1. Load data and set up a function that creates region tags:

library(SummarizedExperiment) 
arab_rse <- readRDS(file.path(getwd(), "datasets", "ch1", "arabidopsis_rse.RDS") ) 

 make_tag <- function(grange_obj){
     paste0( 
        grange_obj@seqnames, 
        ":", 
        grange_obj@ranges@start, 
        "-", 
        (grange_obj@ranges@start + grange_obj@ranges@width) 
    ) 
}

2. Extract data and annotate rows:

counts <- assay(arab_rse)

if ( ! is.null(names(rowRanges(arab_rse))) ){
  rownames(counts) <- names(rowRanges(arab_rse))
} else {
  rownames(counts) <- make_tag(rowRanges(arab_rse))
}