Ye Daihua, Li Tingxuan, Zheng Zicheng, Zhang Xizhou, Chen Guangdeng, Yu Haiying
College of Resources and Environment, Sichuan Agricultural University Chengdu, China.
Front Plant Sci. 2015 Feb 4;6:36. doi: 10.3389/fpls.2015.00036. eCollection 2015.
It is important to seek out plant species, high in phosphorus (P) uptake, for phytoremediation of P-enriched environments with a large amount of organic P (Po). P assimilation characteristics and the related mechanisms of Polygonum hydropiper were investigated in hydroponic media containing various concentrations of Po (1-8 mmol L(-1)) supplied as phytate. The mining ecotype (ME) showed significantly higher biomass in both shoots and roots compared to the non-mining ecotype (NME) at 4, 6, and 8 m mol L(-1). Shoot P content of both ecotypes increased up to 4 mmol L(-1) while root P content increased continually up to 8 mmol L(-1) for the ME and up to 6 mmol L(-1) for the NME. Root P content of the ME exceeded 1% dry weight under 6 and 8 mmol L(-1). The ME had significantly higher P accumulation in both shoots and roots compared to the NME supplied with 6 and 8 mmol L(-1). The ME showed higher total root length, specific root length, root surface area, root volume, and displayed significantly greater root length, root surface area, and root volume of lateral roots compared to the NME grown in all Po treatments. Average diameter of lateral roots was 0.17-19 mm for the ME and 0.18-0.21 mm for the NME. Greater acid phosphatase and phytase activities were observed in the ME grown under different levels of Po relative to the NME. This indicated fine root morphology, enhanced acid phosphatase and phytase activities might be adaptations to high Po media. Results from this study establish that the ME of P. hydropiper is capable of assimilating P from Po media and is a potential material for phytoremediation of polluted area with high Po.
寻找对磷（P）吸收量高的植物物种，用于对富含大量有机磷（Po）的富磷环境进行植物修复，这一点很重要。在以植酸盐形式提供不同浓度Po（1 - 8 mmol L(-1)）的水培介质中，研究了水蓼的磷同化特征及相关机制。在4、6和8 mmol L(-1)时，矿质生态型（ME）的地上部和根部生物量均显著高于非矿质生态型（NME）。两种生态型的地上部磷含量在4 mmol L(-1)时均有所增加，而ME的根部磷含量在8 mmol L(-1)时持续增加，NME则在6 mmol L(-1)时持续增加。在6和8 mmol L(-1)条件下，ME的根部磷含量超过干重的1%。与供应6和8 mmol L(-1)的NME相比，ME的地上部和根部磷积累量显著更高。与在所有Po处理下生长的NME相比，ME的总根长、比根长、根表面积、根体积更大，侧根的根长、根表面积和根体积也显著更大。ME侧根的平均直径为0.17 - 1.9 mm，NME为0.18 - 0.21 mm。相对于NME，在不同水平Po条件下生长的ME中观察到更高的酸性磷酸酶和植酸酶活性。这表明细根形态、增强的酸性磷酸酶和植酸酶活性可能是对高Po介质的适应性表现。本研究结果表明，水蓼的矿质生态型能够从Po介质中吸收磷，是高Po污染区域植物修复的潜在材料。
