十字花科黑腐病菌中一个与HR反应相关的小RNA的鉴定

Identification of a HR-related Small RNA in Xanthomonas campestris pathovar campestris

十字花科黑腐病菌(Xanthomonas campestris pv.campertris,简称Xcc)可以引起寄主植物萝卜、白菜、芥菜等十字花科植物的黑腐病,也可以引起非寄主植物辣椒的高敏反应(hypersensitive response,HR)。最近的研究发现,在一些动植物病原细菌中,除蛋白外,小RNA也在致病和HR反应中起关键的作用。但是,到目前为止,小RNA是否在Xcc的致病和HR反应中起重要作用尚不清楚。在前期工作中,我们采用RNA深度测序(RNA-Seq)方法,在Xcc中鉴定了五百多个候选小RNA,但它们的功能还不清楚。在本研究中,我们对小RNA s RXcc52的生物学功能进行了研究,结果发现,小RNA s RXcc52的过量表达株(OE52)在辣椒上引起HR反应的时间比带有一个空的过量表达载体质粒的野生型菌株(WT/p BBad)的时间提前了2 h。这个结果表明,s RXcc52与Xcc的HR反应有关。我们的结果为深入研究小RNA在Xcc的HR反应中的作用打下了基础。

Xanthomonas campestris pv. campestris(Xcc) causes black rot disease on cruciferous plants such as turnip and triggers hypersensitive response(HR) on the nonhost plant pepper. Recent studies have been shown that,in addition to protein, small RNA(s RNA) plays a key role in the pathogenesis and HR of some animal and plant pathogenic bacteria. However, up to date, whether s RNA is involved in the pathogenesis and HR of Xcc is till unclear. In a previous work, we identified more than 500 s RNAs in Xcc by RNA-seq. In this work, we investigate the biological function of the s RNA s RXcc52 and found that the over-expression strain(OE52) of this s RNA displays an enhanced HR on the nonhost plant pepper compare to the wild type strain containing a empty over-expression vector(wt/p BBad), indicating that s RXcc52 is involved in the HR of Xcc. Our results provided the first step towards the understanding of the role of s RNA in HR of Xcc.