r - Add additional text to string -

how add additional text p= before values in data frame? use gsub?

> pvaluesmir21    seqbuster_filter_mm_mir21_5p$fdr 1                      8.326135e-02 2                      6.336574e-05 3                      3.233019e-17 4                      4.800951e-22 5                      3.054728e-10 6                      6.697357e-11 

it more natural use paste or sprintf

 pvaluemir21[,1] <- paste('p =', pvaluemir21[,1]) 

or

 pvaluemir21[,1] <- sprintf('p = %f', pvaluemir21[,1]) 

but sub can used

 pvaluemir21[,1] <- sub('(.*)', 'p=\\1', pvaluesmir21[,1])