In tobacco, three sequence variants of the TERT gene have been described. We revealed unbalanced levels of TERT variant transcripts in vegetative tobacco tissues and enhanced TERT transcription and telomerase activity in reproductive tissues. Telomerase is a ribonucleoprotein complex responsible for the maintenance of telomeres, structures delimiting ends of linear eukaryotic chromosomes. In the Nicotiana tabacum (tobacco) allotetraploid plant, three sequence variants (paralogs) of the gene coding for the telomerase reverse transcriptase subunit (TERT) have been described, two of them derived from the maternal N. sylvestris genome (TERT_Cs, TERT_D) and one originated from the N. tomentosiformis paternal genome (TERT_Ct). In this work, we analyzed the transcription of TERT variants in correlation with telomerase activity in tobacco tissues. High and approximately comparable levels of TERT_Ct and TERT_Cs transcripts were detected in seedlings, roots, flower buds and leaves, while the transcript of the TERT_D variant was markedly underrepresented. Similarly, in N. sylvestris tissues, TERT_Cs transcript significantly predominated. A specific pattern of TERT transcripts was found in samples of tobacco pollen with the TERT_Cs variant clearly dominating particularly at the early stage of pollen development. Detailed analysis of TERT_C variants representation in functionally distinct fractions of pollen transcriptome revealed their prevalence in large ribonucleoprotein particles encompassing translationally silent mRNA; only a minority of TERT_Ct and TERT_Cs transcripts were localized in actively translated polysomes. Histones of the TERT_C chromatin were decorated predominantly with the euchromatin-specific epigenetic modification in both telomerase-positive and telomerase-negative tobacco tissues. We conclude that the existence and transcription pattern of tobacco TERT paralogs represents an interesting phenomenon and our results indicate its functional significance. Nicotiana species have again proved to be appropriate and useful model plants in telomere biology studies.

Institute of Biophysics Academy of Sciences of the Czech Republic v v i Královopolská 135 612 65 Brno Czech Republic

Institute of Experimental Botany Academy of Sciences of the Czech Republic v v i Rozvojová 263 165 02 Prague Czech Republic

Mendel Centre for Plant Genomics and Proteomics Central European Institute of Technology and Faculty of Science Masaryk University Kamenice 5 625 00 Brno Czech Republic

Zobrazit více v PubMed

Mol Genet Genomics. 2010 Mar;283(3):233-41 PubMed

Plant J. 2003 May;34(3):283-91 PubMed

Mol Biol Cell. 2007 Feb;18(2):669-77 PubMed

Mol Gen Genet. 1996 Sep 13;252(3):342-5 PubMed

Plant Cell. 1998 Oct;10(10):1691-8 PubMed

J Exp Bot. 2011 Nov;62(15):5531-45 PubMed

J Exp Bot. 2012 Jun;63(11):4233-41 PubMed

Protoplasma. 2006 Aug;228(1-3):73-7 PubMed

Proc Natl Acad Sci U S A. 1996 Dec 10;93(25):14422-7 PubMed

Proc Natl Acad Sci U S A. 2011 Jan 4;108(1):73-78 PubMed

FEBS Lett. 1996 Aug 12;391(3):307-9 PubMed

Plant Reprod. 2016 Jun;29(1-2):31-51 PubMed

Cancer Res. 2005 Sep 1;65(17):7585-90 PubMed

Front Plant Sci. 2014 Nov 04;5:593 PubMed

Annu Rev Plant Biol. 2011;62:461-84 PubMed

Ann Bot. 2008 Apr;101(6):815-23 PubMed

Mol Gen Genet. 1995 Jun 10;247(5):633-8 PubMed

Mol Biol Evol. 2011 Oct;28(10):2843-54 PubMed

J Biol Chem. 1999 Jul 23;274(30):20997-1002 PubMed

Plant Cell. 2007 Jan;19(1):23-31 PubMed

J Proteome Res. 2009 Apr;8(4):2015-31 PubMed

Genom Data. 2014 Dec 23;3:106-11 PubMed

Am J Bot. 2002 Jun;89(6):921-8 PubMed

Development. 1998 Oct;125(19):3789-99 PubMed

Mol Gen Genet. 1998 Dec;260(5):470-4 PubMed

Plant J. 2002 Mar;29(5):617-26 PubMed

Plant Mol Biol. 2015 Apr;87(6):591-601 PubMed

Nat Protoc. 2006;1(3):1583-90 PubMed

Plant Mol Biol. 2008 Apr;66(6):637-46 PubMed

FEBS Lett. 1995 May 1;364(1):33-5 PubMed

Chromosome Res. 2012 May;20(4):381-94 PubMed

Science. 2001 Dec 21;294(5551):2507-11 PubMed

Origin and Fates of TERT Gene Copies in Polyploid Plants

Composition and Function of Telomerase-A Polymerase Associated with the Origin of Eukaryotes

Telomeres in Plants and Humans: Not So Different, Not So Similar

Dynamics of the Pollen Sequestrome Defined by Subcellular Coupled Omics

Evolutionary history of callose synthases in terrestrial plants with emphasis on proteins involved in male gametophyte development