杨梅根瘤Frankia菌对重金属的抗性  

Heavy Metal Resistance of Frankia Strains from Root Nodule of Myrica rubra

作　　者：何新华[1] 陈力耕[1] 胡西琴[1] 郭长禄[1] 

机构地区：[1]浙江大学园艺系

出　　处：《水土保持学报》2003年第3期127-129,143,共4页Journal of Soil and Water Conservation

基　　金：浙江省自然科学基金资助项目(编号:302362)

摘　　要：采用生长抑制分析法研究从杨梅根瘤分离的10个Frankia菌菌株对9种重金属元素的抗性。一般所有供试菌株对Hg2+和Ag+敏感,大部分菌株对Pb2+(5～10mmol/L)、Cr2O72-(5～10mmol/L)、AsO2-(5～10mmol/L)不敏感,部分菌株对Cu2+、Co2+、Ni2+和Cd2+也不敏感(MICs≥0.5mmol/L,有的菌株达到5mmol/L)。菌株之间对各种重金属的抗性存在较大差异,其中菌株Mda21对所有供试重金属都敏感,而菌株Mpa11几乎能抗所有供试重金属,且有几个菌株能同时抗多种重金属。低浓度铅能促进抗铅菌株的生长,而高浓度铅对其生长有一定的抑制;抗铅菌株在含铅的培养基中仍具有固氮酶活性,在一定浓度范围内,随铅离子浓度的升高,固氮酶活性有所增强。Frankia菌的抗铅机理可能是其具有结合或螯合铅离子作用,对其他重金属的抗性机制尚不清楚。The resistance of 10 Frankia strains to 9 kinds of heavy metals was determined by a growth inhibition assay. In general, all of the strains were sensitive to low concentrations(<0.5 mmol/L) of Hg2+ and Ag+ , but most of the strains were less sensitive to Pb2+ (5~10 mmol/L),Cr2O72-(5~10mmol/L) and AsO2- (5~10 mmol/L), and some of the strains were also less sensitive to Cu2+,Co2+,Ni2+ and Cd2+(MICs≥0.5 mmol/L, some can reach 5 mmol/L). There were differences in the resistance of Frankia strains to heavy metals. Strain Mda21 was sensitive to all heavy metals tested, while Mpa11 was almost resistance to all heavy metals tested, and some strains were less sensitive to several kinds of heavy metals. The lead of low concentration could accelerate growth of leadresistant strains, while lead of high concentration could inhibit its growth. The leadresistant strains have nitrogenase activity in the medium adding lead and nitrogenase activity was higher with the increase of concentration of lead within the extent of concentration of lead. Pb2+ resistance may involve sequestration or binding mechanisms while the resistance mechanisms of Frankia strains to other heavy metals were not clear. 

关 键 词：杨梅 根瘤菌 重金属 抗性 作用机理 弗兰克氏菌 共生固氮 放线菌 

分 类 号：S667.6[农业科学—果树学] S154.383[农业科学—园艺学]