The Rhizobium etli trpB gene is essential for an effective symbiotic interaction with Phaseolus vulgaris.
The Rhizobium etli trpB gene is essential for an effective symbiotic interaction with Phaseolus vulgaris.
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DOI：
10.1094/mpmi.1999.12.10.926
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发表时间：
1999-10
期刊：
影响因子：
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通讯作者：
R. Tatè;A. Riccio;E. Caputo;M. Cermola;R. Favre;E. Patriarca
中科院分区：
文献类型：
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作者：
R. Tatè;A. Riccio;E. Caputo;M. Cermola;R. Favre;E. Patriarca
分离并鉴定了一株携带Tn5的etli根瘤菌突变株CTNUX4，该突变株不能以铵作为唯一氮源生长。序列分析表明，Tn5插入到trpB（色氨酸合成酶）同源基因中。菌株CTNUX4在普通菜豆（Phaseolus vulgaris）的根上进行试验时，只能诱导出小的、微粉红色的无效（Fix-）根瘤。然而，在自由生长条件下，除非在生长培养基中添加色氨酸，否则菌株CTNUX4无法产生类黄酮诱导的脂质寡糖（Nod因子）。这些数据和组织学观察表明，缺乏色氨酸的生物合成影响了红毛霉的共生行为。
A mutant strain (CTNUX4) of Rhizobium etli carrying Tn5 unable to grow with ammonium as the sole nitrogen source was isolated and characterized. Sequence analysis showed that Tn5 is inserted into a trpB (tryptophan synthase)-homologous gene. When tested on the roots of Phaseolus vulgaris, strain CTNUX4 was able to induce only small, slightly pink, ineffective (Fix-) nodules. However, under free-living conditions, strain CTNUX4 was unable to produce flavonoid-inducible lipo-chitin oligosaccharides (Nod factors) unless tryptophan was added to the growth medium. These data and histological observations indicate that the lack of tryptophan biosynthesis affects the symbiotic behavior of R. etli.