Ectopic Expression of Xylella fastidiosa rpfF Conferring Production of Diffusible Signal Factor in Transgenic Tobacco and Citrus Alters Pathogen Behavior and Reduces Disease Severity
Ectopic Expression of Xylella fastidiosa rpfF Conferring Production of Diffusible Signal Factor in Transgenic Tobacco and Citrus Alters Pathogen Behavior and Reduces Disease Severity
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DOI：
10.1094/mpmi-07-17-0167-r
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发表时间：
2017-11-01
影响因子：
3.5
通讯作者：
De Souza, A. A.
中科院分区：
文献类型：
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作者：
Caserta, R.;Souza-Neto, R. R.;De Souza, A. A.
苛养木杆菌的致病性与其在寄主植物木质部的定殖能力有关。有助于木质部定殖的基因的表达被抑制，而昆虫载体收购所必需的那些随着扩散信号因子（DSF）浓度的增加而增加，其产生依赖于RpfF。我们以前证明，转基因柑橘植物异位表达的rpfF从柑橘株X。苛养亚种对柑橘黄单胞菌的敏感性较低。柑橘，另一种毒力受DSF积累调节的病原体。在这里，我们证明了转基因烟草和甜橙子中rpfF的异位表达也降低了由X. fastidiosa并减少其对那些植物的定殖。转基因植物中疾病严重程度的降低通常与赋予病原体抗性的基因的表达增加和主动运动所必需的基因的表达减少有关，这是植物中实现的种群规模减少的原因，显然是通过限制病原体在植物中的传播。因此，可以利用宿主植物中的植物来源的DSF信号分子来干扰多于一种的病原体，所述病原体的毒力由DSF信号传导控制。
The pathogenicity of Xylella fastidiosa is associated with its ability to colonize the xylem of host plants. Expression of genes contributing to xylem colonization are suppressed, while those necessary for insect vector acquisition are increased with increasing concentrations of diffusible signal factor (DSF), whose production is dependent on RpfF. We previously demonstrated that transgenic citrus plants ectopically expressing rpfF from a citrus strain of X. fastidiosa subsp. pauca exhibited less susceptibility to Xanthomonas citri subsp. citri, another pathogen whose virulence is modulated by DSF accumulation. Here, we demonstrate that ectopic expression of rpfF in both transgenic tobacco and sweet orange also confers a reduction in disease severity incited by X. fastidiosa and reduces its colonization of those plants. Decreased disease severity in the transgenic plants was generally associated with increased expression of genes conferring adhesiveness to the pathogen and decreased expression of genes necessary for active motility, accounting for the reduced population sizes achieved in the plants, apparently by limiting pathogen dispersal through the plant. Plant-derived DSF signal molecules in a host plant can, therefore, be exploited to interfere with more than one pathogen whose virulence is controlled by DSF signaling.