Plant Defense-related Transcription Factor WTRKY6 Plays Both Supportive and Inhibitory Roles in Tobacco mosaic virus Infection

與植物抗病相關之轉錄因子WRKY6在煙草嵌紋病毒感染過程中扮演支持與抑制病毒之雙重角色

陳正恩(Cheng-En Chen) ； 葉信宏(Hsin-Hung Yeh)

《植物病理學會刊》 19卷1期 (2010/03) Pp. 31-40

https://doi.org/10.6649/PPB.201003_19(1).0004

摘要

病毒侵染寄主時，是否可以成功進行複製並完成生活史乃是取決於和寄主產生的交互作用。爲了瞭解病毒感染早期所調控的寄主反應，我們以Microarray系統的分析菸草嵌紋病毒(Tobacco mosaic virus, TMV)感染初期（4小時）會對阿拉伯芥的轉錄體造成哪些影響？結果顯示約2%的寄主基因在TMV感染初期有被顯著的調控（變化大於2倍），而僅有8個基因的變化大於3倍，8個基因中和轉錄調控相關的基因佔了4個。進一步挑選其中一個目標基因WRKY6 transcription factor進行分析。於先前研究已知，WRKY6和許多植物生理功能的調節相關，包括植物的抗性反應、發育以及植物對磷、硼元素缺乏的敏感性皆會受WRKY6影響。在TMV感染WRKY6大量表現或抑制表現的原生質體中，TMV於34小時內的累積量未受到明顯影響；但TMV的累積量在WRKY6大量表現或抑制表現的植物中皆會受到抑制。顯示WRKY6並非是病毒感染初期的所需因子，但WRKY6在植物中同時扮演了促進和抑制病毒感染的角色。

關鍵字

菸草嵌紋病毒 ； 阿拉伯芥 ； Microarray ； WRKY6

並列摘要

The initial stage of crosstalk between a virus and host may determine the successful replication and further infection by the virus. To understand the early stage of host gene regulation in response to viral infection, we used a microarray assay to analyze protoplasts of Arabidopsis thaliana 4 hr after their inoculation with Tobacco mosaic virus (TMV). Approximately only 2% of the host genes showed greater than 2-fold changed expression, and only 8 genes showed greater than 3-fold changed expression. Four of the 8 genes are involved in transcriptional regulation. We selected a versatile transcription factor, WRKY6, involved in plant resistance. development and plant sensitivity in response to phosphorus and boron deficiency for further analysis, Protoplasts derived from WRKY6-overexpressed or-knockout plants were inoculated with TMV, and the accumulation of TMV was not affected 24 hr post-inoculation. However, TMV accumulation was inhibited in both WRKY6-overexpressed and -knockout plants as compared with wild-type inoculated plans. Therefore, WRKY6 may not be essential in the initial establishment of virus infection but may have dual roles in support and inhibition of virus infection.

並列關鍵字

Tobacco mosaic virus ； Arabidopsis thaliana ； Microarray ； WRKY6