Brassinazole resistant 1 (BZR1), a brassinosteroid (BR) signaling component, plays a pivotal role in regulating numerous specific developmental processes. Our study demonstrated that exogenous treatment with 2,4-epibrassinolide (EBR) significantly enhanced the accumulation of carotenoids and chlorophylls in Chinese kale (Brassica oleracea var. alboglabra). The underlying mechanisms was deciphered through yeast one-hybrid (Y1H) and dual-luciferase (LUC) assays, whereby BoaBZR1.1 directly interacts with the promoters of BoaCRTISO and BoaPSY2, activating their expression. This effect was further validated through overexpression of BoaBZR1.1 in Chinese kale calli and plants, both of which exhibited increased carotenoid accumulation. Additionally, qPCR analysis unveiled upregulation of carotenoid and chlorophyll biosynthetic genes in the T1 generation of BoaBZR1.1-overexpressing plants. These findings underscored the significance of BoaBZR1.1-mediated BR signaling in regulating carotenoid accumulation in Chinese kale and suggested the potential for enhancing the nutritional quality of Chinese kale through genetic engineering of BoaBZR1.1.

中文翻译：

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BoaBZR1.1 介导羽衣甘蓝中油菜素类固醇诱导的类胡萝卜素生物合成

油菜素抗性 1 (BZR1) 是一种油菜素类固醇 (BR) 信号成分，在调节许多特定发育过程中发挥着关键作用。我们的研究表明，2,4-表油菜素内酯 (EBR) 的外源处理显着增强了羽衣甘蓝 (Brassica oleracea var. alboglabra) 中类胡萝卜素和叶绿素的积累。通过酵母单杂交 (Y1H) 和双荧光素酶 (LUC) 检测破译了潜在的机制，其中 BoaBZR1.1 直接与 BoaCRTISO 和 BoaPSY2 的启动子相互作用，激活它们的表达。通过在羽衣甘蓝愈伤组织和植物中过表达 BoaBZR1.1，进一步验证了这种效应，这两种植物均表现出类胡萝卜素积累增加。此外，qPCR 分析揭示了 BoaBZR1.1 过表达植物的 T1 代中类胡萝卜素和叶绿素生物合成基因的上调。这些发现强调了BoaBZR1.1介导的BR信号在调节羽衣甘蓝类胡萝卜素积累中的重要性，并表明通过BoaBZR1.1的基因工程提高羽衣甘蓝营养品质的潜力。