Network-guided transcriptomic insights into tissue-specific and temporal salt stress responses in broccoli (Brassica oleracea L. var. italica) Lucia Yepes-Molina, Angel L. Guarnizo, Micaela Carvajal, Juan Nicolas-Espinosa Plant Science, 2026 Salinity is a major constraint on global crop productivity, particularly affecting moderately tolerant species such as broccoli. To elucidate the molecular basis of salt stress adaptation, we performed an untargeted transcriptomic analysis in broccoli roots and aerial tissues at three time points after treatments (6 hours, 3 days, and 10 days). Our results revealed a complex, biphasic response involving an early transcriptional shock, followed by a sustained adjustment phase marked by transcriptional reprogramming. Tissue-specific differences were observed, as each organ exhibiting distinct strategies shaped by its developmental context. ABA signalling (synthesis, catabolism and receptors, PYR/PYL) could be a central regulator, modulating not only individual gene expression but entire metabolic pathways. Also, induction of P5CS1 , involved in proline biosynthesis, further suggests prolonged activation of ABA-dependent osmoprotective pathways. Roots, while showing pronounced salt-specific responses, also retained developmentally driven expression profiles as cell wall reinforcement. While in aerial tissues, global transcriptomic patterns largely followed intrinsic developmental trajectories. Overall, our study highlights the importance of coordinated regulation between stress adaptation mechanisms and ongoing developmental programs. Maintaining this balance, particularly through ABA signalling, osmotic adjustment, and cell wall remodelling, is essential for long-term survival under chronic salinity. • Time-resolved RNA-seq reveals biphasic salt stress response in broccoli. • ABA signalling fine-tunes osmoprotection and transcriptional reprogramming. • Roots reinforce cell walls, while shoots modulate photosynthesis under stress. • WGCNA identifies PYL, MYB46/ANAC043, and P5CS1 as key regulatory nodes. • Stress responses integrate with stable developmental transcriptomic programs.
Physiological and metabolic profiling reveals distinct early salt resilience strategies among pre-commercial broccoli cultivars Angel Almagro-Lopez, Jose M. Mulet, Rosa Porcel, Marina Celdrán, Micaela Carvajal, Juan Nicolas-Espinosa Scientia Horticulturae, 2026 • Coordinated physiological and metabolic responses drive broccoli salt resilience. • A conservative water-use strategy prevents salinity-induced dehydration in BQ1. • Leaf retention of phosphorous and boron supports cellular integrity under ionic stress. • Sucrose and maltose accumulation fuels energy metabolism for salt adaptation. • Early antioxidant induction mitigates oxidative damage during initial stress. Soil salinization represents a primary abiotic constraint to global agricultural productivity, necessitating the development of resilient cultivars. This study assesses the physiological and metabolic responses associated with salinity tolerance in four pre-commercial broccoli ( Brassica oleracea var. italica ) cultivars (BG1, BH1, BX1, and BQ1) during the vegetative stage under salt stress conditions. Among the genotypes, BQ1 demonstrated superior performance at the lowest salinity level assayed (80 mM NaCl), maintaining biomass accumulation and the highest Salt Tolerance Index (STI). This resilience is attributed to a constitutive physiological adaptation characterized by a low stable relative water content (RWC) and water potential, which prevents further salinity-induced dehydration. Furthermore, BQ1 exhibited effective ionic homeostasis by retaining phosphorus (P) and boron (B) in root tissues, alongside an early induction of ascorbate peroxidase (APX) and catalase (CAT) activities. Metabolic profiling revealed that BQ1 uniquely accumulates carbon-based osmolytes, specifically sucrose and maltose, which correlate with increased levels of Krebs cycle intermediates such as malate and aspartate. While certain unique adaptative responses in BQ1 reached a threshold at high salinity, its growth performance remained markedly superior to the other cultivars, suggesting a highly robust mechanism for sustaining metabolic flux and cellular homeostasis under extreme ionic and osmotic constraints.
Comparative adaptations of high-tolerant species and broccoli cultivars to salinity stress during germination and early development stages Angel Almagro-Lopez, Juan Nicolas-Espinosa, Jose M. Mulet, Micaela Carvajal BMC Plant Biology, 2025 Salinity imposes significant physiological and biochemical challenges on plants, disrupting key processes such as germination, involving growth, and water balance. Under saline conditions, plants activate various defense mechanisms to mitigate salinity-induced damage. While many of these mechanisms are well-characterized in mature plants, their role during germination and early seed development remains largely unexplored. In this work, we studied four pre-commercial broccoli (Brassica oleracea L. var. italica) cultivars previously selected for their enhanced salinity tolerance and compared to the high tolerant Eruca vesicaria subsp. sativa. The results provide insights into key mechanisms involved in salinity tolerance, including osmotic potential regulation, mineral homeostasis, antioxidant enzymatic activity and ATP concentration. The ATP availability and utilization emerged as critical determinants of the stress response profiles of the seeds during germination. Notably, the BQ1 cultivar demonstrated the most efficient ATP utilization, suggesting a broader, more sustained, and effective response under saline conditions. These findings highlight ATP as a crucial factor in salinity tolerance during early seeds development.
Light intensity and sulfur deficiency modulate growth and water dynamics in broccoli plants via aquaporin regulation Angel Almagro-Lopez, O. Puma, Valerio Cirillo, Albino Maggio, Juan Nicolás‐Espinosa, et al. Plant Biology, 2025 Sulfur plays a critical role in plant secondary metabolism, particularly in the biosynthesis of glucosinolates, where it functions as a core structural element and participates in molecular regulatory mechanisms. Moreover, sulfur metabolism is intricately connected to nitrogen assimilation, highlighting its multifaceted role in plant physiological processes. Light, another key abiotic determinant, directly modulates crop productivity, with light intensity governing essential processes such as growth kinetics and photosynthetic efficiency. This study aims to elucidate the effects of light stress and sulfur deficiency on broccoli (Brassica oleracea var. italica) growth and water dynamics under controlled environment conditions, both individually and in combination, to identify the physiological and molecular mechanisms activated in response to these stressors. The results revealed that sulfur deficiency has a stronger impact on plant water relations than light stress, while light stress mainly affects photosynthetic activity and biomass accumulation. Combined stresses lead to more pronounced physiological responses, including distinct aquaporin regulation patterns that differ from single stress treatments. These findings suggest a compensatory mechanism that helps maintain water balance, highlighting the complex interplay between sulfur availability, light intensity, and plant adaptation strategies.
Aquaporins: an overlooked key to improving the quality and shelf life of vegetables Micaela Carvajal, Juan Nicolas-Espinosa, Lucia Yepes-Molina International Journal of Vegetable Science, 2025 Plant aquaporins, which regulate water transport across cell membranes, maintain the hydration status and cellular integrity of vegetables and fruits during growth. They also affect postharvest processes such as ripening, enzymatic activity, and responses to stress, potentially reducing spoilage and extending storage duration. Understanding aquaporin function in vegetable products could improve preservation techniques for enhanced quality during storage.
Exploring Phenolic Compounds in Crop By-Products for Cosmetic Efficacy Maria Gomez-Molina, Lorena Albaladejo-Marico, Lucia Yepes-Molina, Juan Nicolas-Espinosa, Eloy Navarro-León, Paula Garcia-Ibañez, Micaela Carvajal International Journal of Molecular Sciences, 2024 Phenolic compounds represent a group of secondary metabolites that serve essential functions in plants. Beyond their positive impact on plants, these phenolic metabolites, often referred to as polyphenols, possess a range of biological properties that can promote skin health. Scientific research indicates that topically using phenolics derived from plants can be advantageous, but their activity and stability highly depend on storage of the source material and the extraction method. These compounds have the ability to relieve symptoms and hinder the progression of different skin diseases. Because they come from natural sources and have minimal toxicity, phenolic compounds show potential in addressing the causes and effects of skin aging, skin diseases, and various types of skin damage, such as wounds and burns. Hence, this review provides extensive information on the particular crops from which by-product phenolic compounds can be sourced, also emphasizing the need to conduct research according to proper plant material storage practices and the choice of the best extracting method, along with an examination of their specific functions and the mechanisms by which they act to protect skin.
The differential expressions of aquaporins underline the diverse strategies of cucumber and tomato against salinity and zinc stress Alberto Martinez‐Alonso, Juan Nicolás‐Espinosa, Micaela Carvajal, Gloria Bárzana Physiologia Plantarum, 2024 Salinity and excess zinc are two main problems that have limited agriculture in recent years. Aquaporins are crucial in regulating the passage of water and solutes through cells and may be essential for mitigating abiotic stresses. In the present study, the adaptive response to moderate salinity (60 mM NaCl) and excess Zn (1 mM ZnSO4) were compared alone and in combination in Cucumis sativus L. and Solanum lycopersicum L. Water relations, gas exchange and the differential expression of all aquaporins were analysed. The results showed that cucumber plants under salinity maintained the internal movement of water through osmotic adjustment and the overexpression of specific PIPs aquaporins, following a “conservation strategy”. As tomato has a high tolerance to salinity, the physiological parameters and the expression of most aquaporins remained unchanged. ZnSO4 was shown to be stressful for both plant species. While cucumber upregulated 7 aquaporin isoforms, the expression of aquaporins increased in a generalized manner in tomato. Despite the differences, water relations and transpiration were adjusted in both plants, allowing the RWC in the shoot to be maintained. The aquaporin regulation in cucumber plants facing NaCl+ZnSO4 stress was similar in the two treatments containing NaCl, evidencing the predominance of salt in stress. However, in tomato, the induced expression of specific isoforms to deal with the combined stress differed from independent stresses. The results clarify the key role of aquaporin regulation in facing abiotic stresses and their possible use as markers of tolerance to salinity and heavy metals in plants.
Exploring the mechanism of blindness physiopathy in Brassica oleracea var italica L. by comprehensive transcriptomics and metabolomics analysis Alvaro Lopez-Zaplana, Juan Nicolas-Espinosa, Lorena Albaladejo-Marico, Micaela Carvajal Plant Physiology and Biochemistry, 2024 Blindness is a physiopathy characterized by apical abortion that particularly affects the Brassica family. The occurrence of blindness has been related to exposure to low temperatures during early developmental stages. However, the causes of this selective sensitivity and how they affect the correct development remain unknown. In this study, we investigated the mechanisms involved in the occurrence of blindness in broccoli plants. The analysis of RNAseq, focused on membrane transporters and the synthesis pathways of glucosinolates and phenolics, was related with physiological changes in nutrient and water uptake, gas exchange, and metabolism. Comparative gene expression analysis between control and blindness-affected broccoli plants revealed distinct regulation patterns in roots and shoots, leading to reduced synthesis of glucosinolates and phenolics. Additionally, the expression levels of aquaporins and potassium transporters were found to be associated with mineral and water transport. In this way, our results revealed the causes of blindness by identifying differentially expressed genes, highlighting those related to secondary metabolism, as well as genes involved in water and nutrient uptake and transport as the crucial involved in the physiopathy appearance.
Deciphering the effect of salinity and boron stress on broccoli plants reveals that membranes phytosterols and PIP aquaporins facilitate stress adaptation Juan Nicolas-Espinosa, Lucia Yepes-Molina, Fuensanta Martinez-Bernal, Miriam Fernandez-Pozurama, Micaela Carvajal Plant Science, 2024 Abiotic stresses, such as salinity and boron toxicity/deficiency, are prevalent in arid and semi-arid regions where broccoli is largely cultivated. This study aimed to investigate the physiological response of broccoli leaves to these stresses, focusing on parameters such as growth, relative water content, stomatal conductance, and mineral concentration after 15 days of treatment application. The effects of individual and combined stresses of salinity and boron (deficiency and toxicity) were examined. Additionally, the study explored the molecular aspects of PIP aquaporins in relation to their presence in the plasma membrane and their interaction with the lipid environment. The results showed that the combined stress of salinity and boron deficiency resulted in a significant reduction in plant biomass, suggesting a specific adaptation to this stress combination. Changes in stomatal conductance and mineral nutrient levels indicated that the adaptation mechanisms were associated with water and boron concentration in the leaves. The expression patterns of PIP aquaporins varied among the different stress treatments, either individually or in combination. Furthermore, the presence of aquaporins in the plasma membrane and microsomal fraction highlighted the potential regulatory roles of trafficking along with the membrane composition, particularly the concentration of phytosterols. The results underscore the importance of water transport by aquaporins and their interaction with the sterol composition in the membranes, in facilitating salinity-boron stress adaptation mechanisms.
