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Article|02 Jun 2023|OPEN
Role of BraRGL1 in regulation of Brassica rapa bolting and flowering
Yudan Wang1 , Shiwei Song1 , , Yanwei Hao1 , Changming Chen1 , Xi Ou1 , Bin He1 , Jiewen Zhang1 , Zhehao Jiang1 , Chengming Li1 , Shuaiwei Zhang1 , Wei Su1 , and Riyuan Chen,1 ,
1Key Laboratory of Horticultural Crop Biology and Germplasm Innovation in South China, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
*Corresponding author. E-mail:,,

Horticulture Research 10,
Article number: uhad119 (2023)
Views: 109

Received: 26 Sep 2022
Accepted: 25 May 2023
Published online: 02 Jun 2023


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 stalk development. However, the regulatory mechanisms underlying this regulation remain unclear. In this study, we report highly efficient and inheritable mutagenesis using the CRISPR/Cas9 gene editing system in BraPDS (phytoene desaturase) and BraRGL1 (key DELLA protein) genes. We observed a loss-of-function mutation in BraRGL1 due to two amino acids in GRAS domain. The flower bud differentiation and bolting time of BraRGL1 mutants were significantly advanced. The expression of GA-regulatory protein (BraGASA6), flowering related genes (BraSOC1BraLFY), expansion protein (BraEXPA11) and xyloglucan endotransferase (BraXTH3) genes was also significantly upregulated in these mutants. BraRGL1-overexpressing plants displayed the contrasting phenotypes. BraRGL1 mutants were more sensitive to GA signaling. BraRGL1 interacted with BraSOC1, and the interaction intensity decreased after GA3 treatment. In addition, BraRGL1 inhibited the transcription-activation ability of BraSOC1 for BraXTH3 and BraLFY genes, but the presence of GA3 enhanced the activation ability of BraSOC1, suggesting that the BraRGL1-BraSOC1 module regulates bolting and flowering of B. rapa through GA signal transduction. Thus, we hypothesized that BraRGL1 is degraded, and BraSOC1 is released in the presence of GA3, which promotes the expression of BraXTH3 and BraLFY, thereby inducing stalk development in B. rapa. Further, the BraRGL1-M mutant promoted the flower bud differentiation without affecting the stalk quality. Thus, BraRGL1 can serve as a valuable target for the molecular breeding of early maturing varieties.