The Fusarium oxysporum Avr2-Six5 Effector Pair Alters Plasmodesmatal Exclusion Selectivity to Facilitate Cell-to-Cell Movement of Avr2
The Fusarium oxysporum Avr2-Six5 Effector Pair Alters Plasmodesmatal Exclusion Selectivity to Facilitate Cell-to-Cell Movement of Avr2
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DOI：
10.1016/j.molp.2018.02.011
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发表时间：
2018-05-07
期刊：
影响因子：
27.5
通讯作者：
Takken, Frank L. W.
中科院分区：
文献类型：
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作者：
Cao, Lingxue;Blekemolen, Mila C.;Takken, Frank L. W.
病原体使用效应蛋白来操纵它们的宿主。在番茄感染期间，尖孢镰刀菌分泌效应子Avr 2和Six 5。Avr 2足以在异源系统中触发I-2介导的细胞死亡，而这两种效应子都是番茄中I-2介导的抗病性所需的。Six 5如何参与触发耐药性尚不清楚。使用双分子荧光互补测定，我们发现Avr 2和Six 5在胞间连丝处相互作用。单细胞转化显示，2xRFP标记蛋白和Avr 2-GFP仅在Six 5存在下移动到相邻细胞。Six 5单独不改变胞间连丝转导，因为2xRFP仅在两种效应物存在下易位。在SIX 5表达的转基因植物中，病毒表达的Avr 2-GFP的分布以及随后I-2介导的细胞死亡的发生与野生型番茄中的不同。总之，我们的数据表明，在Six 5的存在下，Avr 2从细胞移动到细胞，这在易感植物中有助于毒力，但在含I-2的植物中诱导抗性。
Pathogens use effector proteins to manipulate their hosts. During infection of tomato, the fungus Fusarium oxysporum secretes the effectors Avr2 and Six5. Whereas Avr2 suffices to trigger I-2-mediated cell death in heterologous systems, both effectors are required for I-2-mediated disease resistance in tomato. How Six5 participates in triggering resistance is unknown. Using bimolecular fluorescence complementation assays we found that Avr2 and Six5 interact at plasmodesmata. Single-cell transformation revealed that a 2xRFP marker protein and Avr2-GFP only move to neighboring cells in the presence of Six5. Six5 alone does not alter plasmodesmatal transduction as 2xRFP was only translocated in the presence of both effectors. In SIX5-expressing transgenic plants, the distribution of virally expressed Avr2-GFP, and subsequent onset of I-2-mediated cell death, differed from that in wild-type tomato. Taken together, our data show that in the presence of Six5, Avr2 moves from cell to cell, which in susceptible plants contributes to virulence, but in I-2 containing plants induces resistance.