BnaC01.BIN2, a GSK3-like kinase, modulates plant height and yield by regulating cell elongation in Brassica napus

Abstract The modification of plant height is one of the most important goals in rapeseed breeding. Although several genes that regulate rapeseed plant height have been cloned, the genetics mechanisms underlying rapeseed plant height remain poorly understood, and the desirable genetic resource for rapeseed ideotype breeding is scarcity. In present, we show that a rapeseed semi-dominant gene, Df4, profoundly impacts rapeseed plant height. Df4 encodes brassinosteroid-insensitive 2 (BIN2), a glycogen synthase kinase 3 (GSK3), controls the elongation of stem cell. Transcriptome data show that several cell expansion-related genes that involves auxin and brassinosteroids pathways were significantly downregulated in Df4. We demonstrated that a point mutation in BnaC01.BIN2 leads to a semi-dwarf phenotype, and heterozygosity in the Df4 allele results in small stature with no marked differences in other agronomic traits. Furthermore, a kompetitive allele specific PCR marker was developed based on the point mutation. Our results provide a desirable genetic resource for producing small stature rapeseed and support a new scenario for breeding rapeseed varieties with enhanced yield.