Silicate solubilizing and plant growth promoting bacteria interact with biogenic silica to impart heat stress tolerance in rice by modulating physiology and gene expression

Heat stress caused due to increasing warming climate has become a severe threat to global food production including rice. Silicon plays a major role in improving growth and productivity of rice by aiding in alleviating heat stress in rice. Soil silicon is only sparingly available to the crops can be made available by silicate solubilizing and plant-growth-promoting bacteria that possess the capacity to solubilize insoluble silicates can increase the availability of soluble silicates in the soil. In addition, plant growth promoting bacteria are known to enhance the tolerance to abiotic stresses of plants, by affecting the biochemical and physiological characteristics of plants. The present study is intended to understand the role of beneficial bacteria viz. Rhizobium sp. IIRR N1 a silicate solublizer and Gluconacetobacter diazotrophicus, a plant growth promoting bacteria and their interaction with insoluble silicate sources on morpho-physiological and molecular attributes of rice (Oryza sativa L.) seedlings after exposure to heat stress in a controlled hydroponic system. Joint inoculation of silicates and both the bacteria increased silicon content in rice tissue, root and shoot biomass, significantly increased the antioxidant enzyme activities (viz. superoxidase dismutase, catalase and ascorbate peroxidase) compared to other treatments with sole application of either silicon or bacteria. The physiological traits (viz. chlorophyll content, relative water content) were also found to be significantly enhanced in presence of silicates and both the bacteria after exposure to heat stress conditions. Expression profiling of shoot and root tissues of rice seedlings revealed that seedlings grown in the presence of silicates and both the bacteria exhibited higher expression of heat shock proteins (HSPs viz., OsHsp90, OsHsp100 and 60 kDa chaperonin), hormone-related genes (OsIAA6) and silicon transporters (OsLsi1 and OsLsi2) as compared to seedlings treated with either silicates or with the bacteria alone. The results thus reveal the interactive effect of combined application of silicates along with bacteria Rhizobium sp. IIRR N1, G. diazotrophicus inoculation not only led to augmented silicon uptake by rice seedlings but also influenced the plant biomass and elicited higher expression of HSPs, hormone-related and silicon transporter genes leading to improved tolerance of seedling to heat stress

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Sustainable Subsea Pressure Housing for Shallow Water Applications

542-549The design of subsea pressure housing (SPH) with parameters such as hydrostatic external pressure, temperature and salinity prevailing in the marine environment requires a proper selection of materials. The housing is designed to accommodate the data acquisition electronics that is capable of handling a higher sampling rate and a larger capacity power pack for subsea ambient noise measurement mooring system operating at an ocean depth of 100 m in the shallow waters of the Indian coast. The scope of the housing design includes sustenance and operation of the system for a minimum of six months in an open ocean environment withstanding extreme events like cyclones and storm surges prevalent in the sea. The main aim of this paper is to present the work carried out on the design of SPH with three different materials such as high-strength stainless steel (SS316L), aluminium alloy (Al6061-T6) and titanium alloy (Ti-6Al-4V) for shallow-water applications. The design of SPH in a cylindrical shape with an internal diameter of 0.33m (330 mm) and length of 0.7m(700 mm) to withstand a pressure of 1MPa (10 bar) and hoop, axial and Von Mises stresses has been accomplished as per the American Society of Mechanical Engineers (ASME) code/standards. The buckling of cylindrical pressure housing and principle stresses were calculated through a finite element analysis (FEA) using ANSYS software.Further comparative studies on three materials mentioned above on the criteria of maximum stress, critical buckling pressure, formability, corrosive properties and cost of fabrication were carried out. The pressure housing with SS316L material is found to be an optimal choice for shallow-water applications in the open ocean. The subsea housing thus designed has been fabricated with SS316L and operated in the shallow waters of Goa successfully for a period of six months continuously

Proizvodnja, karakterizacija i primjena monoklonskih protutijela za pileći IgY.

Monoclonal antibodies (Mabs) were produced against chicken IgY purified from egg yolks. Purity of the IgY was established using immunoelectrophoresis and reducing and non reducing polyacrylamide gel electrophoresis. Five stable hybrid clones were characterized and Mabs, all belonging to IgG1 isotype, were found to bind to the IgY heavy chain in Western blots. These clones did not cross-react with IgM in enzyme-linked immunosorbent assay (ELISA). One of the Mabs was used as a capture antibody in ELISA for estimation of IgY purified from egg yolk by different methods. Caprylic acid precipitation method gave the highest recovery of IgY and with high purity.Proizvedena su monoklonska protutijela za pročišćeni IgY iz žumanjka jajeta. Čistoća IgY dokazana je imunoelektroforezom te reducirajućom i nereducirajućom elektroforezom u poliakrilamid gelu. Obilježeno je pet stabilnih hibridnih klonova, a za monoklonska protutijela koja su pripadala izotipu IgG1 ustanovljeno je da su se vezala za teški lanac IgY u Western blotu. Ovi klonovi nisu unakrižno reagirali s IgM u imunoenzimnom testu (ELISA). Jedno od monoklonskih protutijela rabljeno je kao vezano protutijelo u imunoenzimnom testu za procjenjivanje pročišćenosti IgY različitim metodama. Metoda precipitacije s kaprilnom kiselinom bila je najosjetljivija u otkrivanju IgY visoke čistoće

Effect of Nitrogen-fixing Bacteria on Germination, Seedling Vigour and Growth of Two Rice (Oryza sativa L.) Cultivars

To evaluate the effect of isolated nitrogen fixing plant growth-promoting bacteria (PGPB) on seed germination and growth promotion of rice cultivars (cv. BPT 5204 and Improved Samba Mahsuri). Eight promising N-fixing PGPB along with two standard cultures (viz. B. japonicum and G. diazotrophicus) were inoculated as seed treatment to rice genotypes and the effect on seed germination, seed vigour index and plant growth promotion of rice cultivars was assessed under in vitro (agar method) and in vivo (pot experiment) net house conditions. PGPBs (viz., Paenibacillus sonchi IIRRBNF1, Paenibacillus sp. IIRRNF2, Ochrobactrum sp. IIRRNF3, Burkholderia cepacia IIRRNF4, Burkholderia sp. IIRRNF5, Stenotrophomonas sp. IIRRNF6, Rhizobium sp. IIRRNF7 and Xanthomonas sacchari IIRRNF8) were enhanced seed germination, seed vigour index, seedling growth and dry matter accumulation (root and shoot dry matter) of rice cultivars under in vitro as well as in vivo conditions. Among all PGPB, Paenibacillus sonchi IIRRBNF1 exhibited the highest ability to stimulate plant growth promotion under both the conditions. The eight PGPB isolates exhibited positive influence on seed germination indices as well as growth promotion traits of rice cultivars at seedling stage and can be further evaluated at different growth stages under pot and field experiment

Table_2_Understanding plant–microbe interaction of rice and soybean with two contrasting diazotrophic bacteria through comparative transcriptome analysis.xlsx

Understanding the beneficial plant–microbe interactions is becoming extremely critical for deploying microbes imparting plant fitness and achieving sustainability in agriculture. Diazotrophic bacteria have the unique ability to survive without external sources of nitrogen and simultaneously promote host plant growth, but the mechanisms of endophytic interaction in cereals and legumes have not been studied extensively. We have studied the early interaction of two diazotrophic bacteria, Gluconacetobacter diazotrophicus (GAB) and Bradyrhizobium japonicum (BRH), in 15-day-old seedlings of rice and soybean up to 120 h after inoculation (hai) under low-nitrogen medium. Root colonization of GAB in rice was higher than that of BRH, and BRH colonization was higher in soybean roots as observed from the scanning electron microscopy at 120 hai. Peroxidase enzyme was significantly higher at 24 hai but thereafter was reduced sharply in soybean and gradually in rice. The roots of rice and soybean inoculated with GAB and BRH harvested from five time points were pooled, and transcriptome analysis was executed along with control. Two pathways, “Plant pathogen interaction” and “MAPK signaling,” were specific to Rice-Gluconacetobacter (RG), whereas the pathways related to nitrogen metabolism and plant hormone signaling were specific to Rice-Bradyrhizobium (RB) in rice. Comparative transcriptome analysis of the root tissues revealed that several plant–diazotroph-specific differentially expressed genes (DEGs) and metabolic pathways of plant–diazotroph-specific transcripts, viz., chitinase, brassinosteroid, auxin, Myeloblastosis (MYB), nodulin, and nitrate transporter (NRT), were common in all plant–diazotroph combinations; three transcripts, viz., nitrate transport accessory protein (NAR), thaumatin, and thionin, were exclusive in rice and another three transcripts, viz., NAC (NAM: no apical meristem, ATAF: Arabidopsis thaliana activating factor, and CUC: cup-shaped cotyledon), ABA (abscisic acid), and ammonium transporter, were exclusive in soybean. Differential expression of these transcripts and reduction in pathogenesis-related (PR) protein expression show the early interaction. Based on the interaction, it can be inferred that the compatibility of rice and soybean is more with GAB and BRH, respectively. We propose that rice is unable to identify the diazotroph as a beneficial microorganism or a pathogen from an early response. So, it expressed the hypersensitivity-related transcripts along with PR proteins. The molecular mechanism of diazotrophic associations of GAB and BRH with rice vis-à-vis soybean will shed light on the basic understanding of host responses to beneficial microorganisms.</p