The morphology and chemical composition of cuticular waxes in some Brazilian liverworts and mosses

ABSTRACT

Background

The cuticle, by ensuring protection against water loss, was a key innovation in plant terrestrialisation. This layer is characterised by the cutin matrix embedded and covered with cuticular waxes. In this study we describe the cuticular waxes on gametophytes of several species of liverworts and mosses, including Brazilian endemics.

Methods

Cuticular waxes from 34 species from different locations in the São Paulo state, Brazil, were analysed by gas chromatography coupled with mass spectrometry. The compounds were identified based on mass spectra fragmentation. The morphology of the epicuticular waxes was analysed using scanning electron microscopy.

Main results

The wax content in the liverwort species varied from 0.1 to 4 μg cm⁻², while in mosses the values ranged from 0.02 to 0.6 μg cm⁻². The main classes of wax compounds were fatty acids, alkanes, and primary alcohols. Aldehydes, alkenes, esters, ketones, triterpenes, a diacid and a secondary alcohol had a more restricted distribution. The morphology of the epicuticular waxes was predominately of the film type.

Conclusions

In general, wax content was higher in the liverworts than in the mosses. Fatty acids and alkanes were the most common class whilst alkenes, ketones, diacid, and a secondary alcohol are described for the first time as wax compounds in bryophyte gametophytes.

KEYWORDS:

• Bryophytes
• cuticle
• liverworts
• micromorphology
• mosses
• surface lipids

Acknowledgments

We are grateful to Dra Claudia Furlan for helping in plant collection, to the technicians Mourisa Ferreira, Aline Bertinatto Cruz and Irwandro Roberto Pires for assistance during GC-MS and SEM analyses.

Additional information

Funding

This work was supported by Coordination for the Improvement of Higher Education Personnel (CAPES) for funding this study [funding code 001].

Notes on contributors

Tamara Machado Matos

Tamara Machado Matos is a biologist interested in plant interactions with biotic and abiotic factors focused on native Brazilian bryophytes.

Denilson Fernandes Peralta

Denilson Fernandes Peralta is a bryologist interested in bryophyte ecology and taxonomy, with an emphasis on native Brazilian species.

Lucas Paradizo Roma

Lucas Paradizo Roma is a biologist interested in plant interactions with biotic and abiotic factors with a focus on the study of surface lipids in native Brazilian species.

Déborah Yara Alves Cursino dos Santos

Déborah Yara Alves Cursino dos Santos is a botanist interested in plant interactions with biotic and abiotic factors, with an emphasis on the study of surface lipids and natural bioactive products of native Brazilian species.