NEP-TC a rRNA Methyltransferase Involved on Somatic Embryogenesis of Tamarillo (Solanum betaceum Cav.)

Abstract

Somatic embryogenesis (SE) is an important biotechnological tool for large-scale clonal propagation and for embryogenesis research. Moreover, genetic transformation and cryopreservation procedures in many species rely on efficient SE protocols. We have been studying different aspects related to SE induction and somatic embryo development in tamarillo ( Solanum betaceum Cav.), a small tree from the Solanaceae family. Previous proteomic analyses identified a protein (NEP-TC, 26.5 kDa) consistently present in non-embryogenic calluses of tamarillo, but absent in the embryogenic ones. In this work, the role of NEP-TC during SE was assessed by gene expression analysis and immunolocalization. The results obtained demonstrated that NEP-TC is a putative member of the SpoU rRNA methylase family. This protein, present in the cytoplasm and nucleus, is expressed in non-embryogenic cells and not expressed in embryogenic cells. Slightly enhanced SE induction levels in tamarillo plants with NEP-TC down-regulated levels also supports the role of this protein on SE induction. Heterologous expression was used to confirm NEP-TC rRNA methyltransferase activity, with enhanced activity levels when rRNA was used as a substrate. These data relate a putative member of the SpoU methylase family with plant morphogenesis, in particular with SE induction.

Primary Metabolite Screening Shows Significant Differences between Embryogenic and Non-Embryogenic Callus of Tamarillo (Solanum betaceum Cav.)

“…The NEC calli show a greater similarity in the mass ratios but a higher disparity in total protein content. These observations are in accordance with previous studies of these types of calli that have shown EC and NEC callus to be morphologically distinct [31] and present the NEC calli as a highly hydrated tissue. Furthermore, previous studies have shown some differences at the proteomic level on similar callus lines [26] and quantitative and qualitative differences in EC-and NEC-callus-secreted proteins [32].…”

Enhancing the Production of Hydrolytic Enzymes in Elicited Tamarillo (Solanum betaceum Cav.) Cell Suspension Cultures

“…Analysis of ICL cellular protein profiles revealed high expression levels of stress-related proteins [ 11 , 12 ], confirming the role of tissue culture systems in inducing molecular reprogramming. During recent experiments, S. betaceum ICL was grown efficiently as PCSs [ 13 ].…”

Molecular mechanism of somatic embryogenesis in paeonia ostii ‘Fengdan’ based on transcriptome analysis combined histomorphological observation and metabolite determination

“…Sandra Correia investigated the role of the rRNA methyltransferase NEP-TC on somatic embryogenesis in Solanum betaceum Cav. and found that when NEP-TC was down-regulated, the induction level of somatic embryos was slightly increased [ 14 ]. In addition, recent advancements in transgenic technology are providing new insights on the regulation of callus formation [ 15 ].…”