The existence of transcripts associated with predicted TR loci showing homology across large taxonomic groups of green plants was demonstrated in species where total RNA-seq data (using rRNA depletion) were available in Sequence Read Archive (SRA) data at NCBI, or in data generated by us (for more details see ‘Data availability’ and Supplementary Table S2). RNA-seq libraries were prepared using TruSeq Stranded Total RNA with Ribo-Zero Plant kit (Illumina) from 1 μg of total RNA as input (concentration and quality checked on Agilent 2200 TapeStation system (Agilent Technologies). Strand-specific Paired-End libraries were sequenced on NovaSeq 6000 System (Illumina) using sequencing kit NovaSeq 6000 SP Reagent Kit v1.5 (200 cycles) (Illumina). In cases where corresponding genome assemblies were available, RNAseq reads were mapped to reference genome using RMTA (25 (link)), otherwise RNAseq data were assembled de novo using TRINITY v2.11.0 (26 (link)). The assembly was done with options for stranded RNA-seq with paired-end fastq data (Trinity –seqType fq –left inputfile_R1.fastq –right inputfile_R2.fastq –SS_lib_type RF –KMER_SIZE 25). TR transcript presence, length and orientation were checked in these data.