Fernanda Leal

Potato (Solanum tuberosum L.), the third most important food crop worldwide, is constrained by phytopathogens, environmental stress, and heavy agrochemical use. Potato micropropagation is a biotechnological strategy for producing genetically uniform, pathogen-free plantlets. However, the acclimatization phase remains a major bottleneck in micropropagation, often resulting in poor survival and stunted growth. In this context, plant growth-promoting bacteria (PGPB) represent a sustainable strategy to improve plantlet establishment and reduce reliance on synthetic inputs. This study evaluated the biofertilization and biocontrol potential of three Douro vineyard-associated bacterial strains, Bacillus velezensis Nb1, Burkholderia pyrrocinia Gs3, and Streptomyces sp. 42s5, identified using 16S rRNA and gyrB sequence analysis. In dual-culture assays, the isolates showed antagonistic activity against Fusarium oxysporum, F. solani, Botrytis cinerea, and Alternaria alternata. All strains also exhibited key plant growth-promoting traits, including indole-3-acetic acid and siderophore production, and phosphate solubilization. The isolates were tested individually and in consortia on micropropagated potato plantlets during acclimatization under greenhouse conditions. Eight treatments (six replicates each), including a non-inoculated control, were evaluated. The results indicated that inoculations significantly improved vegetative growth and yield-related parameters. Notably, the Gs3 + 42s5 combination produced the highest shoot biomass, while the three-strain consortium achieved the greatest total tuber weight (36.91 g/plant) compared to the control (7.75 g/plant). These findings highlight the potential of these native PGPB, particularly when applied in multi-strain combinations, to enhance acclimatization efficiency and support sustainable potato production by reducing dependence on chemical inputs and promoting eco-friendly agricultural practices.

Global climate change predictions point to an increase in the frequency of droughts and floods, which are a huge challenge to food production. During crop evolution, different mechanisms for drought resilience have emerged, and studies suggest that roots can be an important key in understanding these mechanisms. However, knowledge is still scarce, being fundamental to its exploitation. Plant-based protein, especially grain legume crops, will be crucial in meeting the demand for affordable and healthy food due to their high protein content. In addition, grain legumes have the unique ability for biological nitrogen fixation (BNF) through symbiosis with bacteria, which contributes to sustainable agriculture. The exploitation of root phenotyping techniques in grain legumes is an important step toward understanding their drought resilience mechanisms and selecting more resilient genotypes. Different methodologies are available for root phenotyping, including the paper pouch approach, rhizotrons and the semi-hydroponic system. Additionally, different imaging techniques have been employed to assess root traits. This review provides an overview of the root system architecture (RSA) of grain legumes, its role in drought stress resilience and the phenotyping approaches useful for the identification of accessions resilient to water stress. Consequently, this knowledge will be important in mitigating the effects of climate change and improving grain legume production.

According to the climate projections, drought will increase in frequency and severity. Since water stress (WS) impacts a grapevine’s physiology and yield negatively, the evaluation and selection of tolerant genotypes are needed. To analyse the WS effects on the morphology and cell division of three grapevines (Vitis vinifera L.) varieties, “Touriga Franca” (TF), “Touriga Nacional” (TN) and “Viosinho” (VS), in vitro-grown plants were exposed to 10% polyethylene glycol 6000 (PEG) (−0.4 MPa) or 20% PEG (−0.8 MPa), incorporated in the culture medium, for four weeks. Control plants were kept in culture media without PEG. The VS and TN plants showed the highest mean numbers of nodes, shoots and leaves and average mitotic indexes under 20% PEG. The TF and TN plants showed the lowest frequencies of mitotic anomalies under 10% PEG. The VS plant growth was less affected by WS, but TF and TN presented more regular mitosis under moderate WS. Globally, in vitro culture constitutes a cost-effective experimental system for studying grapevine responses to WS and the preliminary selection of resilient genotypes. These approaches could be applied to study plant responses to other abiotic stresses based on additional evaluation techniques (e.g., transcriptional analyses or genome-wide association studies).

Background: “Touriga Franca” (TF) and “Touriga Nacional” (TN) are grapevine varieties cultivated in the ‘Douro Superior’ subregion (Northern Portugal) that experience stressful environmental conditions during the summer. Objectives: Aiming to profile the expression of stress-responsive genes by quantitative real-time PCR (qPCR) in TF and TN plants growing naturally, three candidate reference genes were first tested under controlled conditions. Methods: To simulate a summer’s day, TF and TN in vitro plants were exposed to 32 °C–3 h (heat acclimation) and 42 °C–1 h (severe heat stress, HS) followed by two recovery periods (32 °C–3 h and 24 °C–24 h). Leaf samples were collected at the end of each phase. Control plants were kept at 24 °C. Results: Among the candidate reference genes, the UBC and VAG pair showed the highest stability. The suitability of these genes for qPCR was validated by heat shock protein 17.9A (HSP17.9A) gene profiling. The HSP17.9A expression was up-regulated in both varieties and all experimental phases except in TF control plants. TN showed the highest HSP17.9A relative expression ratio after severe HS. Conclusions: TN responded faster than TF to the induced heat shocks. The UBC, VAG, and HSP17.9A genes revealed to be suitable for further qPCR assays in TF and TN grapevine varieties.

The demand for Vaccinium fruits has skyrocketed due to their nutritional and medicinal properties, notably their high content of phenolic compounds and excellent sensory evaluation. The use of Vaccinium plants and its components as dietary supplements and health ingredients has been on the rise across the world. The attractive fruits contain a high content of anthocyanins and antioxidant compounds. In some popular and valuable cultivars, the conventional propagation methods, exploiting hard or soft wood cuttings, are inefficient. The demand for nursery plants can be fulfilled by micropropagation. This review aims to explore advances in the in vitro culture of Vaccinium plants, focusing on effective disinfection, optimized culture media, and the role of growth regulators in plant development and multiplication. By providing a controlled environment, micropropagation allows the large-scale production of these plants in a short time, ensuring availability throughout the year. Additionally, this technique offers the advantage of studying the effects of abiotic stresses on plants, as well as facilitating research on the production of relevant metabolites. This review seeks to provide an updated overview of the most promising methods and techniques for micropropagation of Vaccinium, thereby contributing to the ongoing development of the blueberry production industry and derivative products.

More than 100 grapevine varieties are registered as suitable for wine production in “Douro” and “Trás-os-Montes” Protected Designations of Origin regions; however, only a few are actually used for winemaking. The identification of varieties cultivated in past times can be an important step to take advantage of all the potential of these regions grape biodiversity. The conservation of the vanishing genetic resources boosts greater product diversification, and it can be considered strategic in the valorisation of these wine regions. Hence, one goal of the present study was to prospect and characterise, through molecular markers, 310 plants of 11 old vineyards that constitute a broad representation of the grape genetic patrimony of “Douro” and “Trás-os-Montes” wine regions; 280 samples, grouped into 52 distinct known varieties, were identified through comparison of their genetic profiles generated via 6 nuclear SSR and 43 informative SNP loci amplification; the remaining 30 samples, accounting for 13 different genotypes, did not match with any profile in the consulted databases and were considered as new genotypes. This study also aimed at evaluating the population structure among the 65 non-redundant genotypes identified, which were grouped into two ancestral genetic groups. The mean probability of identity values of 0.072 and 0.510 (for the 6 SSR and 226 SNP sets, respectively) were determined. Minor differences were observed between frequencies of chlorotypes A and D within the non-redundant genotypes studied. Twenty-seven pedigrees were confirmed and nine new trios were established. Ancestors of eight genotypes remain unknown.

Ginkgo biloba L. leaf extracts and herbal infusions are used worldwide due to the health benefits that are attributed to its use, including anti-neoplastic, anti-aging, neuro-protection, antioxidant and others. The aim of this study was to evaluate the effect of an aqueous Ginkgo biloba extract on HepG2 cell viability, genotoxicity and DNA protection against paraquat-induced oxidative damage. Exposure to paraquat (PQ), over 24 h incubation at 1.0 and 1.5 µM, did not significantly reduce cell viability but induced concentration and time-dependent oxidative DNA damage. Ginkgo biloba leaf extract produced dose-dependent cytotoxicity (IC₅₀ = 540.8 ± 40.5 µg/mL at 24 h exposure), and short incubations (1 h) produced basal and oxidative DNA damage (>750 and 1500 µg/mL, respectively). However, lower concentrations (e.g., 75 µg/mL) of Ginkgo biloba leaf extract were not cytotoxic and reduced basal DNA damage, indicating a protective effect at incubations up to 4 h. On the other hand, longer incubations (24 h) induced oxidative DNA damage. Co-incubation of HepG2 cells for 4 h, with G. biloba leaf extract (75 µg/mL) and PQ (1.0 or 1.5 µM) significantly reduced PQ-induced oxidative DNA damage. In conclusion, the consumption of Ginkgo biloba leaf extract for long periods at high doses/concentrations is potentially toxic; however, low doses protect the cells against basal oxidative damage and against environmentally derived toxicants that induce oxidative DNA damage.

Thymus Plants: A Review—Micropropagation, Molecular and Antifungal Activity | InTechOpen, Published on: 2017-03-08. Authors: Fernanda Leal, Meriem Taghouti, Fernando Nunes, et

ISHS VIII International Symposium on In Vitro Culture and Horticultural Breeding MICROPROPAGATION OF CALENDULA OFFICINALIS AND LAVANDULA ANGUSTIFOLIA FOR GENOTOXICITY AND ANTIGENOTOXICITY STUDIES