Although a species’ sexual system may influence the genetic diversity of its populations in their natural environment, there have been few such studies involving indigenous species of the Atlantic Forest. Here we study Myrsine coriacea, a dioecious tree widely used in reforestation programs despite a lack of information about its natural interpopulation genetic variation. To address this knowledge gap, intra- and interpopulation genetic diversity were measured for male and female individuals of ten natural populations using ISSR markers. Greater intrapopulation genetic diversity indicated interpopulation gene flow, regardless of isolation and distance between populations. Multivariate analyses detected significant differences in genetic diversity between populations, but not between males and females, which indicates that genetic diversity did not differ between the two sex morphs. Distance between populations was unrelated to genetic diversity. Myrsine coriacea has not experienced a loss of genetic variability despite the characteristic segregated spatial distribution of its populations. These results suggest that obligatory cross-pollination and dispersal by birds may be important mechanisms for the maintenance of genetic diversity in natural populations of M. coriacea.

Sex segregation increases the cost of Carica papaya production through seed-based propagation. Therefore, in vitro techniques are an attractive option for clonal propagation, especially of hermaphroditic plants. Here, we performed a temporal analysis of the proteome of C. papaya calli aiming to identify the key players involved in embryogenic callus formation. Mature zygotic embryos used as explants were treated with 20 μM 2,4-dichlorophenoxyacetic acid to induce embryogenic callus. Total proteins were extracted from explants at 0 (zygotic embryo) and after 7, 14, and 21 days of induction. A total of 1407 proteins were identified using a bottom-up proteomic approach. The clustering analysis revealed four distinct patterns of protein accumulation throughout callus induction. Proteins related to seed maturation and storage are abundant in the explant before induction, decreasing as callus formation progresses. Carbohydrate and amino acid metabolisms, aerobic respiration, and protein catabolic processes were enriched throughout days of callus induction. Protein kinases associated with auxin responses, such as SKP1-like proteins 1B, accumulated in response to callus induction. Additionally, regulatory proteins, including histone deacetylase (HD2C) and argonaute 1 (AGO1), were more abundant at 7 days, suggesting their role in the acquisition of embryogenic competence. Predicted protein–protein networks revealed the regulatory role of proteins 14-3-3 accumulated during callus induction and the association of proteins involved in oxidative phosphorylation and hormone response. Our findings emphasize the modulation of the proteome during embryogenic callus initiation and identify regulatory proteins that might be involved in the activation of this process.

Biogenic carbon dots (CDs) are emerging as promising plant biostimulants, yet their effects during early crop establishment remain underexplored. Here, we synthesized and characterized Spirulina-derived CDs and evaluated their efficacy as seed nanopriming agents in rice (Oryza sativa L.). CDs exhibited nanoscale size, abundant surface functionalities, and a highly negative ζ-potential, indicative of stable aqueous dispersions. Spectroscopic characterization (Raman and FTIR) confirmed a graphitic–amorphous carbon structure. Near-infrared spectroscopy coupled to principal component analysis revealed time-dependent metabolic changes during imbibition, identifying 8–12 h as the optimal priming window. Nanopriming with Spirulina CDs (0.2 mg mL⁻¹ for 12 h) increased the seed germination rate (25%), the germination speed index (17%), vigor index I (22%), and root length (37%) compared to hydropriming. Biochemically, the nanoprimed seedlings accumulated higher levels of starch (24%), total carbohydrates (8%), and total phenolics (20%), without evidence of oxidative imbalance, based on antioxidant capacity measurements and proteomic profiling. Proteomic analysis revealed coordinated metabolic reprogramming, characterized by increased abundance of proteins involved in translation, energy metabolism, and ion/nutrient homeostasis, alongside reduced abundance of proteins associated with defense and catabolic processes. This shift from stress-preparation to growth-oriented metabolism supports improved seedling establishment. Overall, Spirulina-derived CDs function as effective nanobiostimulants that promote early metabolic activation and resource mobilization, offering a sustainable strategy to enhance rice seedling establishment.

Plants exhibit phenotypic plasticity in response to environmental variations, which can lead to stable genetic and physiological adaptations if exposure to specific conditions is prolonged. Myrsine coriacea demonstrates this through its ability to thrive in diverse environments. The objective of the article is to investigate the adaptive responses of M. coriacea by cultivating plants from seeds collected at four different altitudes in a common garden experiment. Through integrated physiological and proteomic analyses, we identified 170 differentially accumulated proteins and observed significant physiological differences among the populations. The high-altitude population (POP1) exhibited a unique proteomic profile with significant down-regulation of proteins involved in carbon fixation and energy metabolism, suggesting a potential reduction in photosynthetic efficiency. Physiological analyses showed lower leaf nitrogen content, net CO ₂ assimilation rate, specific leaf area, and relative growth rate in stem height for POP1, alongside higher leaf carbon isotopic composition ( δ13C ) and leaf carbon ( C ) content. These findings provide insight into the complex interplay between proteomic and physiological adaptations in M. coriace a and underscore the importance of local adaptations. This study enhances our understanding of how altitude-specific selection pressures can shape plant molecular biology and physiology, offering valuable perspectives for predicting plant responses to global environmental changes. Highlight: This study unveils proteomic and physiological adaptations in a high-altitude M. coriacea population with reduced carbon fixation and energy metabolism.

A embriogênese somática em cana-de-açúcar possibilita propagação de mudas em larga-escala e a regeneração de plantas geneticamente modificadas, representando uma ferramenta biotecnológica fundamental