International Journal of Plant Biology

21 pages, 12264 KiB

Open AccessArticle

Real-Time Partitioning of Diurnal Stem CO₂ Efflux into Local Stem Respiration and Xylem Transport Processes

by Kolby J. Jardine, Regison Oliveira, Parsa Ajami, Ryan Knox, Charlie Koven, Bruno Gimenez, Gustavo Spanner, Jeffrey Warren, Nate McDowell, Guillaume Tcherkez and Jeffrey Chambers

Int. J. Plant Biol. 2025, 16(2), 46; https://doi.org/10.3390/ijpb16020046 (registering DOI) - 30 Apr 2025

Abstract

The apparent respiratory quotient (ARQ) of tree stems, defined as the ratio of net stem CO₂ efflux (E_{S_CO2}) to net stem O₂ influx (E_{S_O2}), offers insights into the balance between local respiratory CO₂ production and CO [...] Read more.

The apparent respiratory quotient (ARQ) of tree stems, defined as the ratio of net stem CO₂ efflux (E_{S_CO2}) to net stem O₂ influx (E_{S_O2}), offers insights into the balance between local respiratory CO₂ production and CO₂ transported via the xylem. Traditional static chamber methods for measuring ARQ can introduce artifacts and obscure natural diurnal variations. Here, we employed an open flow-through stem chamber with ambient air coupled with cavity ring-down spectrometry, which uses the molecular properties of CO₂ and O₂ molecules to continuously measure E_{S_CO2}, E_{S_O2}, and ARQ, at the base of a California cherry tree (Prunus ilicifolia) during the 2024 growing season. Measurements across three stem chambers over 3–11-day periods revealed strong correlations between E_{S_CO2} and E_{S_O2} and mean ARQ values ranging from 1.3 to 2.9, far exceeding previous reports. Two distinct diurnal ARQ patterns were observed: daytime suppression with nighttime recovery, and a morning peak followed by gradual decline. Partitioning E_{S_CO2} into local respiration and xylem-transported CO₂ indicated that the latter can dominate when ARQ exceeds 2.0. Furthermore, transported CO₂ exhibited a higher temperature sensitivity than local respiration, with both processes showing declining temperature sensitivity above 20 °C. These findings underscore the need to differentiate stem CO₂ flux components to improve our understanding of whole-tree carbon cycling. Full article

(This article belongs to the Section Plant Physiology)

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16 pages, 2764 KiB

Open AccessArticle

Lotus tenuis in Association with Arbuscular Mycorrhizal Fungi Is More Tolerant to Partial Submergence than to High-Intensity Defoliation

by Ileana García

Int. J. Plant Biol. 2025, 16(2), 47; https://doi.org/10.3390/ijpb16020047 - 29 Apr 2025

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Abstract

This study aimed to investigate the effect of the association of Lotus tenuis with arbuscular mycorrhizal fungi (AMF) on its development under high defoliation intensity or partial submergence in a P-deficient soil of the Salado River Basin in a pot experiment. L. tenuis [...] Read more.

This study aimed to investigate the effect of the association of Lotus tenuis with arbuscular mycorrhizal fungi (AMF) on its development under high defoliation intensity or partial submergence in a P-deficient soil of the Salado River Basin in a pot experiment. L. tenuis mycorrhizal plants showed higher tolerance to partial submergence (91%) than to high defoliation intensity (57%). Shoot biomass was the highest in mycorrhizal non-stressed and submerged plants (11.71 g and 12.06 g, respectively), and decreased by 38% in defoliated plants. Both stress conditions caused a negative effect on root growth of plants with or without AMF. High-intensity defoliation can be considered the most stressful scenario for mycorrhizal L. tenuis plants and AMF play a more marked role in P nutrition. Under submergence, AMF caused a net effect on L. tenuis growth, improving carbon and P resource distribution to sustain shoot growth and elongation. Root AMF colonization and nodulation decreased under submergence. High arbuscular colonization percentages were reached under both stress conditions, indicating that the symbiosis may be functional. L. tenuis roots can act as a reservoir of the fungal community under severe stress conditions, allowing the preservation of the AMF inoculum. Full article

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

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15 pages, 3487 KiB

Open AccessArticle

Altered Translocation Pattern as Potential Glyphosate Resistance Mechanism in Blackgrass (Alopecurus myosuroides) Populations from Lower Saxony

by Markus Radziewicz, Dirk M. Wolber, Thomas Pütz and Diana Hofmann

Int. J. Plant Biol. 2025, 16(2), 45; https://doi.org/10.3390/ijpb16020045 - 16 Apr 2025

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Abstract

Glyphosate is a broad-spectrum herbicide widely used. After years of extensive usage, many weed species have developed resistance due to both target-site (TSR) and non-target-site resistance mechanisms (NTSRs). Alopecurus myosuroides is a competitive weed species. Greenhouse monitoring trials in Germany have revealed reduced [...] Read more.

Glyphosate is a broad-spectrum herbicide widely used. After years of extensive usage, many weed species have developed resistance due to both target-site (TSR) and non-target-site resistance mechanisms (NTSRs). Alopecurus myosuroides is a competitive weed species. Greenhouse monitoring trials in Germany have revealed reduced glyphosate efficacy against some populations of Alopecurus myosuroides. In a foregoing dose–response study, individual plants from four out of six tested populations survived full (1800 g a.i. ha⁻¹) or double (3600 g a.i. ha⁻¹) glyphosate dose rates permitted, suggesting the presence of tolerant biotypes with yet unknown resistance mechanisms. Our aim was to investigate the absorption and translocation patterns of glyphosate in these biotypes. The plants were first treated with ¹⁴C-glyphosate, and ¹⁴C-glyphosate absorption and translocation were subsequently visualized by phosphorimaging and finally quantified by liquid scintillation counting. The results showed significant differences in the distribution of glyphosate in different plant organs, with significantly more being translocated out of the treated leaf in glyphosate-resistant compared to sensitive (S-) biotypes. The study’s findings are partly in contrast to previous studies that have found reduced translocation. Our study demonstrates the complex nature of glyphosate resistance and suggests further experiments to finally elucidate the underlying resistance mechanisms in the biotypes of the Alopecurus myosuroides studied. Full article

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

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13 pages, 2364 KiB

Open AccessArticle

Using Moss Walls for Air Quality Monitoring: Extending Their Utility Beyond Traditional Green Infrastructure

by Gana Gecheva, Zhana Petkova, Stoyan Damyanov, Deyana Georgieva, Vesselin Baev, Mariyana Gozmanova, Elena Apostolova-Kuzova and Galina Yahubyan

Int. J. Plant Biol. 2025, 16(2), 44; https://doi.org/10.3390/ijpb16020044 - 14 Apr 2025

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Abstract

Moss walls are acknowledged, though not widely, for their urban environmental benefits: humidity control, noise reduction, and air filtration. In this pioneering study, three outdoor living moss walls were installed in separate urban green spaces in Plovdiv, Bulgaria. One and five months later, [...] Read more.

Moss walls are acknowledged, though not widely, for their urban environmental benefits: humidity control, noise reduction, and air filtration. In this pioneering study, three outdoor living moss walls were installed in separate urban green spaces in Plovdiv, Bulgaria. One and five months later, the primary moss species used, Hypnum cupressiforme, a well-established biomonitor, was analyzed for 12 potentially toxic elements. The content of all measured elements increased, with zinc (Zn) and cadmium (Cd) showing the most significant rises—17-fold and 3-fold, respectively. The element accumulation is believed to originate from industrial activities related to non-ferrous metals. In addition to accumulating toxic elements, the moss exhibited physiological responses to environmental stress. Total lipids and tocopherols, lipophilic antioxidants produced exclusively by photosynthetic organisms, showed adaptive changes. As a molecular biomarker, the expression of the rbcL gene, which encodes the largest subunit of Rubisco, was analyzed, and showed a correlation with the Ecological Risk Index derived from the moss wall data. While living moss walls have been used to some extent to enhance urban aesthetics and improve air quality, this study is the first to highlight their potential as tools for air quality monitoring. Full article

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

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20 pages, 5204 KiB

Open AccessArticle

Comprehensive Metabolomic Profiling of Common Bean (Phaseolus vulgaris L.) Reveals Biomarkers Involved in Viral Disease Detection and Monitoring

by Aggrey Keya Osogo, Clabe Wekesa, Francis N. Muyekho, Hassan Karakacha Were and Patrick Okoth

Int. J. Plant Biol. 2025, 16(2), 43; https://doi.org/10.3390/ijpb16020043 - 7 Apr 2025

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Abstract

Common bean production is crucial in Western Kenya due to its economic, nutritional, environmental, and cultural importance. However, challenges such as diseases, especially viral diseases, cause significant crop losses. This study sought to identify potential biomarkers for BCMV and BCMNV viral diseases by [...] Read more.

Common bean production is crucial in Western Kenya due to its economic, nutritional, environmental, and cultural importance. However, challenges such as diseases, especially viral diseases, cause significant crop losses. This study sought to identify potential biomarkers for BCMV and BCMNV viral diseases by analyzing small molecule metabolites in diseased common bean systems and gain an understanding of related metabolic pathways. Virus-free Rosecoco bean cultivars were planted and exposed to BCMV and BCMNV in specific regions, with healthy plants serving as controls. Diseased and healthy leaves were collected for metabolite extraction and analyzed using liquid chromatography and mass spectrometry. A total of 354 metabolites were identified across seven pathways, with 51 upregulated metabolites, primarily from fatty acids, terpenoids, and alkaloids. Ten metabolites were differentially expressed, with the molecular structures of two successfully determined. These metabolites serve as potential biomarkers for viral disease detection, monitoring, and resistance in common beans. The findings highlight the role of fatty acids and terpenoids, as well as the importance of regional variability in plant hormone regulation in response to stress, suggesting that further research into these pathways will be essential for understanding plant defense mechanisms. Full article

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

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16 pages, 1364 KiB

Open AccessReview

Photosynthetic Adaptation in Poplar Under Abiotic and Biotic Stress: Integrating Molecular, Physiological, and Biotechnological Perspectives

by Dong Wang, Pawan Kumar Jewaria and Jianwei Xiao

Int. J. Plant Biol. 2025, 16(2), 42; https://doi.org/10.3390/ijpb16020042 - 1 Apr 2025

Viewed by 356

Abstract

In the context of global climate change, the carbon storage and sequestration capacity of terrestrial ecosystems is of increasing concern. Poplars are widely planted because of their fast growth and environmental adaptability. We reviewed the effects of abiotic and biotic stresses on photosynthesis [...] Read more.

In the context of global climate change, the carbon storage and sequestration capacity of terrestrial ecosystems is of increasing concern. Poplars are widely planted because of their fast growth and environmental adaptability. We reviewed the effects of abiotic and biotic stresses on photosynthesis in poplar, focusing on the damage caused by adversity conditions to photosynthetic apparatus, which leads to decreased carbon dioxide (CO₂) assimilation and an increase in reactive oxygen species (ROS)-induced oxidative damage. The mechanisms of photosynthesis response to stress in poplar are reviewed, especially the role of genes regulation in regulating photosynthetic efficiency. These findings are particularly important for improving the resilience of poplar under changing environmental conditions. In addition, we discussed a range of strategies to enhance photosynthesis in poplar under stress, such as genetic engineering and synthetic biology. These approaches provide theoretical guidance for improving the resilience of poplar and insights for improving other crops facing similar challenges. Full article

(This article belongs to the Section Plant Physiology)

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21 pages, 4809 KiB

Open AccessArticle

Characterization of TaMYB Transcription Factor Genes Revealed Possible Early-Stage Selection for Heat Tolerance in Wheat

by Manu Maya Magar, Hui Liu and Guijun Yan

Int. J. Plant Biol. 2025, 16(2), 41; https://doi.org/10.3390/ijpb16020041 - 26 Mar 2025

Viewed by 265

Abstract

Wheat quality and quantity are challenged by increasing global temperature, which poses an urgent need for heat tolerance breeding in wheat. The identification of seedling-stage factors highly associated with reproductive-stage performance can enable early-stage selection and enhance the efficiency and effectiveness of breeding. [...] Read more.

Wheat quality and quantity are challenged by increasing global temperature, which poses an urgent need for heat tolerance breeding in wheat. The identification of seedling-stage factors highly associated with reproductive-stage performance can enable early-stage selection and enhance the efficiency and effectiveness of breeding. This study investigated the myeloblastosis (MYB) gene family, one of the largest transcription factor (TF) gene families in plants, for its response to seedling- and reproductive-stage heat stress in wheat. Genome-wide analysis of MYB TF genes identified 876 TaMYB genes, and 48 genes were selected for qRT-PCR expression analysis based on in silico expression analysis under abiotic stresses. Correlation analysis of the quantitative real-time polymerase chain reaction (qRT-PCR) expression pattern of selected TaMYB genes in a heat-tolerant genotype (Perenjori) and two heat-sensitive genotypes (Brazil32 and Yitpi) at the seedling stage and grain-filling stage identified five TaMYB genes (TaMYB-327, TaMYB-049, TaMYB-030, TaMYB-226, and TaMYB-023) for the early-stage selection of heat tolerance and four TaMYB genes (TaMYB-232, TaMYB-343, TaMYB-305, and TaMYB399) for the early-stage selection of heat sensitivity in wheat. As important stress-responsive genes, these MYB genes showed similar expression patterns between early and late developmental stages, indicating the existence of a correlation for heat tolerance at the two stages, and therefore providing the theoretical basis for the early selection of heat tolerance in wheat. Full article

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

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15 pages, 1525 KiB

Open AccessArticle

Cannabis sativa L. Miniature Inverted-Repeat Transposable-Element Landscapes in Wild-Type (JL) and Domesticated Genome (CBDRx)

by Mariana Quiroga, Clara Crociara, Esteban Schenfeld, Franco Daniel Fernández, Juan Crescente, Leonardo Vanzetti and Marcelo Helguera

Int. J. Plant Biol. 2025, 16(2), 40; https://doi.org/10.3390/ijpb16020040 - 25 Mar 2025

Viewed by 367

Abstract

Cannabis sativa L. is a globally cultivated plant with significant industrial, nutritional, and medicinal value. Its genome, comprising nine autosomes and sex chromosomes (X and Y), has been extensively studied, particularly in the context of precise breeding for specific enduses. Recent advances have [...] Read more.

Cannabis sativa L. is a globally cultivated plant with significant industrial, nutritional, and medicinal value. Its genome, comprising nine autosomes and sex chromosomes (X and Y), has been extensively studied, particularly in the context of precise breeding for specific enduses. Recent advances have facilitated genome-wide analyses through platforms like the NCBI Comparative Genome Viewer (CGV) and CannabisGDB, among others, enabling comparative studies across multiple Cannabis genotypes. Despite the abundance of genomic data, a particular group of transposable elements, known as miniature inverted-repeat transposable elements (MITEs), remains underexplored in Cannabis. These elements are non-autonomous class II DNA transposons characterized by high copy numbers and insertion preference in non-coding regions, potentially affecting gene expression. In the present study, we report the sequence annotation of MITEs in wild-type and domesticated Cannabis genomes obtained using the MITE Tracker software. We also develop a simple and innovative protocol to identify genome-specific MITE families, offering valuable tools for future research on marker development focused on important genetic variation for breeding in Cannabis sativa. Full article

(This article belongs to the Special Issue Challenges in Cannabis sativa: Breeding and Secondary Metabolite Synthesis)

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16 pages, 3142 KiB

Open AccessArticle

Allometric Models to Estimate Aboveground Biomass of Individual Trees of Eucalyptus saligna Sm in Young Plantations in Ecuador

by Raúl Ramos-Veintimilla, Hernán J. Andrade, Roy Vera-Velez, José Esparza-Parra, Pedro Panama-Perugachi, Milena Segura and Jorge Grijalva-Olmedo

Int. J. Plant Biol. 2025, 16(2), 39; https://doi.org/10.3390/ijpb16020039 - 24 Mar 2025

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Abstract

(1) Background: Nature-based solutions (NbS), particularly through forest biomass, are crucial in mitigating climate change. While forest plantations play a critical role in carbon capture, the absence of species-specific biomass estimation models presents a significant challenge. This research focuses on developing allometric models [...] Read more.

(1) Background: Nature-based solutions (NbS), particularly through forest biomass, are crucial in mitigating climate change. While forest plantations play a critical role in carbon capture, the absence of species-specific biomass estimation models presents a significant challenge. This research focuses on developing allometric models to accurately estimate the aboveground biomass of Eucalyptus saligna Sm in Ecuador’s Lower Montane thorny steppe. (2) Methods: Conducted at the Tunshi Experimental Station of ESPOCH in Chimborazo, Ecuador, the research involved 46 trees to formulate biomass predictive models using both destructive and non-destructive methods. Sixteen generic models were tested using the ordinary least squares method. (3) Results: The most effective allometric equation for estimating six-year-old E. saligna biomass was Ln(B) = −0.952 + 1.97∗Ln(dbh), where B = biomass in kg/tree, and dbh = diameter at breast height in cm. This model represents a valuable contribution to improve biomass and carbon estimates in mitigation projects in Ecuador. (4) Conclusions: The tested models stand out for their simplicity, requiring only dbh as input, and demonstrate high accuracy and fit to contribute to the field of climate change mitigation. Full article

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

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13 pages, 927 KiB

Open AccessArticle

Integrating Sustainable Cultivation Practices and Advanced Extraction Methods for Improved Cannabis Yield and Cannabinoid Production

by Theerayut Thawonkit, Nednapa Insalud, Rapeephun Dangtungee and Prakash Bhuyar

Int. J. Plant Biol. 2025, 16(2), 38; https://doi.org/10.3390/ijpb16020038 - 21 Mar 2025

Viewed by 614

Abstract

The rising global demand for medicinal cannabis necessitates the optimization of cultivation, harvesting, and extraction techniques to maximize cannabinoid yield and purity. This study investigates the Foi Thong Phu Pha Yon strain under controlled environmental conditions, evaluating the effects of temperature, humidity, CO [...] Read more.

The rising global demand for medicinal cannabis necessitates the optimization of cultivation, harvesting, and extraction techniques to maximize cannabinoid yield and purity. This study investigates the Foi Thong Phu Pha Yon strain under controlled environmental conditions, evaluating the effects of temperature, humidity, CO₂ concentration, and light exposure on plant growth and cannabinoid biosynthesis. A total of 170 seeds were germinated, with an 85% germination success rate, and various growth strategies, including soil composition, nutrient application, and irrigation methods, were tested to determine the most effective approach. The research findings indicate that vegetative growth was optimal at 27 °C, 70% humidity, and 1200 ppm CO₂ while flowering required a reduced temperature (22 °C), lower humidity (50%), and elevated CO₂ levels (1900 ppm) to enhance cannabinoid production and prevent disease. Furthermore, harvest timing significantly influenced CBD yield, with peak cannabinoid content observed when 80% of trichomes were cloudy white. Over two growing cycles, this study produced 43,200 g of fresh buds, resulting in 7560 g of dried cannabis buds. The extraction process, utilizing dynamic maceration with 95% ethanol, followed by winterization and chromatography, yielded 2343.60 g of cannabis extract, including 589.68 g of CBD, with an average purity of 86.599%. Advanced techniques such as flash chromatography and distillation further refined the CBD isolate, ensuring pharmaceutical-grade quality. These findings highlight the effectiveness of precise environmental control, strategic harvesting, and advanced extraction methodologies in optimizing cannabis production. This research provides valuable insights for agricultural researchers, policymakers, and the pharmaceutical industry, supporting sustainable cultivation practices and improved product quality in the expanding medicinal cannabis market. Full article

(This article belongs to the Special Issue Challenges in Cannabis sativa: Breeding and Secondary Metabolite Synthesis)

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Int. J. Plant Biol., Volume 16, Issue 2 (June 2025) – 10 articles

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