Enhancing drought, heat shock, and combined stress tolerance in Myrobalan 29C rootstocks with foliar application of potassium nitrate.

BACKGROUND: Drought and heat stress are significant concerns to food security in arid and semi-arid regions, where global warming is predicted to increase both frequency and severity. To cope with these challenges, the use of drought-tolerant plants or technological interventions are essential. In this study, the effects of foliar potassium nitrate (KNO3) application on the stress tolerance and recovery of Myrobalan 29C rootstocks (Prunus cerasifera Ehrh.) were evaluated. These rootstocks are widely recognized for their adaptability and are extensively used in fruit production. To assess their response, the rootstocks were subjected to drought, heat shock, or a combination of both stressors. Additionally, they were treated with 1.0% KNO3 via foliar application. Throughout the stress and recovery periods, various morphological, physiological, and bio-chemical parameters were measured. RESULTS: Based on our results, KNO3 treatment improved LRWC, Chl stability, SC, and key stress markers like proline, MDA, H2O2, along with antioxidant enzymes CAT, SOD, POD during both stress and recovery phases. Moreover, our results emphasized KNO3's critical role in hormone regulation under stress. KNO3 application significantly altered hormone levels, notably increasing ABA during drought and heat shock stress, essential for stress response and adaptation. In contrast, IAA, GA, and cytokinin's significantly increased during the recovery phase in KNO3-treated plants, indicating improved growth regulation and stress recovery. In addition, KNO3 application improved the recovery process of the rootstocks by restoring their physiological and biochemical functions. CONCLUSION: This study suggests that the application of foliar KNO3 is an effective technique for enhancing the drought and heat tolerance as well as the recovery of Myrobalan 29C rootstocks. These results hold significant value for farmers, policymakers, and researchers, as they offer crucial insights into the development of drought-tolerant crops and the management of climate change's adverse effects on agriculture.

Sodium nitroprusside modulates oxidative and nitrosative processes in Lycopersicum esculentum L. under drought stress.

KEY MESSAGE: Sodium nitroprusside mediates drought stress responses in tomatoes by modulating nitrosative and oxidative pathways, highlighting the interplay between nitric oxide, hydrogen sulfide, and antioxidant systems for enhanced drought tolerance. While nitric oxide (NO), a signalling molecule, enhances plant tolerance to abiotic stresses, its precise contribution to improving tomato tolerance to drought stress (DS) through modulating oxide-nitrosative processes is not yet fully understood. We aimed to examine the interaction of NO and nitrosative signaling, revealing how sodium nitroprusside (SNP) could mitigate the effects of DS on tomatoes. DS-seedlings endured 12% polyethylene glycol (PEG) in a 10% nutrient solution (NS) for 2 days, then transitioned to half-strength NS for 10 days alongside control plants. DS reduced total plant dry weight, chlorophyll a and b, Fv/Fm, leaf water potential (ΨI), and relative water content, but improved hydrogen peroxide (H2O2), proline, and NO content. The SNP reduced the DS-induced H2O2 generation by reducing thiol (-SH) and the carbonyl (-CO) groups. SNP increased not only NO but also the activity of L-cysteine desulfhydrase (L-DES), leading to the generation of H2S. Decreases in S-nitrosoglutathione reductase (GSNOR) and NADPH oxidase (NOX) suggest a potential regulatory mechanism in which S-nitrosylation [formation of S-nitrosothiol (SNO)] may influence protein function and signaling pathways during DS. Moreover, SNP improved ascorbate (AsA) and glutathione (GSH) and reduced oxidized glutathione (GSSG) levels in tomato plants under drought. Furthermore, the interaction of NO and H2S, mediated by L-DES activity, may serve as a vital cross-talk mechanism impacting plant responses to DS. Understanding these signaling interactions is crucial for developing innovative drought-tolerance strategies in crops.

Molecular Mechanisms of CBL-CIPK Signaling Pathway in Plant Abiotic Stress Tolerance and Hormone Crosstalk.

Abiotic stressors, including drought, salt, cold, and heat, profoundly impact plant growth and development, forcing elaborate cellular responses for adaptation and resilience. Among the crucial orchestrators of these responses is the CBL-CIPK pathway, comprising calcineurin B-like proteins (CBLs) and CBL-interacting protein kinases (CIPKs). While CIPKs act as serine/threonine protein kinases, transmitting calcium signals, CBLs function as calcium sensors, influencing the plant's response to abiotic stress. This review explores the intricate interactions between the CBL-CIPK pathway and plant hormones such as ABA, auxin, ethylene, and jasmonic acid (JA). It highlights their role in fine-tuning stress responses for optimal survival and acclimatization. Building on previous studies that demonstrated the enhanced stress tolerance achieved by upregulating CBL and CIPK genes, we explore the regulatory mechanisms involving post-translational modifications and protein-protein interactions. Despite significant contributions from prior research, gaps persist in understanding the nuanced interplay between the CBL-CIPK system and plant hormone signaling under diverse abiotic stress conditions. In contrast to broader perspectives, our review focuses on the interaction of the pathway with crucial plant hormones and its implications for genetic engineering interventions to enhance crop stress resilience. This specialized perspective aims to contribute novel insights to advance our understanding of the potential of the CBL-CIPK pathway to mitigate crops' abiotic stress.

Mitigating salt toxicity and overcoming phosphate deficiency alone and in combination in pepper (Capsicum annuum L.) plants through supplementation of hydrogen sulfide.

While it is widely recognized that hydrogen sulfide (H2S) promotes plant stress tolerance, the precise processes through which H2S modulates this process remains unclear. The processes by which H2S promotes phosphorus deficiency (PD) and salinity stress (SS) tolerance, simulated individually or together, were examined in this study. The adverse impacts on plant biomass, total chlorophyll and chlorophyll fluorescence were more pronounced with joint occurrence of PD and SS than with individual application. Malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) levels in plant leaves were higher in plants exposed to joint stresses than in plants grown under an individual stress. When plants were exposed to a single stress as opposed to both stressors, sodium hydrosulfide (NaHS) treatment more efficiently decreased EL, MDA, and H2O2 concentrations. Superoxide dismutase, peroxidase, glutathione reductase and ascorbate peroxidase activities were increased by SS alone or in conjunction with PD, whereas catalase activity decreased significantly. The favorable impact of NaHS on all the evaluated attributes was reversed by supplementation with 0.2 mM hypotaurine (HT), a H2S scavenger. Overall, the unfavorable effects caused to NaHS-supplied plants by a single stress were less severe compared with those caused by the combined administration of both stressors.

Comparison of ultrasound-guided transversalis fascia plane block and anterior quadratus lumborum block in patients undergoing caesarean delivery: a randomized study.

BACKGROUND: Cesarean section is becoming increasingly common. Well-managed postoperative analgesia improves patient comfort while encouraging early ambulation and breastfeeding. The analgesic efficacy of transversalis facial plane block (TFPB) vs. anterior quadratus lumborum block (QLB) was compared in this study. METHODS: We analyzed the data of 49 pregnant women (gestation, ≥ 37weeks; age, 18-45years) scheduled for elective cesarean delivery (CD) under general anesthesia. They were randomly divided into TFPB and anterior QLB groups. All blocks were administered bilaterally with 25mL of 0.25% bupivacaine under ultrasound guidance prior to extubation. Postoperative morphine consumption and numerical rating scale (NRS) pain scores (static and dynamic [during coughing]) were recorded at 1, 3, 6, 9, 12, 18, and 24h. RESULTS: There was no difference in postoperative morphine consumption between the groups at the third, sixth, and ninth hours, but the anterior QLB group consumed less morphine at the 12th, 18th, and 24th hours. Except for the first hour, resting and dynamic NRS scores were comparable between the groups. The first-hour resting and dynamic NRS scores were lower in the TFPB group (resting NRS, anterior QLB group, median [interquartile range], 2 [2-3] vs. TFPB group, 2 [0-2], p = 0.046; dynamic NRS, anterior QLB group, median [interquartile range], 3 [2-4] vs. TFPB group 2 [0-3], p = 0.001). CONCLUSIONS: In patients undergoing CD, anterior QLB decreased morphine consumption in the late period (9-24h) compared to TFPB, while pain scores were similar between both groups. The reduction in morphine consumption was statistically significant, but not clinically significant.

Analgesic benefits of pre-operative versus postoperative transversus abdominis plane block for laparoscopic cholecystectomy: a frequentist network meta-analysis of randomized controlled trials.

BACKGROUND: Transversus abdominis plane (TAP) block has been utilized to alleviate pain following laparoscopic cholecystectomy (LC). However, the optimal timing of administration remains uncertain. This study aimed to compare the efficacy of pre-operative and postoperative TAP blocks as analgesic options after LC. METHODS: A frequentist network meta-analysis of randomized controlled trials (RCTs) was conducted. We systematically searched PubMed (via the National Library of Medicine), EMBASE, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science up to March 2023. The study included RCTs that enrolled adult patients (≥ 18 years) who underwent LC and received either pre-operative or postoperative TAP blocks. The primary outcome assessed was 24-hour postoperative morphine consumption (mg). Additionally, pain rest scores within 3 hours, 12 hours, and 24 hours, as well as postoperative nausea and vomiting (PONV), were considered as pre-specified secondary outcomes. RESULTS: A total of 34 trials with 2317 patients were included in the analysis. Postoperative TAP block demonstrated superiority over the pre-operative TAP block in reducing opioid consumption (MD 2.02, 95% CI 0.87 to 3.18, I2 98.6%, p < 0.001). However, with regards to postoperative pain, neither pre-operative nor postoperative TAP blocks exhibited superiority over each other at any of the assessed time points. The postoperative TAP block consistently ranked as the best intervention using SUCRA analysis. Moreover, the postoperative TAP block led to the most significant reduction in PONV. CONCLUSIONS: The findings suggest that the postoperative TAP block may be slightly more effective in reducing 24-hour postoperative opioid consumption and PONV when compared to the pre-operative TAP block. TRIAL REGISTRATION: PROSPERO, CRD42023396880 .

Epigenetic and Hormonal Modulation in Plant-Plant Growth-Promoting Microorganism Symbiosis for Drought-Resilient Agriculture.

Plant growth-promoting microorganisms (PGPMs) have emerged as valuable allies for enhancing plant growth, health, and productivity across diverse environmental conditions. However, the complex molecular mechanisms governing plant-PGPM symbiosis under the climatic hazard of drought, which is critically challenging global food security, remain largely unknown. This comprehensive review explores the involved molecular interactions that underpin plant-PGPM partnerships during drought stress, thereby offering insights into hormonal regulation and epigenetic modulation. This review explores the challenges and prospects associated with optimizing and deploying PGPMs to promote sustainable agriculture in the face of drought stress. In summary, it offers strategic recommendations to propel research efforts and facilitate the practical implementation of PGPMs, thereby enhancing their efficacy in mitigating drought-detrimental effects in agricultural soils.

Erector spinae plane block versus its combination with superficial parasternal intercostal plane block for postoperative pain after cardiac surgery: a prospective, randomized, double-blind study.

BACKGROUND: We aimed to compare the effectiveness of bilateral erector spinae plane (ESP) block and superficial parasternal intercostal plane (S-PIP) + ESP block in acute post-sternotomy pain following cardiac surgery. METHODS: Forty-seven patients aged between 18 and 80 years of age with American Society of Anesthesiologists class II-III due to undergo median sternotomy for cardiac surgery were included in this prospective, randomized, double-blinded study. Following randomization into two groups, one group received bilateral ultrasound-guided ESP and the other S-PIP plus ESP block. Morphine consumption within the first 24 h after surgery was the primary outcome of the study while NRS scores at rest, NRS scores when coughing, time taken until extubation, use of rescue analgesic, presence of nausea/vomiting, length of hospital and intensive care unit (ICU) stay, and patient satisfaction were secondary outcome measures. RESULTS: Morphine use up to 24 h following surgery was statistically significantly different between the ESP block and ESP + S-PIP block groups (18.63 ± 6.60 [15.84-21.41] mg/24 h vs 14.41 ± 5.38 [12.08-16.74] mg/24 h, p = 0.021). The ESP + S-PIP block group had considerably reduced pain scores compared to the ESP block group across all time points. Rescue analgesics were required in 21 (87.5%) patients in the ESP block group and seven (30.4%) in the ESP + S-PIP group (p < 0.001). PONV, length of stay in the ICU and hospital, and time to extubation were similar between groups. CONCLUSIONS: In open cardiac surgery, the combination of ESP and S-PIP blocks lowers pain scores and postoperative morphine requirement of patients. TRIAL REGISTRATION: Clinicaltrials Registration No: NCT05191953, Registration Date: 14/01/2022.

Comparison of Ultrasound-Guided Pecto-intercostal Fascial Block and Transversus Thoracic Muscle Plane Block for Acute Poststernotomy Pain Management After Cardiac Surgery: A Prospective, Randomized, Double-Blind Pilot Study.

OBJECTIVE: The objective of the present study was to evaluate morphine consumption and pain scores 24 hours postoperatively to compare the effects of a bilateral pectointercostal fascial block (PIFB) with those of a transversus thoracic muscle plane block (TTMPB) on acute poststernotomy pain in cardiac surgery patients who have undergone median sternotomy. DESIGN: Prospective, randomized, double-blinded. SETTING: The operating room, intensive care unit, and patient ward at a university hospital. PARTICIPANTS: Thirty-nine American Society of Anesthesiologists II-to-III patients aged 18- to-80 years, scheduled for elective cardiac surgery via median sternotomy. INTERVENTIONS: Patients randomly were allocated to groups scheduled to receive bilateral ultrasound-guided PIFB or TTMPB. MEASUREMENTS AND MAIN RESULTS: The primary outcome was postoperative morphine use within the first 24 hours. Secondary outcomes were the numerical pain rating scale (NRS) scores at rest and during coughing, time of first analgesic demand from the patient-controlled analgesia (PCA) device, and rescue analgesia use. The nausea/vomiting scores, time to extubation, length of stays in intensive care and the hospital, patient satisfaction scores, and complications were also recorded. The first 24-hour morphine use did not significantly differ between the PIFB and TTMPB groups (mean ± standard deviation [95% CI], 13.89 ± 6.80 [10.83-16.95] mg/24 h and 15.08 ± 7.42 [11.83-18.33] mg/24 h, respectively, p = 0.608). No significant difference between the two groups in the NRS scores at rest and during coughing was observed; the groups had similar requirements for rescue analgesia in the first 24 hours (n [%], three [15.8] and seven [35], p = 0.273, respectively). The time from PCA to the first analgesia request was longer in the PIFB than in the TTMPB group (median [interquartile range], 660 [540-900] minutes, and 240 [161-525] minutes, respectively, p = 0.002). CONCLUSIONS: PIFB and TTMPB showed similar effectiveness for morphine consumption within 24 hours postoperatively and in pain scores in cardiac surgery patients.

Global population genetic structure and demographic trajectories of the black soldier fly, Hermetia illucens.

BACKGROUND: The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation of H. illucens. Based on 15 novel microsatellite markers, we genotyped and analysed 2862 individuals from 150 wild and captive populations originating from 57 countries on seven subcontinents. RESULTS: We identified 16 well-distinguished genetic clusters indicating substantial global population structure. The data revealed genetic hotspots in central South America and successive northwards range expansions within the indigenous ranges of the Americas. Colonisations and naturalisations of largely unique genetic profiles occurred on all non-native continents, either preceded by demographically independent founder events from various single sources or involving admixture scenarios. A decisive primarily admixed Polynesian bridgehead population serially colonised the entire Australasian region and its secondarily admixed descendants successively mediated invasions into Africa and Europe. Conversely, captive populations from several continents traced back to a single North American origin and exhibit considerably reduced genetic diversity, although some farmed strains carry distinct genetic signatures. We highlight genetic footprints characteristic of progressing domestication due to increasing socio-economic importance of H. illucens, and ongoing introgression between domesticated strains globally traded for large-scale farming and wild populations in some regions. CONCLUSIONS: We document the dynamic population genetic history of a cosmopolitan dipteran of South American origin shaped by striking geographic patterns. These reflect both ancient dispersal routes, and stochastic and heterogeneous anthropogenic introductions during the last century leading to pronounced diversification of worldwide structure of H. illucens. Upon the recent advent of its agronomic commercialisation, however, current human-mediated translocations of the black soldier fly largely involve genetically highly uniform domesticated strains, which meanwhile threaten the genetic integrity of differentiated unique local resources through introgression. Our in-depth reconstruction of the contemporary and historical demographic trajectories of H. illucens emphasises benchmarking potential for applied future research on this emerging model of the prospering insect-livestock sector.

Comparison of Ketamine, Dexmedetomidine and Lidocaine in Multimodal Analgesia Management Following Sleeve Gastrectomy Surgery: A Randomized Double-Blind Trial.

PURPOSE: The aim of this study was to compare the effects of ketamine, dexmedetomidine, and lidocaine infusions added to the multimodal analgesia regimen on pain scores and analgesic requirement in laparoscopic sleeve gastrectomy. DESIGN: A prospective randomized double-blind trial. Seventy-three patients aged 18 to 65 years (ASA II-III) undergoing laparoscopic sleeve gastrectomy were included. The patients were divided into 3 groups. Intravenous (IV) ketamine (0.5 mg/kg/h), dexmedetomidine (0.5 mcg/kg/h), and lidocaine (2 mg/kg/h) were administered to Groups K, D and L, respectively. Postoperative infusions were continued for 12 hours. METHODS: Visual Analog Scale (VAS) scores (during rest and movement) in the admission to postanesthesia care unit, 1, 3, 6, 12, 24, 48 hours, and on day 15 were assessed postoperatively. Rescue analgesia requirement, the number of patients with nausea, retching, and vomiting, time to mobilization, and hospital length of stay (LOS) were recorded. FINDINGS: VASrest values during all measurements in the first 24 hours, and VASmovement values in the first 6 hours and at 24 hours were lower in Group L when compared to Group K and Group D (P < .001, P < .001, P = .008, respectively). VASrest at 48 hours and VASmovement at 12 and 48 hours were lower in Group L when compared to Group K (P = .044, P = .001 and P = .011, respectively). There was no statistically significant difference between Group D compared to the other two groups at these times (P > .05). The requirement of rescue analgesia on postoperative day 1 was significantly higher in Group K (P < .001). Hospital LOS was shorter in Group L than in the other groups (P = .002). CONCLUSIONS: IV lidocaine added to multimodal analgesia provided better pain control in the early postoperative period compared to dexmedetomidine and ketamine and decreased the hospital LOS.

Nitrate reductase is required for salicylic acid-induced water stress tolerance of pepper by upraising the AsA-GSH pathway and glyoxalase system.

A trial was conducted to evaluate whether nitrate reductase (NR) participates in salicylic acid (SA)-improved water stress (WS) tolerance in pepper (Capsicum annuum L.) plants. Before starting WS treatment, 0.5 mM SA was applied to half of the well-watered (WW) plants as well as to WS-plants as a foliar spray once a day for a week. The soil water holding capacity was maintained at 40 and 80% of the full water storing capacity for WS and and well-watered (WW) plants, respectively. Water stress caused substantial decreases in total plant dry weight, Fv /Fm , chlorophyll a and b, relative water content, leaf water potential (ΨI) by 53, 37, 49, 21, 36 and 33%, respectively relative to control, but significant increases in malondialdehyde (MDA), hydrogen peroxide (H2 O2 ), electrolyte leakage (EL), methylglyoxal (MG), proline, key antioxidant enzymes' activities, NO and NR activity. The SA reduced oxidative stress, but improved antioxidant defence system, ascorbate-glutathione (AsA-GSH) cycle enzymes, glyoxalase system-related enzymes, glyoxalase I (Gly I) and glyoxalase II (Gly II), plant growth, photosynthetic traits, NO, NR and proline. SA-induced WS tolerance was further improved by supplementation of sodium nitroprusside (SNP), a donor of NO. NR inhibitor, sodium tungstate (ST) was applied in conjunction with SA and SA + SNP to the WW and WS-plants to assess whether NR contributes to SA-improved WS tolerance. ST abolished the beneficial effects of SA by reducing NO and NR activity in WS-pepper, but the application of SNP along with SA + ST reversed negative effects of ST, showing that NO and NR are jointly needed for SA-induced WS tolerance of pepper plants.

Salicylic acid-induced hydrogen sulphide improves lead stress tolerance in pepper plants by upraising the ascorbate-glutathione cycle.

The contribution of hydrogen sulphide (H2 S) to salicylic acid (SA) induced lead (Pb) stress tolerance modulated by the ascorbate-glutathione (AsA-GSH) cycle was examined in pepper (Capsicum annuum L.) plants. One week after germination, pepper seedlings were sprayed with 0.5 mM SA once a day for a week. Thereafter, seedlings were grown under control (no Pb) or Pb stress (Pb-S treatment consisting of 0.1 mM PbCl2 ) for a further 2 weeks. Lead stress reduced plant growth and leaf water status as well as the activities of dehydroascorbate reductase and monodehydroascorbate reductase. However, lead stress elevated leaf Pb, the proline contents, oxidative stress, activities of glutathione reductase and ascorbate peroxidase, as well as the endogenous H2 S content. Supplements of SA resulted in improvements in growth parameters, biomass, leaf water status and AsA-GSH cycle-related enzyme activities, as well as increasing the H2 S content. The positive effect of SA was further enhanced when sodium hydrosulphide was added. However, 0.1 mM hypotaurine (HT) treatment reversed the beneficial effect of SA by reducing the plant H2 S content. Application of NaHS in combination with SA + HT suppressed the adverse effect of HT mainly by restoring the plant H2 S content, suggesting that higher H2 S content, induced by exogenous SA supply, resulted in elevated regulation of the AsA-GSH cycle.

Comparison of the analgesic effects of two quadratus lumborum blocks (QLBs), QLB type II vs QLB type III, in caesarean delivery: A randomised study.

BACKGROUND: Quadratus lumborum blocks (QLBs) are relatively novel regional anaesthesia techniques, and the efficacy of all three types of QLB for postoperative analgesia in caesarean delivery (CD) has been demonstrated in separate studies. The aim of the present study is to compare the analgesic efficacy of the QLB-II and QLB-III blocks performed at the end of surgery in patients undergoing spinal anaesthesia for CD. METHODS: We conducted a comparative, blinded, prospective, randomised and efficiency study. A total of 80 patients scheduled for elective CD under spinal anaesthesia were randomly allocated to receive either bilateral ultrasound-guided QLB-II or QLB-III block in a 1:1 ratio. The primary outcome was opioid consumption administered by a patient-controlled analgesia in the first 24 hours postoperatively. The secondary outcome of the study was pain intensity. Also, the time of first opioid requirement and the presence of nausea and vomiting were recorded. RESULTS: Morphine consumption was statistically significantly lower in the QLB-III group when compared with the QLB-II group at the 3rd, 6th, 12th and 24th hours (P < .001, P < .001, P = .004, and P = .015, respectively). The QLB-III group showed significantly lower pain scores at rest at the 1st, 3rd, 6th, 9th and 24th hours after surgery (P < .001, P < .001, P < .001, P = .007 and P < .001, respectively). The QLB-III group also showed significantly lower pain score on movement at all measurement times (P < .001). CONCLUSIONS: The analgesic efficacy of QLB-III was superior to QLB-II in patients who had undergone CD under spinal anaesthesia without use of intrathecal opioids and nonsteroidal anti-inflammatory drugs.

Predictive value of perfusion index for mortality in mechanically ventilated patients.

AIM: This study aimed to examine the prognostic significance of the perfusion index (PI) in mechanically ventilated patients. METHODS: Study included sixty patients who had the risk factors for the development of acute respiratory distress syndrome and received mechanical ventilator (MV) support in intensive care unit (ICU) unit between January 2017/January 2018. The demographic characteristics, vital signs, blood gas parameters, lactate levels, prognostic scores, and use of inotropic drugs were recorded. Arterial blood gas and PI measurements at the frontal region were performed at the time of and 12th and 24th hours of admission to the ICU. The patients were followed up for 60 days, and the outcome was recorded. RESULTS: Twelve patients (20%) died during the first 7 days, and 27 patients (45%) died within 60 days of the admission. Multivariate analyses to determine potential predictors of 7 and 30-day mortality showed that only 24th-hour lactate level was independent predictor of 60-day mortality, and the PI at 24th was the sole independent predictor of 7-day mortality. CONCLUSION: The PI did not predict 60-day mortality in MV patients who had risk factors for the development of Acute Respiratory Distress Syndrome (ARDS). However, the PI at 24th may be a significant predictor of 7-day mortality.

Integrative roles of nitric oxide and hydrogen sulfide in melatonin-induced tolerance of pepper (Capsicum annuum L.) plants to iron deficiency and salt stress alone or in combination.

There seems to be no report in the literature on the effect of melatonin (MT) in relieving the detrimental effects of combined application of salt stress (SS) and iron deficiency (ID). Therefore, the effect of MT on the accumulation/synthesis of endogenous nitric oxide (NO) and hydrogen sulphide (H2 S) and how far these molecules are involved in MT-improved tolerance to the combined application of ID and SS in pepper (Capsicum annuum L) were tested. Hence, two individual trials were set up. The treatments in the first experiment comprised: Control, ID (0.1 mM FeSO4 ), SS (100 mM NaCl) and ID + SS. The detrimental effects of combined stresses were more prominent than those by either of the single stress, with respect to growth, oxidative stress and antioxidant defense attributes. Single stress or both in combination improved the endogenous H2 S and NO, and foliar-applied MT (100 µM) led to a further increase in NO and H2 S levels. In the second experiment, 0.1 mM scavenger of NO, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO) and that of H2 S, hypotuarine (HT) were applied along with MT to get further evidence whether NO and H2 S are involved in MT-induced tolerance to ID and SS. MT combined with cPTIO and HT under a single or combined stress showed that NO effect was reversed by the NO scavenger, cPTIO, alone but the H2 S effect was inhibited by both scavengers. These findings suggested that tolerance to ID and SS induced by MT may be involved in downstream signal crosstalk between NO and H2 S.

Responses of nitric oxide and hydrogen sulfide in regulating oxidative defence system in wheat plants grown under cadmium stress.

We conducted a study to evaluate the interactive effect of NO and H2 S on the cadmium (Cd) tolerance of wheat. Cadmium stress considerably reduced total dry weight, chlorophyll a and b content and ratio of Fv/Fm by 36.7, 48.6, 26.7 and 19.5%, respectively, but significantly enhanced the levels of hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA), endogenous H2 S and NO, and the activities of antioxidant enzymes. Exogenously applied sodium nitroprusside (SNP) and sodium hydrosulfide (NaHS), donors of NO and H2 S, respectively, enhanced total plant dry matter by 47.8 and 39.1%, chlorophyll a by 92.3 and 61.5%, chlorophyll b content by 29.1 and 27.2%, Fv/Fm ratio by 19.7 and 15.2%, respectively, and the activities of antioxidant enzymes, but lowered oxidative stress and proline content in Cd-stressed wheat plants. NaHS and SNP also considerably limited both the uptake and translocation of Cd, thereby improving the levels of some key mineral nutrients in the plants. Enhanced levels of NO and H2 S induced by NaHS were reversed by hypotuarine application, but they were substantially reduced almost to 50% by cPTIO (a NO scavenger) application. Hypotuarine was not effective, but cPTIO was highly effective in reducing the levels of NO and H2 S produced by SNP in the roots of Cd-stressed plants. The results showed that interactive effect of NO and H2 S can considerably improve plant resistance against Cd toxicity by reducing oxidative stress and uptake of Cd in plants as well as by enhancing antioxidative defence system and uptake of some essential mineral nutrients.

The role of nitrate reductase in brassinosteroid-induced endogenous nitric oxide generation to improve cadmium stress tolerance of pepper plants by upregulating the ascorbate-glutathione cycle.

A study was performed to assess if nitrate reductase (NR) participated in brassinosteroid (BR)-induced cadmium (Cd) stress tolerance primarily by accelerating the ascorbate-glutathione (AsA-GSH) cycle. Prior to initiating Cd stress (CdS), the pepper plants were sprayed with 0.5 µM 24-epibrassinolide (EBR) every other day for 10 days. Thereafter the seedlings were subjected to control or CdS (0.1 mM CdCl2) for four weeks. Cadmium stress decreased the plant growth related attributes, water relations as well as the activities of monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR), but enhanced proline content, leaf Cd2+ content, oxidative stress-related traits, activities of ascorbate peroxidase (APX) and glutathione reductase (GR), and the activities of antioxidant defence system-related enzymes as well as NR activity and endogenous nitric oxide content. EBR reduced leaf Cd2+ content and oxidative stress-related parameters, enhanced plant growth, regulated water relations, and led to further increases in proline content, AsA-GSH cycle-related enzymes' activities, antioxidant defence system-related enzymes as well as NR activity and endogenous nitric oxide content. The EBR and the inhibitor of NR (tungstate) reversed the positive effects of EBR by reducing NO content, showing that NR could be a potential contributor of EBR-induced generation of NO which plays an effective role in tolerance to CdS in pepper plants by accelerating the AsA-GSH cycle and antioxidant enzymes.

Influence of exogenously applied nitric oxide on strawberry (Fragaria × ananassa) plants grown under iron deficiency and/or saline stress.

A study was carried out to assess the protective effects of exogenously applied nitric oxide (NO) in the form of its donor sodium nitroprusside (SNP) to strawberry seedlings (Fragaria × ananassa cv. Camarosa) grown under iron deficiency (ID), salinity stress or combination of both. The experimental design contained control, 0.1 mM FeSO4 (ID, Fe deficiency); 50 mM NaCl (S, Salinity) and ID + S. Plants were sprayed with 0.1 mM SNP or 0.1 mM sodium ferrocyanide, an analogue of SNP containing no NO. The deleterious effects of ID + S treatments on plant fresh and dry matters, total chlorophyll and chlorophyll fluorescence were more striking than those caused by the ID or S treatment alone. Furthermore, combination of salinity and iron stress exacerbated electrolyte leakage (EL) and the levels of malondialdehyde (MDA) and hydrogen peroxide (H2 O2 ) in plant leaves compared to those in plants grown with either of the single stresses. NO treatment effectively reduced EL, MDA and H2 O2 in plants grown under stress conditions applied singly or in combination. Salt stress alone and with ID reduced the superoxide dismutase (EC1.15.1.1) and catalase (EC 1.11.1.6) activities but increased that of POD (EC 1.17.1.7). Exogenously applied NO led to significant changes in antioxidant enzyme activities in either ID or S than those by ID+S. Overall, exogenously applied NO was more effective in mitigating the stress-induced adverse effects on the strawberry plants exposed to a single stress than those due to the combination of both stresses.

Physiological effects of the brown seaweed Ascophyllum nodosum) and humic substances on plant growth, enzyme activities of certain pepper plants grown under salt stress.

This study was aimed to examine the effects of seaweed extract (SW) and humic acid on the fruit yield, dry weight (DW%), protein, proline, lipid peroxidation (LPO) and antioxidative enzyme activity of pepper plants (Capsicum annuum L.) grown under saline conditions (100 mM). The obtained results indicated that salinity stress affected deleteriously plant growth and all other parameters. Besides, the treatment of seaweed (SW) and humic acid (HA) improved vegetative growth in the plant at all concentration levels applied under salinity conditions. Leaf fresh and dry weight was increased by all SW and HA applications in salinity stressed plant compared to those of control. Furthermore, there was a significant improvement in antioxidant enzyme activity, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities in the plant under salt stress and treated with SW and HA compounds. It suggests that seaweed and humic acid can enhance salt stress tolerance and leads to conservation of pepper plant against oxidative stress.