Brassinosteroids (BRs) have been recognized as the six-class phytohormones after auxin, gibberellin, cytokinin, abscisic acid, and ethylene. They are involved in regulating a variety of physiological processes, such as cell elongation and division, vascular differentiation, reproductive development, stress tolerance, and so on. Due to their extremely low concentrations, complex matrix backgrounds and poor ionization efficiency, it is a great challenge for both botanists and analytical chemists to determine the endogenous contents of BRs accurately, which is also a bottleneck issue for in-depth studying of the physiological roles of BRs.
The Phytohormone Analysis Platform from the Institute of Genetics and Developmental Biology (IGDB), Chinese Academy of Sciences (CAS), developed a more efficient method for determination of plant endogenous brassinosteroids with lower plant samples and shorter analysis time.
The team led by Dr. CHU Jinfang at the Phytohormone Analysis Platform has devoted continuously to development of high-performance and high-sensitivity analysis methods for BRs and made a series of achievements these years. Starting from the chemical structure and physiochemical properties of BRs, they presented a high-efficiency sample pretreatment method based on tandem mixed-mode ion-exchange solid phase extraction combined with high-sensitivity chemical derivatization, which greatly reduced the use of plant tissues to 1 g level from 20-40 g (Plant Physiology, 2013, 162, 2056-2066).
Subsequently, they reported a promising screening and identification strategy for bioactive BRs on the basis of comprehensive MS technologies and the pretreatment method as-mentioned. This strategy can act as an alternative technique to traditional bioactivity-guided screening and be helpful for studying the biosynthetic and metabolic pathway of BRs (Frontiers in Plant Science, 2016, 7: 1786).
Making use of boronate affinity interactions between boronic acids and diol compounds, researchers designed and chemically synthesized boronate affinity magnetic nanoparticles (BAMNPs), which can be used to remove high-abundance endogenous contaminants suppressing MS responses of BRs during detection. Therefore, the sensitivity was improved several folds and reduced the sample use to <200 mg further (Analyst, 2013, 138, 1342-1345).
Recently, they applied BAMNPS to directly fish BRs from plant tissues specifically and designed a two-step oxidation-hydrolysis elution system to raise the BRs recoveries by 2-3 times. The sample use was further lowered to 10 mg level, which made the preparation of plant samples for botanists much easier. In addition, the direct fishing process shortened the analysis time to <3 h and highly improved the throughput.
This work entitled “Pursuing extreme sensitivity for determination of endogenous brassinosteroids through direct fishing from plant matrices and eliminating most interferences with boronate affinity magnetic nanoparticles” was published in
Analytical and Bioanalytical Chemistry Dec 14, 2017 (
DOI: 10.1007/s00216-017-0777-9). Dr. XIN Peiyong from Phytohormone Analysis Platform is the first author.
This work was supported by the National Natural Science Foundation of China and the CAS Key Technology Talent Program.
Figure: Fishing BRs directly from plant tissues and removing contaminants with BAMNPs (Image by IGDB)
Contact:
Dr. CHU Jinfang
