xml xsl transform match tags in entire document

I have xml document, which needs xsl(xsl-fo) transformation to be applied for pdf generation in child nodes containing specific tag, like "bold", "italics", etc.

<root>
  <first><inner>This is 1. <bold>important</bold>, so what</inner></first>
  <first><inner>This is 2. <bold>important</bold>, so what what</inner></first>
  <second><inner2>This is 3. <bold>important</bold>, so what</inner2></second>
  <third><inner3>This is 4. <bold>important</bold>, so what</inner3></third>
</root>

I have tried,

<xsl:template match="bold">
  <fo:inline font-weight="bold">
    <xsl:apply-templates/>
  </fo:inline>
</xsl:template>

But it doesn't seems to work.

Thanks in advance for all your help.