Rhizobial Diversity and Nodulation Characteristics of the Extremely Promiscuous Legume Sophora flavescens
Rhizobial Diversity and Nodulation Characteristics of the Extremely Promiscuous Legume Sophora flavescens
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极度混交豆科植物苦参根瘤菌多样性及结瘤特性
DOI：
10.1094/mpmi-06-15-0141-r
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发表时间：
2015-12-01
影响因子：
3.5
通讯作者：
Chen, Wen Feng
中科院分区：
文献类型：
--
作者：
Jiao, Yin Shan;Liu, Yuan Hui;Chen, Wen Feng
本文报道了含苦参碱的药用豆科植物苦参（Sophora flavescens）根瘤菌的多样性和生物地理特征。此外，我们还研究了不同根瘤菌侵染后黄参根瘤的交叉结瘤、侵染模式、光镜和电镜。在自然土壤中发现根瘤菌属5属17个基因种，共7种nodC基因。在交叉结瘤试验中；α -变形菌纲的代表性根瘤菌，其寄主植物属于不同的交叉结瘤类群，大多数形成有效的不确定根瘤，而β -变形菌纲的代表性根瘤菌在S. flavescens上形成无效的根瘤。豆科根瘤菌的高度寄主特异性生物变异。沃尔夫走过。葡萄球菌)和根瘤菌。这进一步证明了黄菖蒲是一种极混杂的豆科植物，它对根瘤菌的共生基因和决定种的内务基因都没有严格的选择性。根毛感染的模式是根瘤菌进入卷曲的根毛。不同根瘤菌形成的黄参根瘤的超薄切片电镜显示，类杆菌为规则或不规则的棒状和非肿胀型。一些类细菌含有聚β -羟基丁酸酯（PHB），而另一些则不含有，这表明类细菌中PHB的合成依赖于根瘤菌。黄葡萄与不同根瘤菌的极混杂共生关系为进一步研究根瘤菌与豆科植物的分子相互作用提供了基础。
In present study, we report our extensive survey on the diversity and biogeography of rhizobia associated with Sophora flavescens, a sophocarpidine (matrine)-containing medicinal legume. We additionally investigated the cross nodulation, infection pattern, light and electron microscopies of root nodule-sections of S. flavescens infected by various rhizobia. Seventeen genospecies of rhizobia belonging to five genera with seven types of symbiotic nodC genes were found to nodulate S. flavescens in natural soils. In the cross-nodulation tests;most representative rhizobia in class alpha-Proteobacteria, whose host plants belong to different cross-nodulation groups, form effective indeterminate nodules, while representative rhizobia in class beta-Proteobacteria form ineffective nodules on S. flavescens. Highly host-specific biovars of Rhizobium leguminosarum (bv. Wolff and by. viciae) and Rhizobium etli by. phaseoli could establish symbioses with S. flavescens, providing further evidence that S. flavescens is an extremely promiscuous legume and it does not have strict selectivity on either the symbiotic genes or the species-determining housekeeping genes of rhizobia. Root-hair infection is found as the pattern-that rhizobia have gained entry into the curled root hairs. Electron microscopies of ultra-thin sections of S. flavescens root nodules formed by different rhizobia show that the bacteroids are regular or irregular rod shape and nonswollen types. Some bacteroids contain poly-beta-hydroxybutyrate (PHB), while others do not, indicating the synthesis of PHB in bacteroids is rhizobia-dependent. The extremely promiscuous symbiosis between S. flavescens and different rhizobia provide us a basis for future studies aimed at understanding the molecular interactions of rhizobia and legumes.