镉、铅胁迫对芹菜生长及抗氧化酶活性的影响

Effect of Cd,Pb Stress on Growth and the Activity of Antioxidant Enzymes in Apium graveolens

采用外源添加重金属和营养液水培试验研究了重金属镉（Cd）、铅（Pb）单一及复合污染对芹菜生长周期的生长及根系活力、脯氨酸（Pro）含量、抗氧化酶活性的影响。结果表明：（1）6~8 mg/L Cd和60~80 mg/L Pb单一及复合处理对芹菜全生长期内生物量、株高、根系活力、脯氨酸及抗氧化酶活性（SOD、POD）的影响均达到极显著性效应（P〈0.01）;（2）低浓度Cd（≤2 mg/L）、Pb（≤20 mg/L）及Cd-Pb复合（≤（2＋20）mg/L）条件下,镉、铅污染对芹菜植株生物量、株高具有促进效应,而高浓度、长时间胁迫时,植株生物量及受到明显的抑制（P〈0.01）;（3）Cd、Pb单一及复合胁迫对芹菜植株生物量、株高、根系活力、脯氨酸及抗氧化酶活性（SOD、POD）的影响毒性由大到小依次均为Cd-Pb交互、Cd、Pb、CK;（4）低浓度、短时间重金属处理对芹菜根系活力的影响不显著;但高浓度、长时间处理时,根系活力变化呈现极显著负相关性（P〈0.01）;（5）Cd、Pb对芹菜叶POD和SOD活性的影响相似,都表现为低浓度下促进酶活性,而高浓度下抑制酶活性;（6）重金属浓度越高,芹菜叶片内诱导合成脯氨酸越多,这可在一定程度上缓解重金属污染对芹菜植株的毒害作用。

The influences of Cd,Pb single and combined pollution on biomass,plant height,root activities,proline（ Pro）,antioxidant enzyme superoxide dismutase（ SOD）,peroxidase（ POD） of celery（ Apium graveolens）in nutrient solution were studied,which supplied reference for ensuring vegetable production safety. The results showed：（ 1） During the whole growth cycle of celery,the influences of 6- 8 mg / L Cd,60- 80 mg / L Pb single and interactive stress on biomass,plant height,root activities,proline and activities of SOD,POD in the leaves were very significant（ P 〈0. 01）.（ 2） The biomass and plant height of celery were boosted under low contents of Cd（ ≤2 mg / L）,Pb（ ≤20 mg / L） and Cd- Pb interaction（ ≤（ 2 ＋ 20） mg / L）,and were restrained under high concentrations and long time（ P 〈0. 01）.（ 3） The effects of Cd,Pb pollution on biomass,plant height,root activities,proline and antioxidant enzyme system（ SOD,POD） of celery showed the order： Cd- Pb combined pollution Cd Pb CK.（ 4） Root activity was non-significantly affected under low concentrations and short time,but was significantly negative correlated with heavy metal stress under high concentrations and long time（ P 〈0. 01）.（ 5） The effects of Cd and Pb on POD and SOD activities in leaf extracts of celery were similar. The enzyme activities were stimulated under lower metal ion concentrations but were inhabited under higher concentrations.（ 6） The higher heavy metal concentrations,the higher Pro content,which can alleviate Cd and Pb toxicity to celery seedlings.