Photo-thermo-sensitive genic male sterility (PTGMS), which exhibits varying fertility levels under different environmental conditions, is a crucial method for heterosis utilization in wheat. However, the mechanisms underlying fertility conversion remain unclear. In the study, three BS type PTGMS lines were analyzed to study fertility conversion characteristics. The results indicated that the fertility conversion occurred during meiosis and was accompanied by an increase in reactive oxygen species (ROS) under a sterile environment. TaFAR9 encoding a novel fatty acyl CoA reductase was identified using transcriptome sequencing. Expression analysis suggested that TaFAR9 was localized in the endoplasmic reticulum (ER), with high expression levels in anthers. Furthermore, the down-regulation of TaFAR9 expression displayed characteristics of male sterility, accompanied by the accumulation of ROS. Cytological analysis revealed abnormal development in the anther and pollen walls of TaFAR9-silenced lines. Additionally, TaFAR9 and TaFAR10 were confirmed to physically interact using molecular docking simulation, yeast two-hybrid, luciferase complementation, and bimolecular fluorescence complementation assays. The reduced expression of TaFAR10 also exhibited male sterility and ROS burst. Moreover, the co-silencing of TaFAR9 and TaFAR10 produced sterility phenotypes that were similar to those observed when silencing TaFAR9 or TaFAR10 individually. Transcriptome analysis suggested that the ROS burst in BSMV: TaFAR9/10 anthers can result in cellular metabolic disorders. These findings indicate that TaFAR9 and TaFAR10 may form heterodimers that synergistically regulate fertility conversion in PTGMS lines by modulating ROS metabolism. And this study offers a fresh insight into the regulatory processes involved in fertility conversion in PTGMS lines.
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