A novel intergenic long noncoding RNA WTRL1 regulates tillering and contributes to ideal architecture in wheat

Long noncoding RNAs (lncRNAs) are crucial posttranscriptional regulators of plant growth and resistance. To uncover lncRNAs modulating wheat tillering, we analyzed previously published lncRNA datasets from tillering-related near-isogenic lines (NILs) and identified a differentially expressed long intergenic noncoding RNA (lincRNA), designated Wheat Tiller Related Long noncoding RNA 1 (WTRL1), as a candidate regulator. The spatiotemporal expression pattern of WTRL1 was analyzed using RT-qPCR and RNA fluorescence in situ hybridization. Functional validation was performed by overexpressing and silencing WTRL1 in common wheat. Putative targets were identified via transcriptome analysis of transgenic lines and validated using modified dual luciferase reporter (Dual-Luc) assays. WTRL1 was found highly expressed in tiller buds. Overexpression of WTRL1 significantly reduced tiller number and accelerated flowering time, whereas silencing of WTRL1 increased tiller number and delayed flowering. Transcriptomics and Dual-Luc assays identified two target genes, TraesFLD1D01G290100 and TraesFLD1A01G316100, potentially mediating these effects. WTRL1 is a lincRNA that negatively regulates tiller number and promotes flowering in wheat, likely through posttranscriptional regulation of specific target genes. This discovery provides a valuable genetic tool for molecular breeding strategies aimed at optimizing wheat tiller development and flowering time.