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Article|01 Jun 2021|OPEN
Tissue and regional expression patterns of dicistronic tRNA–mRNA transcripts in grapevine (Vitis vinifera) and their evolutionary co-appearance with vasculature in land plants
Pastor Jullian Fabres1,2, Lakshay Anand2, Na Sai1,3, Stephen Pederson4, Fei Zheng1,3, Alexander A. Stewart2, Benjamin Clements2, Edwin R. Lampugnani5, James Breen4, Matthew Gilliham1,3,6, Penny Tricker1, Rakesh David1,3 & Carlos M. Rodríguez López2,
1School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA, Australia
2Environmental Epigenetics and Genetics Group, Department of Horticulture, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA
3ARC Centre of Excellence in Plant Energy Biology, Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA, Australia
4Bioinformatics Hub, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
5School of Biosciences, University of Melbourne, Parkville, VIC 3010, Australia
6ARC Industrial Transformation Training Centre in Innovative Wine Production, Waite Research Institute & School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA, Australia

Horticulture Research 8,
Article number: 137 (2021)
doi: 10.1038/hortres.2021.137
Views: 161

Received: 10 Aug 2020
Revised: 13 Apr 2020
Accepted: 19 Apr 2021
Published online: 01 Jun 2021

Abstract

Transfer RNAs (tRNA) are crucial adaptor molecules between messenger RNA (mRNA) and amino acids. Recent evidence in plants suggests that dicistronic tRNA-like structures also act as mobile signals for mRNA transcripts to move between distant tissues. Co-transcription is not a common feature in the plant nuclear genome and, in the few cases where polycistronic transcripts have been found, they include non-coding RNA species, such as small nucleolar RNAs and microRNAs. It is not known, however, the extent to which dicistronic transcripts of tRNA and mRNAs are expressed in field-grown plants, or the factors contributing to their expression. We analysed tRNA–mRNA dicistronic transcripts in the major horticultural crop grapevine (Vitis vinifera) using a novel pipeline developed to identify dicistronic transcripts from high-throughput RNA-sequencing data. We identified dicistronic tRNA–mRNA in leaf and berry samples from 22 commercial vineyards. Of the 124 tRNA genes that were expressed in both tissues, 18 tRNA were expressed forming part of 19 dicistronic tRNA–mRNAs. The presence and abundance of dicistronic molecules was tissue and geographic sub-region specific. In leaves, the expression patterns of dicistronic tRNA–mRNAs significantly correlated with tRNA expression, suggesting that their transcriptional regulation might be linked. We also found evidence of syntenic genomic arrangements of tRNAs and protein-coding genes between grapevine and Arabidopsis thaliana, and widespread prevalence of dicistronic tRNA–mRNA transcripts among vascular land plants but no evidence of these transcripts in non-vascular lineages. This suggests that the appearance of plant vasculature and tRNA–mRNA occurred concurrently during the evolution of land plants.