Identification and Candidate Gene Analysis of Brcl1, a Novel Gene Confers a Leaf Curled Phenotype in Brassica rapa L.

Leaf shape is an important determinant of photosynthesis, yield and quality in plants. In this study, we obtained a curled leaf mutant, <i>cl1</i>, from an ethyl methanesulfonate (EMS)-induced mutagenesis population. It was designated the <i>Brcl1</i>^YS locus. Bulk segregant RNA sequencing combined with recombinant screening identified the candidate interval responsible for <i>Brcl1</i>^YS in a 97.5 kb region on chromosome A02. Twelve genes were identified within the candidate region. Sequence differences and co-separation verification confirmed that <i>BraA02g017030.3C</i> was the most promising candidate gene underlying the <i>Brcl1</i>^YS locus. It is homologous to <i>Arabidopsis AT1G66350</i> (<i>RGL1</i>), which has been shown to act as a negative regulator of the gibberellin pathway. Combined with cell morphology observation, it is speculated that the loss of function of <i>Brcl1</i>^YS results in differences in cell development, ultimately leading to changes in leaf morphology. The results will contribute to the understanding of the molecular mechanisms underlying leaf curling in <i>B</i>. <i>rapa</i>.