盐胁迫对白榆超氧化物歧化酶(SOD)活性的影响

在东北林业大学育种基地,利用9种浓度(0.3%、06%、0.9%、1.2%、1.5%、1.8%、2.1%、2.4%、3.0%)的Na2CO3和NaHCO3混合液对白榆扦插苗进行胁迫处理,探讨其在盐胁迫下,细胞质膜的伤害程度(电解质的相对外渗率)和质膜保护系统相关酶的活性(超氧物歧化酶)。结果表明,白榆在受到不同浓度的盐胁迫下,其叶片的电解质相对外渗率发生明显的变化。在一定盐浓度范围内叶片的电解质相对外渗率上升的趋势比较缓慢,表明白榆的细胞质膜对盐离子的伤害有较强的抗性。当土壤基质盐浓度大于1.5%时,叶片的电解质相对外渗率显著增加。白榆叶片中SOD的活性在盐浓度低于1.5%时呈现一个上升的趋势,苗木的生长正常,没有受伤害的症状,但是盐浓度超过1.5%时,SOD的活性快速下降,电解质相对外渗率迅速提高。

Effect of salt stress on activity of superoxide dismutase (SOD) in Ulmus pumila L.

The injury tolerance of cell plasma membrane and the correlative enzymes activities of plasma-membrane protection system in the Ulmus pumila leaves treated by nine concentrations (0.3%, 0.6%, 0.9%, 1.2%, 1.5%, 1.8%, 2.1%, 2.4%, 3.0%) of Na2CO3 and NaHCO3 mixtures were studied in a greenhouse of Northeast Forestry University, Harbin, China. The rate of electrolyte leakage (REL) and SOD (Superoxide dismutase) activity in leaves of different samples were determined. Results showed that the REL in leaves of U. pumila pre-sented a slowly increasing trend at the salt concentrations less than 1.5%, which indicated that cell plasma membrane of U. pumila leaves had rather strong resistance to the injury of salt ion, and had a significant increase at the salt concentrations more than 1.5%. The SOD ac-tivities in leaves of U. pumila presented an increased trend at salt concentrations less than 1.5%, the growth of seedlings did not decline, and tress and leaves had no symptom of injury, while the salt concentrations exceeded 1.5%, SOD activities sharply decreased and REL in-creased promptly.