Aug 2026· Journal of Experimental Botany· 0 citations
Medicine
TL;DR
It is demonstrated that oil accumulation in avocado mesocarp is driven by a tightly regulated developmental reprogramming of carbon metabolism, closely associated with the induction of fatty acid biosynthetic enzymes.
Abstract
Avocado mesocarp is a unique non-seed tissue capable of accumulating high levels of oil, yet the metabolic regulation underlying this process during fruit development remains poorly understood. We investigated how central carbon metabolism is coordinated with fatty acid biosynthesis in two avocado cultivars with contrasting oil accumulation patterns, 'Hass' and 'Fuerte', using integrated metabolomic and proteomic analyses. Fatty acid profiling revealed cultivar-dependent differences in timing and rate of lipid accumulation, with 'Fuerte' exhibiting earlier fatty acid synthesis and 'Hass' showing a delayed but prolonged accumulation phase. Metabolite profiling indicated a developmental shift in carbon partitioning, characterized by declining soluble sugars and polyols alongside increasing organic acids and amino acids. Proteomic analyses revealed extensive reprogramming of glycolysis, the pentose phosphate pathway, and the tricarboxylic acid cycle, closely associated with the induction of fatty acid biosynthetic enzymes. Integration of protein abundance with fatty acid content using partial least squares regression identified acetyl-CoA carboxylase, β-ketoacyl-ACP synthase, and stearoyl-ACP desaturase as key metabolic steps linking carbon sources to lipid accumulation. Pathway reconstructions further highlighted cultivar-specific temporal strategies coordinating carbon metabolism with triacylglycerol biosynthesis. Together, these findings demonstrate that oil accumulation in avocado mesocarp is driven by a tightly regulated developmental reprogramming of carbon metabolism.
ABSTRACT Megasphaera cerevisiae is a well‐known beer spoilage organism, capable of producing undesirable flavours and turbidity. Although the biosynthesis of medium‐chain fatty acids (MCFAs) has been extensively studied in different Megasphaera species, the metabolic behaviour of M. cerevisiae in controlled environments remains largely unexplored. This study examines the MCFAs production from diverse substrates and reports flux analyses of core metabolism for the first time using a genome‐scale model. The results suggest that acetate stimulates butyrate production but not caproic acid production. Butyrate supplementation, either alone or in combination with acetate, promoted CA synthesis. Lactate supplementation primarily led to the formation of propionic acid and acetic acid. The metabolic network model was manually curated and validated against the different experimental data. The metabolic flux results showed that butyrate production facilitated via the reverse β‐oxidation (RBO) pathway, with a minor contribution from the fatty acid synthesis (FAS) pathway. Conversely, CA synthesis was mainly synthesised through the FAS pathway, irrespective of the substrate used. The pathway analyses results highlighted the critical role of hydrogen production in M. cerevisiae metabolism, particularly under conditions where lactate is utilised. Collectively, these findings offer novel insights into the metabolic versatility and pathway preferences of M. cerevisiae .
W. Sabra, Sonia Villotti, Joachim Fensterle et al.· Environmental Microbiology R...· 0 citations
Deciphering the metabolic basis of high-yield antibiotic production in Streptomyces is crucial for strain optimization. Atmospheric and room-temperature plasma (ARTP) mutagenesis of Streptomyces xinghaiensis sf106 generated a mutant with a 30% increase in tylosin-equivalent concentration (μg/mL). 4D-FastDIA quantitative proteomics identified 279 differentially abundant proteins enriched in the Type I polyketide synthase (PKS) pathway, with increased abundance of key macrolide-biosynthesis-related proteins. Lysine-acetylome profiling identified 1152 differentially abundant acetylation sites and revealed altered acetylation of enzymes involved in fatty acid metabolism and the tricarboxylic acid (TCA) cycle, suggesting adjustments in central metabolism associated with acyl-CoA precursor availability and energy generation. Integration of proteomic and acetylomic data suggests coordinated changes in protein abundance and lysine acetylation associated with the increased tylosin-equivalent concentration. These results highlight candidate nodes for rational metabolic engineering of S. xinghaiensis.
Findings indicate that neonicotinoid resistance in Nilaparvata lugens is supported by coordinated remodelling of central metabolism and detoxification and identify two candidate metabolic nodes for further resistance management research.
Perilla (Perilla frutescens) is an important oil-bearing crop rich in α-linolenic acid (ALA), and seed oil quality varies greatly among different germplasms. However, the molecular and metabolic mechanisms underlying genotypic differences in ALA accumulation remain unclear. In this study, four Perilla varieties with distinct seed phenotypic traits were used to investigate the variations in seed quality, metabolome, and transcriptome. Significant genotypic differences were observed in seed color, thousand-grain weight, and oil content. QO8 showed the highest seed oil content, while QS5 and QO10 exhibited relatively lower oil accumulation levels. Metabolome analysis revealed that lipid metabolism was the dominant metabolic category in Perilla seeds. Multiple differentially accumulated metabolites (DAMs), including ALA, stearic acid, traumatic acid, and 10-OPDA, displayed genotype-specific accumulation patterns. KEGG enrichment demonstrated that α-linolenic acid metabolism and unsaturated fatty acid biosynthesis were the most significantly divergent pathways among different Perilla germplasms. Transcriptome analysis identified numerous differentially expressed genes (DEGs) involved in fatty acid and ALA biosynthesis, such as FAD2, LOX, AOS, AOC, OPR, KAT, ECH, and ACOX. Integrated transcriptome and metabolome analysis further confirmed that the differential expression of structural genes altered the metabolic flux of the ALA and downstream jasmonic acid pathway, resulting in varied accumulation of core lipid intermediates. In addition, WRKY and MYB transcription factors were identified as key upstream regulators that positively or negatively modulated ALA metabolic homeostasis. This study systematically clarified the phenotypic, metabolic, and transcriptional differences in seeds of different Perilla varieties and revealed the core regulatory network of ALA biosynthesis. These findings provide valuable candidate genes and a theoretical foundation for elucidating the molecular mechanism of high ALA accumulation and quality improvement in Perilla seeds.
Oil palm (Elaeis guineensis Jacq.) is the most productive oil-bearing crop globally, yet the molecular basis of mesocarp development and lipid accumulation remains poorly understood. Ultra-deep data-independent acquisition mass spectrometry (DIA-MS) was applied to characterize proteome dynamics in two contrasting genotypes, seedless (KS) and thin-shelled (TS), across five developmental stages (P1-P5) spanning fruit development to mature oil accumulation. Phenotypic analysis revealed higher mesocarp proportion and oil content in KS during late maturation. A total of 137,615 peptides corresponding to 12,163 protein groups were identified, providing a temporal proteomic landscape of mesocarp development. Multivariate analysis indicated that developmental progression was the primary contributor to proteomic variation, whereas genotype-associated differences increased during lipid accumulation. Differentially abundant proteins were mainly associated with carbohydrate metabolism, photosynthesis, proteolysis, antioxidant responses, and lipid biosynthesis. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and KOG analyses suggested extensive remodeling of metabolic networks, including developmental changes in photosynthesis-associated proteins and increased representation of lipid-associated pathways during maturation. Weighted protein co-expression network analysis identified 17 modules associated with developmental progression and lipid accumulation, highlighting candidate proteins involved in carbon metabolism, energy production, and cellular protection. Genes encoding selected hub protein candidates were further examined by RT-qPCR. Biochemical analyses supported these proteomic patterns, showing increased acetyl-CoA availability, enhanced antioxidant enzyme activities (SOD, CAT, APX, and GR), improved GSH/GSSG balance, and reduced oxidative damage in KS. Together, these findings provide a temporal proteomic and biochemical framework for understanding genotype-associated differences in oil accumulation and identify candidate metabolic networks for functional studies.
Muhammad Imran, Zhen Zhao, Ruo-Yu Zhou et al.· Plant physiology and biochem...· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
