Foreign RsMYB28 Allele Boosts Glucosinolate Accumulation in Rapeseed

These bioactive compounds, found primarily in Brassicaceae plants, play crucial roles in plant defense, contribute to distinctive food flavors, and have potential health benefits, including cancer prevention. In particular, aliphatic glucosinolates (AGSLs) are essential for enhancing crop resistance to pests and diseases. By investigating an Ogu CMS (cytoplasmic male sterility) restorer line of rapeseed, R2260, the team uncovered the key regulatory role of a foreign RsMYB28 allele introduced from radish.

Glucosinolates serve multiple functions in plants, particularly in defense against herbivores and pathogens, while also contributing to distinct flavors in foods like cabbage, broccoli, and mustard. In recent years, GSLs have gained attention for their health benefits, particularly the anti-cancer properties of certain hydrolysis products like sulforaphane. In rapeseed, enhancing GSL content, particularly AGSLs, is vital for improving both plant resistance to biotic stress and the nutritional value of the seeds. The pathway for AGSL biosynthesis is complex, involving multiple enzymatic steps, with MYB28 transcription factors playing a crucial role in regulating this process.

A study (DOI: 10.48130/seedbio-0025-0021) published in Seed Biology on 28 November 2025 by Mingli Yan's team, Hunan Academy of Agricultural Sciences, opens up new possibilities for breeding rapeseed with improved resistance, enhanced nutritional quality, and tailored glucosinolate profiles.

In this study, the researchers utilized UPLC-MS to analyze the GSL content in leaves and seeds of rapeseed cultivar R2260, comparing it with the common cultivar Westar. They identified eleven GSLs, including six AGSLs such as Glucoraphanin (RAA) and Gluconapin (GNA), four indolic glucosinolates (IGSLs), and one aromatic glucosinolate (ArGSL). Results showed that R2260 exhibited significantly higher AGSL content compared to Westar, both in leaves and seeds, with particular increases in TAGSL, 4C-AGSL, and 5C-AGSL compounds. Notably, R2260 seeds had 3.6 to 11.4 times higher AGSL content than Westar seeds, with some AGSLs like GNF detected only in R2260. The study also performed transcriptome analysis across leaf, flower, silique pericarp, and seed tissues, identifying genes up-regulated in R2260, particularly those involved in glucosinolate biosynthesis. Gene enrichment analyses revealed significant activation of glucosinolate biosynthesis-related pathways, including sulfur metabolism and tryptophan metabolism. The researchers focused on key biosynthetic genes such as BCAT4, IMDH3, and CYP83A1, which showed higher expression in R2260 compared to Westar. Moreover, the expression of RsMYB28, a transcription factor identified in the radish genome, was significantly elevated in R2260 and linked to AGSL accumulation. Overexpression of RsMYB28 in Westar resulted in a substantial increase in AGSL content, particularly GNA, PRO, and GBN, and activated the expression of key biosynthetic genes such as BnaIMDH3 and BnaCYP83A1. These findings suggest that RsMYB28 plays a crucial role in regulating AGSL biosynthesis in rapeseed, offering valuable insights for improving rapeseed quality and resistance through genetic engineering.

The findings of this study have significant implications for rapeseed breeding. By enhancing AGSL content in rapeseed through the overexpression of RsMYB28, it is possible to develop varieties with improved resistance to pests and pathogens. Additionally, the increased GSLs can confer added nutritional benefits, such as anti-inflammatory and anti-cancer properties, making the seeds more valuable for both agricultural and health purposes. The ability to modulate GSL profiles in crops also opens up possibilities for tailoring specific flavors and health benefits, meeting consumer demand for functional foods.