Results for “Triticeae evolution”

PubMed2025

The complete chloroplast genome of Secale strictum ssp. strictum provides insights into Triticeae evolution and breeding.

The complete chloroplast genome of Secale strictum ssp. strictum (Poaceae: Triticeae) was sequenced and analyzed to support its use in rye and wheat breeding. The genome is 137,063 bp long and includes a pair of inverted repeats (IRs; 21,580 bp each) that separate the small (SSC; 12,817 bp) and large (LSC; 81,086 bp) single-copy regions. It contains 113 genes: 74 protein-coding, 30 tRNA, four rRNA genes, and five conserved open reading frames. A total of 42 repeat sequences were identified, mainly in the LSC region, with direct repeats being most common. All mononucleotide SSRs consisted of A/T motifs. Seven highly variable regions were identified, offering potential as molecular markers for species identification and phylogenetic studies. Phylogenetic analysis based on 73 protein-coding genes confirmed the systematic placement of the species and showed that S. strictum ssp. strictum is closely related to S. cereale and other S. strictum accessions. This study presents the first complete plastome of S. strictum ssp. strictum, now available as a reference genome under GenBank accession number OL979486.

Genome, Chloroplast↗

PubMed2026

Transposable element-driven expansion of enhancer RNA repertoires underlies regulatory innovation and polyploid adaptation in cereal crops.

Cereal genomes have undergone repeated polyploidization and transposable element (TE) proliferation, collectively generating complex regulatory landscapes. However, the evolutionary trajectories and functional implications of these landscapes remain largely unexplored. Using chromatin-bound RNA sequencing across seven cereal species, we systematically mapped 45,952 regulatory element transcripts (RETs), including 32,867 distal RETs corresponding to enhancer RNAs (eRNAs). Our analysis revealed that 56% of lineage-specific eRNAs originated from TE expansions, indicating that TEs serve as major reservoirs of species-specific regulatory innovation in cereals. Notably, we identified remarkable conservation in defense-related functions, root-specific expression, and TE-derived origins of eRNAs across both ancient and recent evolutionary layers of Triticeae, suggesting recurrent recruitment of TE-derived, root-associated regulatory elements throughout Triticeae evolution. Furthermore, we found that young eRNA pairs in hexaploid wheat with high sequence similarity, many originating from RLG_famc8.3 and DTC_famc4.3, exhibited pronounced root specificity and coordinated expression, suggesting targeted amplification and refinement of successful ancestral regulatory strategies established after Triticeae divergence. To facilitate community access, we developed Cereal-eRNAdb (http://bioinfo.cemps.ac.cn/Cereal-eRNAdb/), a comprehensive database integrating 69,426 eRNAs with functional annotations across 296 samples. Our findings suggest that TE-mediated innovation of root-specific eRNAs may contribute to Triticeae adaptation and provide a foundational resource for exploiting regulatory variation in cereal crop breeding.

Enhancer RNAs↗