IRON-DEFICIENCY INDUCED BY CHRYSOBACTIN IN SAINTPAULIA LEAVES INOCULATED WITH ERWINIA-CHRYSANTHEMI
IRON-DEFICIENCY INDUCED BY CHRYSOBACTIN IN SAINTPAULIA LEAVES INOCULATED WITH ERWINIA-CHRYSANTHEMI
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DOI：
10.1104/pp.102.3.967
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发表时间：
1993-07-01
期刊：
影响因子：
7.4
通讯作者：
EXPERT, D
中科院分区：
文献类型：
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作者：
NEEMA, C;LAULHERE, JP;EXPERT, D
在这篇通讯中，我们研究了由菊花Erwinia对其宿主Saintpaulia ionantha引起的软腐病发病过程中铁的命运。由这种肠杆菌引起的软腐病的传播先前被证明依赖于一个功能性基因位点，该基因位点编码一个高亲和力的铁同化系统，该系统涉及儿茶酚型铁载体黄曲蛋白。对健康植物叶片胞间液中的铁含量及其对细菌生长的可利用性进行了分析。使用一种基于离子交换树脂的铁结合特性的新方法，将其与来自患病植物的液体进行比较，以确定强铁配体的存在。进一步的表征允许在病变组织中鉴定黄曲蛋白，从而为在发病过程中外部释放微生物铁载体提供了第一个证据。还通过植物-细菌细胞系统研究了营养铁的竞争：在细菌处理的悬浮大豆细胞中，纳入植物铁蛋白的铁似乎大大减少。同样的效果在大豆细胞用菊花接种的圣保利叶的细胞间液或用黄曲霉素处理时也可见。
In this communication, we examine the fate of iron during soft rot pathogenesis caused by Erwinia chrysanthemi on its host, Saintpaulia ionantha. The spread of soft rot caused by this enterobacterium was previously shown to depend on a functional genetic locus encoding a high-affinity iron assimilation system involving the catechol-type siderophore chrysobactin. Leaf intercellular fluid from healthy plants was analyzed with regard to the iron content and its availability for bacterial growth. It was compared to the fluid from diseased plants for the presence of strong iron ligands, using a new approach based on the iron-binding property of an ion-exchange resin. Further characterization allowed the identification of chrysobactin in diseased tissues, thus providing the first evidence for the external release of a microbial siderophore during pathogenesis. Competition for nutritional iron was also studied through a plant-bacterial cell system: iron incorporated into plant ferritin appeared to be considerably reduced in bacteria-treated suspension soybean cells. The same effect was visualized during treatment of soybean cells with axenic leaf intercellular fluid from E. chrysanthemi-inoculated saintpaulia leaves or with chrysobactin.