Biology subjects

Berardocco, S.

Publications and source records attributed to Berardocco, S..

3 recordsLinked to original sources

bioRxiv2026

Cracking vacuolar fumarate and malate transport shows its function in Arabidopsis metabolism and growth.

Malate and fumarate constitute a significant transient carbon stock that is dynamically synthesized during the photoperiod. These organic acids are diurnally stored and remobilised from the vacuole, and they have a key role in the cellular metabolic regulation. This function is well known in C4 and CAM plants. However, in C3 species that are the majority of terrestrial plants, the importance of the vacuolar accumulation/release and its influence on plant growth is still an open question. In Here we addressed this issue generating multiple knockout mutants in Arabidopsis thaliana lacking vacuolar anion channels of the Aluminium-Activated Malate Transporter (ALMT) family, to impair malate and fumarate transport to the vacuole. We show that in these mutants reducing vacuolar transport of malate and fumarate in mesophyll cells leads to a dramatic growth impairment. Metabolic and fluxomic analysis revealed that vacuolar malate and fumarate transport influences plant carbon and nitrogen metabolism as well as cellular pH and ionic homeostasis. In conclusion, our results show that the transport organic acids like malate and fumarate across the vacuolar membrane is essential for plant growth in a C3 plant too. These results establish the importance of the vacuolar pools of malate and fumarate in plant metabolism.

plant biology↗

bioRxiv2026

Morph-specific plasticity drives divergent host-shift and acclimation strategies in aphids

Understanding how organisms cope with environmental change is central to eco-evolutionary theory, yet a key unresolved challenge is distinguishing anticipatory plasticity, where phenotypes are pre-configured using predictive cues, from responsive plasticity, where phenotypes are adjusted after environmental exposure. Empirically testing these strategies is challenging because phenotypes measured after environmental transitions integrate both prior cue-dependent state configuration and post-exposure adjustment, obscuring when plastic responses are initiated. Systems with predictable environmental transitions and discrete life-history stages provide a powerful opportunity to resolve this challenge. Here, we use host-alternating aphids to test how plasticity strategies are organized across morphs experiencing the same seasonal host shift but facing different ecological constraints. We quantified fitness, transcriptomic responses, and host chemical landscapes across three morphs transferred among secondary hosts differing in phloem composition. Migratory spring morphs maintained uniformly high survival and showed minimal transcriptional change, consistent with anticipatory plasticity mediated by pre-configured metabolic and detoxification programs. In contrast, summer morphs exhibited host-dependent survival costs and extensive regulatory remodeling, indicating responsive plasticity. By integrating fitness, transcriptomics, and metabolomics, we show that predictable environmental transitions can favor the evolution and partitioning of plasticity strategies across life-history stages. More broadly, our results provide mechanistic evidence linking environmental predictability, regulatory architecture, and the evolution of plastic responses to heterogeneous environments.

evolutionary biology↗

bioRxiv2022

Validation of carbon isotopologue distribution measurements by GC-MS and application to 13C-metabolic flux analysis of plant tricarboxylic acid cycle

The estimation of metabolic fluxes in photosynthetic organisms represents an important challenge that has gained interest over the last decade with the development of 13C-Metabolic Flux Analysis at isotopically non-stationary steady-state. This approach requires a high level of accuracy for the measurement of Carbon Isotopologue Distribution in plant metabolites. But this accuracy has still not been evaluated at the isotopologue level for GC-MS, leading to uncertainties for the metabolic fluxes calculated based on these fragments. Here, we developed a workflow to validate the measurements of CIDs from plant metabolites with GC-MS by producing tailor-made E. coli standard extracts harboring a predictable binomial CID for some organic and amino acids. Overall, most of our TMS-derivatives mass fragments were validated with these standards and at natural isotope abundance in plant matrices. Then, we applied this validated MS method to investigate the light/dark regulation of plant TCA cycle by incorporating U-13C-pyruvate to Brassica napus leaf discs. We took advantage of pathway-specific isotopologues/isotopomers observed between two and six hours of labeling to show that the TCA cycle can operate in a cyclic manner under both light and dark conditions. Interestingly, this forward cyclic flux mode has a nearly four-fold higher contribution for pyruvate-to-citrate and pyruvate-to-malate fluxes than the phosphoenolpyruvate carboxylase (PEPc) flux reassimilating carbon derived from some mitochondrial enzymes. The contribution of stored citrate to the mitochondrial TCA cycle activity was also questioned based on dynamics of 13C-enrichment in citrate, glutamate and succinate and variations of citrate total amounts under light and dark conditions. Interestingly, there was a light-dependent 13C-incorporation into glycine and serine showing that decarboxylations from pyruvate dehydrogenase complex and TCA cycle enzymes were actively reassimilated and could represent up to 5% to net photosynthesis.

plant biology↗