A positive feedback loop between the lncRNA TaHTMAR and TaHGSNAT is essential for thermo-sensitive male fertility in...

Wheat thermo-sensitive male sterility with Aegilops kotschyi cytoplasm (K-TCMS) is a promising system for hybrid breeding, yet the molecular mechanisms governing fertility conversion remain elusive. In the K-TCMS line KTM3315A, we identified a gene pair: TaHGSNAT (encoding a heparin-α-glucosaminide N-acetyltransferase) and its antisense long non-coding RNA, TaHTMAR. These two transcripts synchronized co-expression patterns during pollen development. Distinct subcellular localizations (membrane for TaHGSNAT, cytoplasm for TaHTMAR) were also observed. Virus-induced gene silencing (VIGS) demonstrated that both TaHGSNAT and TaHTMAR are essential for normal pollen development and anther dehiscence. Mechanistic studies using dual-luciferase reporter assays and GUS staining revealed that TaHTMAR functionally upregulates TaHGSNAT expression, suggesting a bidirectional positive feedback loop. Collectively, our findings define a TaHTMAR-TaHGSNAT regulatory module and provide new molecular insights into the genetic control of thermo-sensitive male fertility in wheat.