Root discrimination and vapor buffering control mangrove lipid hydrogen isotope fractionation to resolve the greenhouse-field paradox

Description

This dataset includes the concentrations of n-alkanes and n-fatty acids, as well as the stable hydrogen and oxygen isotopic compositions (δ²H and δ¹⁸O) of various water sources associated with the mangrove species Sonneratia apetala, sampled during the peak wet season. The analyzed water pools include surface water (SW), xylem water (XW), and leaf water (LW). The dataset highlights isotopic fractionation associated with key physiological stages: water uptake from surface water to xylem (αXW-SW), transpiration between leaf and xylem water (αLW-XW), and lipid biosynthesis between mangrove waxes (n-fatty acids and n-alkanes) and leaf water (αLipid-LW). Additionally, it presents the apparent net fractionation between mangrove lipids and surface water (αLipid-SW).

Steps to reproduce

1. Study Site and Sample Collection Location: Samples were collected from the Zhanjiang estuary, where wet season are characteristic of tropical and subtropical climates. Sampling Periods: Sampling occurred during the peak wet season. Sample Types: Leaf samples from the mangrove species Sonneratia apetala were collected, along with surface water, xylem water, and leaf water for isotopic comparison. 2. Water Sample Collection Surface Water (SW): Collected directly from the estuary. Xylem Water (XW): Obtained by cutting stems and immediately sealing them in glass vials to prevent evaporation. Leaf Water (LW): Isolated by cryogenic vacuum distillation from the leaves immediately after collection. 3. Lipid Extraction and Analysis Lipid Extraction: Leaf waxes were extracted from leaf samples using an organic solvent extraction method. Separation of Lipid Classes: n-Alkanes and n-fatty acids were separated using silica gel column chromatography. Quantification: Concentrations of n-alkanes and n-fatty acids were quantified using gas chromatography-flame ionization detection (GC-FID). 4. Isotope Analysis Hydrogen Isotope Ratios (δ²H): Measured for n-alkanes and n-fatty acids using gas chromatography coupled to isotope ratio mass spectrometry (GC-IRMS). Water Isotope Ratios (δ²H and δ¹⁸O): The hydrogen and oxygen isotope compositions of surface water, xylem water, and leaf water were measured using EA Isolink-253 Plus (Thermo Scientific). 5. Data Interpretation Fractionation factors between different water pools (αXW-SW, αLW-XW) were calculated using isotopic composition data. Net hydrogen isotope fractionation between mangrove leaf lipids and different water sources was calculated for the wet season. Trends in hydrogen isotope fractionation were analyzed to determine the effects of salinity on S. apetala physiology and lipid biosynthesis. 6. Software and Data Analysis Data processing and statistical analysis were conducted using OriginLab and R software. Regression analyses were performed on both platforms to assess the relationship between salinity and hydrogen isotope fractionation. Figures illustrating the δ²H and δ¹⁸O values and fractionation factors were created using OriginLab. 7. Reagents and Instruments Solvents: Dichloromethane and methanol for lipid extraction. Instruments: Gas chromatograph for lipid analysis, isotope ratio mass spectrometer for δ²H measurements, and EA Isolink-253 Plus for water isotope measurements. Vials and Syringes: Used for collecting water samples and sealing plant stems to avoid isotopic alteration.

Institutions

• Guangdong Ocean University

  Guangdong, Zhanjiang
• Guangzhou Institute of Geochemistry

  Guangdong, Guangzhou
• California Institute of Technology

  California, Pasadena

Categories

Funders

• Guangdong Basic and Applied Basic Research Foundation

  Grant ID: No. 2026A1515012122
• Shenzhen Science and Technology Program

  Grant ID: No. JCYJ20230807120401003
• National Science Foundation of China

  Grant ID: Grant No. 42203028
• Core Techniques for Multi-Objective Coupled Ecological Restoration of Mangrove Forests on Jinniu Island

  Grant ID: 30301052301

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