Col-0 transgenic plants expressing MSH1P::FLAG::RPL18 were generated in both msh1 homozygous mutant (SAIL-877-F01) and wild type backgrounds with cloned MSH1 sequence described in Xu et al. (2011) and with transformation by the floral dip method (Clough and Bent, 1998). Positive transgenic lines were screened for FLAG tag by immunoblotting methods. Polysomal mRNA from MSH1-specific cells was obtained by ribosome purification using the TRAP method essentially as reported by (Reynoso et al., 2015) from floral stem tissues. Overall design: Two samples from each Col-0 wild type TRAP, msh1 TRAP, Col-0 Total, and msh1 Total. Floral stem tissue was used.