作　　者： ; ; ;

机构地区： 嘉应学院生命科学学院

出　　处： 《嘉应学院学报》 2012年第5期61-66,共6页

摘　　要： 以红树植物桐花树2a生龄苗为试验材料,采用淡水水培法研究了不同浓度Pb2+(0 mg/L(对照组)、10mg/L、25 mg/L、50 mg/L、100 mg/L、300mg/L、500 mg/L)对桐花树叶片的超氧负离子(O2-)、丙二醛(MDA)含量、过氧化物酶(POD)与超氧化物歧化酶(SOD)活性、蛋白质以及可溶性总糖量含量的影响.结果表明:随着Pb2+浓度的升高,桐花树叶片中O2-和MDA含量均呈上升趋势,且均显著高于对照,最高值范围是在Pb2+浓度100～500mg/L;而蛋白质含量和POD的活性则呈下降趋势,且均显著低于对照.SOD活性在铅胁迫浓度为10 mg/L时达到最大,当高于10mg/L时,则随Pb2+浓度的升高而下降.可溶性糖含量在Pb2+浓度为0～300 mg/L时,随Pb2+浓度的升高而显著增大.试验表明:桐花树叶片在浓度为10～100mg/L铅处理下,可以通过自身的内在调控抵御铅污染,即轻度的铅污染有利于桐花树的生长;在300～500mg/L高浓度铅胁迫下,各种生理指标出现衰减,显示高浓度铅胁迫的抑制效应,不利于桐花树生长. Two - year - old plants of Aegiceras comiculatum cultivated in fresh water were exposed to different con- centrations of Pb2＋ （0 mg/L（ CK）, 10mg/L,25 mg/L,50 mg/L, 100 mg/L,300mg/L and 500 mg/L） to investigate the effect of lead exposure on the contents of superoxide radical （ 02 - ）, malonie dialdehyde （ MDA）, peroxidase （POD） and superoxide dismutase （SOD）, protein and soluble sugar. Results indicated that, with the increase of Pb2＋, 02 - and MDA increased to significantly higher than those under control, and reached the highest values un- der Pb2＋100 - 500mg/L; whereas protein content and POD activity declined significantly as Pb2＋ increased. SOD activity reached the highest value at 10 mg/L Pb2＋ , and decreased with raised Pb2＋ concentrations. Soluble sugar content significantly increased with the increase of Pb2＋ within the range of 0 - 300 mg/L. The conclusion is that： exposure of Pb2＋ at 10 - 100mg/L stimulated growth of Aegiceras comiculatum,indicating there existed an intrinsic adaptive mechanism to light lead stress in the plant; but as concentration of lead increased to 300 - 500mg/L, growth of Aegiceras comiculatum was significantly inhibited, with all physiological indexes significantly declined.

关 键 词： 铅胁迫 叶片 生理指标

领　　域： [生物学]