De novo characterization of the Iris lactea var. chinensis transcriptome and an analysis of genes under cadmium or lead exposure

- Iris lactea var. chinensis is tolerant to accumulations of cadmium and lead.
- The transcriptome of Iris lactea var. chinensis was investigated under cadmium or lead stress.
- Provide a resource for identifying common mechanisms in the detoxification of different heavy metals.

Iris lactea var. chinensis (I. lactea var. chinensis) is tolerant to accumulations of cadmium (Cd) and lead (Pb). In this study, the transcriptome of I. lactea var. chinensis was investigated under Cd or Pb stresses. Using the gene ontology database, 31,974 unigenes were classified into biological process, cellular component and molecular function. In total, 13,132 unigenes were involved in enriched Encyclopedia of Genes and Genomes (KEGG) metabolic pathways, and the expression levels of 5904 unigenes were significantly changed after exposure to Cd or Pb stresses. Of these, 974 were co-up-regulated and 1281 were co-down-regulated under the two stresses. The transcriptome expression profiles of I. lactea var. chinensis under Cd or Pb stresses obtained in this study provided a resource for identifying common mechanisms in the detoxification of different heavy metals. Furthermore, the identified unigenes may be used for the genetic breeding of heavy-metal tolerant plants.

Differential gene expression analyses of the I. lactea var. chinensis transcriptome after exposure to Pb and Cd are shown in Venn diagrams. (A) Up-regulated unigenes; (B) Down-regulated unigenes.98