摘要
采用液体培养法,研究了铅(Pb)和镉(Cd)及其复合胁迫对黄菖蒲(Iris pseudacorus)幼苗生长及生理的响应。将黄菖蒲幼苗培养于250mL培养瓶中,以1/2Hoagland营养液预培养7d后,然后进行500mg/LPb、25mg/LCd和500mg/LPb+25mg/LCd复合胁迫处理,28d后测定幼苗的各项生长及生理指标。结果表明,在500mg/LPb和25mg/LCd+500mg/LPb胁迫下,黄菖蒲幼苗地上部和地下部干重与对照相比都显著下降,所有处理的地下部干重与对照处理相比都显著下降;在所有处理下,幼苗的叶绿素a含量都下降;在500mg/LPb和25mg/LCd+500mg/LPb处理下,幼苗的叶绿素b和胡萝卜素含量下降都不显著;在500mg/LPb和25mg/LCd+500mg/LPb处理下,幼苗根和叶中的丙二醛(MDA)含量、脯氨酸(Pro)含量和过氧化物酶(POD)活性都增加,但是在25mg/LCd处理下,幼苗根和叶中的POD活性和叶中的MDA含量都显著减少。Pb和Cd可以有效诱导黄菖蒲幼苗Pro的合成,能提高黄菖蒲幼苗的抗性。
The Effects of lead （Pb）,cadmium （Cd）,and their compound stress on the growth,physiological and biochemical characteristics response of Iris pseudacorus seedling were researched with the method of the hydroponic experiment.Similar sized seedlings of Iris pseudacorus were pretreated in 250mL culture flask with 1/2 Hoagland nutrient solution for 1 week,than add 500mg/L Pb （supplied with Pb（NO 3） 2）,25mg/L Cd （supplied with Cd （NO 3） 2） and complex treatment with 500mg/L Pb＋25 mg/L Cd,respectively,3 reduplicates for every treatment.In order to preventing sediment occurred,0.5 mmol/L EDTA-Na 2 was added to all treatment and control.The growth index and plant physiological parameters were tested in 28 days after heavy metals exposure.The results showed that the dry weights of both shoots and roots of Iris pseudacorus decreased significantly at 500mg/L Pb and 25 mg/L Cd ＋500mg/L Pb treatments and the dry weights of root under all treatments decreased significantly in comparison with that of control （n=3,p0.05）.The dry weights of roots which was treated with 500mg/L Pb,25mg/L Cd and complex treatment of 500mg/L Pb＋25mg/L Cd were 78%,86% and 71%,respectively,that of control.Comparing the control,the contents of chla in the leaves of Iris pseudacorus decreased significantly at all treatments and the contents of chlb reached significantly level （n= 3,p0.05） except 25mg/L Cd treatment.The contents of carotenoid under treatments of 500mg/L Pb and 25mg/L Cd decreased significantly,while,there was no significance to complex treatment of 500 mg/L Pb＋25mg/L Cd.The cell membrane permeability at the treatment of 25mg/L Cd in the cells of roots and leaves decreased 10% and 13%,respectively,compared with control.The cell membrane permeability in roots and in leaves of Iris pseudacorus treated with 500mg/L Pb were 140% and 110%,respectively and those under complex treatment of 500mg/L Pb＋25mg/L Cd,122% and 103%,respectively.The malondialdehyde contents in both of shoots and roots increased significantly under treatment of 500mg/L Pb as well as the complex treatment of 25mg/L Cd＋500 mg/L Pb and malondialdehyde contents in the shoots decreased significantly at 25mg/L Cd treatment.The variation of proline contents had the same trend with malondialdehyde and the proline contents in roots and in leaves treated with 500mg/L Pb were 123% and 1 589%,respectively,compared with that of control.The peroxidase activity in roots treated with 500 mg/L Pb increased 61% compared with that of control and complex treatment of 25mg/L Cd＋500mg/L Pb increased 136%.Proline and peroxidase activity play important roles in the tolerance of Iris pseudacorus seedlings under Pb and Cd combination stress.
出处
《湿地科学》
CSCD
北大核心
2012年第4期487-491,共5页
Wetland Science
基金
国家自然科学基金项目(30771520)
江西省自然基金项目(2008GZN0064)资助
关键词
黄菖蒲
淡水湿地
铅
镉
胁迫
生理反应
Iris pseudacorus
lead （Pb）
cadmium （Cd）
stress
physiological responses
