锑胁迫对蜈蚣草根系分泌物的影响

Effect of Antimony Stress on Root Exudates of Pteris vittata L.

蜈蚣草(Pteris vittata L.)是锑矿区发现的一种高富集植物,以其为供试材料,研究不同浓度(0, 50,100, 200, 500 mg/kg)锑胁迫下,蜈蚣草各部位锑的积累及其根系分泌物中有机酸、氨基酸以及可溶性糖的变化情况。结果表明:锑在蜈蚣草各部位锑积累顺序表现为根>茎>叶,且随着锑胁迫浓度增大而显著增多,其中,根部是蜈蚣草积累锑的主要部位。随着锑胁迫浓度的增大,蜈蚣草根系分泌物中有机酸的总量、氨基酸的总量以及可溶性糖的含量均显著增加。所有处理组中均检出6种有机酸及17种氨基酸,有机酸和氨基酸的组成成分没有随锑胁迫浓度的变化发生改变,锑胁迫主要影响的是各组成成分的分泌量。同时,有机酸和氨基酸的总量、有机酸和氨基酸中大部分组成成分的分泌量、可溶性糖的含量均与蜈蚣草根部锑含量显著相关,说明根系分泌的有机酸、氨基酸和可溶性糖可能在蜈蚣草累积锑的过程中起着促进作用。通过研究锑胁迫与蜈蚣草根系分泌物之间的相互关系,有利于进一步探究蜈蚣草对锑的耐性及富集机制。

Pteris vittata L. is a high antimony enrichment plant found in antimony mining areas. Using it as the test material, the accumulation of antimony in Pteris vittata L. and the changes of organic acids, amino acids and soluble sugars in its root exudates was studied under the stress of different antimony concentrations(0, 50, 100, 200,500 mg/kg). The results showed that the order of antimony accumulation in each part of Pteris vittata L. was root>stem>leaf, and it increased significantly with the increase of antimony stress concentration. Among them, the root was the main part of Pteris vittata L. accumulating antimony. With the increase of Sb stress concentration, the amount of total organic acids, total amino acids and soluble sugars secreted by Pteris vittata L. roots increased significantly. Six organic acids and seventeen amino acids were detected in all treatment groups. The composition of organic acids and amino acids did not change with the concentration of antimony stress. Antimony stress mainly affected the secretion of each component. At the same time, the total amount of organic acids and amino acids, the secretion of most components in organic acids and amino acids, and the content of soluble sugars are significantly related to the antimony content of the roots of Pteris vittata L., indicating that the organic acids, amino acids and soluble sugars secreted by roots may play a role in promoting the accumulation of antimony in Pteris vittata L. By studying the relationship between antimony stress and centipede root exudates, it is helpful to further explore the antimony tolerance and enrichment mechanism of Pteris vittata L..