Brassinosteroid modulates ethylene synthesis and antioxidant metabolism to protect rice (Oryza sativa) against heat stress-induced inhibition of source‒sink capacity and photosynthetic and growth attributes.

This study presents an exploration of the efficacy of brassinosteroids (BRs) and ethylene in mediating heat stress tolerance in rice (Oryza sativa). Heat is one of the major abiotic factors that prominently deteriorates rice production by influencing photosynthetic efficiency, source‒sink capacity, and growth traits. The application of BR (0.5 mM) and ethylene (200 µl l-1) either individually and/or in combination was found to alleviate heat stress-induced toxicity by significantly improving photosynthesis, source‒sink capacity and defense systems; additionally, it reduced the levels of oxidative stress markers and ethylene formation. The study revealed the positive influence of BR in promoting plant growth responses under heat stress through its interplay with ethylene biosynthesis and enhanced plant defense systems. Interestingly, treatment with the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG) substantiated that BR application to heat-stressed rice plants enhanced ethylene-dependent pathways to counteract the underlying adversities. Thus, BR action was found to be mediated by ethylene to promote heat tolerance in rice. The present study sheds light on the potential tolerance mechanisms which can ensure rice sustainability under heat stress conditions.

The emerging key role of reactive sulfur species in abiotic stress tolerance in plants.

In plants, sulfur plays a critical role in the formation of important biomolecules such as cysteine, methionine, and tripeptide glutathione. Thiol groups, composed of sulfur, are essential to numerous metabolic processes. The easy and reversible oxidation and reduction of thiol groups have drawn attention to the redox regulation of cellular metabolism. Reactive sulfur species (RSS), including hydrogen sulfide (H2 S), persulfides, and polysulfides, are synthetized in all living organisms, mainly from cysteine, and have been recognized in the last two decades as very important molecules in redox regulation. RSS are considered potent signaling molecules, being involved in the regulation of virtually all aspects of cell function. With regard to stress, reactive species and the antioxidant machinery maintain a delicate balance that gets disturbed under stress conditions, wherein reactive species biosynthesis, transportation, scavenging, and overall metabolism become decisive for plant survival. While reactive oxygen and nitrogen species have been much discussed over recent years, research into RSS biosynthesis, signaling, and relation to abiotic stresses is still nascent. RSS evolved long before reactive oxygen species, and because both are metabolized by catalase, it has been suggested that "antioxidant" enzymes originally evolved to regulate RSS and may still do so today. In this review, we have tried to summarize the generation, signaling, and interaction of RSS in plant systems and to discuss in detail the roles under various abiotic stresses.

Buprenorphine for acute post-surgical pain: A systematic review and meta-analysis.

Our study was designed to evaluate the efficacy of buprenorphine for the management of acute post-surgical pain reported in published studies in the years 2015-2022. Comprehensive research was performed by using online resources like PUBMED and the Wiley Library database to gather the relevant literature. Two authors were assigned to independently collect the information. Cochran's Q-test and I square statistic were used to determine the heterogeneity across the studies. Publication bias was estimated by using the Egger regression analysis and found to be significantly present once the P value <0.05. In this review, 15 studies were included. The pooled ratio of pain reduction after 12 hours of surgery was reported as 11.2% with 97% heterogeneity. Day one shows 5.9 reductions in pain with 98% heterogeneity. The 3% more pain was reduced on day 2. The day 3 pooled pain reduction score was observed as 1.9%. The overall pool prevalence of pain reduction was noted as 6.2% at different time duration with significant heterogeneity of 100%. Buprenorphine transdermal and sublingual both have significant pain relief scores. The analgesic drug consumption was reduced at the end of the follow-up duration.

Ethylene Suppresses Abscisic Acid, Modulates Antioxidant System to Counteract Arsenic-Inhibited Photosynthetic Performance in the Presence of Selenium in Mustard.

Arsenic (As) stress provokes various toxic effects in plants that disturbs its photosynthetic potential and hampers growth. Ethylene and selenium (Se) have shown regulatory interaction in plants for metal tolerance; however, their synergism in As tolerance through modification of the antioxidant enzymes and hormone biosynthesis needs further elaboration. With this in view, we investigated the impact of ethylene and Se in the protection of photosynthetic performance against As stress in mustard (Brassica juncea L.). Supplementation with ethephon (2-chloroethylphosphonic acid; ethylene source) and/or Se allayed the negative impact of As-induced toxicity by limiting As content in leaves, enhancing the antioxidant defense system, and decreasing the accumulation of abscisic acid (ABA). Ethylene plus Se more prominently regulated stomatal behavior, improved photosynthetic capacity, and mitigated As-induced effects. Ethephon in the presence of Se decreased stress ethylene formation and ABA accumulation under As stress, resulting in improved photosynthesis and growth through enhanced reduced glutathione (GSH) synthesis, which in turn reduced the oxidative stress. In both As-stressed and non-stressed plants treated with ethylene action inhibitor, norbornadiene, resulted in increased ABA and oxidative stress with reduced photosynthetic activity by downregulating expression of ascorbate peroxidase and glutathione reductase, suggesting the involvement of ethylene in the reversal of As-induced toxicity. These findings suggest that ethephon and Se induce regulatory interaction between ethylene, ABA accumulation, and GSH metabolism through regulating the activity and expression of antioxidant enzymes. Thus, in an economically important crop (mustard), the severity of As stress could be reduced through the supplementation of both ethylene and Se that coordinate for maximum stress alleviation.

The Functional Interplay between Ethylene, Hydrogen Sulfide, and Sulfur in Plant Heat Stress Tolerance.

Plants encounter several abiotic stresses, among which heat stress is gaining paramount attention because of the changing climatic conditions. Severe heat stress conspicuously reduces crop productivity through changes in metabolic processes and in growth and development. Ethylene and hydrogen sulfide (H2S) are signaling molecules involved in defense against heat stress through modulation of biomolecule synthesis, the antioxidant system, and post-translational modifications. Other compounds containing the essential mineral nutrient sulfur (S) also play pivotal roles in these defense mechanisms. As biosynthesis of ethylene and H2S is connected to the S-assimilation pathway, it is logical to consider the existence of a functional interplay between ethylene, H2S, and S in relation to heat stress tolerance. The present review focuses on the crosstalk between ethylene, H2S, and S to highlight their joint involvement in heat stress tolerance.

Efficacy of regional anesthesia using ankle block in ankle and foot surgeries: a systematic review.

Ankle blocks are commonly used as surgical anesthetics and for postoperative analgesia during foot surgeries. It is chiefly an infiltration block which utilizes a localized anesthetic approach for providing surgical anaesthesia for a variety of foot procedures. Thus, in this systematic review, we focus primarily on the use, effectiveness, success and failures of regional ankle blocks in outpatient surgeries and hereby compare them with other anesthetic techniques and agents commonly used. Literature search was carried out using PubMed, Medline, Embase, Scopus and Cochrane Library for the studies existing till April 2021. Search was conducted by two independent reviewers separately keeping in view the structured format of the review. Data were thoroughly read and were extracted manually into a structured data extraction form. After going through the databases, 252 relevant articles were identified as per the search strategy. Among those 99 duplicate records were taken away. Among the remaining one hundred fifty-three records, one hundred thirty-eight records were excluded majorly going through their titles and abstracts. Next matching our inclusion criteria and going through the full texts, fifteen studies were excluded. Lastly, after excluding the reviews and case studies we included relevant 11 studies that compared the efficacy of ankle block in outpatient foot and ankle surgery in the present analysis. Seven studies used anatomic landmark guided (ALG) approach, three studies used ultrasound guided (USG) approach, while one study included both approaches. The results showed a significantly lower VAS score postoperatively at 24 hrs. It was observed that in general, immediately after surgery the VAS pain scores are low due to the continued analgesic effect provided by the ankle block. 0.25%-0.5% bupivacaine was the most common single long-acting local anesthetics used. Patient satisfaction ranged from 66%-95.8%. Major complications included block failure and consequent requirement of general anesthesia and few cases of transient nerve injuries. Therefore, this systematic review supports the fact that ankle block has advantages like excellent success rates with minimal side effects, high levels of patient satisfaction and decreased hospital expenses. Thus, it proves to be a safe and highly effective means of regional anesthesia for the majority of foot and ankle surgeries in outpatient settings.

Exogenously-Sourced Ethylene Positively Modulates Photosynthesis, Carbohydrate Metabolism, and Antioxidant Defense to Enhance Heat Tolerance in Rice.

The effect of exogenously-applied ethylene sourced from ethephon (2-chloroethyl phosphonic acid)was studied on photosynthesis, carbohydrate metabolism, and high-temperature stress tolerance in Taipei-309 and Rasi cultivars of rice (Oryza sativa L.). Heat stress increased the content of H2O2 and thiobarbituric acid reactive substances (TBARS)more in Rasi than Taipei-309. Further, a significant decline in sucrose, starch, and carbohydrate metabolism enzyme activity and photosynthesis was also observed in response to heat stress. The application of ethephon reduced H2O2 and TBARS content by enhancing the enzymatic antioxidant defense system and improved carbohydrate metabolism, photosynthesis, and growth more conspicuously in Taipei-309 under heat stress. The ethephon application enhanced photosynthesis by up-regulating the psbA and psbB genes of photosystem II in heat-stressed plants. Interestingly, foliar application of ethephoneffectively down-regulated high-temperature-stress-induced elevated ethylene biosynthesis gene expression. Overall, ethephon application optimized ethylene levels under high-temperature stress to regulate the antioxidant enzymatic system and carbohydrate metabolism, reducing the adverse effects on photosynthesis. These findings suggest that ethylene regulates photosynthesis via carbohydrate metabolism and the antioxidant system, thereby influencing high-temperature stress tolerance in rice.