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耐性机理的系统解析对于旱柳在土壤Pb污染控制上的应用具有重要意义.为了明确旱柳对Pb的耐性机理,通过盆栽试验研究了旱柳对Pb的耐性、富集、转运特征,采用STEM、EDAX、FTIR分析了旱柳对Pb的胁迫响应机制.结果表明:低含量(≤600 mg·kg-1)Pb对旱柳生长有促进作用,高含量(≥1000 mg·kg-1)Pb明显抑制旱柳的生长;旱柳对Pb具有很高的耐性,耐性指数TI(%)可达108.32,属Pb高耐性植物;旱柳对Pb的富集能力较强,富集系数均值可达7.5773,而对Pb的转运能力较弱,转运系数均小于1;低含量Pb胁迫不影响叶绿素的合成,也不会促生丙二醛(MDA),而高含量Pb胁迫明显抑制叶绿素的合成,促使MDA大量生成,导致严重的细胞膜脂过氧化和膜损伤;抗氧化酶(POD、CAT、SOD)及可溶性蛋白能够对低含量Pb胁迫做出积极有效的响应,但无法清除高含量Pb胁迫所产生的毒害;扫描透射电镜(STEM)分析表明,Pb胁迫使根系发黑、萎蔫,茎部破败、堵塞,叶片褶皱、卷曲,破坏气孔结构;傅里叶红外光谱(FTIR)分析表明,Pb胁迫使导致膜脂过氧化和膜损伤的自由羟基增多,而使对Pb具有络合、螯合作用的连生羟基、巯基、羰基数量减少;能谱(EDAX)分析表明,Pb胁迫抑制了Ca、K的吸收,同时干扰其他矿质元素的吸收利用.
The systematic analysis of tolerance mechanism is of great significance to the application of Salix matsutake in the control of Pb pollution in soil.In order to clarify the tolerance mechanism of Salix matsudana to Pb, pot experiments were conducted to study the tolerance, enrichment and transport characteristics of Salix matsudana to Pb, , EDAX and FTIR were used to analyze the response mechanism of drought stress to Pb. The results showed that low Pb (≤600 mg · kg-1) Pb could promote the growth of H. amurense. Pb (≥1000 mg · kg-1) Pb The content of TI was up to 108.32, which was a Pb-tolerant plant. The content of Cd in the willow was higher than that in the control 7.5773, while the transport capacity of Pb was weaker, and the transmissibility coefficients were all less than 1. Low Pb stress did not affect the synthesis of chlorophyll and did not promote malondialdehyde (MDA), while high Pb stress significantly inhibited chlorophyll synthesis, Which led to the massive production of MDA, which led to severe lipid peroxidation and membrane damage. Antioxidant enzymes (POD, CAT, SOD) and soluble protein could respond positively and effectively to low Pb stress but could not clear the high Pb stress Toxicity generated; Scanning Transmission Electron Microscopy (STEM) analysis showed that Pb stress caused roots FTIR analysis showed that Pb stress led to the increase of free hydroxyl groups leading to membrane lipid peroxidation and membrane damage, EDAX analysis showed that Pb stress inhibited the absorption of Ca and K and at the same time interfered with the absorption and utilization of other mineral elements.