Climate change and a growing world population challenge modern agriculture to maintain sustainable production over time on increasingly scarce arable land. The use of plant biostimulants emerges as a safe and environmentally friendly alternative to improve crop production and yield under these unfavorable conditions. Among all plant biostimulants, higher plant-derived biostimulants (hPDBs) are of special interest, due to all the advantages they present in terms of sustainability, production costs, safety, and, mainly, due to the diversity of bioactive compounds that compose them¹. In this work, a novel type of biostimulant, based on yellow carrot cell culture, was developed through biotechnological production. Using elicitation techniques², the production of bioactive compounds with a described biostimulant effect, mainly phytosterols and phenolic compounds, was increased in cell suspensions. A compositionally stable product was prepared, which was applied for tomato seed priming, subjected to salt stress conditions to evaluate its potential biostimulant effect. The germination index (GI) and typical oxidative stress markers in tomato seedlings were determined.

References

1. Martínez-Lorente SE et al., Antioxidants, 2024; https://doi.org/10.3390/antiox13030318.
2. Sabater-Jara, A. B. et al., PCTOC, 2013; https://doi.org/10.1007/s11240-013-0320-4.

Acknowledgements

The Agroalnext Programme was supported by MCIN with funding from the European Union NextGenerationEU (PRTR-C17.I1) and Comunidad Autónoma de la Región de Murcia–Fundación Séneca and Fundación Séneca-Agencia de Ciencia y Tecnología (22016/PI/22), “Ayudas a proyectos para el desarrollo de investigación científica y técnica por grupos competitivos” from “Programa Regional de Fomento de la Investigación Científica y Técnica (Plan de Actuación 2022)”. S.E.M-L. received a grant from Ministerio de Ciencia, Innovación y Universidades of Spain (FPU21/01593), and J.M.M-G. received a grant from Universidad de Murcia (109144/2022).

Common centaury (Centaurium erythraea Rafn) is an important plant species in traditional medicine because it has been used for the treatment of numerous diseases since ancient times. Moreover, centaury is rich source of antioxidants and antimicrobial compounds and, as such, can be considered as a potential food additive. Considering that, in nature, centaury can often be found on moderately saline soils, it was interesting to investigate the effects of salinity stress, caused by sodium chloride (NaCl), on total phenolic, flavonoid, and hydroxycinnamic acid content and antioxidative capacity, in shoots and roots grown in vitro. Centaury shoots were cultured on a solid ½MS medium supplemented with graded NaCl concentrations (0, 50, 100, 150, and 200 mM). Centaury roots were also grown in vitro but in liquid ½MS medium containing the same graded NaCl concentrations. After eight weeks, the content of total phenolic, flavonoid, and hydroxycinnamic acid content and antioxidative capacity were determined using colorimetric methods. The results obtained in this work showed that graded NaCl concentrations induced the accumulation of total phenols in both shoots and roots. Regarding total flavonoid content, the graded NaCl concentrations also induced the accumulation of total flavonoids in roots, while in shoots the highest content was detected in the presence of 50 mM NaCl. On the other hand, the increment of NaCl in nutrient media promoted the accumulation of total hydroxycinnamic acid content in both shoots and roots, with the exception of roots grown in the presence of 200 mM NaCl. Finally, the DPPH test has shown an increased antioxidative capacity in shoots and roots, which was dependent on applied NaCl concentration. It can be concluded that salinity stress affected shoots and roots’ total phenolic, flavonoid, and hydroxycinnamic acid content differently but also elevated antioxidative capacity.

Adverse edaphoclimatic conditions derived from climate change and anthropogenic pressure are challenging modern agriculture. Thus, it is necessary to develop strategies that increase crop yield without causing significant harm to the environment. Biostimulants have been proved to alleviate the effects of abiotic stress on plants growing under unfavourable conditions, especially those classified as higher plant-derived biostimulants (hPDBs), as they can modulate plants' physiological processes and ensure zero environmental impact. However, the production of these biostimulants is often heterogeneous, as their composition depends on the harvest season and the variety of the source used. In this work, we evaluate the potential of an orange carrot cell-culture-derived biostimulant (OCB), a novel type of hPDB based on plant cell cultures, as they constitute stable production systems of bioactive compounds. The OCB was applied as a priming agent in Brassica seeds subjected to salinity stress, with the goal of producing more competitive and tolerant seedlings to the effect of climate change and improving their vigor and quality. Finally, we describe its positive effect on the germination parameters and oxidative stress markers.

References. Martínez-Lorente SE, Martí-Guillén JM, Pedreño MA, Almagro L, Sabater-Jara AB. Higher Plant-Derived Biostimulants: Mechanisms of Action and Their Role in Mitigating Plant Abiotic Stress. Antioxidants. 2024; 13(3):318. https://doi.org/10.3390/antiox13030318

Acknowledgements. Funding was received from the Agroalnext Programme, supported by MCIN, with funding from European Union NextGenerationEU (PRTR-C17.I1), and Comunidad Autónoma de la Región de Murcia, Fundación Séneca and Fundación Séneca, Agencia de Ciencia y Tecnología (22016/PI/22), “Ayudas a proyectos para el desarrollo de investigación científica y técnica por grupos competitivos” from “Programa Regional de Fomento de la Investigación Científica y Técnica (Plan de Actuación 2022)”. S.E.M-L. received a grantfrom Ministerio de Ciencia, Innovación y Universidades of Spain (FPU21/01593), and J.M.M-G. received a grant ffrom Universidad de Murcia (109144/2022).

In potato (Solanum tuberosum) crops, fungicides are essential to protect against fungal pathogens, but their high toxicity drives the search for safer alternatives. Natural products with high antioxidant activity are presented as a viable option to mitigate pathogen damage and strengthen plant defense mechanisms.

The main aim of this study is to evaluate the antioxidant response in the foliar system of potato crops inoculated with Rhizoctonia solani and treated with a biofungicide based on colored pulp extract. The profiles and concentrations of phenolic compounds were evaluated by high-performance liquid chromatography with diode array detection (HPLC-DAD), and the antioxidant activity by chemical methods in the foliar part of potato crops subjected to eight treatments, including inoculation with the pathogen Rhizoctonia solani, commercial fungicides, and a nanoencapsulated extract (SNL) based on a colored pulp extract (FCP) with a potential biofungicidal effect, at two doses (20 and 40 mg L^-1).

Four phenolic compounds from the hydroxycinnamic acid and flavonol families were detected, where 5-caffeoylquinic acid and quercetin-rutinoside were the most abundant compounds. The highest concentrations of total phenols were detected in the treatment with applications of SNL-FCP at a dose of 20 mg L^-1, reaching a concentration of 33.69 mg g^-1. The antioxidant activity with the best response was detected by way of the CUPRAC method, when the same treatment was applied.

These results suggest that the application of the encapsulated extract does not significantly increase phenolic compound concentrations under pathogen inoculation, but it does regulate antioxidant activity, similar to the control without R. solani inoculation. Thus, the use of this encapsulated extract has potential beneficial effects for potato crops.

ACKNOWLEDGMENTS: ANID/FONDECYT 1230587 Project.

Chestnuts (Castanea spp.) are widely cultivated in Europe, the United States, and some parts of Asia for their culinary and therapeutic properties, as well as their contributions to biodiversity through hardwood forests. However, chestnut productivity is severely threatened by both abiotic and biotic factors, with chestnut blight disease caused by Cryphonectria parasitica being the primary biotic threat. European chestnut (Castanea sativa), a valuable species grown in Hungary, has been heavily impacted by this disease, with 50% of orchard trees dying since its introduction in 1960.

Molecular identification is crucial for understanding the genetic diversity and phylogenetic analysis of C. parasitica and tracking its spread. Using ITS and TEF primers, we confirmed the presence of C. parasitica in our collected samples. Due to the limited efficacy and environmental concerns of chemical fungicides, biological control methods are increasingly being explored. Hypovirulent strains, characterized by their white mycelia and the presence of mycovirus in their cytoplasm, have shown high potential for controlling chestnut blight. In our study, we tested eight different Trichoderma species against both virulent and hypovirulent strains of C. parasitica. Six species exhibited significant biocontrol activity and inhibited the pathogen’s growth, including the virulent and hypovirulent samples, indicating the effectiveness of Trichoderma as a potential biological control agent.

Our findings highlight the potential of integrating molecular techniques and biological control strategies, such as the use of hypovirulent strains and Trichoderma species, to manage chestnut blight effectively, reducing the reliance on chemical fungicides and promoting the health and productivity of chestnut trees in both agricultural and natural ecosystems.

Plant pests impact trade, crop production, human health, and the environment. To detect these species, it is important to develop molecular identification tools that are efficient, sensitive, and reliable. We used plants from the genus Amaranthus to start developing these tools. Some species in this group are regulated in Canada (A. tuberculatus, also known as tall waterhemp) or in the U.S. (A. palmeri, also known as palmer amaranth), due to their invasiveness, herbicide resistance, and impact on crops like corn and soybean.

We assembled 28 chloroplast genomes and nuclear ribosomal DNA regions corresponding to 15 Amaranthus species to find molecular fingerprints (DNA barcodes) to distinguish target species of concern. Additionally, we implemented a bioinformatics pipeline that allowed us to discover unique fixed alleles in the nuclear genome from accessions representing five Amaranthus species.

Using chloroplast polymorphic regions, we adapted CRISPR-Cas12 gene-editing technology to design fluorescent assays to identify Amaranthus species. We achieved a 90% accuracy rate in identifying A. palmeri in a batch of 60 blind samples. We also performed preliminary testing of this technology to identify the causal agent of sudden oak death (Phytophthora ramorum). Most P. ramorum isolates obtained for preliminary testing were correctly identified. The proposed CRISPR-Cas12 enzymatic assay provides results in less than 30 minutes without lab equipment, and we are currently working on a method that may streamline DNA extraction to fluorescent detection in under an hour.

Finally, we applied Matrix Assisted Laser Desorption/Ionization (MALDI) protein biotyping to determine if single Amaranthus seeds could provide consistent and distinctive protein spectra for species classification. After generating a protein spectra database of 16 Amaranthus species, testing two batches of 15 and 60 blind samples resulted in 100% and 87% correct species identification, respectively.

Plant roots release significant amounts of root exudates into the surrounding soil, shaping rhizosphere dynamics and mediating plant-soil interactions. These exudates include high-molecular-weight compounds such as proteins and mucilage, as well as a diverse array of low-molecular-weight compounds like primary metabolites (e.g., amino acids, sugars, carboxylates) and secondary metabolites (e.g., sorgoleone, flavonoids, coumarins). Understanding the composition and functions of these exudates is essential for elucidating mechanisms of plant-to-plant communication. However, the effects of environmental stressors, such as drought, on these interactions remain poorly understood, representing a critical knowledge gap for advancing crop resilience strategies.

In this study, we investigated root exudate secretion under controlled conditions, testing three sterilized substrates—river sand, glass beads, and epoxy-resin-coated sand. Additionally, we developed an innovative 3D-printed pot system that physically separates two root-growing environments while allowing unidirectional root communication. This setup enabled the evaluation of self and non-self interactions between the roots of Solanum lycopersicum L. and Tagetes patula L. Two irrigation methods were compared: nutrient solution recirculation and daily irrigation with discharge of percolating solution. To optimize exudate collection, we tested two eluents: distilled water and a methanol:water:formic acid mixture (50:49.9:0.1, v/v).

Our findings emphasize the importance of selecting appropriate substrates, eluents, and experimental setups for root exudate studies. These insights advance our understanding of crop resilience mechanisms, providing valuable tools for improving agricultural sustainability under climate change.

Funded by the European Union- Next Generation EU, Mission 4, Component 1, CUP C53D23003410006.

Salicornia europaea L. is a halophyte used for many industrial purposes and can also be consumed as a raw vegetable. It is well known that vegetables can become contaminated by human pathogenic microorganisms (HPMOs) during cultivation, e.g., through contaminated soil or water. There are many reports about outbreaks of infections linked to various vegetables. Although S. europaea tissue extracts have antimicrobial properties, the ability of this plant to be colonized by HPMOs has never been studied.

The main objective of our work was to study the susceptibility of S. europaea to colonization by HPMOs under different salinity conditions and to identify possible plant host defence responses to such infections.

S. europaea was cultivated under sterile conditions and inoculated with three bacterial strains: Escherichia coli, Salmonella enterica, and Listeria monocytogenes. Four weeks after inoculation, 2000 plants were collected for further analysis: (i) assessment of the plants' growth parameters; (ii) determination of the total bacteria and HPMO abundance in the shoots and roots using culture-dependent and -independent (qPCR) methods; and (iii) a comparative analysis of the transcriptomic profiles.

The obtained results revealed significant differences in the plants' growth parameters between the control and the treatments inoculated with different HPMOs. Moreover, it was shown that the rhizosphere and plant organs can harbor complex microbial communities, which may be involved in regulating or eliminating the occurrence of HPMOs. The transcriptomic analyses revealed differentially expressed genes only in response to some of the HPMOs tested.

In conclusion, the presence of HPMOs in S. europaea can be attributed to the plant's differential gene expression in response to bacteria, as well as the potential role of the plant's endophytic community in regulating host colonization by HPMOs.

Funding:

This research was conducted as a part of the SaliFood project funded by the National Science Centre (NCN, Poland) (UMO-2019/33/B/NZ9/02803).

African Indigenous Vegetables (AIVs) are integral to traditional diets, providing resilience against climatic challenges while delivering essential nutritional benefits. Nonetheless, their production and consumption are hindered by several barriers, including the limited access to high-quality seeds, insufficient agronomic knowledge, challenges relating to disease and post-harvest management, and fragmented market structures. This study evaluated eight amaranth (Amaranthus spp.) lines for their agronomic performance and analysed the nutritional composition of three species, Amaranthus cruentus, Amaranthus hypochondriacus, and Amaranthus spinosus, as well as their respective plant parts (leaves and seeds). Field trials were conducted utilising a randomised complete block design with three replications, during which parameters such as plant height, disease infestation, leaf count, biomass (both fresh and dry), and 1000-seed weight were assessed. Nutritional analyses were performed following AOAC and ISO-approved food analysis standards. Statistically significant differences (p < 0.005) were observed across the measured traits. The line GR326 exhibited the tallest plant height (112 cm), whereas GR3802 recorded the highest fresh (125,199 kg/ha) and dry biomasses (34,005 kg/ha). A nutritional analysis indicated a higher protein content in leaves (27.96 ± 0.72% in A. Cruentus), as well as notable levels of ash (19.04 ± 0.00% in A. cruentus), calcium (4.27 ± 0.61% in A. hypochondriacus), and potassium (3.80 ± 0.43% in A. spinosus). The seeds demonstrated relatively high fat (5.65 ± 0.81% in A. Spinosus) and fiber (20.05 ± 1.11%) contents. The iron concentration was highest in A. cruentus leaves (2515.64 ± 8.73 mg/g), as were the zinc levels (79.75 ± 8.38 mg/g). These findings highlight the agronomic and nutritional potential of amaranth lines for both vegetable and grain applications. The results suggest that AIVs possess significant potential to mitigate dietary deficiencies, enhance food and nutrition security, and support climate adaptation strategies in Zimbabwe and beyond.

Selecting water-use-efficient (WUE) soybean genotypes is one of the main strategies of addressing climate change. Understanding soil carbon dioxide emissions is important for identifying production systems with plants that are more adapted to climate change, meeting Sustainable Development Goals 12 (responsible consumption and production) and 13 (climate action). This study aimed to verify whether there is a relationship between water use efficiency in soybean genotypes and soil carbon dioxide emissions (FCO₂). Twenty-five soybean genotypes were evaluated in a randomized block design with three replicates. At 60 days after crop emergence, the following variables were evaluated in each experimental unit: net photosynthesis (A, mmol CO₂ m^-2 s^-1), transpiration (E, mmol H₂O m^-2 s^-1), and FCO₂. The WUE was calculated by the ratio between A and E evaluated in three plants of each plot using an infrared gas analyzer (IRGA Li-6400XT) and was assessed using the portable EGM-5 system. Initially, the data were subjected to analysis of variance and grouping of means. Subsequently, the data were subjected to Pearson’s correlation. There was a significant difference between the soybean genotypes for the variables evaluated. The correlation between WUE and FCO₂ is of low magnitude. However, it is possible to select genotypes with higher WUE and lower FCO₂. The results reported here may guide selection strategies in soybean breeding programs.