盐胁迫对柽柳超氧化物歧化酶活性的影响

利用不同浓度的Na_2CO_3和NaHCO_3混合液对柽柳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(相对电导率)和质膜保护系统相关酶的活性(超氧化物歧化酶(SOD))。结果表明,柽柳在受到不同浓度的盐胁迫下,其叶片的相对电导率发生明显的变化。在一定盐浓度范围内,叶片的相对电导率上升的趋势比较缓慢,当土壤基质盐的质量分数大于2．1%时,叶片的相对电导率显著增加。柽柳叶片中SOD总体水平较高,清除活性氧、维持活性氧代谢平衡的能力较强,在一定盐浓度范围能够有效地避免活性氧对树种本身的氧化胁迫伤害。

Effect of Salt Stress on Superoxide Dismutase Activity of Tamarix chinensis

The injury tolerance of cell plasma membrane and the correlative enzyme activity of plasma-membrane protection sys- tem in the cutting seedlings of Tamarix chinensis treated by different concentrations of Na_2 CO_3 and NaHCO_3 mixtures were studied in a greenhouse of Northeast Forestry University,Harbin, China.The relative conductivity and superoxide dis- mutase(SOD)activity in leaves of different samples were determined.Results showed that the relative conductivities in leaves of Tamarix chinensis present obvious change under different concentrations of salt stress.At a limiting salt concen- tration,the relative conductivities of leaves show a slowly increasing trend.At a more than 2.1% of salt concentration,the relative conductivities increase significantly.As a whole,the SOD activity has a higher level in leaves of Tamarix chinensis treated by salt,it has higher abilities of clearing reactive oxygen and maintaining the metabolism balance of reactive oxy- gen.and it can effectively avoid the injury of oxidative stress for the tree from reactive oxygen.