高磷处理下矿山生态型水蓼根系耐受特征  

Root tolerance characteristics of mining ecotype Polygonum hydropiper under high P application

作　　者：刘嫣含 李廷轩 蒲勇 高东东 叶代桦 LIU Yan-han;LI Ting-xuan;PU Yong;GAO Dong-dong;YE Dai-hua(College of Resources,Sichuan Agricultural University,Chengdu,Sichuan 611130,China;Luzhou Municipal Bureau of Agriculture and Rural Affairs,Luzhou,Sichuan 646000,China;Sichuan Academy of Environmental Sciences,Chengdu,Sichuan 610042,China)

机构地区：[1]四川农业大学资源学院,四川成都611130 [2]泸州市农业农村局,四川泸州646000 [3]四川省生态环境科学研究院,四川成都610042

出　　处：《植物营养与肥料学报》2021年第12期2160-2169,共10页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金项目(31972499,32000064);四川省科技厅基本科研项目(2021JDKY0022)。

摘　　要：【目的】磷富集植物对高磷具有良好的耐性是其应用于植物修复的前提。本研究探讨磷富集植物矿山生态型水蓼根系对高磷的耐受能力,为后期利用其修复环境中的过量磷提供一定的理论依据。【方法】采用矿山生态型和非矿山生态型水蓼(ME和NME)进行了水培试验,营养液中设置无机磷2、4、8、16 mmol/L 4个高浓度处理,以正常磷0.5 mmol/L浓度为对照,分析对比了两种生态型水蓼根系对高磷的耐受特征。【结果】随着磷浓度的增加,ME地上部和根系生物量和磷积累量均先显著增加后降低,在磷浓度4 mmol/L时出现峰值,而NME则大体呈降低趋势。高磷处理ME地上部和根系生物量分别为NME的1.35~2.56和1.18~1.86倍,除磷浓度16 mmol/L处理外,ME地上部和根系磷积累量分别为NME的1.35~2.58和1.36~1.96倍,磷积累能力更强。ME根系质膜开始受到明显损伤的营养液磷浓度是8 mmol/L,而NME是磷浓度4 mmol/L。随着磷浓度的增加,ME根系中H_(2)O_(2)、MDA和NME根系中的MDA含量均表现为先稳定后显著增加,而NME根系中的H_(2)O_(2)含量则持续增加;两种生态型水蓼根系SOD、POD和CAT活性均先显著增高后降低,分别在磷浓度4和2 mmol/L时显著高于对照。与NME相比,ME根系抗氧化酶活性更高,对H_(2)O_(2)和MDA的清除能力更强。两种生态型水蓼根系亚细胞组分磷含量均表现为可溶部分(含液泡)>细胞壁>细胞器。随着磷浓度的增加,两种生态型水蓼各亚细胞组分磷含量均显著增加,且在磷浓度2和4 mmol/L处理下,根系可溶部分(含液泡)磷分配比例明显高于对照,液泡是其磷素储存的重要场所。【结论】矿山生态型水蓼对高磷的耐受能力和磷积累能力均强于非矿山生态型水蓼。高磷处理下矿山生态型水蓼存在根系自由基和保护酶动态平衡、细胞壁固持和可溶部分的液泡区隔化现象,这是其根系的重要耐受特征。【Objectives】Phosphorus(P)accumulation tolerance is fundamental to the phytoremediation of excessive P in the environment.Previous studies have reported mining ecotype Polygonum hydropiper as a hyperaccumulator of P.【Methods】We conducted a hydroponic experiment using mining ecotype Polygonum hydropiper(ME)and non-mining ecotype Polygonum hydropiper(NME)as test materials.The treatments were high inorganic P concentrations in nutrient solution at 2,4,8,and 16 mmol/L,taking normal P concentration at 0.5 mmol/L as the control.We investigated the tolerance of ME and NME roots to high P.【Results】Compared to normal P control,the shoot and root biomass of ME increased when exposed to P concentrations 2 and 4 mmol/L but decreased when exposed to P concentrations 8 and 16 mmol/L.The shoot and root biomass of ME was 1.35–2.56 and 1.18–1.86 times those of NME under high P treatments,showing higher tolerance to high P than NME.The shoot and root P accumulation of ME increased when exposed to P concentrations 2 and 4 mmol/L but decreased when exposed to P concentrations8 and 16 mmol/L.The shoot and root P accumulation of ME was 1.35-2.58 and 1.36-1.96 higher than NME,indicating the former's stronger P accumulation potential.The ME and NME were stained when exposed to 8 and 4 mmol/L P concentration respectively.This showed that the plasma membranes of the root cells were(P<0.05)damaged at P concentrations 8 mmol/L for ME and P concentrations 4 mmol/L for NME.With increasing P concentration,SOD,POD,and CAT activities in ME roots increased and then decreased.The concentrations of H_(2)O_(2) and MDA were stable at first and then increased.However,the concentration of H_(2)O_(2) exhibited a constant increase in NME roots.The P in the roots of both ME and NME was mostly distributed in the soluble fraction(containing the vacuole)and cell walls.The P content in the subcellular component(P<0.05)increased in both ME and NME roots with increasing P concentrations.The soluble fraction(containing the vacuole)P(P<0.05)increas

关 键 词：高磷胁迫 水蓼 耐性 抗氧化酶系统 亚细胞组分 

分 类 号：Q945[生物学—植物学]