Biology subjects

Rosental, L.

Publications and source records attributed to Rosental, L..

5 recordsLinked to original sources

bioRxiv2026

Resolving Gene-Metabolism Links through Multi-Metabolite mQTL Commonality Analysis

High-throughput metabolomics detects so many compounds that most studies use only a fraction of them, focusing on the few metabolites with an annotated structure or substructure. Metabolite genome-wide association studies of specialized metabolism detect many metabolite quantitative trait loci (mQTLs), but most associated metabolite features remain unannotated, limiting gene discovery. In leaves of 362 tomato accessions under control and water-deficit conditions, only 13 of the 826 metabolite features associated with 77 reproducible mQTLs were annotated with good confidence. To study the mQTLs with the largest impact, we developed commonality analysis, an approach that does not depend on well-studied pathways. Commonality analysis uses biologically defined groups, such as the features associated with one mQTL, to infer relatedness between metabolites. By identifying the fragments, neutral losses or mass transformations that are common in a group, it links the group to a substructure, pathway or reaction, and can extend annotation within the group. Most high-impact mQTLs had a significantly distinct fragment commonality, whose outstanding fragments suggested the pathway involved and its candidate gene. We demonstrate the approach in three representative mQTLs: (i) common fragments pointed to a sinapoyl-hexose pathway and a serine carboxypeptidase-like candidate acyltransferase; (ii) common fragments marked the features associated with a purine permease as nitrogen-containing, which isotope labeling then supported; (iii) a common 2.02 Da transformation pointed to a double-bond reduction and a putative reductase. Overexpression of each gene reproduced the commonality patterns, supporting the candidate genes and showing that the approach also applies to experimentally defined metabolite groups.

plant biology↗

bioRxiv2024

Genetic architecture of the tomato fruit lipidome; new insights link lipid and volatile compounds

Tomato (Solanum lycopersicum L.) fruit flavor is determined by a combination of multiple volatile compounds, including several derived from lipids and fatty acids. Although fruit flavor has been intensively studied, the linkage between lipid metabolism and flavor remains largely undefined. Here, we performed a genome-wide association study (GWAS) and QTL mapping for the fruit lipid content from 550 tomato accessions and 107 backcross inbred lines (BILs) in two consecutive seasons. Over 130 lipid compounds were identified and mapped, allowing for the identification of over 600 metabolic QTL (mQTL). We further described and validated candidate genes associated with lipid content. Among them is a lipase-like protein (TomLLP) whose function was validated in vivo using overexpression lines in tomato and knockout mutants in Arabidopsis. We also identified functions for three enzymes: a class III lipase (Sl-LIP8), a cyclopropane-fatty-acyl-phospholipid synthase (CFAPS1), and Lipoxygenase C (TomLoxC). By utilizing knockout lines for CFAPS1 and CRISPR-Cas9 loss-of-function lines for Sl-LIP8 and TomLoxC, we demonstrated the functional importance of these enzymes in fruit lipid metabolism. Our study provides a comprehensive analysis of the tomato fruit lipidome and insights into key genes that shaped the natural variation in tomato lipid content and their links to flavor-associated volatile compounds.

molecular biology↗

bioRxiv2024

Comparative analysis of the plasma metabolome of migrating passerines during stopover: Novel insights into flight metabolism

During long distance migration, many birds may experience periods of either prolonged fasting, during endurance flights, or extensive feeding during stopovers. It was previously shown that habitat selection during stopover can largely affect the migration outcome of an individual. Despite decades of research of the avian metabolism during stopover and migration, many questions have remained unanswered, as such research mainly focused on targeted metabolites and fat metabolism. Here, we examined the plasma-metabolome of migrating passerines prior to their crossing the Sahara Desert. Birds were sampled at two sites populated by Pistacia trees, bearing fat-rich fruits, and at an additional site dominated by blooming Eucalyptus trees. The blood samples were analyzed using both GC-MS and LC-MS, using an untargeted approach. We found that birds from one of the sites had a distinguish metabolic profile, suggesting recent landing. Examination of metabolic pathways activated during stopovers indicated a crucial role for cycling glucose through the Cori and Cahill cycles in resting and recovery processes. This novel perspective, conducted on free-ranging birds, suggests the evolution of avian insulin resistance due to factors such as endurance exercise, fasting, and a preference for fatty acid oxidation during migration, akin to cell trauma recovery. Additionally, we investigated inter-site variations in birds metabolic profiles. Significant variations were observed in both polar and lipophilic metabolites among the sites. Differences in polar metabolites were primarily attributed to variations in the physiological state of the birds between sites, while distinctions in the lipophilic profiles of rested birds were linked to variations in their primary food sources. This study underscores the challenge of interpreting commonly used indicators for assessing migrating birds physiological states and site quality, which are predominantly derived from lipid metabolism, in complex ecological systems.

ecology↗

bioRxiv2023

Autophagy in maternal tissues contributes to Arabidopsis thaliana seed development.

Seeds are an essential food source, providing nutrients for germination and early seedling growth. Degradation events in the seed and the mother plant accompany seed development. One degradation mechanism is autophagy, facilitating cellular component breakdown in the lytic organelle. Autophagy influences various aspects of plant physiology, specifically nutrient availability and remobilization, suggesting its involvement in source-sink interactions. During seed development, autophagy was shown to affect nutrient remobilization from mother plants and function in the embryo. Yet, these studies examined autophagy-knockout (atg mutant) plants, making it impossible to distinguish between the contribution of autophagy in the source (i.e., the mother plant) and the sink tissue (i.e., the embryo). To address this, we employed a novel approach to differentiate between autophagy in source and sink tissues. We investigated how autophagy in the maternal tissue affects seed development by performing reciprocal crosses between WT and atg mutant Arabidopsis thaliana plants. Although F1 seedlings possessed a functional autophagy mechanism, etiolated F1 plants from maternal atg mutants displayed reduced growth. This was attributed to altered protein but not lipid accumulation in the seeds, suggesting autophagy differentially regulates carbon and nitrogen remobilization. Surprisingly, F1 seeds of maternal atg mutants exhibited faster germination, resulting from different seed coat development. Our study emphasizes the significance of examining autophagy in a tissue-specific manner, revealing valuable insights into the interplay between different tissues during seed development. It sheds light on the tissue-specific functions of autophagy, offering potential for new research into the underlying mechanisms governing seed development and crop yield.

plant biology↗

bioRxiv2020

Autophagy is required for lipid homeostasis during dark-induced senescence in Arabidopsis

Autophagy is an evolutionarily conserved mechanism that mediates the degradation of cytoplasmic components in eukaryotic cells. In plants, autophagy has been extensively associated with the recycling of proteins during carbon starvation conditions. Even though lipids constitute a significant energy reserve, our understanding of the function of autophagy in the management of cell lipid reserves and components remains fragmented. To further investigate the significance of autophagy in lipid metabolism, we performed an extensive lipidomic characterization of Arabidopsis (Arabidopsis thaliana) autophagy mutants (atg) submitted to dark-induced senescence conditions. Our results revealed an altered lipid profile in atg mutants, suggesting that autophagy affects the homeostasis of multiple lipid components under dark-induced senescence. The acute degradation of chloroplast lipids coupled with the differential accumulation of triacylglycerols (TAGs) and plastoglobuli indicates an alternative metabolic reprogramming towards lipid storage in atg mutants. The imbalance of lipid metabolism compromises the production of cytosolic lipid droplets and the regulation of peroxisomal lipid oxidation pathways in atg mutants. One-sentence summaryAutophagy is required for the mobilization of membrane lipid components and lipid droplet dynamics during extended darkness in Arabidopsis.

plant biology↗