Hydrogel modified uptake of salt ions and calcium in Populus euphratica under saline conditions
Hydrogel modified uptake of salt ions and calcium in Populus euphratica under saline conditions
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DOI：
10.1007/s00468-003-0267-x
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发表时间：
2004-03-01
影响因子：
2.3
通讯作者：
H端ttermann, A
中科院分区：
文献类型：
--
作者：
Chen, SL;Zommorodi, M;H端ttermann, A
在盐渍条件下，研究了水凝胶对胡杨（Populus euphratica）生长和离子关系的影响。所使用的水凝胶是stocksorb K410，这是一种高度交联的聚丙烯酰胺，约40%的酰胺基水解成羧基。用0.6%的水凝胶对盐碱地（钾矿渣）进行改良，在2年内改善了幼苗的生长（生物量提高了2.7倍），尽管植物的生长受到盐度的影响。水凝胶处理过的植物的根长和根表面积比未处理过的盐渍土高出约3.5倍。此外，超过6%的根聚集在凝胶碎片中。组织和细胞离子分析表明，生长的改善似乎是盐排除能力增加和Ca2+吸收增强的结果。根室的x射线显微分析表明，聚合物的存在限制了幼根和老根的外胞质Na+，限制了老根的外胞质和细胞塑质Cl-，而增加了幼根和老根皮质液泡中的Cl-区隔。总的来说，盐离子（Na+和Cl-）通过皮层进入木质部的自由基运输减少，随后的轴向运输受到限制。水凝胶处理增强了Ca2+的吸收，微量分析表明根组织中Ca2+的富集主要发生在外质体中。综上所述，胡杨对Ca2+的吸收增强和对盐的排异能力增强是土壤有效溶液Ca2+/Na+浓度提高的结果。由于聚合物的阳离子交换特性，水凝胶改进剂通过降低含盐量和丰富Ca2+吸收来提高土壤溶液的质量。因此，根聚集使根与Ca2+源接触良好，减少了与Na+和Cl-的接触，这可能是胡杨耐盐性增强的主要原因。
The effects of hydrogel on growth and ion relationships of a salt resistant woody species, Populus euphratica, were investigated under saline conditions. The hydrogel used was Stockosorb K410, a highly crosslinked polyacrylamide with about 40% of the amide group hydrolysed to carboxylic groups. Amendment of saline soil (potassium mine refuse) with 0.6% hydrogel improved seedling growth (2.7-fold higher biomass) over a period of 2 years, even though plant growth was reduced by salinity. Hydrogel-treated plants had approximately 3.5-fold higher root length and root surface area than those grown in unamended saline soil. In addition, over 6% of total roots were aggregated in gel fragments. Tissue and cellular ion analysis showed that growth improvement appeared to be the result of increased capacity for salt exclusion and enhancement of Ca2+ uptake. X-ray microanalysis of root compartments indicated that the presence of polymer restricted apoplastic Na+ in both young and old roots, and limited apoplastic and cytoplastic Cl- in old roots while increasing Cl- compartmentation in cortical vacuoles of both young and old roots. Collectively, radical transport of salt ions (Na+ and Cl-) through the cortex into the xylem was lowered and subsequent axial transport was limited. Hydrogel treatment enhanced uptake of Ca2+ and microanalysis showed that enrichment of Ca2+ in root tissue mainly occurred in the apoplast. In conclusion, enhanced Ca2+ uptake and the increased capacity of P. euphratica to exclude salt were the result of improved Ca2+/Na+ concentration of soil solution available to the plant. Hydrogel amendment improves the quality of soil solutions by lowering salt level as a result of its salt-buffering capacity and enriching Ca2+ uptake, because of the polymer's cation-exchange character. Accordingly, root aggregation allows good contact of roots with a Ca2+ source and reduces contact with Na+ and Cl-, which presumably plays a major role in enhancing salt tolerance of P. euphratica.