Plant Physiological Responses Research Articles

Advances in Plant Epigenetic Regulation of Abiotic Stress Response

With global climate change and increasing environmental pollution, plants are facing increasingly severe abiotic stresses, such as drought, salinization and heavy metal pollution. These stresses not only affect plant growth and development, but also pose a threat to agricultural production and ecosystem stability. In order to adapt to these unfavorable environments, plants have evolved a series of complex response mechanisms, among which epigenetic regulation, as an important means of regulation, has gradually attracted the attention of researchers. By modifying gene expression without modifying the DNA sequence, epigenetic control uses a variety of techniques, including DNA methylation, histone modification, and non-coding RNAs (ncRNA). These mechanisms are crucial for plant responses to abiotic stresses and can significantly enhance plant resistance and adaptive capabilities. DNA methylation can enhance plant resistance by controlling the expression of stress response-related genes; histone modification can regulate plant physiological responses by altering the structure of chromatin and affecting the accessibility of genes; and ncRNAs, especially microRNAs and siRNAs, can regulate plant physiological responses by targeting the expression of stress response-related genes. In-depth study of the role of plant epigenetic regulation in abiotic stress response is of great theoretical and practical significance for improving crop resistance and ensuring food security

Physiological and Biochemical Responses of Plants to Rooftop and Ground-level Conditions in Urban Green Spaces

An understanding of plant adaptation to rooftop environments is essential for improvising urban greening strategies; however, limited research has systematically examined the physiological and biochemical responses of plants at urban rooftops. This study addressed this gap by evaluating physiological and biochemical alterations of six herbaceous perennial species, Rosa hybrids, Murraya paniculata, Cestrum nocturnum, Pittosporum tenuifolium, Duranta, and Hibiscus rosa sinensis, cultivated in an intensive rooftop garden environment vs. optimal ground conditions. These species, acclimatized to the local climate of Pakistan, were assessed to determine the transpiration rate, photosynthetic rate, chlorophyll contents, and respiration rate using on-site measurements and standardized leaf tissue analyses. The results demonstrated significant differences in physiological and biochemical parameters between rooftop and ground-level plants. Seasonal variations and elevation profoundly influenced plant physiology and significant biochemical alterations observed in response to rooftop conditions. Photosynthetic and transpiration rates were reduced by up to 30% in winter under low light conditions, while summer conditions led to a 25% increase in transpiration rates for rooftop plants. Ground-level plants exhibited the highest respiration rates during the summer season. A leaf analysis revealed that rooftop-grown plants exhibited higher pH levels and 15% increased chlorophyll and ascorbic acid contents but 20% lower water use efficiency compared with their ground-level counterparts. Despite this, rooftop plants showed a 10% higher air pollution tolerance index. Pearson’s correlation analysis confirmed a strong positive relationship between most biochemical parameters and physiological activities with increased elevation, except for relative water content, which exhibited a negative correlation under rooftop conditions. The results indicated that those plants on rooftops exhibited reduced water use efficiency compared with that of ground-level plants undergoing distinct physiological and biochemical adaptations and showed more resilience to the pollution index in response to urban rooftop conditions. These findings provide new insights into plant adaptability in urban environments and can transform future strategies for sustainable urban greening and species selection in roof garden systems.

Elevated CO2 alleviates negative impacts of high temperature and salinity on phytohormones, photosynthesis, and redox reactions in leaves of Caragana korshinskii kom.

In this research, we sought to investigate how high temperature, salinity, and CO2 affect endogenous phytohormones, photosynthesis, and redox homeostasis in Caragana korshinskii Kom (C. korshinskii) leaves, as well as to comprehensively evaluate the plant's physiological response to multiple environmental stressors. The elevated temperature (e[T]), elevated Na+ (e[Na]), and elevated temperature and Na+ (e[T-Na]) treatments increased abscisic acid (ABA) and reduced zeatin-riboside (ZR), indole-3-acetic acid (IAA), and gibberellic acid (GA3). These changes induced stomatal closure, and the subsequent reduction in photosynthetic rate triggered the generation of superoxide anion (O2·-) and hydrogen peroxide (H2O2). In response, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activity increased, and free proline and total soluble sugars were accumulated. However, membrane lipid peroxidation was still aggravated. Under elevated CO2 (e[CO2]), the dramatic hormonal fluctuations and photosynthetic inhibition resulting from e[T], e[Na], and e[T-Na] were alleviated. Moreover, e[CO2] reduced ROS generation caused by e[T], e[Na], and e[T-Na], and stabilized antioxidant enzyme activities and non-enzymatic compound concentrations. Compared with e[T], e[Na], and e[T-Na], the increased malondialdehyde (MDA) content was effectively alleviated under elevated CO2 and temperature (e[CO2-T]), elevated CO2 and Na+ (e[CO2-Na]), and elevated CO2, temperature, and Na+ (e[CO2-T-Na]). Overall, our research suggest that e[CO2] may alleviate the negative impacts of e[T] and e[Na] on plant physiology.

Impact of tryptophan on physiological and histological responses of pepper plants under salt stress

Salt stress is a significant abiotic stressor adversely affecting plant functions. Tryptophan, a precursor to IAA, plays a crucial role in plant growth under such stress. This study investigated the effects of different tryptophan doses (L-tr) on young pepper plants subjected to salt stress. Preceding salinity stress, three L-tr doses were administered to plant roots, excluding control and salt applications. Subsequently, all plants except controls received 150 mM salinity (NaCl) during irrigation. The experiment concluded after 35 days post-salinity treatment. Significant variations were noted in histological (cortex and cell diameters, xylem and midrib diameters, epidermis thickness) and physiological (leaf water content, membrane permeability, chlorophyll and carotenoid concentrations, total phenolic content) parameters among treatments. Evaluation of these parameters revealed L-tr’s positive impact on osmotic regulation. L-tr applications increased xylem, midrib, and cortical cell diameter, cortex, and epidermis thickness compared to salt stress, while cortical cell number also decreased. Particularly, NaCl + L-tr 100 µM treatment exhibited a 25% increase in xylem conduit diameter, a 30% increase in midrib diameter, and a significant 15% increase in epidermis thickness compared to controls. Overall, NaCl + L-tr 100 µM treatment displayed values closest to controls across various parameters. This study suggests the potential utility of L-tr in mitigating salinity stress in pepper plants.

Vicia faba overcomes drought stress by spraying with Xerophytic Anabasis setifera extract

Drought stress is a prevalent environmental factor significantly impacting the faba bean (Vicia faba L.) crop. Anabasis setifera, a plant extract (ASE), has been found to potentially regulate plant responses to drought stress for the first time. The study examined the effects of applying an exogenous ASE on the physiological, biochemical, and yield responses of faba bean plants under three soil water regimes: well-watered (8-day irrigation intervals), moderate drought stress (12-day irrigation intervals), and severe drought stress (16-day irrigation intervals). The HPLC analysis of ASE revealed that it contains major phenolic compounds such as rutin, chlorogenic acid, gallic acid, ferulic acid, and coumaric acid. The extract also contains catechin, quercetin, syringic acid, pyro catechol, and methyl gallate. The study found that faba bean plants showed enhanced drought resistance after treatment with ASE. This treatment improved growth parameters like shoot and root length, fresh and dry weight, leaf and flower number, and reduced the negative impacts of drought stress on chlorophyll levels and metabolic activities. The study indicates that plants treated with ASE, including catalase, peroxidase, and polyphenol oxidase, can significantly mitigate drought stress effects, improve yield trials, and enhance seed components, making it cost-effective and ecologically beneficial.

Antioxidant Response of Vicia faba Plant to Foliar Spray of Green Synthesis Zirconium Oxide Nanoparticles

Previous studies have reported a positive influence of zirconium oxide nanoparticles on plants, the present effort was conducted to investigate the impact of two distinct concentrations of biosynthesized zirconium oxide nanoparticles (75 and 150 mg L-1) on the physiological and antioxidant responses of Vicia faba Plants. Zirconium oxide nanoparticles (ZrO2NPs) were synthesized using Matricaria chamomilla L. plant extracts. And their morphology and extent were determined Using X-Ray Diffraction and Transmission electron microscopy The diffuse reflectance spectra were measured using UV-Vis spectroscopy, the response of V. faba plants to foliar sprays regarding concentrations of (0, 75 and 150 Mg / l-1) M-ZrO2NPs was studied. The largest concentrations of chlorophyll a and b, carotenoids. Total pigments were documented in plants receiving 75mg / l-1 of M-ZrO2NPs associated to the control, secondary metabolite (Phenolics, Flavonoids, and Tannins) were gathered in response to M-ZrO2NPs treatment Glycosides, Terpenoid, Alkaloids (Mayer reagent) and Fuocoumarins. Moreover Tannins, Resins and Saponins, in addition to the levels of enzymatic and non-enzymatic antioxidants, rose by about two-fold in plant exposed to M-ZrO2NPs compared to control plants. The nitrogen, phosphorus, the contents of bean plants in terms also potassium, calcium, zinc, iron were noted in response to two applied quantities of M-ZrO2NPs. Spraying shrubberies by 75 Mg /l-1 of M-ZrO2NPs promoted plant development in addition to the buildup of antioxidants, osmolytes, and secondary metabolites that can help plants cope with the harmful consequences of environmental stress.

Photosynthetic responses to temperature across the tropics: a meta-analytic approach.

Tropical forests exchange more carbon dioxide (CO2) with the atmosphere than any other terrestrial biome. Yet, uncertainty in the projected carbon balance over the next century is roughly three-times greater for the tropics than other ecosystems. Our limited knowledge of tropical plant physiological responses, including photosynthetic, to climate change is a substantial source of uncertainty in our ability to forecast the global terrestrial carbon sink. We used a meta-analytic approach, focusing on tropical photosynthetic temperature responses, to address this knowledge gap. Our dataset, gleaned from 18 independent studies, included leaf-level light saturated photosynthetic (Asat) temperature responses from 108 woody species, with additional temperature parameters (35 species) and rates (250 species) of both maximum rates of electron transport (Jmax) and Rubisco carboxylation (Vcmax). We investigated how these parameters responded to mean annual temperature (MAT), temperature variability, aridity, and elevation, as well as also how responses differed among successional strategy, leaf habit, and light environment. Optimum temperatures for Asat (ToptA) and Jmax (ToptJ) increased with MAT but not for Vcmax (ToptV). Although photosynthetic rates were higher for "light" than "shaded" leaves, light conditions did not generate differences in temperature response parameters. ToptA did not differ with successional strategy, but early successional species had ~4 °C wider thermal niches than mid/late species. Semi-deciduous species had ~1 °C higher ToptA than broadleaf evergreen. Most global modeling efforts consider all tropical forests as a single "broadleaf evergreen" functional type, but our data show that tropical species with different leaf habits display distinct temperature responses that should be included in modeling efforts. This novel research will inform modeling efforts to quantify tropical ecosystem carbon cycling and provide more accurate representations of how these key ecosystems will respond to altered temperature patterns in the face of climate warming.

Respostas fisiológicas de <i>Theobroma cacao</i> L. submetidas ao alagamento por longos períodos

The aim of this study was to evaluate the physiological responses of cocoa plants (Theobroma cacao L.) subjected to water stress under flooding in different periods. The study was conducted in a greenhouse at the Capixaba Institute for Research, Technical Assistance and Rural Extension (INCAPER), located in Linhares-Es. The cultivars used for Theobroma cacao L. were cocoa varieties CCN 51 and TSH 1188, the first being used as a scion and the second as a rootstock. The experiment was carried out with cocoa seedlings under stress in a flooded environment, arranged in buckets and submerged in water, under different time conditions. Readings were taken at 0, 1, 2, 4 and 8 days of flooding. Measurements of net CO2 assimilation, stomatal conductance, transpiration and water use efficiency were performed, all using IRGA. The treatment 2 days after flooding did not differ from the control treatment (without flooding), while in the treatment 4 DAA there was a reduction in the net CO2 assimilation content. Plants flooded for 8 days showed lenticel growth, showing an attempt to alleviate environmental conditions. There was no interference by flooding in the PI and PII photosystems; the photosynthetic apparatus remained stable.

Rainfall fluctuation causes the invasive plant Prosopis juliflora to adapt ecophysiologically and change phenotypically.

Understanding the impact of rainfall variability on the ecophysiology of invasive plants in tropical grasslands is crucial for sustainable ecosystem management. Climate change alters rainfall patterns, which, in turn, may influence the functional traits and physiological responses of plants. Recent studies have explored how fluctuating precipitation affects plant growth and broader ecological dynamics. In this study, we examined these effects on Prosopis juliflora under three different rainfall treatments using rainout shelters: low rainfall (LR, 500mm, 50% less than ambient), normal rainfall (NR, 1000mm, representing average ambient rainfall), and high rainfall (HR, 1400mm, 40% more than ambient). Each shelter was divided into three replicate plots (2m x 2m) in a randomized block design. P. juliflora seedlings (20 seedlings per subplot) were transplanted into each subplot within a 4m2 area, with a 0.5m distance between each plant, and data were collected one year after plot establishment (2020). The physiological parameters measured included leaf traits, growth metrics such as biomass, height, diameter, photosynthetic rate, leaf area (LA), specific leaf area (SLA), leaf carbon (LC), the leaf carbon-to-nitrogen (C/N) ratio, and the root-to-shoot ratio. These parameters showed significant positive responses to changes in precipitation i.e. increase with the increase in rainfall. However, water use efficiency (WUE), leaf nitrogen (LN), leaf dry matter content (LDMC), and root length (RL) showed negative responses i.e. decrease with the increase in rainfall and were highest in the LR plots. Our findings suggest that the ecophysiology and functional traits of P. juliflora are strongly influenced by rainfall variability. The species exhibits considerable phenotypic plasticity, thriving in both drought and elevated precipitation conditions. This adaptability has important implications for its invasive potential and the overall functioning of ecosystems under shifting climatic conditions.

Effects of Ferrous Iron Toxicity on Growth, Biochemical Alterations and Enzymatic Antioxidant Status in Capsicum annuum L

Ferrous iron toxicity is the most important problem of heavy metal research due to its widespread environmental occurrence and its harmful effects on plant growth and metabolism. Evaluating the impact of ferrous iron induced toxicity provides valuable insights into the biochemical and physiological responses of plants, including alterations in growth parameters, nutrient content and antioxidant defense systems. This study is aimed to investigate the effects of ferrous iron toxicity on growth, biochemical alterations and enzymatic antioxidant status in Capsicum annuum L. Experimental Capsicum annuum plants were divided into 4 groups. Group 1 served as control, received normal nutrients and water, while Groups 2, 3 and 4 were treated with increasing concentrations of ferrous iron 100, 200 and 400 mg respectively. The results demonstrated that ferrous iron significantly reduced several growth parameters, including germination percentage, root length, shoot length, fresh weight, dry weight and vigour index. Moreover, higher concentrations of ferrous iron led to a decrease in carbohydrate and protein levels, as well as reduction in the activities of important enzymic antioxidants such as catalase and superoxide dismutase indicating a weakened oxidative defense system. The findings highlight the harmful effects of ferrous iron toxicity in Capsicum annuum, underscoring the potential risks to agricultural productivity. This research not only deepens our understanding of ferrous iron induced toxicity but also emphasizes the necessity to developing strategies to protect crops from metal toxicity, ensuring sustainable agriculture and food security in contaminated environments.

Causal determinism by plant host identity in arbuscular mycorrhizal fungal community assembly

Abstract An assumption in ecology is that plant identity plays a central role in the assembly of root‐colonising arbuscular mycorrhizal (AM) fungal communities. While numerous correlational studies support this notion, with evidence of host selectivity among fungal taxa and host‐specific responses to different AM fungi, empirical demonstrations of host‐driven AM fungal community assembly remain surprisingly limited. We conducted a factorial experiment growing two globally significant crop species, wheat (Triticum aestivum) and sorghum (Sorghum bicolor), with a common pool of AM fungal species, or without AM fungi. We hypothesised strong differences in AM fungal community structure between the two species driven by strong habitat filtering. Plants were harvested at two time points in which we analysed the community structure of AM fungi in the roots, the phylogenetic diversity, and interactions with plant physiological responses. As we expected, there were distinct trajectories in both the composition and phylogenetic diversity of AM fungal communities between the two host plants through time. However, the effect of habitat filtering during community assembly differed between the two species. In sorghum roots, AM fungal communities exhibited increased richness and became more phylogenetically clustered over time. This shift suggests that community assembly was primarily driven by habitat filtering, or selectivity, imposed by the host which was accompanied by significant increases in plant mycorrhizal growth (from 11.83% to 43.67%) and phosphorus responses (from −0.6% to 43.3%). In contrast, AM fungal communities in wheat displayed little change in diversity, remained phylogenetically unstructured, and provided minimal benefits to the host, indicating a more stochastic assembly process with a stronger influence of competitive interactions. As the field looks to understand what determines the distribution of AM fungi and their community composition while simultaneously seeking to utilise AM fungi for ecosystem benefits, it is important to know the extent to which host identity can influence fungal assembly within plant roots. Our results provide empirical support of host‐determinism in AM fungal community assembly and suggest that this determinism is associated with the growth and nutrient benefits provided by the symbiosis to plants. Read the free Plain Language Summary for this article on the Journal blog.

Smart agriculture: utilizing machine learning and deep learning for drought stress identification in crops

Plant stress reduction research has advanced significantly with the use of Artificial Intelligence (AI) techniques, such as machine learning and deep learning. This is a significant step toward sustainable agriculture. Innovative insights into the physiological responses of plants mostly crops to drought stress have been revealed through the use of complex algorithms like gradient boosting, support vector machines (SVM), recurrent neural network (RNN), and long short-term memory (LSTM), combined with a thorough examination of the TYRKC and RBR-E3 domains in stress-associated signaling proteins across a range of crop species. Modern resources were used in this study, including the UniProt protein database for crop physiochemical properties associated with specific signaling domains and the SMART database for signaling protein domains. These insights were then applied to deep learning and machine learning techniques after careful data processing. The rigorous metric evaluations and ablation analysis that typified the study’s approach highlighted the algorithms’ effectiveness and dependability in recognizing and classifying stress events. Notably, the accuracy of SVM was 82%, while gradient boosting and RNN showed 96%, and 94%, respectively and LSTM obtained an astounding 97% accuracy. The study observed these successes but also highlights the ongoing obstacles to AI adoption in agriculture, emphasizing the need for creative thinking and interdisciplinary cooperation. In addition to its scholarly value, the collected data has significant implications for improving resource efficiency, directing precision agricultural methods, and supporting global food security programs. Notably, the gradient boosting and LSTM algorithm outperformed the others with an exceptional accuracy of 96% and 97%, demonstrating their potential for accurate stress categorization. This work highlights the revolutionary potential of AI to completely disrupt the agricultural industry while simultaneously advancing our understanding of plant stress responses.

Effect of coexisting nutrient divalent cations on cadmium transport in soil-herbal crop systems

Cadmium (Cd) pollution in Chinese herbal medicines poses a serious risk to medication safety. Regulating Cd uptake, transport, and accumulation in plants through ion-ion interactions offers a novel, environmentally sustainable, and practical approach to address this issue. However, the effects and underlying mechanisms of coexisting divalent cations zinc (Zn), magnesium (Mg), and manganese (Mn) on Cd uptake by Ligusticum sinense cv. Chuanxiong (L. chuanxiong) have not been comprehensively studied or well understood. In this study, the application of coexisting these cations (Zn, Mg, Mn) could significantly promote the growth of L. chuanxiong (21.11%–36.04%) and change the mobility of Cd in the soil-crop system. Specifically, adding Zn decreased Cd content in soil and plants by 18.23% and 20.62%, respectively, while Mg increased it by 10.99% and 62.27%. Mn addition, however, had no significant effect. Similar trends in soil enzyme activity were also observed with Zn, Mg, and Mn treatments. Simultaneously, the findings explore how coexisting divalent cations influence plant physiological responses, including photosynthesis and antioxidant capacities, enabling L. chuanxiong to better manage Cd stress. This study underscores the potential of ion-to-ion interactions as an effective approach to mitigate Cd accumulation, offering a practical and sustainable solution for enhancing the safety of Chinese herbal medicines. Additionally, the effects of mixed cation applications on Cd dynamics are complex, shaped by interactions between ion types, dosages, and their specific properties. These insights provide a foundation for developing more effective remediation strategies for Cd-contaminated soils, particularly in the cultivation of medicinal plants.

Integrating Solar Induced Fluorescence with High Throughput Plant Screening for Advanced Phenotyping of plants

There is an urgent need to address the escalating impacts of climate change, particularly the exacerbation of drought conditions, which pose significant threats to global food security and agricultural sustainability. Innovative solutions are imperative, and one such solution involves integrating advanced technologies like the "PlantArray" system to monitor and enhance plant physiological responses to water scarcity. The "PlantArray" system enables the precise measurement of critical whole-plant physiological traits such as transpiration rate, canopy stomatal conductance (Gs canopy), and growth rate with an exceptional spatiotemporal resolution. Augmenting this system with photosynthesis measurements offers an additional layer of information, facilitating a more focused interpretation of the system parameters. To overcome the limitations of single-leaf photosynthesis measurement techniques, this study employs a remote sensing approach to rapidly scan numerous samples at multiple time points, revealing insights into drought stress responses of S. licopersicum lines. An ultra-spectral spectroradiometer mounted on a mobile cart was positioned above an experimental matrix comprising drought-stressed S. licopersicum obsolete and mutagenic lines. Our findings reveal that the vegetation index PRI exhibited greater sensitivity to drought stress compared to other vegetation and photosynthesis remote sensing indices. Photosynthesis indices demonstrated increased sensitivity to daily biomass accumulation and served as predictors of final plant yield. Interestingly, Solar-Induced Fluorescence (SIF) parameters, solely indicative of photosynthesis-emitted fluorescence, exhibited no correlation with stress levels or final biomass production. This study articulates the potential to monitor plant responses to agricultural stressors through real-time physiological tracking across complete diel cycles, thereby enriching our understanding of plant-environment interactions. Ultimately, this integrated system shows promise in screening and developing crop cultivars with ideal physiological and photosynthetic traits, vital to cultivating resilient crops in extreme droughts and weather conditions.

Integrating conspecifics negative density dependence, successional and evolutionary dynamics: Towards a theory of forest diversity

Tree successional diversity is evident even to casual observers and has a well-understood physiological basis. Various life history trade-offs, driven by interspecific variation in a single trait, help maintain this diversity. Conspecific negative density dependence (CNDD) is also well-documented and reduces tree vital rates independently of succession strategies. The CNDD hypothesis is frequently justified by specialist natural enemies at a separate trophic level. We integrate these processes into an analytical demographic model, spanning short-term plant physiological responses to the dynamics of a large forest mosaic connected to a metacommunity. Surprisingly, multiple trade-offs do not necessarily increase diversity, as suboptimal trait combinations lead to strategies that cannot compete for successional niches, explaining the weak correlation between functional traits and succession position. Succession alone can sustain half of the species in the metacommunity, with diversity increasing linearly with CNDD strength. The steeper increase with larger metacommunities suggests CNDD plays a greater role in tropical forests. However, if each successional type contains multiple equivalent species, CNDD maintains diversity but becomes less effective in promoting successional diversity, consistent with some tropical forests being less successional diverse. Additionally, CNDD enhances the likelihood of successful speciation and shifts life-history trait frequency by affecting more late-successional species.

Rhizosphere Cercozoa reflect the physiological response of wheat plants to salinity stress

Rhizosphere Cercozoa reflect the physiological response of wheat plants to salinity stress

Low-cost nano biochar: a sustainable approach for drought stress mitigation in faba bean (Vicia faba L.).

This study tends to reach some objectives of the sustainable development goals, which call for responsible consumption and production and climate action. Long-term global food security is affected by drought and the optimal use of water in agricultural areas under climate change scenarios. Our approach aims to amend soil for cultivation under drought stress and improve plant growth to contribute to food security. In this context, a biochar was prepared from peanut shell and thoroughly examined as a soil enhancer for broad bean cultivation during drought stress. The produced biochar exhibited 0.307 g cm-3 bulk density, 9.6 cmol kg-1 cation exchange capacity, -15.5 mV zeta potential, and an average diameter of 21.86 nm. Surprisingly, the application of biochar increased soil water holding capacity and organic matter by 66% and 220%, respectively. Moreover, its application under drought improved plant growth as indicated by stem height, leaf area index, pod number/plant, pod weight, protein level, chlorophyll content, nutrient levels in leaves, and reduced lipid peroxidation and electrolyte leakage. The principal component and factorial analysis of the current study demonstrated correlations between the physiological response of faba bean plants and soil physiochemical parameters after the application of peanut shell-derived biochar. This study presents promising nano biochar that could be an effective sustainable practice for disposing residual materials.

Physiological changes in shrub species due to different sources of dust pollution in an urban environment.

Plants effectively filter ambient air by adsorbing particulate matter. The correct selection of landscape plants can exert greater dust retention benefits in different polluted areas. However, few studies have focused on the dust retention ability and related physiological responses of plants under continuous dust pollution from different dust sources. Here, we assessed the particle retention dynamics and plant physiology (chlorophyll content, soluble protein content, soluble sugar content, and peroxidase activity) of six shrubs (Berberis thunbergii var. atropurpurea, Ligustrum vicaryi, Rosa multiflora, Sorbaria sorbifolia, Swida alba, and Syzyga oblata) under continuous dust pollution from different dust sources (industrial sources: area below the direction of the coal-fired thermal power plant in Chengyang District, Qingdao, China; traffic sources: both sides of the road in each direction at the intersection of Great Wall Road and Zhengyang Road, Chengyang District, Qingdao, China; clean sources: Qingdao Agricultural University Campus, Qingdao Olympic Sculpture Park). The results showed that R. multiflora had the highest dust retention per unit leaf area of 3.27 ± 0.018g·m-2 and 2.886 ± 0.02g·m-2 in the experimental treatments of fuel source dust and clean source dust, respectively. The chlorophyll content of the tested shrubs significantly decreased due to the influence of dust treatment time, the range of cellular osmoregulatory substances (soluble sugars, soluble proteins, proline) tended to first increase and then decrease, and the antioxidant enzyme activities (superoxide dismutase, peroxidase) tended to increase and then decrease after continuous dust treatment. The greatest physiological changes were observed in plants within the industrial dust treatment area. The peroxidase activity and chlorophyll could be used as sensitive indicators of dust pollution in plants. R. multiflora showed better resistance to dust and had a greater dust retention capacity than other shrubs, making it more suitable for planting as a greening tree in industrial and traffic-polluted areas. S. alba and S. sorbifolia are sensitive to dust pollution, so they can be used as sensitive tree species to indicate atmospheric dust pollution. Our results may help design a feasible approach for urban shrub greening.

Physiological and biochemical response of AtEXPA1 transgenic tobacco plants to salinity stress

Physiological and biochemical response of AtEXPA1 transgenic tobacco plants to salinity stress

Plants Under Stress: Exploring Physiological and Molecular Responses to Nitrogen and Phosphorus Deficiency.

Nitrogen (N) and phosphorus (P) are essential mineral macronutrients critical for plant structure and function. Both contribute to processes ranging from cellular integrity to signal transduction. Since plants require these nutrients in high concentrations, replenishing them in soil often involves chemical fertilizers. However, the main source of P, rock phosphate, is non-renewable and in decline. N, second only to carbon, oxygen, and hydrogen in plant requirements, is vital for synthesizing proteins, nucleic acids, and plant pigments. Although N is available to plants through biological fixation or fertilizer application, the frequent application of N is not a sustainable solution due to environmental concerns like groundwater contamination and eutrophication. Plants have developed sophisticated mechanisms to adapt to nutrient deficiencies, such as changes in root architecture, local signaling, and long-distance signaling through the phloem. A dual deficiency of N and P is common in the field. In addition to individual N and P deficiency responses, this review also highlights some of the most recent discoveries in the responses of plants to the combined N and P deficiencies. Understanding the molecular and physiological responses in plants to mineral deficiency will help implement strategies to produce plants with high mineral use efficiency, leading to the reduced application of fertilizers, decreased mineral runoff, and improved environment.