RNA-seq analysis of the peduncle development of Rht12 dwarf plants and primary mapping of Rht12 in common wheat

摘要

Rht12, a dominant dwarfing gene that reduces plant height by approximately 40.0% and substantially decreases peduncle development by 45.0%, has been suggested as an alternative dwarfing gene for wheat improvement. However, the mechanism of dwarf caused by Rht12 is unclear and efficient molecular markers of Rht12 is also lacking in breeding. To explore candidate genes involved in peduncle elongation and to construct a genetic map of Rht12, RNA-seq analysis was applied using the peduncle samples at heading stages of the tall and dwarf residual heterozygous lines derived from the cross of Ningchun45 (rht12rht12) and Karcagi12 (Rht12Rht12). Differentially expressed genes were screened and annotated, genes involved in polyamine oxidation, carotenoid biosynthesis, protein ubiquitination process and ascorbate pathway were found to be associated with peduncle elongation. Moreover, ten KASP markers on chromosome 5AL closely linked with Rht12 were developed using the SNPs from the RNA-seq data with an F-2 mapping population. Furthermore, these markers were mapped to the wheat genome sequence and Rht12 was predicted within the region of 673.7-689.9 Mb on chromosome 5AL. These results provide a better understanding of the molecular mechanisms underlying the development of the peduncle and other stems in wheat, especially in Rht12 dwarf plants, and also promote fine mapping of Rht12.