拟南芥WRKY48转录调控因子调控植物病毒系统侵染的分子机制研究

The WRKY gene family is widely involved in plant stress signaling pathways and plays important roles in the regulation of transcriptional reprogramming associated with plant stress responses. Our recent study demonstrated that WRKY48 may participate in the regulation of plant antivirus defence response. Gene expression analysis showed that WRKY48 was induced by wounding and ABA treatment，while suppressed by TMV-Cg infection. Analysis using the wrky48 mutant demonstrated that WRKY48 is involved in the regulation of TMV-Cg's systemic transportation and accumulation in plants. Further analysis showed that the expression of beta-1,3-glucanase 2 in systemic leaves of wrky48 mutant were 5 fold stronger than that of WT's after infection by TMV-Cg for 6 days. Both yeast two-hybrid experiment and BiFC analysis showed that WRKY48 interacted with ATG8i in the protein level, implying that autophagy may also involve in plant antivirus defence response. Based on these results, we will further explore the molecular function of WRKY48 transcription factor in the regulation of plant antivirus defence response, aiming to the identification of WRKY48's direct target genes and interacting partners， and illustrating the signaling pathway and molecular mechanism of plant antivirus defence response that controlled by WRKY48.

WRKY基因家族广泛参与植物逆境信号转导过程，在调控植物响应逆境胁迫过程中发挥重要功能。我们最近的研究结果表明WRKY48参与调控植物抗病毒信号转导过程。基因表达分析表明WRKY48受伤害和ABA等诱导表达而受TMV-Cg抑制表达。利用wrky48突变体分析证实，WRKY48参与调控了植物病毒TMV-Cg在植株系统性叶片中的运输与积累，同时在TMV-Cg侵染6天后的wrky48突变体中beta-1,3-glucanase 2的表达要比WT中提高5倍。利用酵母双杂交及BiFC实验证实WRKY48和ATG8i在蛋白水平上发生相互作用，暗示植物自嗜途径可能参与调控植物对病毒侵染反应的响应过程。在此基础上我们将进一步分析WRKY48调控植物抗病毒方面的分子生物学功能，寻找WRKY48的直接调控靶基因及相互作用蛋白，详细阐明WRKY48调控植物抗病毒建立的信号转导途径及分子生物学机制。

WRKY基因家族广泛参与植物逆境信号转导过程，在调控植物响应逆境胁迫过程中发挥重要功能。我们的研究表明AtWRKY48参与调控植物抗病毒信号转导过程。基因表达分析表明AtWRKY48受伤害和ABA等诱导表达而受TMV-Cg抑制表达。利用wrky48突变体及高表达植株分析证实，AtWRKY48参与调控了植物病毒TMV-Cg在植株系统性叶片中的运输与积累，同时在TMV-Cg侵染6天后的wrky48突变体中beta-1,3-glucanase 2（PR2）的表达要比WT中提高5倍。利用酵母双杂交及BiFC实验证实AtWRKY48和DELLA在蛋白水平上发生相互作用，暗示植物赤霉素途径途径可能参与调控植物对病毒侵染反应的响应过程。进一步研究发现WRKY48可以直接抑制PR2的表达，而AtWRKY48与RGL1的互作可以部分解除WRKY48对PR2的抑制作用。同时PR2能抑制病毒在植株系统性叶片中的运输与积累。我们的研究结果证实WRKY48通过与DELLA蛋白互作并通过直接调控PR2的表达来调控植株对病毒的抗性过程。我们的研究结果为未来利用生物技术手段调控植物病毒抗性提供了理论依据。