Search Results (47)

Salinization hinders the restoration of vegetation in salt-affected soils by negatively impacting plant growth and development. Halophytes play a key role in the restoration of saline and degraded lands due to unique features explaining their growth aptitude in such extreme ecosystems. Suaeda fruticosa is an euhalophyte well known for its medicinal properties and its potential for saline soil phytoremediation. However, excessive salt accumulation in soil limits the development of this species. Research findings increasingly advocate the use of extremophile rhizosphere bacteria as an effective approach to reclaim salinized soils, in conjunction with their salt-alleviating effect on plants. Here, a pot experiment was conducted to assess the role of a halotolerant plant growth-promoting actinobacterium, Glutamicibacter sp., on the growth, nutritional status, and shoot content of proline, total soluble carbohydrates, and phenolic compounds in the halophyte S. fruticosa grown for 60 d under high salinity (600 mM NaCl). Results showed that inoculation with Glutamicibacter sp. significantly promoted the growth of inoculated plants under stress conditions. More specifically, bacterial inoculation increased the shoot concentration of proline, total polyphenols, potassium (K⁺), nitrogen (N), and K⁺/Na⁺ ratio in shoots, while significantly decreasing Na⁺ concentrations. These mechanisms partly explain S. fruticosa tolerance to high saline concentrations. Our findings provide some mechanistic elements at the ecophysiological level, enabling a better understanding of the crucial role of plant growth-promoting rhizobacteria (PGPRs) in enhancing halophyte growth and highlight their potential for utilization in restoring vegetation in salt-affected soils. Full article

This study investigated how Leucaena leucocephala, a dry forest plant, copes with soil copper and herbivory caused by Schistocerca piceifrons, crucial for understanding species adaptation in stressed environments. A 33-day factorial experiment with three copper and two herbivory treatments assessed seedling growth rates (relative growth rate of biomass—RGR_B, and leaf area—RGR_LA), morphology, net assimilation rate (NAR), biomass allocation, and survival. Seedlings demonstrated compensatory growth in terms of RGR_B and RGR_LA under high copper and herbivory. Although copper decreased overall survival, surviving individuals effectively compensated for herbivory damage. These tolerance responses, primarily driven by an increased NAR (accounting for 98% of compensation), aligned with the limiting resource model. While most morphological components remained stable, herbivory specifically increased the root–shoot ratio. These findings indicate L. leucocephala possesses significant resilience through physiological adjustments, like enhancing NAR, and biomass reallocation strategies, allowing it to persist despite multiple stressors common in dry forests. Full article

Lavandula angustifolia Mill., lavender, is an aromatic plant in the Lamiaceae family. Lavender, which is native to the Mediterranean region but cultivated throughout the world, is an important economic plant. Several studies have investigated two aspects of this aromatic plant: (1) which pollinators, particularly bees, pollinate lavender, and (2) the composition of lavender essential oil. However, little research has been conducted to investigate how pollination affects either the yield or phytochemistry of lavender. The current study, which was conducted in North America, investigates which bee species visit lavender and how pollination affects plant chemistry, specifically the essential oil produced by lavender. Over the course of the 5-week observational period, a total of 12 species (across 10 genera) of bees were identified visiting lavender. Compared to previous studies on cultivated lavender at the same site (Mt. Nebo Botanical Farm, Mona, UT), four bee species not previously observed on lavender were identified. These included Hoplitis producta, Nomada sp., Osmia trevoris, and Megachile snowi. Pollinated lavender, compared to lavender excluded from pollinators, produced more essential oil (yield (w/w) = 1.49% vs. 1.07%), lower relative amounts of linalool (35.4% vs. 39.9%), and higher relative amounts of linalyl acetate (21.3% vs. 16.8%). The findings of this study demonstrate the ecological interactions between pollinators and lavender, and how those interactions impact phytochemistry. Full article

Long non-coding RNAs (lncRNAs) are key regulators of genetic networks in numerous biological processes. Micro-nanoplastics represent a novel abiotic stress, having a direct xenobiotic impact on plant cells, while the regulation of lncRNAs in Arabidopsis thaliana under this kind of abiotic stress remains largely unclear. We explored RNA-seq data sets of A. thaliana roots treated with two types of micro-nanoplastics: transparent polyethylene terephthalate (Tr-PET) and blue polyethylene terephthalate (Bl-PET) to reveal known and new unannotated lncRNAs. Our findings showed that the Tr-PET changed the expression of 104 lncRNAs, while the Bl-PET changed the expression of just 19. We speculate on the possible significance of the differential expressions for plant tolerance and resistance to micro-nanoplastic stress. A key finding of this work is that the studied lncRNAs tend to regulate their neighboring protein-coding genes. Consistent with this regulatory role, their promoters were found to contain cis-acting regulatory elements responsive to abscisic acid, light, MeJA, MYC/MYB, and other stress-related signals. Furthermore, some of the miRNAs that participate in plant development and defense were also predicted to be sponged by the differentially expressed lncRNAs. In summary, this study adds to our knowledge of A. thaliana lncRNAs through the discovery of new transcripts, describing their expression under micro-nanoplastic stress, and revealing their possible roles in post-transcriptional gene regulation. Full article

Plant mapping was introduced in soybean, but its illustrative capabilities in stress response are yet to be implemented. Methods to track the soybean physiological response are explained in this note by mapping pods in a coordinate system. A growth chamber study was conducted to measure the specific impact of simulated moisture stress on crop yield and pod development across three stages of crop growth. The treatment growth stages were R2, R3, and R5 (Full Bloom, Beginning Pod, and Beginning Seed, respectively), with two moisture stress durations of 7 and 14 days. A coordinate system was developed to understand soybean pod setting and yield by plotting each unique point on the plant using a set of numerical coordinates. This method summarizes soybean morphology during its vegetative and reproductive growth. Utilizing this method, we found that the growth stages during which moisture stress is experienced and the duration of the stress determined and influenced the location of pods on the soybean plant. The stress level factors impact the yield on the mainstem and branches by pod capacity at different magnitudes. This encoding procedure assists in tracking the location of aborted pods. It protects the yield by retaining pods, thereby leading to a better understanding of the stress experienced by these plants. Full article

An attempt was made to simulate the conditions prevailing in an agricultural crop to investigate whether and how geotextile microplastics alter the movement and accumulation of heavy metals in plants. For this purpose, a pot experiment, lasting 149 days, was carried out on soil obtained from a rural area, where pieces of a geotextile in mesoplastic dimensions, of the same chemical composition as that used by farmers in the Greek countryside, were added. Furthermore, metal solutions (Cu, Zn, Cd) were incorporated in the pots at two levels, and incubation prior to planting was carried out for two weeks. Then, industrial hemp was cultivated, while continuous measurements of its horticultural characteristics and of the levels of metals moved from the soil to the plant were made. The plants appeared to be highly resistant to the rather harsh growing conditions, and furthermore, it was observed that the cumulative metal capacity of cannabis was enhanced in most cases. The simultaneous presence of metals and geotextile (plastic) fragments enhanced the amount of Zn and Cd transfer into the soil-to-plant system. Hemp plants exhibited strong resilience abilities in the particularly stressful soil environment, possibly developing defense mechanisms. The experiments are particularly encouraging as they prove that simple and habitual practices in cultivated soils that lead to post-weather erosion of the geotextile may contribute positively in terms of remediation methods for heavy-metal-laden soils, as they indirectly help the plant to remove larger amounts of metal elements. The experiments should be intensified on a wider range of soils of different soil reactions and particle sizes and, of course, should be carried out under real field conditions in Mediterranean soil environments. Full article

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

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

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

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

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

Guar is a legume cultivated for its high seed galactomannan content. India is the major guar producer globally and the U.S. has the largest guar market worldwide. Guar is drought-tolerant and suitable as a summer rotational crop in dryland farming systems. Studies have shown correlations between carbon δ13 isotope (C13) discrimination and water-use efficiency in other crops. The objective of this study was to assess the variation in carbon δ13 isotope discrimination among 30 guar accessions. Accessions were grown under greenhouse conditions in 3.79 L pots, including drought-stressed and well-watered treatments. For each accession, beginning at the V5–V8 growth stage, one pot was continuously irrigated, whereas irrigation was withheld from the other until wilting symptoms appeared after 50 days. Each treatment pair (well-watered/drought-stressed) was organized in a completely randomized design with three replications. Aboveground fresh and dry biomass data were collected, and the dry leaves were used for C13 isotope analysis. The results showed an increase in leaf C13 under drought stress. There were no differences among genotypes in C13 for well-watered plants (p = 0.63), but drought-stressed plants differed (p < 0.001). Significant positive correlations were identified between C13 under drought stress and the fresh (r = 0.70) and dry biomass (r = 0.68) of drought-stressed plants. These results demonstrate that C13 has potential as a criterion to identify drought-tolerant guar lines. Full article

Investigating the impact of oxygen-enriched water combined with LED light on lettuce growth for two consecutive cycles is essential for advancing greenhouse cultivation in Mediterranean climates, where summer heat poses significant challenges. This study investigates the combined impact of oxygen-enriched water (O₂EW) and LED lighting on physiological, biochemical, and growth responses of two lettuce cultivars across two cultivation cycles in a controlled environment. The two lettuce types, Lactuca sativa var. ‘Lollo Bionda’ (Lugano) and Lactuca sativa var. ‘Lollo Rosso’ (Carmesi), were cultivated employing the Nutrient Film Technique (NFT) method within a regulated greenhouse setting. A randomized complete block design (RCBD) evaluated lettuce growth in an NFT system under three treatments: natural water (NW), oxygen-enriched water (O₂EW), and O₂EW with LED light (380–840 nm) (LED + O₂EW). The plants were exposed to natural oxygen levels (NW) of 6.2–7.4 mg L⁻¹ in the first and 7.4–8.1 mg L⁻¹ in the second period. Under O₂EW, levels reached 8.0–8.6 mg L⁻¹ and 8.7–9.2 mg L⁻¹, respectively, while LED + O₂EW concentrations were 8.4–8.5 mg L⁻¹ in the first and 8.8–8.4 mg L⁻¹ in the second period. The PPFD for ‘Lugano’ ranged from 426 to 486 µmol m⁻² s⁻¹ in the first cycle and 437–511 µmol m⁻² s⁻¹ in the second, averaging 448.66 and 460.65 µmol m⁻² s⁻¹, respectively. For ‘Carmesi’, it ranged from 421 to 468 and 441 to 492.3 µmol m⁻² s⁻¹, with averages of 438.66 and 457.1 µmol m⁻² s⁻¹. Statistical analysis was performed using two-way ANOVA and Tukey’s HSD test (p < 0.05) in IBM SPSS Statistics (version 29.0.2.0). The applied treatments significantly influenced the plants’ physiological parameters, including the photosynthetic rate, stomatal conductance, transpiration rate, and antioxidant activity. These treatments also significantly (p < 0.05) affected plant growth metrics such as the height, diameter, mass, number of leaves, root length, root mass, as well as biochemical components like chlorophyll, nitrate, and glucose content. The applied treatments significantly enhanced plant growth, biochemical components, and physiological parameters. Via comparative analysis, we concluded that the overall physiological performance of the plants in the second cycle was approximately 21.18% higher compared to the first cycle when combining all attributes. ‘Lugano’ showed stronger growth in height, mass, and root traits, while ‘Carmesi’ excelled in antioxidant activity, especially under LED + O₂EW treatment. Oxygen treatments boosted photosynthesis and transpiration in both varieties, with ‘Carmesi’ showing higher rates and ‘Lugano’ demonstrating greater growth, especially in the second cycle. In conclusion, O₂EW and LED treatments significantly enhance lettuce growth and resilience, particularly under warmer conditions, highlighting their potential to support sustainable year-round greenhouse cultivation. Full article

Drought poses a significant challenge to cowpea growth and productivity, necessitating the development of drought-tolerant cultivars through detailed morpho-physiological and molecular analyses. This study evaluated drought stress responses in cowpea cultivars using polypropylene plastic boxes under greenhouse conditions. RT-qPCR was conducted to assess the relative expression of five photosynthetic and abiotic stress-related genes in a subset of seven contrasting cultivars at 7-, 14-, and 28-days post-treatment initiation (DPTI) and 24 h post-rewatering. Drought-stressed plants showed progressive wilting and a declining chlorophyll content, with plant greenness scores ranging from 2.2 (TVu11987) to 4.7 (TVu2428). California Blackeye (72.2%) and TVu11987 (69.4%) had the highest recovery rates, indicating greater drought tolerance, while TVu2428 had the lowest (2.8%). Gene expression analyses revealed significant drought-induced variation across cultivars and time points. Transcript levels were notably higher in drought-tolerant cultivars, particularly at 14 DPTI and 24 h post-rewatering, aligning with the morpho-physiological screening results. However, gene expression declined as the drought severity increased. These results suggest that California Blackeye, TVu11987, Lobia-I-Sefade, K929, and Aloomba were more drought tolerant compared to Mississippi Silver and TVu2428. Future research using transcriptomic profiling could unravel the complex molecular mechanisms of drought responses in cowpeas, providing valuable insights for breeding genotypes with improved resiliency to drought. Full article

Water scarcity is a major challenge in northeastern Brazil, where efficient water management strategies are essential for sustainable agriculture. This study aimed to evaluate the performance of melon hybrids in terms of biomass production and nutritional status under varying irrigation levels and mycorrhizal fungi (AMF) inoculation. The experiment was conducted in a greenhouse at the State University of Bahia (Juazeiro, BA, Brazil) using a randomized block design with a 4 × 2 × 4 sub-subdivided plot scheme. The treatments included four irrigation levels (50%, 75%, 100%, and 125% of crop evapotranspiration—ETc), two melon hybrids (Juazeiro and Mandacaru), and four AMF inoculation treatments (non-inoculated with AMF, Entrophospora etunicata, Acaulospora longula, and their combination), with 10 replications. The results indicated that the inoculation with A. longula significantly improved biomass production and plant nutrition, particularly for the Juazeiro hybrid. The most significant improvements were observed in biomass production and nutritional status when this mycobiont was used, highlighting the potential of AMF inoculation as a strategy to enhance water use efficiency and plant tolerance under water-limited conditions. Root colonization in melon plants ranged from 6% to 60%, with an overall average of 36.2%, in Experiment I, and from 6% to 72%, with an average of 40%, in Experiment II. Melon biomass production responded differently to irrigation levels, with Experiment I showing polynomial decreases in biomass as water levels decreased, while Experiment II exhibited linear increases in biomass with higher irrigation, likely influenced by supplementary fertilization. When evaluated, the levels of macronutrients present in the aerial part of the plants did not show significant differences for the treatments concerning the levels of P, K, and Mg, except for Ca. These findings suggest that A. longula is a suitable mycobiont for optimizing melon plant performance in regions with limited water resources, like northeastern Brazil. The study also emphasizes the importance of selecting appropriate Mycorrhizal fungi to maximize symbiotic benefits in melon cultivation under deficit irrigation systems. Full article