Leaf wax composition and distribution of Tillandsia landbeckii refects moisture gradient across the hyperarid Atacama Desert
Date
2022Author
Contreras, Sergio
Landahur, Manlio
García, Karla
Latorre, Claudio
Reyers, Mark
Rethemeyer, Janet
Jaeschke, Andrea
Publisher
Plant Systematics and EvolutionDescription
Artículo de publicación WOS - SCOPUSMetadata
Show full item recordAbstract
In the hyperarid Atacama Desert, water availability plays a crucial role in allowing plant survival. Along with scant rainfall,
marine advective fog frequently occurs along the coastal escarpment fueling isolated mono-specifc patches of Tillandsia
vegetation. In this study, we investigate the lipid biomarker composition of the bromeliad Tillandsia landbeckii (CAM plant)
to assess structural adaptations at the molecular level as a response to extremely arid conditions. We analyzed long-chain
n-alkanes and fatty acids in living specimens (n=59) collected from the main Tillandsia dune ecosystems across a 350 km
coastal transect. We found that the leaf wax composition was dominated by n-alkanes with concentrations (total average
160.8±91.4 µg/g) up to three times higher than fatty acids (66.7±40.7 µg/g), likely as an adaptation to the hyperarid environment. Signifcant diferences were found in leaf wax distribution (Average Chain Length [ACL] and Carbon Preference
Index [CPI]) in the northern zone relative to the central and southern zones. We found strong negative correlations between
fatty acid CPI and n-alkane ACL with precipitation and surface evaporation pointing at fne-scale adaptations to low moisture availability along the coastal transect. Moreover, our data indicate that the predominance of n-alkanes is refecting the
function of the wax in preventing water loss from the leaves. The hyperarid conditions and good preservation potential of
both n-alkanes and fatty acids make them ideal tracers to study late Holocene climate change in the Atacama Desert.