Transcriptome comparison between pluripotent and non-pluripotent calli derived from mature rice seeds

In vitro plant regeneration involves a two-step practice of callus formation and de novo organogenesis. During callus formation, cellular competence for tissue regeneration is acquired, but it is elusive what molecular processes and genetic factors are involved in establishing cellular pluripotency. To explore the mechanisms underlying pluripotency acquisition during callus formation in monocot plants, we performed a transcriptomic analysis on the pluripotent and non-pluripotent rice calli using RNA-seq. We obtained a dataset of differentially expressed genes (DEGs), which accounts for molecular processes underpinning pluripotency acquisition and maintenance. Core regulators establishing root stem cell niche were implicated in pluripotency acquisition in rice callus, as observed in Arabidopsis. In addition, KEGG analysis showed that photosynthetic process and sugar and amino acid metabolism were substantially suppressed in pluripotent calli, whereas lipid and antioxidant metabolism were overrepresented in up-regulated DEGs. We also constructed a putative coexpression network related to cellular pluripotency in rice and proposed potential candidates conferring pluripotency in rice callus. Overall, our transcriptome-based analysis can be a powerful resource for the elucidation of the molecular mechanisms establishing cellular pluripotency in rice callus.