An experimental test of the rhizopine concept Rhizobium meliloti
An experimental test of the rhizopine concept Rhizobium meliloti
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DOI：
10.1128/aem.62.11.3991-3996.1996
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发表时间：
1996-11-01
影响因子：
4.4
通讯作者：
Murphy, PJ
中科院分区：
文献类型：
--
作者：
Gordon, DM;Ryder, MH;Murphy, PJ
在一些根瘤菌-豆科植物共生中，称为根瘤菌碱的化合物由类细菌合成，随后由生产菌株的自由活细胞分解代谢。有研究表明，根际碱作为一种专有的生长基质，在与根际微生物群落的相互作用中增强了生产菌株的竞争能力。将产生根瘤素的野生型meliloti根瘤菌L5-30和缺乏根瘤素合成或分解代谢的突变株L5-30接种到苜蓿寄主植物上进行竞争试验。这些实验表明，合成根碱的能力并没有明显的优势，而当生物体与没有这种能力的菌株竞争时，分解根碱的能力提供了明显的优势。结果表明，当生物体与缺乏分解代谢的突变体竞争时，分解根瘤素的能力会导致结瘤率的提高。实验结果与根际碱的唯一作用是作为生产菌株自由生活群体的专有生长基质的假设不一致。
In some Rhizobium-legume symbioses, compounds known as rhizopines are synthesized by bacteroids and subsequently catabolized by free-living cells of the producing strain. It has been suggested than rhizopines act as proprietary growth substrates and enhance the competitive ability of the producing strain in its interactions with the diverse microbial community found within the rhizosphere. Wild-type, rhizopine-producing Rhizobium meliloti L5-30 and mutant L5-30 strains deficient for either rhizopine synthesis or catabolism were inoculated onto lucerne host plants in competition experiments. These experiments demonstrated that no apparent advantage resulted from the ability to synthesize a rhizopine, whereas the ability to catabolize rhizopine provided a clear advantage when an organism was in competition with a strain without this ability. The results suggest that when an organism is in competition with a catabolism-deficient mutant, the ability to catabolize rhizopine results in enhanced rates of nodulation. The results of the experiments were not consistent with the hypothesis that the sole role of rhizopines is to act as proprietary growth substrates for the free-living population of the producing strain.