bioRxiv Science⌕ Search

bioRxiv · 10.1101/2024.12.02.624615

Roots of coastal plants stabilize carbon fixed by marine algae

Abstract

Coastal vegetated ecosystems are key-nature based solutions for climate change mitigation. Mangroves, seagrass meadows and saltmarshes contribute to carbon sequestration not only through their photosynthetic activity but also by anchoring sediments with their extensive root systems. By modulating flow coastal vegetation creates a low energy environment for sediment that includes carbon to accumulate. These roots physically stabilize the sediment, prevent erosion and enhance long-term retention of organic carbon. Hence, we hypothesized marine, algae derived organic matter may especially accumulate in plant vegetated ecosystems. We used algal and plant glycans as carbon sequestration proxy to trace the input and stabilization from source to sink and found those molecules in 93 sediment cores across different coastal vegetated ecosystems from temperate to tropical regions. Specific monoclonal antibodies showed algal-derived fucoidans were present in sediments of coastal vegetated ecosystems. Our findings suggest that the restoration of plant ecosystems that fix carbon dioxide, protect coasts and enhance biodiversity should also be enumerated for the stored carbon from distant donors. Conclusively, carbon sequestration is a synergistic outcome of photosynthetic contributors acting in concert across different ecosystems.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Hellige, I., Mundanatt, A. A., Massing, J. C., Hehemann, J.-H.. 2024-12-02. Roots of coastal plants stabilize carbon fixed by marine algae. https://doi.org/10.1101/2024.12.02.624615

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Aging Remodels the Female Skeletal Muscle Proteome Toward Matrix, Chromatin and Lysosomal Programs that Track Loss of Physical Function

Loss of skeletal muscle strength and mobility is among the most consequential features of human aging, yet the molecular programs that accompany this decline in women remain poorly understood. Here, we performed deep comprehensive data-independent acquisition (DIA) proteomic profiling of vastus lateralis biopsies from 10 younger (24-30 years) and 10 older (70-84 years) healthy women enrolled through the NIH Common Fund Cellular Senescence Network (SenNet), with matched measurements of grip strength and gait speed. Of 2,391 quantified protein groups, 163 were significantly altered with age, and partial least squares-discriminant analysis completely separated the age groups (cross-validated AUC = 1.00). Older muscle showed increased extracellular matrix and vascular remodeling proteins (TIMP3, COL8A1, ELN, FBN1), nuclear, chromatin and RNA-binding proteins (HMGB1, HMGB2, histone H1.0, MATR3, NCL), and lysosomal and senescence-associated secretory phenotype (SASP)-associated proteins (CTSZ, CTSD, PSAP), together with reduced glycolytic and energetic proteins (GAPDH, ENO3, PHKA1, CYCS). Age effects were robust to adjust for body mass index (BMI). Integrating differential abundance, multivariate importance and participant-level consistency, we defined a 24-protein skeletal muscle aging signature whose score separated all younger from all elderly women. Combining grip strength and gait speed into a combined function score, we found that 23 of the 24 signature proteins correlated with physical function (FDR < 0.05), and the signature score correlated strongly with function (r = -0.79). The senescence-associated alarmins HMGB1 and HMGB2 emerged as lead proteins: HMGB1 showed the strongest association with function (r = -0.86), and both remained associated after adjustment for age group. Together, these data define a senotype proteomic program in aging female skeletal muscle and a molecular signature of muscle function that, after validation, may serve as a readout for interventions that aim to preserve physical performance in elderly women.

biochemistry↗

SUMOylation Regulates IRF2BP2 Nuclear Localization and Stability

Interferon Regulatory Factor-2 Binding Protein 2 (IRF2BP2) is a transcriptional cofactor implicated in diverse biological processes. Although it functions primarily as a repressor, it can also activate gene expression. However, the mechanisms governing IRF2BP2 regulation remain poorly understood. Here, we demonstrate that IRF2BP2 interacts with UBE2I, the SUMO E2 ligase, and undergoes multi-SUMOylation, which enhances its nuclear localization. We further show that IRF2BP2 nuclear import is importin-{beta}-dependent and requires the functional nuclear localization signal (NLS). IRF2BP2 preferentially accumulates in transcriptionally active euchromatin in both resting and S-phase cells, consistent with its role in transcriptional control. We further reveal that SUMOylation contributes to IRF2BP2 stability. Moreover, IRF2BP2 is also ubiquitinated, predominantly through K6-linked ubiquitin chains, a non-proteolytic modification that aligns with our observation that IRF2BP2 is not degraded by the proteasome. Together, these findings identify SUMOylation and non-proteolytic ubiquitination as key mechanisms regulating IRF2BP2, highlighting a novel SUMO1-NLS-importin-{beta}-dependent pathway that governs its localization.

biochemistry↗

S-adenosylmethionine supply controls DNA methylation turnover in synovial sarcoma

Background: Methionine is the nutrient source of the metabolite S-adenosylmethionine (SAM) used to methylate chromatin for regulation of gene expression. Disruptions to this metabolic supply, including nutritional deficiency of certain B vitamins, alter chromatin methylation and have been implicated in tumor growth. Objective: To define how cellular SAM supply controls DNA methylation dynamics and the disruption of oncogenic gene expression in synovial sarcoma. Methods: Cell line models of synovial sarcoma were treated with the DNA methyltransferase inhibitor azacitidine or the small-molecule MAT2A inhibitor AG-270, which blocks SAM synthesis from methionine. Intracellular SAM concentrations were quantified by liquid chromatography-mass spectrometry. Global DNA methylation rates were measured by stable isotope tracing with [2H3-methyl]-methionine. Genomic sites of altered DNA methylation were identified by EM-seq and the associated transcriptional changes measured by RNA-seq. Results: Inhibition of SAM synthesis reduced intracellular SAM concentration from 94 uM to 5.6 uM (p value < 0.0001) at 24 hours. This was associated with a 19% decrease (p value < 0.0001) in the global 5-methyldeoxycytosine turnover rate, while total DNA methylation levels were maintained. In contrast to the global DNA hypomethylation induced by azacitidine, SAM depletion resulted in a redistribution of DNA methylation with loss at 252 and gain at 206 genomic sites, and the transcriptional response to SAM depletion was not associated with changes in promoter methylation at the altered genes. Both azacitidine and SAM depletion activated mesenchymal genes, while suppressing cell cycle progression. Conclusions: Metabolic supply of SAM is a major regulator of DNA methylation turnover providing a mechanism by which nutritional or genetic disruptions to SAM metabolism can alter chromatin methylation and gene expression.

biochemistry↗