A Comprehensive and Effective Mass Spectrometry-Based Screening Strategy for Discovery and Identification of New...

Area of Science:

• Plant Biochemistry
• Natural Product Discovery
• Mass Spectrometry

Background:

• Brassinosteroids (BRs) are crucial plant hormones regulating growth and development.
• Identifying novel BRs is essential for understanding their biosynthesis and expanding chemical diversity.
• Traditional methods for BR discovery are inefficient, labor-intensive, and lack sensitivity.

Purpose of the Study:

• To develop a facile and efficient screening strategy for discovering and identifying novel brassinosteroids (BRs) from plant tissues.
• To elucidate the structures of newly identified BRs using advanced mass spectrometry techniques.
• To validate the identified compounds and assess their significance in BR biosynthesis.

Main Methods:

• Utilized ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) for high-throughput screening.
• Employed multiple reaction monitoring (MRM) data-dependent enhanced product ion (EPI) scans for structural elucidation.
• Incorporated high-resolution MS and MS survey-dependent MS/MS for comprehensive analysis.
• Confirmed identified compounds through comparison with reference standards and analysis in rice BR mutants.

Main Results:

• Discovered and identified 14 potential brassinosteroid (BR) compounds from 1 gram of rice tissues.
• Structurally elucidated novel BRs using a combination of advanced MS techniques.
• Identified a new BR compound, 6-deoxo-28-homotyphasterol, for the first time in BR biosynthesis.
• Confirmed the identity and presence of other identified BRs in rice.

Conclusions:

• The developed UPLC-MS based strategy is effective for discovering novel BRs and their biosynthetic intermediates in plants.
• This method significantly advances the study of BR biosynthesis and metabolism by expanding the known chemical diversity.
• The strategy holds potential for discovering unknown compounds in other plant hormone classes and their metabolites.