Silicified structures affect leaf optical properties in grasses and sedge

Area of Science:

• Plant Biology
• Biogeochemistry
• Spectroscopy

Background:

• Silicon (Si) is a key structural element accumulating in grasses and sedges.
• Si accumulation may influence leaf optical properties, affecting light interactions.

Purpose of the Study:

• To investigate the role of Si in light/leaf interactions in Si-rich species.
• To analyze the relationship between leaf Si content, structure, and optical properties.

Main Methods:

• Examined total Si, silica phytoliths, leaf biochemistry, and morphology.
• Measured reflectance and transmittance spectra in selected grass and sedge species.
• Utilized redundancy analysis to correlate leaf properties with spectral data.

Main Results:

• Grasses contained >1% phytoliths (dry mass), sedge 0.4%; significant Si/phytolith differences between developing/mature leaves.
• Near-surface silicified structures, phytoliths, and Si content explained most spectral variability.
• Transmittance spectra were also influenced by chlorophyll a and calcium levels.

Conclusions:

• Leaf Si content and structures, particularly silicified epidermal features, are major drivers of leaf optical properties in grasses and sedges.
• Developing and mature leaves exhibit distinct Si accumulation and spectral characteristics.
• Chlorophyll a and calcium levels also play a role in modulating leaf transmittance.