如何在带有R的pdf中插入可点击链接

我用R pdf()函数保存了一个用R生成的图(见下文).是否可以在此图中添加可点击的超链接？pdf()欢迎替代方案.

pdf(file="plot.pdf",width=20,height=50)
q <- ggplot(df, aes(x=reorder(desc,Value, FUN=median), y=Value))
q + geom_boxplot(aes(fill = factor(role)))+ coord_flip()
dev.off()

其中,df$desc如下所示:

[1] "http://www.jcvi.org/cgi-bin/tigrfams/HmmReportPage.cgi?acc=TIGR02914  #  EpsI_fam: EpsI family protein  # Role: 141"                                        
[2] "http://www.jcvi.org/cgi-bin/tigrfams/HmmReportPage.cgi?acc=TIGR03067  #  Planc_TIGR03067: Planctomycetes uncharacterized domain TIGR03067  # Role: 157"     
[3] "http://www.jcvi.org/cgi-bin/tigrfams/HmmReportPage.cgi?acc=TIGR03021  #  pilP_fam: type IV pilus biogenesis protein PilP  # Role: 91"   

在pdf中,链接不可点击.