Molecular identification and characterization of the tomato flagellin receptor LeFLS2, an orthologue of Arabidopsis FLS2 exhibiting characteristically different perception specificities
Molecular identification and characterization of the tomato flagellin receptor LeFLS2, an orthologue of Arabidopsis FLS2 exhibiting characteristically different perception specificities
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DOI：
10.1007/s11103-007-9173-8
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发表时间：
2007-07-01
影响因子：
5.1
通讯作者：
Boller, Thomas
中科院分区：
文献类型：
--
作者：
Robatzek, Silke;Bittel, Pascal;Boller, Thomas
已知细菌鞭毛蛋白可以刺激哺乳动物和植物的宿主免疫反应。在拟南芥中，受体激酶Fls2通过与鞭毛蛋白N端的一个高度保守的表位相互作用来介导鞭毛蛋白的感知，该表位以来自紫丁香假单胞菌的肽flg22为代表。多肽flg22在许多植物物种中作为激发子具有很高的活性。相反，来自大肠杆菌的同一表位的一个缩短版本flg15(大肠杆菌)在番茄中作为激发子具有很高的活性，但在拟南芥或本氏烟草中不具有激发子活性。在这里，我们利用这些物种特有的鞭毛蛋白感知能力的差异来确定LeFls2是番茄中的鞭毛蛋白受体。LeFls2与AtFls2的亲缘关系最近，可能代表番茄的鞭毛蛋白受体。LeFLS2基因在拟南芥中的表达并没有导致其相应基因产物的积累，这一点通过LeFLS2-GFP融合的实验表明。相反，LeFls2-GFP融合基因在本氏番茄中的表达明显是功能性的，与番茄一样属于茄科植物。N.benthamiana植物瞬时表达LeFLS2-GFP融合基因，获得了对flg15(大肠杆菌)的反应性，而它们通常对flg15没有反应。因此，LeFLS2编码一种功能性的、特异的鞭毛蛋白受体，这是第一个在十字花科以外的植物家族中发现的受体。
Bacterial flagellin is known to stimulate host immune responses in mammals and plants. In Arabidopsis thaliana, the receptor kinase FLS2 mediates flagellin perception through physical interaction with a highly conserved epitope in the N-terminus of flagellin, represented by the peptide flg22 derived from Pseudomonas syringae. The peptide flg22 is highly active as an elicitor in many plant species. In contrast, a shortened version of the same epitope derived from Escherichia coli, flg15(E coli), is highly active as an elicitor in tomato but not in A. thaliana or Nicotiana benthamiana. Here, we make use of these species-specific differences in flagellin perception abilities to identify LeFLS2 as the flagellin receptor in tomato. LeFLS2 is most closely related to AtFLS2, indicating that it may represent the flagellin receptor of tomato. Expression of the LeFLS2 gene in Arabidopsis did not result in accumulation of its corresponding gene product, as indicated by experiments with LeFLS2-GFP fusions. In contrast, expression of LeFLS2-GFP fusions in N. benthamiana, a species that, like tomato, belongs to the Solanaceae, was obviously functional. N. benthamiana plants transiently expressing a LeFLS2-GFP fusion acquired responsiveness to flg15(E coli) to which they are normally unresponsive. Thus, LeFLS2 encodes a functional, specific flagellin receptor, the first to be identified in a plant family other than the Brassicaceae.