Plant Physiology Research Articles

Short-term airborne ultrasound induced cell death in tobacco cells and changed their wall components

The effects of low-intensity ultrasound on plants such as piezoelectric and ultrasonic water baths, on plants have been extensively studied. However, the specific effect of airborne ultrasound on plant cells has yet to be reported. The present study was conducted to elucidate the physiological responses of plant cells to airborne US. Homogeneous suspension-cultured tobacco cells (Nicotiana tabacum L. cv Burley 21) were subjected to airborne US at 24 kHz in two pulsatile and continuous modes for 10 and 20 s. The study’s outcome revealed that airborne US triggered the production of H2O2, elevated internal calcium concentration, and reduced antioxidant capacity upon cavitation. Alteration of covalently bound peroxidase and other wall-modifying enzyme activities was accompanied by reduced cellulose, pectin, and hemicellulose B but increased lignin and hemicellulose A. The biomass and viability of tobacco cells were also significantly decreased by airborne US, which ultimately resulting in PCD and secondary necrosis. The results highlight the potential risks of even short-time exposure to the airborne US on plant physiology and cell wall chemical composition raising significant concerns about its implications.

Harnessing Spectral Libraries From AVIRIS-NG Data for Precise PFT Classification: A Deep Learning Approach.

The generation of spectral libraries using hyperspectral data allows for the capture of detailed spectral signatures, uncovering subtle variations in plant physiology, biochemistry, and growth stages, marking a significant advancement over traditional land cover classification methods. These spectral libraries enable improved forest classification accuracy and more precise differentiation of plant species and plant functional types (PFTs), thereby establishing hyperspectral sensing as a critical tool for PFT classification. This study aims to advance the classification and monitoring of PFTs in Shoolpaneshwar wildlife sanctuary, Gujarat, India using Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) and machine learning techniques. A comprehensive spectral library was developed, encompassing data from 130 plant species, with a focus on their spectral features to support precise PFT classification. The spectral data were collected using AVIRIS-NG hyperspectral imaging and ASD Handheld Spectroradiometer, capturing a wide range of wavelengths (400-1600 nm) to encompass the key physiological and biochemical traits of the plants. Plant species were grouped into five distinct PFTs using Fuzzy C-means clustering. Key spectral features, including band reflectance, vegetation indices, and derivative/continuum properties, were identified through a combination of ISODATA clustering and Jeffries-Matusita (JM) distance analysis, enabling effective feature selection for classification. To assess the utility of the spectral library, three advanced machine learning classifiers-Parzen Window (PW), Gradient Boosted Machine (GBM), and Stochastic Gradient Descent (SGD)-were rigorously evaluated. The GBM classifier achieved the highest accuracy, with an overall accuracy (OAA) of 0.94 and a Kappa coefficient of 0.93 across five PFTs.

Hidden hunger: from a plant biologist's perspective.

In recent years, changes in dietary patterns from an omnivore diet to a moderate-to-restrictive diet that includes more plant food are becoming popular for various reasons and the associated health benefits. Despite the increased consumption of plant food as recommended by these seemingly healthy diets, micronutrient deficiency is still prevalent particularly among the health-conscious populations. The aim of this review is to help guide interventions by understanding micronutrient deficiency trends from a dietary habit and plant physiology context. In this review, the author discusses how modern agricultural practices coupled with climate change, and with particular emphasis on the extreme dietary habits that lack variation and excessive consumption, may contribute to an increased ingestion of antinutrients which in turn potentially exacerbate vitamin and mineral deficiencies. While plants possess a wide range of secondary metabolites that exert beneficial health effects, some of these compounds are also antinutrients that interfere with the digestion and absorption of nutrients and micronutrients. Furthermore, the article also raises questions concerning the fate of antinutrient traits in future crops that were to be redesigned with improved stress tolerance, and the impacts it may have on human nutrition and the environment. © 2025 Society of Chemical Industry.

Nitro-fatty acids modulate germination onset through S-nitrosothiol metabolism.

-Nitro-fatty acids (NO2-FAs) have emerged as key components of nitric oxide (NO) signalling in eukaryotes. We previously described how nitro-linolenic acid (NO2-Ln), the major NO2-FA detected in plants, regulates S-nitrosoglutathione (GSNO) levels in Arabidopsis (Arabidopsis thaliana). However, the underlying molecular mechanisms remain undefined. Here, we used a combination of physiological, biochemical, and molecular approaches to provide evidence that NO2-Ln modulates S-nitrosothiol (SNO) content through S-nitrosylation of S-nitrosoglutathione reductase1 (GSNOR1) and its impact on germination onset. The aer mutant (a knockout mutant of the alkenal reductase enzyme; AER) exhibits higher NO2-Ln content and lower GSNOR1 transcript levels, reflected by higher SNO content and S-nitrosylated proteins. Given its capacity to release NO, NO2-Ln mediates the S-nitrosylation of GSNOR1, demonstrating that NO2-FAs can indirectly modulate total SNO content in plants. Moreover, the ectopic application of NO2-Ln to dormant seeds enhances germination success similarly to the aer germination rate, which is mediated by the degradation of master regulator ABSCISIC ACID INSENSITIVE 5 (ABI5). Our results establish that NO2-FAs regulate plant development through NO and SNO metabolism and reveal a role of NO2-FAs in plant physiology.

Unraveling the multifaceted role of ethephon in plant physiology: from seed germination to crop maturation and harvesting

Unraveling the multifaceted role of ethephon in plant physiology: from seed germination to crop maturation and harvesting

The Role of Leaf Area Changes Within Plant CO2 Physiological Impacts on the Global Hydrological Cycle

AbstractRising atmospheric CO2 concentrations enhance greenhouse warming and drive changes to plant physiology, leading to innumerable climate impacts. This study explores the impacts of plant responses on hydrological cycling at 2x preindustrial CO2 concentrations by analyzing simulations that isolate plant physiological effects using the Community Earth System Model versions 1 and 2. We find that leaf area growth increases canopy evaporation, which offsets transpiration declines, and dampens changes in global mean evapotranspiration, precipitation, and runoff in a CESM2 experiment with dynamic leaf area. These leaf area impacts are also evident in the differences between CESM1 and CESM2, with CESM2 better capturing observed leaf area magnitudes but potentially overestimating leaf area‐CO2 sensitivity, highlighting the importance of plant CO2 physiology on hydrological cycle changes and the need to improve its representation in climate models.

24-epibrassinolide regulates oxytetracycline-induced phytotoxicity and its detoxification mechanism.

Oxytetracycline (OTC), a crop-absorbable antibiotic, poses a health risk to humans through the food chain. Conversely, 24-epibrassinolide (EBL), a plant growth hormone, mitigates the toxic effects of various pollutants on plants. However, the mechanism by which exogenous EBL affects the growth of rape seedlings exposed to OTC remains largely unknown. In this study, we found that environmental OTC concentrations significantly inhibited plant growth and metabolism, whereas exogenous EBL could restore plant growth characteristics. Exogenous EBL significantly decreased reactive oxygen species (ROS) accumulation, alleviating OTC-induced cell membrane lipid peroxidation. This was achieved by increasing the antioxidant capacity and secondary metabolism levels. Notably, our findings suggested that EBL stimulated glutathione S-transferase (GST) and glutathione reductase (GR) activities, enhancing reduced glutathione synthesis and participating in plant OTC detoxification. OTC residues in EBL + OTC-treated seedlings at 21 d were significantly reduced by 29 % compared with OTC alone. Further transcriptomic and metabolomic analyses revealed that the differentially expressed genes and metabolites in the EBL and OTC alone or combined treatment groups were primarily involved in the regulation of phenylpropanoid biosynthesis, glutathione metabolism, and lant hormone signal transduction pathways in response to phytotoxic effects and detoxification mechanisms, as compared to the control group.

Microbiome-Mediated Mechanisms Regulating Adaptability to Iron Deficiency in the Intercropping System of Soybean and Maize

Iron (Fe) deficiency is a pervasive agricultural concern on a global scale. Intercropping plays a pivotal role in activating soil nutrient cycling and crop nutrient uptake and utilization. This study integrates plant physiology, soil physicochemical determination, high-throughput sequencing, and metabolomics techniques to conduct pot experiments using field-collected soils with soybean and maize plants. This study aims to investigate the mechanisms through which microorganisms in a soybean–maize intercropping system regulate Fe deficiency adaptation. The results revealed that intercropping enhances the resilience of soybean and maize in Fe-deficient environments, facilitates nutrient absorption by plants, and enriches soil nutrient content. Moreover, intercropping fostered more intricate microbial interactions in comparison to monocropping. The dominant microorganisms in the rhizosphere of intercropped soybean and maize included genera Microbacterium, Sphingomonas, Shinella, and Rhizobium. Microbacterium, Sphingomonas, Shinella, and Rhizobium have the potential to produce Fe chelators or enhance plant Fe absorption. Additionally, intercropping notably modified the composition of root exudates derived from soybean and maize. The soybean and maize rhizosphere exhibited significant enrichment with oleamide, coumestrol, glycitein, and daidzein. Coumestrol may have an effect of promoting Fe absorption, and it is significantly positively correlated with the genus Nakamurella in the maize rhizosphere and the genus Pirellula in the soybean rhizosphere. Consequently, these findings suggested that the rhizosphere of intercropped soybean and maize significantly enriches specific microbial communities and root exudates, thereby enhancing microecosystem stability and improving plant tolerance to Fe deficiency.

Roles and Regulations of Acid Invertases in Plants: Current Knowledge and Future Perspectives

Acid invertases (Ac-Invs) are crucial enzymes in plant physiology, regulating sucrose metabolism and hydrolyzing sucrose into glucose and fructose. These sugars serve not only as energy sources and structural components but also as signaling molecules, influencing diverse developmental processes, including seed and fruit growth, flowering, and stress responses. Ac-Invs are classified into cell wall invertases (CWINs) and vacuolar invertases (VINs) based on their subcellular localization, with both playing distinct roles in sucrose unloading, osmotic regulation, and sugar accumulation. Recent studies have also highlighted their involvement in abiotic stress adaptation and hormonal regulation, emphasizing their central role in plant resilience and productivity. However, gaps remain in understanding their regulatory mechanisms, particularly their interactions with plant hormones, defective invertases, and responses to environmental stresses. This review summarizes the biochemical characteristics, functions, and regulatory mechanisms of Ac-Invs, providing insights into their evolutionary significance and potential applications in crop improvement. Future research directions are proposed to elucidate unresolved questions and leverage Ac-Invs for enhancing agricultural sustainability.

Mitigation of High Temperatures with Ascophyllum nodosum Biostimulants in Papaya (Carica papaya L.) Seedlings

High temperatures can interfere with plant metabolism and physiology, compromising productivity. One tactic to minimize the effects of heatwaves on agriculture is the use of bio-stimulants. This study evaluated two commercial products (Baltiko® and Acadian®) containing Ascophyllum nodosum in ‘Aliança’ papaya (Carica papaya L.) seedlings. Six doses (0, 1, 2, 3, 4, and 8 mL L−1) were applied weekly for four weeks at two distinct times, considering moderate and high temperatures. The results indicated distinct effects on gas exchange, seedling development, and nutrient content in leaves and roots. During the moderate temperature period, increasing doses enhanced gas exchange and aerial development, along with increases in potassium and boron levels in the leaves, while root growth decreased. Acadian® provided higher levels of boron in leaves and roots compared to Baltiko®. During the period of elevated temperature, increases were observed in leaf area, root dry mass, and leaf content of phosphorus, potassium, sulfur, and zinc, along with potassium in the roots. These increases were primarily attributed to the effects of the applied biostimulants. A lower dose (3 mL L−1) is recommended during mild temperatures, while a higher dose (6 mL L−1) is suggested for elevated temperatures.

The Dynamics, Degradation, and Afterlives of Pectins: Influences on Cell Wall Assembly and Structure, Plant Development and Physiology, Agronomy, and Biotechnology.

Pectins underpin the assembly, molecular architecture, and physical properties of plant cell walls and through their effects on cell growth and adhesion influence many aspects of plant development. They are some of the most dynamic components of plant cell walls, and pectin remodeling and degradation by pectin-modifying enzymes can drive developmental programming via physical effects on the cell wall and the generation of oligosaccharides that can act as signaling ligands. Here, we introduce pectin structure and synthesis and discuss pectin functions in plants. We highlight recent advances in understanding the structure-function relationships of pectin-modifying enzymes and their products and how these advances point toward new approaches to bridging key knowledge gaps and manipulating pectin dynamics to control plant development. Finally, we discuss how a deeper understanding of pectin dynamics might enable innovations in agronomy and biotechnology, unlocking new benefits from these ubiquitous but complex polysaccharides.

Characterization of LBD Genes in Cymbidium ensifolium with Roles in Floral Development and Fragrance

LBD transcription factors are critical regulators of plant growth and development. Recent studies highlighted their significant role in the transcriptional regulation of plant growth and metabolism. Thus, identifying the CeLBD gene in Cymbidium ensifolium, a species abundant in floral scent metabolites, could provide deeper insights into its functional significance. A total of 34 LBD genes were identified in C. ensifolium. These CeLBDs fell into two major groups: Class I and Class II. The Class I group contained 30 genes, while the Class II group included only 4 genes. Among the 30 Class I genes, several genes in the Ie branch exhibited structural variations or partial deletions (CeLBD20 and CeLBD21) in the coiled-coil motif (LX6LX3LX6L). These changes may contribute to the difficulty in root hair formation in C. ensifolium. The variations may prevent normal transcription, leading to low or absent expression, which may explain the fleshy and corona-like root system of C. ensifolium without prominent lateral roots. The expansion for CeLBDs was largely due to special WGD events in orchids during evolution, or by segmental duplication and tandem duplication. CeLBDs in different branches exhibit similar functions and expression characteristics. Promoter analysis enriched environmental response elements, such as AP2/ERF, potentially mediating the specific expression of CeLBDs under different stresses. CeLBDs were predicted to interact with multiple transcription factors or ribosomal proteins, forming complex regulatory networks. CeLBD20 was localized in the cytoplasm, it may act as a signaling factor to activate other transcription factors. CeLBD6 in Class II was significantly up-regulated under cold, drought, and ABA treatments, suggesting its role in environmental responses. Furthermore, metabolic correlation analysis revealed that its expression was associated with the release of major aromatic compounds, such as MeJA. These findings offer valuable insights for further functional studies of CeLBD genes in C. ensifolium.

Non-Targeted Metabolome Analysis with Low-Dose Selenate-Treated Arabidopsis

Selenate, the most common form of selenium (Se) in soil environments, is beneficial for higher plants. Selenate is similar to sulfate in terms of the structure and the manner of assimilation by plants, which involves the reduction of selenate to selenide and the replacement of an S moiety in the organic compounds such as amino acids. The nonspecific incorporation of seleno-amino acids into proteins induce Se toxicity in plants. Selenate alters the plant metabolism, particularly the S metabolism, which is comparable to the responses to S deficiency (−S). However, previous analyses involved high concentrations of selenate, and the effects of lower selenate doses have not been elucidated. In this study, we analyzed the metabolic changes induced by selenate treatment through a non-targeted metabolome analysis and found that 2 µM of selenate decreased the S assimilates and amino acids, and increased the flavonoids, while the glutathione levels were maintained. The results suggest that the decrease in amino acid levels, which is not detected under −S, along with the disruptions in S assimilation, amino acid biosynthesis pathways, and the energy metabolism, present the primary metabolic influences of selenate. These results suggest that selenate targets the energy metabolism and S assimilation first, and induces oxidative stress mitigation, represented by flavonoid accumulation, as a key adaptive response, providing a novel, possible mechanism in plant stress adaptation.

Bacillus subtilis inoculated in organic compost could improve the root architecture and physiology of soybean under water deficit.

Bacillus subtilis is known to promote root growth and improve plant physiology, while organic compost enhances soil water retention. This study explored the combined effect of inoculating B. subtilis in organic compost on soybean growth under water deficit. The treatments included chemical fertilization, non-inoculated organic compost, and organic compost inoculated with B. subtilis which were assessed under well-watered and water-deficit conditions. The organic compost inoculated with B. subtilis increased root biomass, length, volume, and the number of root tips under well-watered conditions, although it reduced root diameter. Under water deficit, the organic compost inoculated with B. subtilis increased root tip number (∼150%), biomass (∼95%) and number (∼85%) of nodules. Water deficit negatively affected soybean physiology, reduced photosynthesis, transpiration, and stomatal conductance, while increased internal CO₂ concentration. However, the organic compost inoculated with B. subtilis mitigated these effects, enhancing photosynthesis (∼20%) and water use efficiency (∼25%). Under water deficit, this treatment also increased shoot biomass by 15% and the drought tolerance index by 51% compared to the control. The combination of B. subtilis and organic compost improved root architecture, nodulation, and drought tolerance. These results suggest that B. subtilis inoculated in the organic compost is a promising strategy for enhancing soybean productivity and resilience under water stress, offering a novel approach to mitigating drought effects in agriculture.

Monitoring CO as a plant signaling molecule under heavy metal stress using carbon nanodots.

Carbon monoxide (CO) is widely recognized as a significant environmental pollutant and is associated with numerous instances of accidental poisoning in humans. However, it also serves a pivotal role as a signaling molecule in plants, exhibiting functions analogous to those of other gaseous signaling molecules, including nitric oxide (NO) and hydrogen sulfide (H2S). In plant physiology, CO is synthesized as an integral component of the defense mechanism against oxidative damage, particularly under abiotic stress conditions such as drought, salinity, and exposure to heavy metals. Current research methodologies have demonstrated a lack of effective tools for monitoring CO dynamics in plants during stress conditions, particularly in relation to heavy metal accumulation across various developmental stages. Therefore, development of a sensor capable of detecting CO in living plant tissues is essential, as it would enable a deeper understanding of its biological functions, underlying mechanisms, and metabolic pathways. In response to this gap, the present study introduces a novel technique for monitoring CO production and activity in plants using nitrogen-doped carbon quantum dots (N-CQDs). These nanodots exhibited exceptional biocompatibility, low toxicity, and environmentally sustainable characteristics, rendering them an optimal tool for CO detection via fluorescence quenching mechanism, with a detection limit (LOD) of 0.102 μM. This innovative nanomarker facilitated the detection of trace quantities of CO within plant cells, providing new insights into plant stress responses to heavy metals such as Cu, Zn, Pb, Ru, Cr, Cd, and Hg, as well as the processes involved in seed germination. Additionally, confocal microscopy validated the interaction between CO and N-CQDs, yielding visual evidence of CO binding within plant cells, further enhancing the understanding of CO's role in plant biology.

Positive impacts of typical desert photovoltaic scenarios in China on the growth and physiology of sand-adapted plants

Positive impacts of typical desert photovoltaic scenarios in China on the growth and physiology of sand-adapted plants

Effects of microbial biocontrol agents on tea plantation microecology and tea plant metabolism: a review

Effects of microbial biocontrol agents on tea plantation microecology and tea plant metabolism: a review

Effectiveness of Liquid Smoke Concentration of Red Fruit Seed Waste as A Bioherbicide on the Physiology and Yield of Moai Upland Rice by Intercropping with Black Soybeans in Jayawijaya District

Bioherbicide from red fruit seed waste and contains phenolic compounds. The objective are: 1) to analyze the effectiveness of red fruit seed waste on the physiology and yield of Moai upland rice; 2) to analyze which concentration of red fruit seed waste liquid smoke is most effective on the physiology and yield of Moai upland rice plants. The design used in this research was a Complete Randomized Block Design with two treatment factors, namely two factors intercropping Moai with black soybeans (T1), Moai rice monoculture (T2), and the second factor is: a) Concentration of 0 ml liquid smoke/l water (S0); b) Concentration of 200 ml liquid smoke/l water (S1); c) Concentration of 250 ml liquid smoke/l water (S2); d) Concentration of 300 ml liquid smoke/1 water (S3). Conclusion: 1) Liquid smoke from red fruit seed waste is effective on the net assimilation rate and growth rate of Moai; number of panicles, dry weight of 100 seeds, number of hollow seeds and number of pithy seeds of Moai; harvest index and chlorophyll content of Moai; 2) The most effective concentration of red fruit seed waste liquid smoke on the physiology and yield of Moai plants is the concentration of red fruit seed waste liquid smoke of 250 ml liquid smoke/l water (S2).

Effects of Deficit Irrigation on Growth, Yield, and Quality of Pomegranate (Punica granatum) Grown in Semi-Arid Conditions

Water scarcity, especially in countries like Egypt, is one of the biggest challenges facing agricultural development. Pomegranate (Punica granatum) is drought-resistant but only if the irrigation can be optimized. This can be a crucial approach toward the country’s agricultural development. The impact of deficit irrigation on pomegranate growth, yield, and overall fruit quality was observed during this study, which focused on two consecutive years from 2023 to 2024 at a private farm located in El Khatatba, Egypt. It was determined that deficit irrigation of pomegranate was able to achieve a high level of water productivity whilst also achieving a reasonable yield. Trees receiving moderate deficit irrigation had a yield decrease of 10% in comparison to full irrigation; however, this yield decrease did not have a huge overall impact because the level of water saved during the process made up for the reduced yield. Moreover, fruit soluble solids content (SSC) was high when trees received moderate deficit irrigation. Trees that were given severe deficit irrigation had the lowest fruit yields with less juice content, which limits targeted uses like the juice market. Still, these trees produced the highest SSC indicating that sugar becomes concentrated in the fruit when plants are water-stressed. In general, the most efficient treatment was moderate deficit irrigation as it balanced the yield and quality parameters with less water. The resulting data provide assurance that moderate deficit irrigation can be effectively and suitably implemented for pomegranate production in arid regions where water conservation and market quality standards must be satisfied in order to be economically viable. There is also a need to examine the longer-term effects of DI on economic sustainability, plant physiology, and soil biomes.

Exploring the Potential of Selenium-Containing Amine (Se-AMA) to Enhance Photosynthesis and Leaf Water Content: New Avenues for Carbonic Anhydrase Modulation in Arabidopsis thaliana.

Global changes and growing demands have led to the development of new molecular approaches to improve crop physiological performances. Carbonic anhydrase (CA) enzymes, ubiquitous across various life kingdoms, stand out for their critical roles in plant photosynthesis and water relations. We hypothesize that the modulators of human CAs could affect plant physiology. Our research demonstrated that foliar treatments with a synthetic selenium-containing CA activator (Se-AMA) influenced the physiological performances of Arabidopsis thaliana. Se-AMA increased net photosynthesis (A + 31.7%) and stomatal conductance (gs + 48.2%) at 100 µM, with the most notable effects after 10 days of treatment. Se-AMA at 300 µM proved to be even more effective, boosting A and gs by 19.9% and 55.3%, respectively, already after 3 days of application. Morning treatment with Se-AMA at 300 µM enhanced photosynthetic performances throughout the day, suggesting that the positive effect of Se-AMA lasted for several hours. Additionally, Se-AMA increased water content in plants by 17.1%, suggesting that Se-AMA treatment may have improved plant water absorption and resource management. This effect might be linked to Se-AMA's role in modulating specific CA isoforms working with aquaporins. Although preliminary, these findings suggest that Se-AMA could enhance plant physiological performances under the conditions of non-limiting water availability.