Fenghua-6) and (2) low internal Cd translocation efficiency cultivars (Huayu-20andHuayu-23). Compared withFenghua-6, low Cd translocation cultivarsHuayu-20andHuayu-23showed higher biomass production, especially in stems and leaves, leading to dilution of metal concentrations. Results also showed that Cd concentration in roots increased significantly with increasing Cd concentrations in soils when Cd was applied in the root zone. However, there were no significant differences in the root Cd concentrations between different pod zone Cd treatments and the control, suggesting that root uptake, rather than pod uptake, is responsible for Cd accumulation in the roots of peanuts. Significant differences of Cd distribution were observed between pod and root zone Cd exposure treatments. The three peanut cultivars revealed higher kernel over total Cd fractions for pod than for root zone Cd exposure if only extra applied Cd was considered. This suggests that uptake through peg and pod shell might, at least partially, be responsible for the variation in Cd re-distribution and accumulation among peanut cultivars. Cd uptake by plants via two routes (i.e., via roots and via pegs and pods, respectively) and internal Cd translocation appear to be important mechanisms in determining Cd accumulation in the kernels of peanuts.