Organ-level distribution tandem mass spectrometry analysis of three structural types of brassinosteroids in rapeseed

Jianhua Tong; Wenkui Zhao; Keming Wang; Danyi Deng; Langtao Xiao

doi:10.3389/fpls.2024.1308781

Organ-level distribution tandem mass spectrometry analysis of three structural types of brassinosteroids in rapeseed

Front Plant Sci. 2024 Mar 7:15:1308781. doi: 10.3389/fpls.2024.1308781. eCollection 2024.

Authors

Jianhua Tong¹, Wenkui Zhao², Keming Wang³, Danyi Deng¹, Langtao Xiao¹

Affiliations

¹ Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Laboratory of Yuelu Mountain, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China.
² College of Chemistry and Materials, Hunan Agricultural University, Changsha, China.
³ Assets and Laboratory Management Department, Hunan Agricultural University, Changsha, China.

Abstract

Background: Brassinosteroids (BRs) are a class of naturally occurring steroidal phytohormones mediating a wide range of pivotal developmental and physiological functions throughout the plant's life cycle. Therefore, it is of great significance to determine the content and the distribution of BRs in plants.Regretfully, although a large number of quantitative methods for BRs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) have been reported, the in planta distribution of BRs is still unclear because of their lower contents in plant tissues and the lack of effective ionizable groups in their chemical structures.

Methods: We stablished a novel analytical method of BRs based on C18 cartridge solid-phase extraction (SPE) purification, 4-(dimethylamino)-phenylboronic acid (DMAPBA) derivatization, and online valve-switching system coupled with ultra-high performance liquid chromatography-electro spray ionization-triple quadrupole mass spectrometry (UHPLC-ESI-MS/MS). This method has been used to quantify three structural types of BRs (epibrassinolide, epicastasterone, and 6-deoxo-24-epicastaster one) in different organs of Brassica napus L. (rapeseed).

Results: We obtained the contents of three structural types of BRs in various organ tissues of rapeseed. The contents of three BRs in rapeseed flowers were the highest, followed by tender pods. The levels of three BRs all decreased during the maturation of the organs. We outlined the spatial distribution maps of three BRs in rapeseed based on these results, so as to understand the spatial distribution of BRs at the visual level.

Conclusions: Our results provided useful information for the precise in situ localization of BRs in plants and the metabolomic research of BRs in future work. The in planta spatial distribution of BRs at the visual level has been studied for the first time.

Keywords: 4-(dimethylamino)-phenylboronic acid; brassinosteroids; derivatization; online valve-switching; organ-level distribution; solid-phase extraction.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This research was supported by the National Natural Science Foundation of China (grant number: 90817101 and 32261143733).