李氏禾耐铜胁迫的积累特征及生理响应

ACCUMULATION CHARACTERISTICS AND PHYSIOLOGICAL RESPONSE OF COPPER UPTAKE BY LEERSIA HEXANDRA SWARTZ

在重金属铜(Cu)的胁迫作用下,通过水培李氏禾(Leersia Hexandra Swartz)研究其对Cu的耐受积累能力及生理响应特征,为植物修复Cu污染土壤提供理论支撑。结果表明:在不同Cu处理浓度下,李氏禾茎和叶部分对Cu的最大积累量可达到841.65mg/kg;高浓度Cu胁迫作用下,李氏禾叶片中的叶绿素含量降低,丙二醛(MDA)含量显著增加,叶片中超氧化物歧化酶(SOD)、过氧化物酶(CAT)、过氧化氢酶(POD)和抗坏血酸过氧化物酶(APX)的酶活性呈先升后降的趋势。随着Cu处理浓度的增加,脂质过氧化作用加剧,生长细胞受到严重损伤,李氏禾生长受阻,生物量下降。李氏禾虽不是典型的Cu超富集植物,但却对高浓度的Cu污染水体有较好的富集效果,可作为Cu污染区域的潜在修复植物。

This paper was aimed to study the tolerance and physiological response characteristics of hydroponic L.Hexandra under the stress of heavy metal copper, and provide technical support for phytoremediation of Cu-polluted soils.The results indicated that under different Cu concentration, the maximum accumulation of Cu in stems and leaves of L.Hexandra could reach 841.65 mg/kg;under high concentration of Cu stress, the chlorophyll content in leaves decreased and the content of malondialdehyde (MDA) increased significantly;the activities of superoxide dismutase (SOD), peroxidase (CAT), catalase (POD) and ascorbate peroxidase (APX) in leaves of L.Hexandra first increased and then decreased;with the increase of Cu concentration, lipid peroxidation was intensified, and the growth of cells were seriously damaged, growth of L.Hexandra was blocked and its biomass declined.Therefore, L.Hexandra isn’t a typical copper-rich plant, but has a good enrichment effect on high-concentration copper-contaminated water, and can be listed as a potential repairing plant for Cu-contaminated areas.