Role of <i>BraRGL1</i> in regulation of <i>Brassica rapa</i> bolting and flowering

Abstract Gibberellin (GA) plays a major role in controlling Brassica rapa stalk development. As an essential negative regulator of GA signal transduction, DELLA proteins may exert significant effects on However, the regulatory mechanisms underlying this regulation remain unclear. In study, we report highly efficient and inheritable mutagenesis using CRISPR/Cas9 gene editing system BraPDS (phytoene desaturase) BraRGL1 (key protein) genes. We observed loss-of-function mutation due to two amino acids GRAS domain. mutants displayed significantly increased time flower bud differentiation bolting. The expression GA-regulatory protein (BraGASA6), flowering related genes (BraSOC1, BraLFY), expansion (BraEXPA11) xyloglucan endotransferase (BraXTH3) was also upregulated these mutants. BraRGL1-overexpressing plants contrasting phenotypes. were more sensitive signaling. interacted with BraSOC1, interaction intensity decreased after GA3 treatment. addition, inhibited transcription-activation ability BraSOC1 for BraXTH3 BraLFY genes, but presence enhanced activation suggesting that BraRGL1-BraSOC1 module regulates bolting B. through transduction. Thus, hypothesized is degraded, released GA3, which promotes BraLFY, thereby inducing development rapa. Further, BraRGL1-M mutant promoted without affecting quality. can serve as valuable target molecular breeding early maturing varieties.