Transcriptome analysis of the irregular shape of shoot apical meristem in dt (dou tou) mutant of Brassica napus L.

Rapeseed (Brassica napus L.) is an important oil crop in the world. In order to fulfill the requirement of mechanized harvesting and raised production, it is highly desirable to gain a better understanding of the regulatory networks controlling the main agronomic traits of this crop. In this study, we obtained a natural mutant of rapeseed with more main stems named as dt (duo tou, meaning more main stems in Chinese). The dt mutant exhibits abnormal differentiation of stems, increased leaves, and decreased plant height. Phenotype and tissue section analysis showed that abnormal development of the shoot apical meristem (SAM) led to the dt phenotype. Genes that participated in SAM activity maintenance, cytokinin biosynthesis, and signal transduction displayed greatly variation at transcriptional level, which was associated with the high level of cytokinin in the dt mutant. These results provide desirable material for improving the breeding and production of Brassica napus.