International Journal of Plant Biology

13 pages, 2980 KB

Open AccessArticle

Pilot Multilocus DNA-Barcoding Assessment of Four Morus alba L. Accessions from Mangystau, Kazakhstan, with Low-Coverage Oxford Nanopore Quality Control

by Akzhunis Imanbayeva, Nurzhaugan Duisenova, Nazerke Tolep, Aidyn Orazov, Ainur Tuyakova and Akimzhan Lukmanov

Int. J. Plant Biol. 2026, 17(7), 59; https://doi.org/10.3390/ijpb17070059 - 13 Jul 2026

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Abstract

The reliable identification of cultivated and naturalised mulberries is complicated by morphological plasticity, the historical movement of the planting material, and partly discordant nuclear and plastid signals. We evaluated four field-identified Morus alba L. trees, one from each of four localities in Mangystau, [...] Read more.

The reliable identification of cultivated and naturalised mulberries is complicated by morphological plasticity, the historical movement of the planting material, and partly discordant nuclear and plastid signals. We evaluated four field-identified Morus alba L. trees, one from each of four localities in Mangystau, Western Kazakhstan, using archived consensus sequences for ITS, matK, rbcL, and trnH-psbA, together with a low-coverage Oxford Nanopore Technologies (ONT) dataset. Because the design comprised one tree per locality (n = 4), analyses were restricted to accession-level descriptive comparisons, and no population-genetic, phylogeographic, or formal phylogenetic inference was attempted. Archived alignment summaries indicated mean pairwise distances of 0.13% for matK, 0.44% for ITS, 0.94% for rbcL, and 2.92% for trnH-psbA; these values are reported as retained dataset descriptors rather than estimates of population diversity. An additional product generated with Rosaceae-derived s6pdh primers was excluded because the target identity and orthology could not be verified. The ONT run yielded 19,958 pass reads (69.27 Mb; read N50 3574 bp). Reference-enriched assembly produced a 14,824 bp candidate plastid-associated contig, approximately 9.3% of a typical Morus plastome. Its short length, incomplete and non-collinear annotations, and the absence of retained depth, polishing, assembly graph, and join support diagnostics preclude its interpretation as a complete, circular, or structurally validated plastome. This study provides a transparent pilot baseline for Mangystau mulberries and establishes quality control criteria for replicated sampling, validated markers, and deeper organelle sequencing. Full article

(This article belongs to the Section Plant Ecology and Biodiversity)

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20 pages, 10156 KB

Open AccessArticle

Physiological and Biochemical Mechanisms of Methylglyoxal-Priming-Mediated Salt Tolerance in Barley Seedlings

by Md. Shahidul Islam, Abdul Hannan, Mohammad Anwar Hossain, Md. Motiar Rohman and Richard William Bell

Int. J. Plant Biol. 2026, 17(7), 58; https://doi.org/10.3390/ijpb17070058 - 12 Jul 2026

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Abstract

Methylglyoxal (MG), a reactive carbonyl species, is now recognized as a novel signaling molecule regulating abiotic stress tolerance and plant growth. Using tolerant (BHL-25 and BHL-27) and susceptible (BARI Barley-6 and BHL-26) genotypes, the study aimed to reveal the detailed mechanisms of MG-priming-induced [...] Read more.

Methylglyoxal (MG), a reactive carbonyl species, is now recognized as a novel signaling molecule regulating abiotic stress tolerance and plant growth. Using tolerant (BHL-25 and BHL-27) and susceptible (BARI Barley-6 and BHL-26) genotypes, the study aimed to reveal the detailed mechanisms of MG-priming-induced salt stress tolerance in barley (Hordeum vulgare L.). Seeds were primed with MG, and seven-day-old seedlings were transferred to hydroponic solution. After one week of seedling growth in hydroponic solutions, the salinity stress was imposed. The five treatments were as follows: control (0 salt + 0 mM MG), salt (16 dS m⁻¹) + 0 mM MG, salt + 0.25 mM MG, salt + 0.5 mM MG, and salt + 1 mM MG. Significant genotype-dependent changes were observed in response to salt stress based on morphological, physiological and biochemical traits. Salt stress significantly impaired shoot length, shoot dry weight, root volume, root dry weight, relative water content, leaf Na⁺ content and K⁺/Na⁺ ratio. Salinity stress caused a significant increase in oxidative indices in all genotypes; however, the tolerant genotypes showed a lower increase. Importantly, in plants grown from MG-primed seeds, the negative effects of salt stress were reversed by modulating the K⁺/Na⁺ ratio, the activities of antioxidative and glyoxalase pathway enzymes as well as the redox state of ascorbate and glutathione. In conclusion, MG-mediated salt tolerance was linked to a reduction in reactive oxygen species (ROS) and activation of ROS and MG detoxification processes as well as favorable regulation of the K⁺/Na⁺ ratio, glutathione and ascorbate redox state that improved the growth of the barley plants under salinity. Full article

(This article belongs to the Topic Plant Responses and Tolerance to Salinity Stress, 2nd Edition)

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27 pages, 4953 KB

Open AccessArticle

Salicylic Acid Modulates Morphophysiological Responses of Paubrasilia echinata Seedlings Irrigated with Saline Water

by Thayná Kelly Formiga de Medeiros, Francisco Thiago Coelho Bezerra, Gleyse Lopes Fernandes de Souza, Marcos Vinícius da Silva, Maria Beatriz Ferreira, Dayane Gomes da Silva, Daniela Rosário de Mello, Robevania da Silva Alves Almeida, Francisco Eudes da Silva, Igor Eneas Cavalcante, Alberício Pereira de Andrade, Olaf Andreas Bakke, Ivonete Alves Bakke and Riselane de Lucena Alcântara Bruno

Int. J. Plant Biol. 2026, 17(7), 57; https://doi.org/10.3390/ijpb17070057 - 8 Jul 2026

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Abstract

Rising salt concentration in water induces osmotic stress and ionic toxicity, compromising photosynthesis, growth, and survival of threatened species such as Paubrasilia echinata and highlighting the need for stress-mitigating compounds such as salicylic acid. This study evaluated the effect of salicylic acid on [...] Read more.

Rising salt concentration in water induces osmotic stress and ionic toxicity, compromising photosynthesis, growth, and survival of threatened species such as Paubrasilia echinata and highlighting the need for stress-mitigating compounds such as salicylic acid. This study evaluated the effect of salicylic acid on the morphophysiological responses of P. echinata seedlings irrigated with saline water. Treatments were arranged in a 2 × 3 factorial scheme, with two electrical conductivity levels of irrigation water (0.5 and 6.0 dS m⁻¹) and three salicylic acid concentrations (0, 2, and 3 mM), randomized across 24 experimental plots containing five plants each in a randomized complete block design. Analyses included growth, relative water content, chlorophyll indices and fluorescence of seedlings. Irrigation water with an electrical conductivity of 6.0 dS m⁻¹ reduced leaf number by 9.09% and PSII efficiency by 26.94%. Under saline conditions, salicylic acid at 2 and 3 mM increased root dry matter by 49.28% and 60.29%, respectively. The highest total chlorophyll index (79.03) was obtained at 2 mM, whereas leaf area peaked at 734.74 cm² per plant at 3 mM. Salicylic acid enhances salt tolerance in P. echinata. At 2 mM, it improves seedling morphophysiological traits and may support restoration in salinized sites. Full article

(This article belongs to the Section Plant Response to Stresses)

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6 pages, 824 KB

Open AccessBrief Report

Direct Interaction of Arabidopsis SGO1 with PP2A B′ Subunits Revealed by Microscale Thermophoresis

by Behzad Heidari, Dugassa Nemie-Feyissa and Cathrine Lillo

Int. J. Plant Biol. 2026, 17(7), 56; https://doi.org/10.3390/ijpb17070056 - 8 Jul 2026

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Abstract

Accurate chromosome segregation during meiosis requires protection of centromeric cohesion mediated by shugoshin (SGO) proteins and Protein Phosphatase 2A (PP2A). In Arabidopsis thaliana, genetic and cytological studies have demonstrated that PP2A B′ regulatory subunits are essential for maintaining centromeric cohesion; however, direct [...] Read more.

Accurate chromosome segregation during meiosis requires protection of centromeric cohesion mediated by shugoshin (SGO) proteins and Protein Phosphatase 2A (PP2A). In Arabidopsis thaliana, genetic and cytological studies have demonstrated that PP2A B′ regulatory subunits are essential for maintaining centromeric cohesion; however, direct biochemical evidence for their interaction with SGO1 in plants is lacking. Here, we used microscale thermophoresis (MST) to investigate and quantify the binding between fluorescently labeled GST-SGO1 and the PP2A B′α and B′β subunits. SGO1 exhibited concentration-dependent binding to both subunits, with dissociation constants (Kd) of 5.49 ± 0.88 µM for B′α and 1.89 ± 0.38 µM for B′β, indicating an approximately threefold higher affinity for B′β. These results provide direct quantitative biochemical evidence for a specific interaction between Arabidopsis SGO1 and PP2A B′ subunits. Full article

(This article belongs to the Section Plant Reproduction)

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13 pages, 990 KB

Open AccessArticle

Effects of Indole-3-Butyric Acid Concentration and Explant Origin on Rooting-Related Traits and Early Ex Vitro Growth of Regenerated Physalis peruviana Shoots

by Griselida Rojas-Campos, Raúl Vargas, Anyela Marcela Ríos-Ríos, Eyner Huaman, Amilcar Valle-Lopez and Manuel Oliva-Cruz

Int. J. Plant Biol. 2026, 17(7), 55; https://doi.org/10.3390/ijpb17070055 - 6 Jul 2026

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Abstract

Physalis peruviana L. is an Andean crop of high nutritional and commercial value; however, the limited availability of uniform planting material restricts its large-scale propagation. Indole-3-butyric acid (IBA) is widely used to promote adventitious rooting, although its concentration and application methods influence the [...] Read more.

Physalis peruviana L. is an Andean crop of high nutritional and commercial value; however, the limited availability of uniform planting material restricts its large-scale propagation. Indole-3-butyric acid (IBA) is widely used to promote adventitious rooting, although its concentration and application methods influence the response observed throughout the different stages of root development. This study evaluated how IBA concentration and explant origin influenced rooting-related traits and early vegetative growth of in vitro-regenerated P. peruviana shoots during a 30-day ex vitro acclimatization phase. The evaluated variables included rooting percentage, root number, longest root length, root fresh and dry mass, shoot length, leaf and node number, stem diameter, shoot fresh and dry mass, leaf area, and photosynthetic pigment contents. The experiment followed a completely randomized design with a 2 × 4 factorial arrangement consisting of two explant origins (cotyledon and hypocotyl) and four IBA concentrations (0, 400, 800, and 1600 mg L⁻¹), with five biological replicates per treatment combination. All shoots formed at least one visible root, resulting in 100% rooting across all treatment combinations. IBA concentration significantly affected root fresh and dry mass and several shoot-growth traits, whereas root number and longest root length were not significantly affected. Among the concentrations tested, 800 mg L⁻¹ produced the highest root biomass and favorable responses in selected shoot-growth traits, whereas 1600 mg L⁻¹ was associated with lower values for some growth variables. Hypocotyl-derived shoots had more leaves and nodes, greater stem diameter, and higher shoot dry mass than cotyledon-derived shoots. These results indicate a concentration- and trait-dependent response to IBA and identify 800 mg L⁻¹ as the most favorable concentration among those tested for increasing root biomass and selected shoot-growth traits under the evaluated acclimatization conditions. Full article

(This article belongs to the Topic Advances in Cultivation Techniques for Increasing Crop Yield)

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17 pages, 1336 KB

Open AccessArticle

Synergistic Effects of Arbuscular Mycorrhizal Fungi and Foliar Nitrogen–Phosphorus Application on Maize Productivity Under Irrigated and Rainfed Conditions

by Mst. Lailatul Ferdows, Saima Biswas, Mizanur Rahman, F. M. Jamil Uddin, Md. Nayan, Aporna Tabassum Api, Mohaiminul Islam, Nadia Islam, Swapan Kumar Paul and Md. Harun Rashid

Int. J. Plant Biol. 2026, 17(7), 54; https://doi.org/10.3390/ijpb17070054 - 4 Jul 2026

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Abstract

A field experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University to evaluate the effects of arbuscular mycorrhizal fungi (AMF) inoculation and foliar supplementation of nitrogen (N) and phosphorus (P) on the performance of maize (Zea mays L.) under [...] Read more.

A field experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University to evaluate the effects of arbuscular mycorrhizal fungi (AMF) inoculation and foliar supplementation of nitrogen (N) and phosphorus (P) on the performance of maize (Zea mays L.) under irrigated and rainfed conditions. The experiment followed a randomised complete block design with two levels of AMF (inoculated and non-inoculated) and four foliar treatments (no N and P, N only, P only, and combined N + P). The recommended dose of fertiliser (RDF) was applied as a soil application to all treatments. AMF inoculation significantly increased grain yield by 8.1% under rainfed and 10.0% under irrigated conditions compared with non-inoculated plants. Foliar application of N and P, especially when they were applied together, significantly improved yield components, including cob length, number of grains per cob, and 1000-grain weight. The highest grain yield (9.08 t ha⁻¹ under rainfed and 10.91 t ha⁻¹ under irrigated conditions) was obtained from the combined treatment of AMF inoculation and foliar N + P application. Redundancy analysis (RDA) and linear mixed-effects modelling (LMM) confirmed that water availability was the dominant factor controlling maize productivity, while AMF inoculation exhibited a stronger independent effect than foliar fertilisation. Under rainfed conditions, the treatment responses were reduced, and maize responded better to foliar N application in combination with AMF than combined N + P application. These findings indicate that the integrated use of AMF and foliar nutrient management enhances maize productivity, but optimal combinations depend strongly on moisture regimes. Full article

(This article belongs to the Section Plant–Microorganisms Interactions)

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14 pages, 1842 KB

Open AccessArticle

Foliar Damage Thresholds Associated with Enallodiplosis discordis Infestation in Neltuma pallida Seedlings in the Tropical Dry Forest of Northern Peru

by Silvana Marigorda-Castro, Karol Vilchez-Estrada, Javier Javier-Alva, Yuliana Mendoza-Martínez, Delia Talledo-Ancajima, Krizia Pretell-Monzón, Benoit Diringer, Carlos Granda-Wong, William Nauray-Huari and Gastón Cruz

Int. J. Plant Biol. 2026, 17(7), 53; https://doi.org/10.3390/ijpb17070053 - 3 Jul 2026

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Abstract

Neltuma pallida is a multi-purpose tree species of the seasonally dry tropical forests of northern Peru, where it provides essential ecological and socioeconomic functions. However, recurrent defoliation associated with the cecidomyiid gall midge Enallodiplosis discordis may compromise early seedling establishment and the success [...] Read more.

Neltuma pallida is a multi-purpose tree species of the seasonally dry tropical forests of northern Peru, where it provides essential ecological and socioeconomic functions. However, recurrent defoliation associated with the cecidomyiid gall midge Enallodiplosis discordis may compromise early seedling establishment and the success of forest restoration programs. This study evaluated the effects of larval infestation on foliar integrity and established quantitative damage thresholds in N. pallida seedlings under dry forest conditions. Insects collected from naturally infested plants were identified using an integrative taxonomic approach that combined classical morphological diagnosis with COI-based DNA barcoding obtained by Sanger sequencing. Morphological assessment assigned the defoliating dipteran to E. discordis, while BLASTn v2.17.0. analysis of the 576-bp partial COI sequence showed 92.6% identity and 100% query coverage with Cecidomyiidae records, supporting its taxonomic placement within this family. Field bioassays conducted over a 17-week period, in which 25 individual seedlings were evaluated (N = 25), revealed a strong and significant positive correlation between larval density and foliar damage percentage (r = 0.872; p < 0.001), with moderate damage levels predominating throughout the evaluation period. Despite sustained larval presence, seedlings did not reach severe damage categories, suggesting potential relative tolerance to partial defoliation under the evaluated field conditions. Temperature and relative humidity were not significantly associated with infestation intensity or foliar damage during the study period. Overall, these findings indicate that E. discordis-associated foliar damage represents a relevant, although not necessarily lethal, biotic constraint for the early regeneration of N. pallida under the field conditions assessed. The quantitative thresholds reported here provide useful criteria for dry forest restoration programs, phytosanitary monitoring, and integrated pest management strategies in the Peruvian dry forest. Full article

(This article belongs to the Special Issue Plant Resistance to Insects)

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17 pages, 1193 KB

Open AccessArticle

Genotypic Variation in Foliar Heat Tolerance Among 35 Malus Genotypes: Implications for Urban Tree Selection Under Climate Change

by Glynn C. Percival

Int. J. Plant Biol. 2026, 17(7), 52; https://doi.org/10.3390/ijpb17070052 - 29 Jun 2026

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Abstract

The frequency and intensity of heatwaves are increasing annually worldwide due to climate change. Combined with the urban heat island effect, elevated heat stress episodes threaten the survival and performance of urban trees, in turn reducing their ecosystem benefits. For this reason, the [...] Read more.

The frequency and intensity of heatwaves are increasing annually worldwide due to climate change. Combined with the urban heat island effect, elevated heat stress episodes threaten the survival and performance of urban trees, in turn reducing their ecosystem benefits. For this reason, the foliar heat tolerance of 35 Malus genotypes (two species, 32 cultivars, one variety, one hybrid) was evaluated under controlled laboratory assays. Heat injury to foliar tissue was quantified using chlorophyll fluorescence (Fv/Fm) to assess photosystem II (PSII) damage and an electrolyte leakage index (ELI) to evaluate cellular membrane integrity. A preliminary dose–response experiment using six genotypes exposed to a temperature gradient (40–50 °C) was conducted to establish thermal response curves and derive LT₅₀ values (temperature at 50% decline in Fv/Fm). These analyses confirmed substantial genotypic variation in thermal tolerance and identified 45 °C as an optimal discriminatory temperature for large-scale screening. This temperature was subsequently applied to assess heat injury across all 35 genotypes. Measurements were conducted in May (spring foliage) and August (summer foliage) to evaluate ontogenetic influences. In some instances, only one genotype was available for experimental purposes. Consequently, conclusions regarding genotypic differences in heat tolerance are based on replicated datasets, whereas genotypes represented by single-tree sampling are presented for descriptive purposes only. Heat stress significantly affected Fv/Fm and ELI, with strong genotype and seasonal effects recorded. In most genotypes, foliar damage was greater in spring than in summer. Good correlations between Fv/Fm and ELI confirmed their value as complementary physiological measures of heat tolerance in plants. Of the 35 genotypes evaluated, Malus sargentii, M. ‘Prairifire’, M. baccata ‘Jackii’, M. ‘Royal Fountain Huber’ and M. Donald Wyman were the most heat tolerant. The substantial variation in foliar heat tolerance detected across the 35 genotypes tested demonstrates potential for selecting Malus genotypes with superior foliar heat tolerance and highlights opportunities for identifying heat resilient candidates among other under-utilized urban tree taxa. Full article

(This article belongs to the Special Issue Plants in Urban Environments)

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16 pages, 2252 KB

Open AccessArticle

Simple Blue LED-Excited Fluorescence and Chromaticity Measurements as Screening Indices for Avocado Ripeness

by Ichiro Tono, Makoto Saito, Fujio Terai, Yoshiro Baba and Hiroyasu Ishikawa

Int. J. Plant Biol. 2026, 17(7), 51; https://doi.org/10.3390/ijpb17070051 - 28 Jun 2026

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Abstract

In response to the need for a simple, non-destructive method for evaluating avocado ripeness, we measured chlorophyll-related fluorescence and chromaticity of the outer skin using simple optical equipment and evaluated their relationship with whole-fruit compression (wfc), which was used as a firmness-based ripeness [...] Read more.

In response to the need for a simple, non-destructive method for evaluating avocado ripeness, we measured chlorophyll-related fluorescence and chromaticity of the outer skin using simple optical equipment and evaluated their relationship with whole-fruit compression (wfc), which was used as a firmness-based ripeness index. A compact system consisting of a blue LED excitation source and a small spectrometer was used to measure fluorescence spectra, and a commercially available colorimeter was used to evaluate chromaticity. Hass avocado samples purchased from multiple retail stores in Japan and stored for different periods were examined. The combination of the fluorescence intensity ratio I₇₄₀/I₆₈₅ and the lightness parameter L* showed a moderate correlation with wfc, with R² = 0.48. The fluorescence ratio I₇₄₀/I₆₈₅ was treated not as a direct measure of chlorophyll content, but as a spectral index associated with ripening-related changes in avocado skin, including chlorophyll-related fluorescence and skin optical properties. These results suggest that the combination of simple blue LED-excited fluorescence and chromaticity measurements may be useful as a practical screening approach for roughly estimating avocado ripeness in commercially available fruit. Full article

(This article belongs to the Section Plant Physiology)

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40 pages, 3160 KB

Open AccessReview

Nutraceutical Potential of Argan Tree (Argania spinosa): Structure–Function Insights and Health-Promoting Bioactivities of Key Phytochemicals

by Mohamed Ouknin, Youssef Karra, Hasnaâ Harrak, Abderraouf El Antari, Omar Drissi, Abdelghani Tahiri, Ahmed Wifaya, Fouad Elame, Meriyem Koufan, Redouan Qessaoui, Rachid Bouharroud and Naima Ait Aabd

Int. J. Plant Biol. 2026, 17(7), 50; https://doi.org/10.3390/ijpb17070050 - 28 Jun 2026

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Abstract

Argan tree (Argania spinosa L. Skeels), an endemic Moroccan species, is widely recognized for its traditional medicinal and nutritional uses. It has long been employed to promote skin and cardiovascular health, regulate blood glucose levels, and support overall wellbeing. Traditionally, different parts [...] Read more.

Argan tree (Argania spinosa L. Skeels), an endemic Moroccan species, is widely recognized for its traditional medicinal and nutritional uses. It has long been employed to promote skin and cardiovascular health, regulate blood glucose levels, and support overall wellbeing. Traditionally, different parts of the argan tree, including argan oil, leaves, and other plant-derived preparations, have been used to manage various health conditions such as diabetes, gastritis, gastric ulcers, rheumatism, joint and muscle pain, skin disorders including acne, eczema, and inflammation, as well as wound healing and dental problems. This narrative critical review compiles and evaluates current knowledge on the ethnobotany, phytochemistry, pharmacology, and toxicology of argan tree to support its evidence-based application. Relevant literature was collected from major English and French scientific databases, focusing on studies addressing the plant and its principal bioactive constituents. Ethnobotanical data indicate the extensive use of argan oil, leaves, and other plant parts in traditional remedies and dietary practices. Phytochemical investigations reveal a rich composition dominated by unsaturated fatty acids, tocopherols, phytosterols, and polyphenolic compounds. Experimental studies highlight a broad spectrum of biological activities, including antioxidant, antidiabetic, antibacterial, and anti-obesity effects, along with emerging applications in nanotechnology. Toxicological findings generally suggest low toxicity and good safety profiles under tested conditions. Overall, A. spinosa exhibits substantial ethnopharmacological relevance and diverse bioactivities, supporting its continued exploration for nutraceutical and therapeutic applications. Full article

(This article belongs to the Special Issue Chemical Signatures, Biological Functions, and Valorization Potential of Plant Extracts)

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Int. J. Plant Biol., Volume 17, Issue 7 (July 2026) – 10 articles

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