Biology subjects

Mano, J.

Publications and source records attributed to Mano, J..

4 recordsLinked to original sources

bioRxiv2025

Oxylipin carbonyl compositions in the chloroplast compartments

Aldehydes and ketones derived from oxidized lipids (oxylipin carbonyls) accumulate in plants under stress conditions, acting as signaling molecules or cytotoxic agents through electrophilic modification of biomolecules. Because chloroplasts generate reactive oxygen species and contain lipids rich in unsaturated fatty acids, they are likely major sites of oxylipin carbonyl formation. To identify chloroplast-derived carbonyl species and their sub-organellar distribution, we analyzed carbonyls in spinach leaves, whole chloroplasts, thylakoids, envelopes and stroma. A total of 26 carbonyl species were detected, of which 13 were identified. Chloroplasts contained 14 species, including formaldehyde, propionaldehyde, acetaldehyde, acetone, butyraldehyde, (E)-2-pentenal, (Z)-3-hexenal, (E)-2-hexenal, n-hexanal and 4-hydroxy-(E)-2-hexenal. Phenylacetaldehyde and n-pentanal, which were abundant in leaves, were not associated with chloroplasts. Thylakoid membranes contained all chloroplast carbonyls except acetone, indicating that they are a major site of carbonyl formation. Formaldehyde was highly enriched in thylakoids and envelopes, providing evidence that it can be generated within chloroplasts, most likely from membrane lipids. Estimated concentrations of several carbonyls in membranes reached over 1 millimolar. This high-resolution mapping of oxylipin carbonyls within chloroplast compartments, achieved here for the first time, provides a spatial framework for understanding their formation and functional roles in plant stress responses.

plant biology↗

bioRxiv2025

Plant-specific tau class glutathione transferases safeguard against lipid oxidation stress through dual detoxification of lipid peroxides and reactive carbonyl species

O_LIOxidation of membrane lipids results in the formation of lipid peroxides (LOOHs) and reactive carbonyl species (RCS), that induce lipid oxidation stress in plants. The plant-specific tau class of glutathione transferases (GSTUs) possess both LOOH peroxidase and RCS-conjugating activities, but their overall contribution to stress tolerance remains unclear. C_LIO_LIWe systematically examined 16 GSTU isozymes of Arabidopsis thaliana and found that all catalysed glutathione-dependent reduction of LOOHs. GSTU17, showing the highest activity, recognized five different isomers of linoleic acid-derived hydroperoxides within comparable catalytic efficiencies. C_LIO_LIT-DNA mutants lacking GSTU3, GSTU17, GSTU18, GSTU19 or GSTU25--isoforms with strong conjugation activities toward acrolein, 4-hydroxynonenal or crotonal--displayed enhanced sensitivity to photooxidative stress, indicating that detoxification of RCS is crucial for oxidative protection. C_LIO_LITranscriptome analyses revealed that exposure to RCS (crotonal, 2-pentenal or 2-hexenal) strongly induced 12 GSTU genes, while other GST classes showed little response. Collectively, these results demonstrate that GSTUs function as a major enzymatic system mitigating lipid oxidation stress in A. thaliana through the combined detoxification of lipid peroxides and their reactive carbonyl products. C_LI

plant biology↗

bioRxiv2025

Searching for Acrolein-Scavenging Compounds in Plants: Isoalliin from Onion as an Excellent Scavenger

Reactive carbonyl species (RCS), such as acrolein (Acr), are generated through the degradation of lipid peroxides and exert cytotoxic effects. To identify natural RCS scavengers, we examined 80% ethanol extracts from 46 angiosperm species for Acr-trapping activity using an HPLC-based assay. Strong activities were observed in several taxa, including garlic, spinach, avocado, broccoli, and lotus. In garlic, the active metabolite was identified as S-allyl-L-cysteine sulfoxide (alliin), a characteristic Allium amino acid. Alliin and its S-(1E)-propenyl and S-methyl derivatives (isoalliin and methiin, respectively) trapped up to two Acr molecules at the amino group and exhibited higher activities than known scavengers such as carnosine and epigallocatechin gallate. These findings highlight S-alk(en)yl-L-cysteine sulfoxides as potent secondary antioxidants and suggest that structurally diverse RCS scavengers remain to be discovered in plants.

plant biology↗

bioRxiv2024

Embedding bioprinting of low viscous, photopolymerizable blood-based bioinks in a self-healing transparent supporting bath

Protein-based hydrogels have great potential to be used as bioinks for biofabrication-driven tissue regeneration strategies due to their innate bioactivity. Nevertheless, their use as bioinks in conventional 3D bioprinting is impaired due to their intrinsic low viscosity. Using embedding bioprinting, a liquid bioink is printed whithin a support that physically holds the patterned filament. Inspired by the recognized microencapsulation technique complex coacervation, we introduce crystal self-healing embedding bioprinting (CLADDING) based on a highly transparent crystal supporting bath. The suitability of distinct classes of gelatins was evaluated (i.e., molecular weight distribution, isoelectric point and ionic content), as well as the formation of gelatin-gum arabic microparticles as a function of pH, temperature, solvent and mass ratios. Characterizing and controlling this parametric window resulted in high yields of support bath with ideal self-healing properties for interaction with protein-based bioinks during bioprinting. This support bath achieved transparency, which boosted light permeation within the bath. CLADDING bioprinted constructs fully composed of platelet lysates encapsulating a co-culture of human mesenchymal stem cells and endothelial cells were obtained, demonstrating high-dense cellular network with excellent cell viability and stability over a month. CLADDING broadens the spectrum of photocrosslinkable materials with extremely low viscosity that can now be bioprinted with sensitive cells using embedding bioprinting without any additional support.

bioengineering↗