A Depth-Controlled Longitudinal Cutting Strategy Enhances MALDI-MSI of Entire Leaves

Area of Science:

• Plant science
• Metabolomics
• Analytical chemistry

Background:

• Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is crucial for spatial metabolite analysis in plant leaves.
• Longitudinal sectioning offers detailed insights into tissue heterogeneity but is technically challenging.

Purpose of the Study:

• To develop a novel depth-controlled longitudinal cutting (DCLC) strategy for plant leaf processing.
• To enable high-resolution spatial analysis of metabolites within leaf tissues using MALDI-MSI.

Main Methods:

• An in-house device was utilized for depth-controlled longitudinal cutting of various plant leaves.
• Sections as thin as 5 μm were prepared, with 30 μm chosen to optimize tissue integrity and MALDI-MSI performance.
• The DCLC strategy facilitates exposure of internal tissues and reduces ion suppression from cuticles.

Main Results:

• The DCLC strategy successfully produced thin longitudinal leaf sections suitable for MALDI-MSI.
• This method enhances the detection of internal metabolites by minimizing cuticle interference.
• Multiple sections can be obtained from a single leaf, allowing for multi-plane analysis.

Conclusions:

• DCLC is an effective method for preparing plant leaf samples for detailed spatial metabolomic studies.
• This technique advances the application of MALDI-MSI for understanding plant metabolic spatial variations.
• DCLC offers potential for resolving complex metabolic zonation within leaf tissues.