Biology subjects

Perata, P.

Publications and source records attributed to Perata, P..

7 recordsLinked to original sources

bioRxiv2025

A BBX-HY5 photomorphogenic module induces anthocyanin synthesis in purple tomato fruits

Over the last decades, the search for novel nutraceutical foods led to the development of several anthocyanin enriched crops, with the purple tomato being one of the most prominent examples. In non-GM purple tomato, anthocyanin biosynthesis in fruits is conferred by the introgression of specific alleles of Anthocyanin fruit (Aft) and atroviolacea (atv) genes, which allow the pigmentation of the epicarp under optimal environmental conditions. Light induces anthocyanin synthesis through ELONGATED HYPOCOTYL 5 (HY5), whose levels are in turn controlled by CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1)-targeted destabilization. In recent years, light-related HY5-independent factors have been object of research. In this work, we have identified two novel transcription factors, belonging to the BBX protein family, modulating anthocyanin synthesis in purple tomato fruits at different stages of the pathway, including transcriptional and post-translational levels, and showing both HY5-dependent and independent functions. Our results contribute to expanding the knowledge on the light-induced regulation of anthocyanin synthesis in tomato and may serve for the development of novel anthocyanin enriched lines able to overcome the threat posed by non-optimal light conditions.

plant biology↗

bioRxiv2025

Hydrogen sulfide modulates plant hypoxic responses through the persulfidation of Plant Cysteine Oxidases

Hydrogen sulfide (H2S) is a gaseous molecule historically regarded as toxic. Nevertheless, increasing evidence has brought to light important physiological roles in both animals and plants. In plants, H2S is involved in environmental and developmental responses, such as stomatal closure and seed germination, and in tolerance mechanisms to different stress conditions like salinity, drought and waterlogging. In this study, we report a function of H2S as a modulator of hypoxic responses in Arabidopsis thaliana. A combination of biochemical and genetic evidence demonstrates that H2S inhibits the activity of Plant Cysteine Oxidases, the molecular sensors of oxygen, through protein persulfidation to modulate hypoxia-associated responses. Furthermore, we show that H2S physiology contributes to responses to low oxygen, as disturbing H2S production impaired activation of hypoxia-responsive genes and submergence tolerance. Overall, this work introduces H2S as signalling modulator in plant hypoxic responses and adds a regulatory layer to the plant oxygen-sensing mechanism.

plant biology↗

bioRxiv2025

Severe Fe deficiency promotes hypoxia inducible responses in Arabidopsis thaliana

In plants, Fe homeostasis and O2 metabolism are strictly related, indeed several Fe-requiring enzymes catalyze reactions that also involve oxygen, as a reagent, product, entry or end point of the metabolic pathway in which the enzyme takes part. Oxygen sensing itself relies on Fe-dependent enzymes, the Plant cysteine oxidase (PCO) family of 2-OG independent thiol dioxygenases. PCOs are responsible for the degradation of ERFVII ethylene-responsive factors through a proteasomal N-degron pathway that connects hypoxia-inducible responses to the stabilization of the ERFVII transcription factors. Here, we investigated the interplay between low oxygen and Fe-deficiency stresses in A. thaliana. We used plants expressing a genetically encoded reporter of ERFVII protein stability and measured the expression of anaerobic genes to infer PCO activity in vivo. Our results highlight that Fe deprivation can elicit hypoxia-like responses depending on its severity. To test the involvement the ERFVII factors further, we examined the response of a pentuple erfVII mutant to Fe-deficiency stress, individually or combined with low oxygen. Our data indicate that the ERFVIIs might take part to the acclimation to chronic Fe deficiency by acting as positive regulators of starvation-responsive genes. Moreover, our results suggest that the ERFVIIs fine-tune nutrient mobilization to the shoots of submerged plants growing on moderately Fe-deficient substrates. This work expands the known functions of the ERFVII factors and provides new information to understand plant responses to combined environmental stresses.

plant biology↗

bioRxiv2024

Genotype-environment association across precipitation regimens reveals the mechanism of plant adaptation to rainy environments

In an era characterized by rapidly changing and less-predictable weather conditions fueled by the climate crisis, understanding the mechanisms underlying local adaptation in plants is of paramount importance for the conservation of species. As the frequency and intensity of extreme precipitation events increase, so are the flooding events resulting from soil water saturation. The deriving onset of hypoxic stress is one of the leading causes of crop damage and yield loss. By combining genomics and remote sensing data, today it is possible to probe natural plant populations that have evolved in different rainfall regimes and look for molecular adaptation to hypoxia. Here, using an environmental genome-wide association study (eGWAS) on 934 non-redundant georeferenced Arabidopsis ecotypes, we have identified functional variants for the gene MED25 BINDING RING-H2 PROTEIN 1 (MBR1). This is a ubiquitin-protein ligase that regulates MEDIATOR25 (MED25), part of a multiprotein complex that interacts with transcription factors which act as key drivers of the hypoxic response in Arabidopsis, namely the RELATED TO AP2 proteins, RAP2.2 and RAP2.12. Through experimental validation, we show that natural variants of MBR1 have a differential impact on the stability of MED25 and, in turn, on hypoxic tolerance. Our study also highlights the pivotal role of the MBR1/MED25 module in establishing a comprehensive hypoxic response. Our findings show that molecular candidates for plant environmental adaptation can be effectively mined from large datasets. This thus supports the need for the integration of forward and reverse genetics with robust molecular physiology validation of the outcomes.

genetics↗

bioRxiv2020

Evidences for a nutritional role of iodine in plants

Little is known about the role of iodine in plant physiology. We evaluated the impact of low concentrations of iodine on the phenotype, transcriptome and proteome of Arabidopsis thaliana. Our experiments showed that removal of iodine from the nutrition solution compromises plant growth, and restoring it in micromolar concentrations is beneficial for biomass accumulation and leads to early flowering. In addition, iodine treatments specifically regulate the expression of several genes, mostly involved in the plant defence response, suggesting that iodine may protect against both biotic and abiotic stress. Finally, we demonstrated iodine organification in proteins. Our bioinformatic analysis of proteomic data revealed that iodinated proteins identified in the shoots are mainly associated with the chloroplast and are functionally involved in photosynthetic processes, whereas those in the roots mostly belong and/or are related to the action of various peroxidases. These results suggest that iodine should be considered as a plant nutrient.

plant biology↗

bioRxiv2020

Nighttime gibberellin biosynthesis is influenced by fluctuating environmental conditions and contributes to growth adjustments of Arabidopsis leaves.

Optimal plant growth performance requires that the action of growth signals, such as gibberellins (GA), are coordinated with the availability of photo-assimilates. Here, we studied the links between gibberellin biosynthesis and carbon availability, and the subsequent effects on growth. The results presented here show that carbon availability, light and dark cues, and the clock ensure the timing and magnitude of gibberellin biosynthesis and that disruption of these mechanisms results in reduced gibberellin levels and expression of downstream genes. Carbon dependent nighttime induction of GIBBERELLIN 3-BETA-DIOXYGENASE 1 (GA3ox1) was severely hampered when preceded by a day of lowered light availability, leading specifically to reduced bioactive GA4 levels, and coinciding with a decline in leaf expansion rate during the night. We attribute this decline in leaf expansion mostly to reduced photo-assimilates. However, plants where gibberellin limitation was alleviated had significantly improved expansion demonstrating the relevance of gibberellins in growth control under varying carbon availability. Carbon dependent expression of upstream gibberellin biosynthesis genes (KAURENE SYNTHASE, KS and GIBBERELLIN 20 OXIDASE 1, GA20ox1) was not translated into metabolite changes within this short timeframe. We propose a model where the extent of nighttime biosynthesis of bioactive GA4 by GA3ox1 is determined by starch, as the nighttime carbon source, and so provides day-to-day adjustment of gibberellin responses.

plant biology↗

bioRxiv2020

Differential submergence tolerance between juvenile and adult Arabidopsis plants involves the ANAC017 transcription factor

Plants need to attune stress responses to the ongoing developmental programs to maximize their efficacy. For instance, successful submergence adaptation is often associated to a delicate poise between saving resources and their expenditure to activate measures that allow stress avoidance or attenuation. We observed a significant decrease in submergence tolerance associated with aging in Arabidopsis thaliana, with a critical step between two and three weeks of post-germination development. This sensitization to flooding was concomitant with the transition from juvenility to adulthood. Transcriptomic analyses indicated that a group of genes related to ABA and oxidative stress response was more expressed in juvenile plants than in adult ones. These genes are induced by endomembrane tethered ANAC factors that were in turn activated by submergence-associated oxidative stress. A combination of molecular, biochemical and genetic analyses showed that these genes are located in genomic regions that move towards a heterochromatic state with adulthood, as marked by lysine 4 dimethylation of histone H3. We concluded that, while the mechanism of flooding stress perception and signal transduction were unaltered between juvenile and adult phases, the sensitivity that these mechanisms set into action is integrated, via epigenetic regulation, into the developmental programme of the plant.

plant biology↗