Modern Comprehensive Metabolomic Profiling of Pollen Using Various Analytical Techniques

Area of Science:

• Plant biology and biochemistry
• Analytical chemistry
• Ecosystem science

Background:

• Pollen's complex structure is vital for plant reproduction, genetic diversity, and ecosystem health.
• Understanding pollen's chemical composition is crucial for studying plant-pollinator interactions, pollination, and allergies.

Purpose of the Study:

• To perform comprehensive metabolite profiling of pollen using a multimodal analytical approach.
• To investigate chemical differences between pollen from Magnoliophyta and Pinophyta.
• To explore the utility of metabolomics data for taxonomic differentiation and understanding pollen's ecological roles.

Main Methods:

• Fourier transform infrared spectrometry (FTIR) for initial metabolite class overview.
• Atmospheric Solids Analysis Probe-MS (ASAP-MS) for characterizing the pollen's hydrophobic outer layer.
• Matrix-Assisted Laser Desorption/Ionization (MALDI) and ultra-high-performance liquid chromatography-MS (UHPLC-MS) for detailed lipid, carbohydrate, and polyphenol profiling.

Main Results:

• FTIR identified phenylpropanoid, lipid, and carbohydrate structures.
• ASAP-MS revealed esters, phytosterols, and terpenoids in the pollen's outer layer.
• UHPLC-MS demonstrated significant chemical distinctions between Magnoliophyta and Pinophyta pollen, with variations also noted within Magnoliophyta species.

Conclusions:

• Multimodal mass spectrometry effectively differentiated pollen at the taxonomic level.
• Metabolomics data provide insights into pollen's role in reproduction, ecological interactions, and potential applications.
• The study highlights the chemical diversity of pollen and its ecological significance.