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Flax ( Linum usitatissimum L.), one of the oldest cultivated crops, continues to be widely grown for oil, fiber and food. Furthermore, the plants show a metal tolerance dependent on species so is ideal for research. Present study was conducted to find out the influence of copper (Cu) toxicity on plant biomass, growth, chlorophyll content, malondialdehyde (MDA) contents, proline production, antioxidative enzymes and metal up taken by L. usitatissimum from the soil grown under mixing of Cu-contaminated soil with natural soil by 0:1 (control), 1:0, 1:1, 1:2 and 1:4. Results revealed that, high concentration of Cu in the soil affected plant growth and development by reducing plant height, plant diameter and plant fresh and dry biomass and chlorophyll contents in the leaves compared with the control. Furthermore, Cu in excess causes generation of reactive oxygen species (ROS) such as superoxide radical (O – ) and hydroxyl radicals (OH), which is manifested by high malondialdehyde (MDA) and proline contents also. The increasing activities of superoxidase dismutase (SOD) and peroxidase (POD) in the roots and leaves of L. usitatissimum are involved in the scavenging of ROS. Results also showed that L. usitatissimum also has capability to revoke large amount of Cu from the contaminated soil. As Cu concentration in the soil increases, the final uptake of Cu concentration by L. usitatissimum increases. Furthermore, the soil chemical parameters (pH, electrical conductivity and cation exchange capacity) were increasing to highest levels as the ratio of Cu concentration to the natural soil increases. Thus, Cu-contaminated soil is amended with the addition of natural soil significantly reduced plant growth and biomass, while L. usitatissimum is able to revoke large amount of Cu from the soil and could be grown as flaxseed and a potential candidate for phytoremediation of Cu.

In sweet cherry trees, flowering is commercially important because the flowers, after fertilization, will generate the fruits. In P. avium, the flowering induction and flower organogensis are the first developmental steps towards flower formation and they occur within specialized organs known as floral buds during the summer, nine months before blooming. During this period the number of floral buds per tree and the bud fruitfulness (number of flowers per bud) are stablished affecting the potential yield of orchards and the plant architecture. The floral bud development is sensitive to any type of stress and the hotter and drier summers will interfere with this process and are calling for new adapted cultivars. A better understanding of the underlying molecular and hormonal mechanisms would be of help, but unlike the model plant Arabidopsis, very little is known about floral induction in sweet cherry. To explore the molecular mechanism of floral bud differentiation, high-throughput RNA sequencing was used to detect differences in the gene expression of P. avium floral buds at five differentiation stages. We found 2,982 differentially expressed genes during floral bud development. We identified genes associated with floral initiation or floral organ identity that appear to be useful biomarkers of floral development and several transcription factor families (ERF, MYB, bHLH, MADS-box and NAC gene family) with novel potential roles during floral transition in this species. We analyzed in deep the MADS-box gene family and we shed light about their key role during floral bud and organs development in P. avium. Furthermore, the hormonal-related signatures in the gene regulatory networks and the dynamic changes of absicic acid, zeatin and indolacetic acid contents in buds suggest an important role for these hormones during floral bud differentiation in sweet cherry. These data provide a rich source of novel informacion for functional and evolutionary studies about floral bud development in sweet cherry and new tools for biotechnology and breeding.

Climate change is intensifying the simultaneous occurrence of biotic and abiotic stresses in fruit crops, but yet the molecular mechanisms underlying plant responses remain poorly understood. The physiological and transcriptomic responses of two sweet cherry (Prunus avium L.) cultivars, Santina and Bing, grafted onto Gisela 12, were investigated under single and combined stresses imposed by Pseudomonas syringae pv. syringae and water deficit. Although biomass, gas exchange, and hormone accumulation showed only minor changes, combined stress triggered distinct cultivar-dependent transcriptional reprogramming. The cultivar Bing exhibited a pronounced response with 4261 differentially expressed genes (DEGs), characterized by strong repression of photosynthetic processes and activation of defense- and hormone-related pathways. In contrast, the cultivar Santina showed a moderate response with 674 DEGs, primarily reinforcing structural and secondary metabolism. Cultivar-specific modulation of abscisic acid sensitivity was associated with the contrasting regulation of WRKY40 and Sin3-like repressors, despite comparable ABA levels. Strikingly, both cultivars upregulated the GIGANTEA gene, underscoring its role as a central regulatory hub linking circadian rhythm, stomatal function, and hormonal crosstalk under dual stress. Collectively, these results reveal non-additive, genotype-specific transcriptional strategies in sweet cherry trees, providing insights into stress integration in fruit trees and identifying regulatory genes that may inform breeding and management strategies for resilience under climate change.

BACKGROUND AND AIMS: Salinity can affect germination of seeds either by creating osmotic potentials that prevent water uptake or by toxic effects of specific ions. Most studies have only used monosaline solutions, although these limit the extent to which one can interpret the results or relate them to field conditions. The aim of this work was to evaluate the germination of Prosopis strombulifera seeds under increasing salinity by using the most abundant salts in central Argentina in monosaline or bisaline iso-osmotic solutions, or in solutions of mannitol and polyethylene glycol. METHODS: Seeds were allowed to germinate under controlled conditions in a germination chamber at 30 ± 1 °C and at 80 % r.h. Salinizing agents were KCl, NaCl, Na₂SO₄, K₂SO₄, NaCl + Na₂SO₄ and KCl + K₂SO₄ and osmotic agents were polyethylene glycol 6000 and mannitol. Treatments for all osmotica consisted of 0·0, -0·4, -0·8, -1·2, -1·5, -1·9 and -2·2 MPa solutions. KEY RESULTS: The percentage of germination decreased as salinity increased. SO4(2-) in monosaline solutions, with osmotic potentials -1·2 MPa and lower, was more inhibitory than Cl⁻ at iso-osmotic concentrations. This SO4(2-) toxicity was alleviated in salt mixtures and was more noticeable in higher concentrations. K⁺ was more inhibitory than Na⁺ independently of the accompanying anion. CONCLUSIONS: Different responses to different compositions of iso-osmotic salt solutions and to both osmotic agents indicate specific ionic effects. This study demonstrates that the germination of P. strombulifera is strongly influenced by the nature of the ions in the salt solutions and their interactions. Comparative studies of Cl⁻ and [Formula: see text] effects and the interaction between SO4(2-) and Cl⁻ in salt mixtures indicate that extrapolation of results obtained with monosaline solutions in the laboratory to field conditions can be speculative.

To improve crop yields the application of fertilizers to provide nutrients to soils is recommended. An alternative option to substitute nutritional supplements of chemical origin is the use of biofertilizers. This study evaluated the effectiveness of a biofertilizer of natural origin, Macrocystis pyrifera algal extracts and its combination with the plant growth–promoting bacterium Azospirillum brasilense, on the germination and establishment of lettuce seedlings (Lactuca sativa) under two different water irrigation treatments. Results demonstrated that germination energy and germination power improved upon inoculation of lettuce seeds with the seaweed extract. After 7 days of culture, seedlings showed increased root growth which would help to ensure their establishment. The application of bacteria and algae individually or in combination exerted a positive effect on lettuce plant growth compared with controls (without applications). In addition, treatments with the brown seaweed extract favoured seedlings adaptation to an unfavourable environment (water deficit) by increasing their root mass and protecting them from the negative effects imposed by stress. These results suggest that the use of M. pyrifera extract to improve plant growth and to provide stress protection may be considered an interesting tool for agricultural purposes. Nevertheless, when A. brasilense (whose plant growth–promoting properties are largely known) is combined with the brown seaweed extract, a new biofertilizing formula is obtained and proposed for future seed inoculation technology, based on the promising effects observed in this work.

The aim of this study was to generate knowledge and technology to increase the efficacy of biological products to improve peanut production. The percentage incidence of plant pathogens, germination responses and seedling growth parameters of Arachis hypogaea seeds subjected to algal extracts were evaluated in order to generate a fungal biological agent for application on peanut seeds. Results of this study demonstrate that the application of algal extracts have a positive effect favouring germination responses of peanut seeds. The fungal load detected was the lowest when the algal extract combined with 50% recommended dose of a commercial fungicide combination was applied, demonstrating that this combination of algal extract would represent a new sustainable agronomic practice for the environment since it considerably reduces the use of chemical fungicide agents. These results suggest that the components of algal extracts, such as salicylic and jasmonic acids, have chemical properties that could be considered for the specific control of fungi. This biological product is a new source of bioactive compounds with potential applications in agriculture, showing activity for the control of fungal load of seeds, as well as a promoter of germination.

Phytohormones have essential roles in plant growth responses under salinity. A better understanding of gibberellin (GA) function in woody plant responses under different sodium salts could help to develop new strategies to improve plant tolerance to salinity. In this study, the role of GA in morpho-physiological responses of halophytic woody Prosopis strombulifera plants under salinity was analyzed. Plants were grown in hydroponic solutions and exposed to NaCl, Na 2 SO 4 , or their iso-osmotic mixture at − 1.0, − 1.9, and − 2.6 MPa. Control (without salt) and salt-treated plants were sprayed with gibberellin A 3 (GA 3 ), or chlormequat chloride (CCC), an inhibitor of its synthesis. Growth responses, anatomical alterations and ABA, active GA forms (GA 1 , GA 3, and GA 4 ) and inactive GA forms (GA 8 and GA 34 ) endogenous levels were evaluated. The application of GA 3 increased growth in control plants more than in salt-treated plants. Roots and leaves of salt-treated plants showed high levels of ABA and active GA forms after exposure to GA 3 , and lower endogenous levels of active GA when receiving the inhibitor. CCC triggered stress-alleviating responses in these plants, such as anatomical and hormonal changes that included an increase in spine length and the number of palisade cell layers, and a reduction in levels of ABA and GA 4 . Na 2 SO 4 -treated plants showed reduced growth, high ABA levels and an active GA metabolism to control the levels of active GA. This study indicates that the suppression of GA signaling would contribute to sodium salts tolerance in the native halophytic woody P. strombulifera plants.

The most critical phase in plant life is seed germination, which is influenced by environmental factors. Drought and salinity are key environmental factors that affect seed germination. Reduction or alterations of germination when seeds are exposed to these factors have been shown to be due to either the adverse effects of water limitation and/or specific ion toxicity on metabolism. Phytohormones are chemical messengers produced within the plant that control its growth and development in response to environmental cues; small fluctuations of phytohormone levels alter the cellular dynamics and, hence, play a central role in regulating plant growth responses to these environmental factors. To integrate current knowledge, the present review focuses on the involvement of endogenous phytohormones in plant adaptative responses to drought and salinity at one of the plant's developmental phases.

The effects of changes in auxin transport in response to different osmotic potentials (Ψo) were analyzed in the roots and leaves of two leguminous species with different degrees of salt tolerance: the halophyte Prosopis strombulifera (Lam.) Benth. and the glycophyte Glycine max L. The potentials were generated with sodium chloride (NaCl), sodium sulfate (Na2SO4), and the iso-osmotic mixture of both salts (NaCl + Na2SO4). The values evaluated were −1, −1.8, and −2.6 MPa for P. strombulifera, and −0.47, −0.69, and −0.87 MPa for G. max. In addition, the plants were sprayed with 2,3,5-triiodobenzoic acid (TIBA), an auxin transport inhibitor. The parameters measured included root length, shoot height, number of leaves, relative membrane permeability in roots, and endogenous levels of abscisic acid (ABA), indole-3-acetic acid (IAA), and zeatin (Z). Significant responses were observed at the lowest potentials evaluated (−2.6 MPa for P. strombulifera and −0.89 MPa for G. max). Treatment with Na2SO4 inhibited plant growth more than the others, increased the relative membrane permeability, and enhanced ABA production to its highest levels. These toxic effects were slightly reversed in the presence of iso-osmotic mixture. TIBA brought about impaired development in shoots and roots, the highest values for membrane permeability, alterations in the distribution of endogenous ABA, IAA, and Z, as well as harmful effects on the growth response of both species. In general, the alterations in auxin transport intensified the effects of salinity, which confirms the essential role of this mechanism in plants under salt stress or in normal, non-stressful conditions.