Physiological Analysis Research Articles

Azolla pinnata and Lemna minor as comparative hyperaccumulators for livestock wastewater treatment: morpho-physiological and genetic approach.

The potential of two different aquatic macrophytes, Azolla pinnata R.Br. and Lemna minor L., to treat livestock wastewater through phytoremediation was investigated. The physiological analysis includes the removal efficiency of manganese (Mn) from livestock wastewater by AAS. Morphological observation was performed by using a scanning electron microscope (SEM) and visual observation. RAPD analysis was applied to observe the DNA profile. It was observed that the removal efficiency of Mn was higher in L. minor with a 92% removal rate, while in A. pinnata RE, it was at a 77% rate. The higher removal rate of Mn by L. minor showed that plants had a significant impact on the removal of heavy metals, with a p ≤ 0.05. Retention time and the removal of heavy metals were found to be positively correlated. As early as 24h after exposure to livestock wastewater (LW), the stomata on the leaves of A. pinnata and L. minor have both shrunk, and the root surfaces have shortened. According to the RAPD analysis, A. pinnata only shows an increase in band intensities and no polymorphism, whereas L. minor has 19% polymorphisms that indicate higher tolerance as hyperaccumulators. As a conclusion, L. minor showed no signs of necrosis and performed more efficiently as a hyperaccumulator in LW, with a higher removal efficiency.

Physiological and transcriptomic analysis provide new insights into the mechanisms regulating the maintenance of postharvest quality of goji berry fruit in response to 1-MCP

Physiological and transcriptomic analysis provide new insights into the mechanisms regulating the maintenance of postharvest quality of goji berry fruit in response to 1-MCP

An integrated quality, physiological and transcriptomic analysis reveals mechanisms of kiwifruit response to postharvest transport vibrational stress

An integrated quality, physiological and transcriptomic analysis reveals mechanisms of kiwifruit response to postharvest transport vibrational stress

Grapevine and maize: Two guard cell shaped strategies to cope with repeated drought stress

Adaptation of crops to recurrent drought stress is crucial for maintaining agricultural productivity and achieving food security under changing climate. Guard cells, pivotal regulators of plant water usage and assimilation, are central to this adaptation process. However, the metabolic dynamics of guard cells under drought stress remain poorly understood, particularly in grapevine, a prominent crop grown in arid regions, and maize, a staple crop with substantial water requirements. In this study, differences in guard cells metabolism during drought stress of grapevine and maize were investigated by performing physiological and metabolomic analyses. Metabolomic analysis highlighted differential responses in amino acids and sugars, with grapevine guard cells displaying greater stability in amino acid and sugar signatures, while maize showed marked increases in sugar levels. These findings suggest two distinct adaptive strategies, a vigorous acclimation of guard cells, as observed in maize, and an attenuated acclimation of guard cells, shown in grapevine. Understanding these metabolic adjustments is helpful for enhancing drought resilience in agricultural systems.

Integrative transcriptome and metabolome analyses reveal the mechanism of melatonin in delaying postharvest senescence in cowpeas

Rapid postharvest senescence and quality deterioration severely limit logistics of cowpeas. Melatonin (MEL) is a pivotal bioactive molecule that can modulate multiple physiological attributes in plants. In this study, physiological, transcriptomic and metabolomic analyses were conducted to explore the effects of exogenous MEL on cowpea senescence and its underlying mechanisms. Physiological results showed that 100 μM MEL treatment maintained sensory quality (greeness, firmness and soluble solids content), reduced weight loss as well as inhibited the degradation of chlorophyll (Chl) and protopectin. Preservation of color and firmness in cowpeas was greatly attributed to inhibition of expression of genes related to Chl and cell wall metabolism, which was based on a transcriptomic analysis. Integrated transcriptomic and metabolomic analyses revealed that MEL promoted transcription of genes associated with amino acid and carbohydrate metabolism, resulting in the accumulation of amino acid and sugar metabolites. Additionally, by integrating transcription factor-binding site analysis with cis-acting element analysis, we constructed a regulatory network of transcription factors underlying MEL-mediated antisenescence. The present study found a series of potential candidate genes and metabolites involved in regulating senescence process and provided an insight into improving postharvest quality of cowpeas.

Integrated analysis of physiology, antioxidant activity and transcriptomic of Lactobacillus plantarum 120 in response to acid stress

This research examined the effects of acid stress on the physiological and antioxidant activity of Lactobacillus plantarum 120 (Lp-120) and explored its underlying mechanisms. The results revealed that the survival rates of the strain significantly decreased as the pH decreased from 5.5 to 4.5. Meanwhile, the ATP concentrations of the strain decreased from 0.51 to 0.12, and the reactive oxygen species levels rose 1.26-fold with a decrease in pH. However, as the pH decreased, the free radical (DPPH, O2−, and OH−) scavenging activity, reducing power, superoxide dismutase, glutathione peroxidase activities, and the total antioxidant capacities of Lp-120 all increased (P<0.05). Among them, the DPPH scavenging power and superoxide radical scavenging power reached the highest value of 35.5% and 30.74% respectively at pH 4.5, and the hydroxyl radical scavenging power reached the highest value of 53.2% at pH 5.0, which indicated that appropriate acid stress could improve the antioxidant activities of the strain. Transcriptomics data showed that the expression levels of genes (ndh, trxA, etc.) were upregulated (0.39-10.54-fold) under acid stress, which related to the “NADH oxidase/ NADH peroxidase” system, glutaredoxin system and thioredoxin system. Taken altogether, this study brought valuable insights for enhancing the antioxidant activities of Lp-120 and provided valuable information on the application of Lactobacillus plantarum as antioxidant starter cultures in fermented foods.

A World of Pain

When we undertake the project of a phenomenology of pain, and even a deconstruction of the experience of pain, we discover that pain is not merely something that is felt by a subject, but rather pain—and chronic pain, especially—causes the subject to live in a new world. This essay is an investigation of that world. Moving from questions of mind/body dualism to whether or not pains are subjective representations of some material-physical state of the body, a philosophical and physiological analysis of pain is undertaken in an attempt to show how a world of pain emerges and then functions once established. Along the way, issues concerning the measurement of pain, the value of pain, the mystery of the phantom limb in pain, the use of placebos to treat pain, and the question of whether or not pain is necessarily a private experience are taken up, ultimately leading to the conclusion that an established world of pain can usher in a collapse of the distinction between subjects and their pain such that chronic pain sufferers might meaningfully be said to become their pain.

Metabolomic and Transcriptomic Analysis Revealed the Maturation Mechanism of White-Fleshed Strawberry

Strawberry (Fragaria ananassa) is a widely grown horticultural crop, which exists in red, yellow, and white varieties. In recent years, the white-fleshed strawberry variety is gaining more attention from consumers for its unique taste and appearance, but a comprehensive understanding of the molecular processes governing the ripening of white-fleshed strawberry remains undisclosed. In this study, based on the joint analysis of physiology, metabolome, and transcriptome, we screened and identified the key metabolites that were highly correlated to the maturation of white-fleshed strawberry (cv. ‘snow white’, SW for short) fruits. In contrast to red-fleshed strawberries, SW fruits exhibited three main ripening stages during the maturation, accompanied by the increases in total soluble solid and total sugar and the declines in total anthocyanin and total acid. Metabolomic analysis identified 832 differential accumulated metabolites (DAMs) at the secondary level of LC-MS/MS, and further investigations suggested that the increase in sucrose, citric acid, and epicatechin levels potentially play a role in the ripening process of SW fruits. Furthermore, abscisic acid and methyl jasmonate were recognized as the primary phytohormones involved in the production of these metabolites. The enrichment analysis of RNA-Seq data revealed that the differential expressed genes (DEGs) were primarily attributed to the pathways of ‘Starch and sucrose metabolism’ and ‘Plant hormone signal transduction’ but were undetected in ‘Flavonoid biosynthesis’ at the late ripening stage. Moreover, the de novo biosynthesis pathway, WGCNA, and Pearson correlation analysis indicated a direct relationship between FaSPS1, FaSPP1, and FaSPP2 with sucrose, FaPEPC1, FaV-PPase2, and FaV-PPase3 with citric acid, and Fa4CL2, Fa4CL3, and FaANR1 with anthocyanin. Further analysis revealed a co-expression of MYBs, bHLHs, NACs, and WRKYs with the structural genes mentioned. Overall, our findings uncovered a molecular mechanism regulating the maturation of white-fleshed strawberry, providing valuable insights for enhancing the flavor of white-fleshed strawberry through the gene-editing technique.

Anthocyanin accumulation enhances drought tolerance in purple-leaf Brassica napus: transcriptomic, metabolomic, and physiological evidence

Anthocyanins are flavonoid compounds that provide plants with various advantages, including resistance to abiotic stress, pollinator attraction, and antioxidant properties. The present study aimed to investigate the impact of anthocyanin accumulation on drought tolerance in two genotypes of Brassica napus; purple-leaf (PL) and green-leaf (GL). Transcriptomic, metabolomic, and physiological analyses were conducted under drought conditions induced by polyethylene glycol (PEG-6000) for 4 and 8 days, with an additional evaluation after 4 days of re-watering. After drought stress, the PL genotype showed higher anthocyanin content, relative water content, and total soluble sugar compared to the GL genotype. Furthermore, the PL genotype exhibited reduced levels of reactive oxygen species, higher antioxidant enzyme activities, and less damage to the chloroplast ultrastructure than the GL genotype. These results indicate that the PL genotype shows significant advantages over GL, demonstrating improved water holding capability and stress tolerance. Moreover, under mild drought and re-watering conditions, the PL genotype of B. napus exhibited significant upregulation of structural genes expression associated with the biosynthesis of flavonoids. These correlate with increased anthocyanin content, particularly cyanidin glycosides and flavanols. The PL genotype showed greater gene expression related to flavonoid biosynthesis, particularly anthocyanin production, compared to GL. Alongside, PL accumulated higher levels of anthocyanin-related metabolites. These results suggest that enhanced flavonoid production contributes to greater drought resistance in PL. Additionally, by identifying important genes and metabolites related to anthocyanin accumulation and drought response, this integrated study provides insights into the intricate regulatory network that underlies these processes. These findings emphasize the potential of PL as a valuable genetic resource for developing drought-resistant rapeseed cultivars.

Sulfuric acid effects in seed dormancy break of Ipomoea batatas evaluated by enzymatic, anatomic and physiological approaches

ABSTRACT The recommended method to overcome seed coat dormancy in sweet potato seeds is exposure to sulfuric acid, which can damage the embryo and affect seedling development depending on exposure time. This study aimed to determine the ideal immersion period using physiological, anatomical, and enzymatic analyses. Seeds were scarified with concentrated sulfuric acid for nine immersion periods. Physiological analyses included germination tests, germination speed index, first germination count, emergence test, and emergence speed index. Image analysis quantified the primary root length, root-to-hypocotyl ratio, and seedling length. Catalase and superoxide dismutase enzyme activities were analysed. Seed coat anatomy, including thickness, wear, and colour, was also assessed. Exposure to sulfuric acid for 30 min effectively broke dormancy without impacting the antioxidant system or seedling development. Thermal chambers confirmed that chemically scarified seeds absorb water and activate metabolism faster. Plant anatomy helped illustrate how sulfuric acid breaks dormancy by eroding physical barriers.

Investigating the action model of the resistance enhancement induced by bacterial volatile organic compounds against Botrytis cinerea in tomato fruit

IntroductionInducing natural resistance against pathogen infection in postharvest tomatoes is a sustainable strategy for reducing postharvest losses. The action model underlying the resistance enhancement of tomatoes induced by bacterial volatile organic compounds (VOCs) against Botrytis cinerea, however, have not been explored.MethodsIn this study, RNA-seq, metabolomics and physiological analysis were used to evaluate global change of defense response induced by VOCs in tomatoes.ResultsThe application of VOCs inhibited the damage to tomatoes caused by B. cinerea. VOCs treatment had remarkable beneficial effects on the activities of the main defence-related enzymes, including chitinases, glucanases, peroxidases, ascorbate peroxidases, polyphenol oxidases, and phenylalanine ammonia-lyases. The expression of response genes involved in salicylic acid and jasmonic acid biosynthesis and signalling pathways was enhanced upon VOCs treatment. Metabolomics data demonstrated that VOC treatment triggered the accumulation of phenolic acids, including substrates in phenolic acid biosynthesis pathways, hydroxycinnamic acid, hydroxybenzoic acid, and their derivatives. Transcriptomics analysis and qRT-PCR verification revealed that VOCs treatment significantly upregulates the expression of core genes related to phenolic acid biosynthesis, specifically in shikimate pathway (SlDAHPS, SlSDH, SlCS, and SlADT3) and phenylalanine metabolic pathway (SlPAL, Sl4CL, SlBAHD1, SlCYP98A2 and SlCAP84A1).DiscussionResults confirmed that VOCs enhanced tomatoes postharvest resistance against B. cinerea by regulating defence enzyme activity, SA/JA signalling, and phenolic acid biosynthesis pathway. This study provides new insights into the mechanisms by which VOCs fumigation manages postharvest grey mould in tomatoes.

Pseudomonas machongensis sp. nov. and Stenotrophomonas capsici sp. nov., isolated from wilted pepper plants.

Two Gram-stain-negative, aerobic, rod-shaped, non-endospore-forming bacteria, designated as strain MH1T and MH2T, were isolated from branches of wilted pepper plants (Capsicum annuum) collected from a farmland in Machong town, Guangdong, China, and investigated using a polyphasic approach. MH1T grew at temperatures of 4-42 °C (optimum 28 °C), with 0-6.0 % (w/v) NaCl and at pH 4.0-10.0 (optimum pH 4.0). MH2T grew at temperatures of 4-42 °C (optimum 28 °C), with 0-6.0% (w/v) NaCl and at pH 4.0-10.0 (optimum pH 5.0). Analysis of the 16S rRNA gene sequence indicated that MH1T belongs to Stenotrophomonas and MH2T belongs to Pseudomonas. Genome-based phylogenetic analysis further established that MH1T shares the closest evolutionary relationships with Stenotrophomonas humi DSM 18929 and Stenotrophomonas terrae DSM 18941, and MH2T is sister to Pseudomonas wayambapalatensis RW3S1. Whole-genome comparisons between MH1T and known Stenotrophomonas species revealed average nucleotide identity (ANI) values up to 84.5%, as well as digital DNA-DNA hybridization (dDDH) values up to 28.3%, both substantially lower than the accepted thresholds for species delineation (ANI: 95%; dDDH: 70%). The ANI and dDDH values between MH2T and known Pseudomonas species were at most 94.6 and 59.2 %, respectively. Additional biochemical and physiological analyses further support that MH1T and MH2T represent a novel species in Stenotrophomonas and Pseudomonas, respectively. Notably, the differences in carbon source utilization could differentiate MH1T and its close relatives in Stenotrophomonas. The major fatty acids were iso-C15 : 0, iso-C16 : 0 and iso-C14 : 0 for MH1T and were C16 : 0, C18 : 1 ω7c/C18 : 1 ω6c (summed feature 8), C16 : 1 ω7c/C16 : 1 ω6c (summed feature 3) and C17 : 0 cyclo for MH2T. Therefore, we propose a new species Stenotrophomonas capsici sp. nov., with MH1T (=GDMCC 1.3749T=JCM 36317T) as the type strain, and a new species Pseudomonas machongensis sp. nov., with MH2T (=GDMCC 1.3750T=JCM 36318T) as the type strain. The MH1T genome has a size of 4.18 Mb and a GC-content of 67.19 mol%, while the MH2T genome has a size of 5.71 Mb and a GC-content of 63.12 mol%.

In Silico Integrative scRNA Analysis of Human Colonic Epithelium Indicates Four Tuft Cell Subtypes.

This study integrated and analyzed human single-cell RNA sequencing data from four publicly available datasets to enhance cellular resolution, unveiling a complex landscape of tuft cell heterogeneity within the human colon. Four tuft subtypes (TC1-TC4) emerged as defined by unique gene expression profiles, indicating potentially novel biological function. Tuft cell 1 (TC1) was characterized by an antimicrobial peptide signature; TC2 had an increased transcription machinery gene expression profile consistent with a progenitor-like cell; TC3 expressed genes related to ganglion (neuronal) development; and TC4 expressed genes related to tight junctions. Our analysis of subtype-specific gene expression and pathway enrichment showed variances in tuft cell subtypes between healthy individuals and those with inflammatory bowel disease (IBD). The frequency of TC1 and TC2 differed between healthy controls and IBD. Relative to healthy controls, TC1 and TC2 in IBD-tissue showed an upregulation of gene expression, favouring increased metabolism and immune function. These findings provide foundational knowledge about the complexity of the human colon tuft cell population and hint at their potential contributions to gut health. They provide a basis for future studies to explore the specific roles these cells may play in gut function during homeostasis and disease. We demonstrate the value of in silico approaches for hypothesis generation in relation to the putative functions of low-frequency gut cells for subsequent physiological analyses.

Combined physiological, biochemical, and multi-omic analyses provide insight into the cause of differential browning in early and late harvested fresh-cut yams

Tissue browning reduces the cosmetic quality of fresh-cut yams and poses a marketing problem. The degree of browning of fresh-cut yams varies depending on when they are harvested. In this study, transcriptomic and metabolomic analyses were conducted in yams harvested in September (DHPS) and October (DHPO) to determine the mechanisms responsible for the browning of fresh-cut yams. Results showed that the browning index, total phenol and lignin content, polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia-lyase (PAL), 4-coumarate: CoA Ligase(4CL), and cinnamic acid-4-hydroxylase(C4H) activity in fresh-cut DHPO yams were lower than they were in fresh-cut DHPS yams. Flavonoids and catalase (CAT) activity remained consistently higher during storage in DHPO yams than in DHPS yams. The browning of fresh-cut DHPO yams was mitigated by the regulation of the expression of genes and the abundance of metabolites associated with phenolic metabolism, phytohormones, and signal transduction, as well as sucrose and starch metabolism. The level of browning enzyme activity in DHPO yams was significantly lower than it was in DHPS yams. Our study provides a basis for the selection of optimum harvest date for yams that will undergo fresh-cut processing.

Genome-Wide Identification of AGO, DCL, and RDR Genes and Their Expression Analysis in Response to Drought Stress in Peach

Small RNAs (sRNAs) control a wide range of development and physiological pathways in plants. To address the response of sRNA biogenesis to drought stress, we identified sRNA biogenesis genes, including 11 encoding argonautes (AGO), 8 encoding Dicer-like proteins (DCL), and 9 encoding RNA-dependent RNA polymerases (RDR) in the peach genome. Notably, the largest numbers of sRNA biogenesis genes are located to chromosome 1. The PAZ, PIWI, and MID domains were identified in PpAGOs, while the ribonuclease IIIa and IIIb domains were characterized in PpDCLs. The RDRP domain was recognized in PpRDRs. Orthologous similarity and collinearity analyses between Arabidopsis and peach revealed 5, 1, and 2 collinear blocks in AGOs, DCLs, and RDRs, respectively. Moreover, 41, 40, and 42 cis-acting elements were located in the promoters of PpAGOs, PpDCLs, and PpRDRs, respectively, with the majority related to drought stress response. Analysis of RNA sequencing (RNA-seq) data revealed that sRNA biogenesis genes were involved in drought stress response in different tissues. Furthermore, the expression of candidate genes was verified in two peach cultivars, Beijing 2-7 (BJ2-7) and Sinai (SN), which are tested as drought-tolerant and sensitive cultivars, respectively, based on the physiological and biochemical analyses, which revealed that the Chinese peach cultivar ‘BJ2-7’ exhibits greater drought resistance compared to the Egyptian peach cultivar ‘SN’. Interestingly, the expression of PpAGO2b, PpDCL2b, PpDCL4, and PpRDR4 genes was induced in ‘BJ2-7’ but inhibited in ‘SN’ under drought stress. Overall, this study provides insight into the roles of sRNA biogenesis genes in response to drought stress in peach.

Deciphering the Genetic and Biochemical Drivers of Fruit Cracking in Akebia trifoliata.

This study investigates the molecular mechanisms underlying fruit cracking in Akebia trifoliata, a phenomenon that significantly impacts fruit quality and marketability. Through comprehensive physiological, biochemical, and transcriptomic analyses, we identified key changes in cell wall components and enzymatic activities during fruit ripening. Our results revealed that ventral suture tissues exhibit significantly elevated activities of polygalacturonase (PG) and β-galactosidase compared to dorsoventral line tissues, indicating their crucial roles in cell wall degradation and structural weakening. The cellulose content in VS tissues peaked early and declined during ripening, while DL tissues maintained relatively stable cellulose levels, highlighting the importance of cellulose dynamics in fruit cracking susceptibility. Transcriptomic analysis revealed differentially expressed genes (DEGs) associated with pectin biosynthesis and catabolism, cell wall organization, and oxidoreductase activities, indicating significant transcriptional regulation. Key genes like AKT032945 (pectinesterase) and AKT045678 (polygalacturonase) were identified as crucial for cell wall loosening and pericarp dehiscence. Additionally, expansin-related genes AKT017642, AKT017643, and AKT021517 were expressed during critical stages, promoting cell wall loosening. Genes involved in auxin-activated signaling and oxidoreductase activities, such as AKT022903 (auxin response factor) and AKT054321 (peroxidase), were also differentially expressed, suggesting roles in regulating cell wall rigidity. Moreover, weighted gene co-expression network analysis (WGCNA) identified key gene modules correlated with traits like pectin lyase activity and soluble pectin content, pinpointing potential targets for genetic manipulation. Our findings offer valuable insights into the molecular basis of fruit cracking in A. trifoliata, laying a foundation for breeding programs aimed at developing crack-resistant varieties to enhance fruit quality and commercial viability.

Modified multiscale Renyi distribution entropy for short-term heart rate variability analysis.

Multiscale sample entropy (MSE) is a prevalent complexity metric to characterize a time series and has been extensively applied to the physiological signal analysis. However, for a short-term time series, the likelihood of identifying comparable subsequences decreases, leading to higher variability in the Sample Entropy (SampEn) calculation. Additionally, as the scale factor increases in the MSE calculation, the coarse-graining process further shortens the time series. Consequently, each newly generated time series at a larger scale consists of fewer data points, potentially resulting in unreliable or undefined entropy values, particularly at higher scales. To overcome the shortcoming, a modified multiscale Renyi distribution entropy (MMRDis) was proposed in our present work. The MMRDis method uses a moving-averaging procedure to acquire a family of time series, each of which quantify the dynamic behaviors of the short-term time series over the multiple temporal scales. Then, MMRDis is constructed for the original and the coarse-grained time series. The MMRDis method demonstrated superior computational stability on simulated Gaussian white and 1/f noise time series, effectively avoiding undefined measurements in short-term time series. Analysis of short-term heart rate variability (HRV) signals from healthy elderly individuals, healthy young people, and subjects with congestive heart failure and atrial fibrillation revealed that MMRDis complexity measurement values decreased with aging and disease. Additionally, MMRDis exhibited better distinction capability for short-term HRV physiological/pathological signals compared to several recently proposed complexity metrics. MMRDis was a promising measurement for screening cardiovascular condition within a short time.

Impaired pheromone detection and abnormal sexual behavior in female mice deficient for ancV1R.

Ancient vomeronasal receptor type-1 (ancV1R), a putative vomeronasal receptor, is highly conserved across a wide range of vertebrates and is expressed in the majority of vomeronasal sensory neurons, co-expressing with canonical vomeronasal receptors, V1Rs and V2Rs. The pseudogenization of ancV1R is closely associated with vomeronasal organ (VNO) degeneration, indicating its critical role in pheromone sensing. However, the specific role of ancV1R remains unknown. In this study, to elucidate the function of ancV1R, we conducted phenotypic analyses of ancV1R-deficient female mice. Behavioral analyses showed that ancV1R-deficient females exhibited rejective responses toward male sexual behavior and displayed no preference for male urine. Physiological analyses demonstrate that the loss-of-function mutation of ancV1R reduced VNO response to various pheromone cues, including male urine, the sexual enhancing pheromone exocrine gland-secreting peptide 1 (ESP1), and β-estradiol 3-sulfate. Pre-exposure to ESP1 did not overcome the rejection behavior caused by ancV1R deficiency. Analysis of neural activity in the vomeronasal system revealed increased responses in the medial amygdala and posteromedial cortical amygdala of mutant females upon contact with males but not in response to male urine alone. Additionally, upon male contacts, ancV1R-deficient females exhibited increased neural activity in the lateral septum, a stress-associated brain region, along with elevated stress hormone levels. Such effects were not observed in females exposed solely to male urine. These findings suggest that, in females, ancV1R facilitates VNO responses to pheromone stimuli and plays a crucial role in perceiving males as mating partners. The absence of ancV1R results in failure of male perception, leading to abnormal sexual behaviors and stress responses upon male contact.

Advancements in maize cultivation: synergistic effects of dry atmospheric plasma combined with plasma-activated water

Abstract In this study, we investigate the effects of pre-germinative and post-germinative plasma treatments, applied separately or in combination, to improve maize germination and early seedling development. Pre-germinative treatment consists of priming the seeds with a dry atmospheric plasma (DAP) generated by a dielectric barrier device, characterized by minimal radiative emission, low electrical power (4 W) and high emissions of O, OH and NO radicals. Post-germinative treatment, known as plasma-activated water (PAW), uses a single pin electrode device (SPED) to generate a DC discharge that features a power of 126 W and produces large amounts of OH radicals. The resulting PAW, after 5 min of SPED treatment, induces a slight acidification and increased concentrations of nitrate ions (from 24 to 250 mg l−1), nitrite ions (from less than 0.1 to 56.1 mg l−1) and hydrogen peroxide (from 0.3 to 18.5 mg l−1). Results indicate that DAP applied on maize seeds for 20 min boosts their germination rate by up to 90% (versus only 65% for untreated seeds) while reducing the median germination time by 37.5%. Then, seedling growth monitoring is achieved on control, DAP, PAW and DAP + PAW groups to assess stem length, hypocotyl length, leaf count, collar diameter and fresh/dry mass. The DAP + PAW group shows the most robust growth, demonstrating a synergistic effect of the combined treatments, particularly with significantly longer stem lengths. Additionally, physiological analyses of seedling leaves indicate a decrease in chlorophyll content despite enhanced growth, while fluorescence microscopy reveals a reduction in stomatal density in leaves treated with DAP and PAW, especially in the combined treatment group, potentially impacting photosynthetic efficiency and water regulation.

Contribution of physiological dynamics in predicting major depressive disorder severity

AbstractThis study aimed to explore the physiological dynamics of cognitive stress in patients with Major Depressive Disorder (MDD) and design a multiparametric model for objectively measuring severity of depression. Physiological signal recordings from 40 MDD patients and 40 healthy controls were collected in a baseline stage, in a stress‐inducing stage using two cognitive tests, and in the recovery period. Several features were extracted from electrocardiography, photoplethysmography, electrodermal activity, respiration, and temperature. Differences between values of these features under different conditions were used as indexes of autonomic reactivity and recovery. Finally, a linear model was designed to assess MDD severity, using the Beck Depression Inventory scores as the outcome variable. The performance of this model was assessed using the MDD condition as the response variable. General physiological hyporeactivity and poor recovery from stress predict depression severity across all physiological signals except for respiration. The model to predict depression severity included gender, body mass index, cognitive scores, and mean heart rate recovery, and achieved an accuracy of 78%, a sensitivity of 97% and a specificity of 59%. There is an observed correlation between the behavior of the autonomic nervous system, assessed through physiological signals analysis, and depression severity. Our findings demonstrated that decreased autonomic reactivity and recovery are linked with an increased level of depression. Quantifying the stress response together with a cognitive evaluation and personalization variables may facilitate a more precise diagnosis and monitoring of depression, enabling the tailoring of therapeutic interventions to individual patient needs.