Sugar-binding activity of pea lectin enhances heterologous infection of transgenic alfalfa plants by Rhizobium leguminosarum biovar viciae.
Sugar-binding activity of pea lectin enhances heterologous infection of transgenic alfalfa plants by Rhizobium leguminosarum biovar viciae.
复制标题
豌豆凝集素的糖结合活性增强了豆根瘤菌豌豆变种对转基因苜蓿植物的异源感染。
DOI：
10.1104/pp.126.1.133
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发表时间：
2001
期刊：
影响因子：
7.4
通讯作者：
A. Hirsch
中科院分区：
文献类型：
--
作者：
P. V. Rhijn;N. Fujishige;P. Lim;A. Hirsch
转基因苜蓿（Medicago sativa L.）将大豆凝集素（Soybean lectin）基因和豌豆（Pisum sativum）种子凝集素（PSL）基因分别接种到大豆根瘤菌（Bradyrhizobium japonicum）和豌豆根瘤菌（Rhizobium leguminosarum bv viciae）的根上，并与接种对照的反应进行比较。我们发现根瘤菌只有在产生苜蓿根瘤菌的结瘤因子时才能在苜蓿根上形成根瘤样结构。在很低的接种浓度下，大豆凝集素转基因植物的根上形成了未感染的结节状结构，但即使在B. japonicum产生合适的S.苜蓿结瘤因子与此相反，转PSL基因的植株不仅表现出良好的侵染性，而且表现出侵染线的形成。豆科根瘤菌（Leguminosarum bv viciae）的S.苜蓿nod基因。在转PSL基因植株根部的一些根瘤中，甚至发现了根瘤菌的定殖。豌豆根瘤菌表达S.苜蓿结瘤基因，但植物是黄色和衰老，表明固氮没有发生。外泌多糖似乎是根瘤发育和侵染线形成所绝对需要的，因为在接种Exo（-）R后的转PSL基因植物根中两者都没有发生。蚕豆根瘤菌产生S.苜蓿结瘤因子
Transgenic alfalfa (Medicago sativa L. cv Regen) roots carrying genes encoding soybean lectin or pea (Pisum sativum) seed lectin (PSL) were inoculated with Bradyrhizobium japonicum or Rhizobium leguminosarum bv viciae, respectively, and their responses were compared with those of comparably inoculated control plants. We found that nodule-like structures formed on alfalfa roots only when the rhizobial strains produced Nod factor from the alfalfa-nodulating strain, Sinorhizobium meliloti. Uninfected nodule-like structures developed on the soybean lectin-transgenic plant roots at very low inoculum concentrations, but bona fide infection threads were not detected even when B. japonicum produced the appropriate S. meliloti Nod factor. In contrast, the PSL-transgenic plants were not only well nodulated but also exhibited infection thread formation in response to R. leguminosarum bv viciae, but only when the bacteria expressed the complete set of S. meliloti nod genes. A few nodules from the PSL-transgenic plant roots were even found to be colonized by R. leguminosarum bv viciae expressing S. meliloti nod genes, but the plants were yellow and senescent, indicating that nitrogen fixation did not take place. Exopolysaccharide appears to be absolutely required for both nodule development and infection thread formation because neither occurred in PSL-transgenic plant roots following inoculation with an Exo(-) R. leguminosarum bv viciae strain that produced S. meliloti Nod factor.