BoaBZR1.1 mediates brassinosteroid-induced carotenoid biosynthesis in Chinese kale

Abstract

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 mechanism 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.

Acknowledgements

This work was supported by National Natural Science Foundation of China (32372732, 32072586, 32372683, 31500247), Natural Science Foundation of Sichuan Province (2022NSFSC1689), Project of New Varieties Breeding of Sichuan Vegetable Innovation Team (sccxtd-2023-05), Agro-Industry Technology Research System of China (CARS-23-A07), ‘131’ Innovative Team Construction Project of Tianjin (201923), and the Guizhou Provincial Key Technology R&D Program ((2021) No.207).

Author contributions

B.S., Y.T., F.Z., H.L., and Q.W. conceived and designed the research. C.Z., Q.L., S.L., and X.Y. performed the experiments. V.H.E., W.C., and Z.H. analysed the data. C.Z., Q.L., and S.L. wrote the manuscript. All authors read and approved the manuscript.

Data availability

Sequencing data of BoaBZR1s were deposited in the SRA Database in NCBI (Accession numbers: SUB13973624, SUB13979239, SUB13979529). Other data supporting our findings are available in the manuscript file or from its supplementary files.

Conflict of interest statement

The authors declare that they have no conflicts of interest.

Supplementary data

Supplementary data is available at Horticulture Research online.

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