Małek W, Kowalski M
Acta Microbiol Pol. 1977;26(4):351-9.
Nodules produced by ineffective mutants of R. meliloti strain L5-30 requiring arginine+uracil (arg-55) and cysteine requiring mutants (cys-243, cys-244, cys-246) studied under light microscopy were found to be occupied by bacteria. This indicates on defect in transformation of these mutants into N2 fixing bacteroids. These defects were not associated with auxotrophy. In the nodules induced by histidine requiring mutant (his-240) only few host plant cells were occupied by bacteria. This indicate that his-240 mutant is defective in liberation from the infection thread and its multiplication since supplementation of the plant growth medium with 50 microgram/ml of L-histidine enabled establishment of fully effective association. Prototrophic transductants and revertants were fully effective.
在光学显微镜下研究发现，苜蓿中华根瘤菌L5 - 30株系的无效突变体（需要精氨酸 + 尿嘧啶的arg - 55突变体和需要半胱氨酸的突变体cys - 243、cys - 244、cys - 246）所产生的根瘤被细菌占据。这表明这些突变体在转化为固氮类菌体方面存在缺陷。这些缺陷与营养缺陷型无关。在由需要组氨酸的突变体（his - 240）诱导形成的根瘤中，只有少数宿主植物细胞被细菌占据。这表明his - 240突变体在从感染丝中释放及其增殖方面存在缺陷，因为在植物生长培养基中添加50微克/毫升的L - 组氨酸能够建立完全有效的共生关系。原养型转导子和回复突变体是完全有效的。
