The demand for agricultural crops continues to escalate with an increasing population. To meet this demand, marginal land can be used as a sustainable source for increased plant productivity. ...However, moisture stress not only affects crop growth and productivity but also induces plants' susceptibility to various diseases. The positive role of plant growth hormone, salicylic acid (SA), on the defence systems of plants has been well documented. With this in mind, a combination of plant growth promoting rhizobacteria (PGPR) and SA was used to evaluate its performance on wheat grown under rainfed conditions (average moisture 10-14%). The selected bacterial strains were characterized for proline production, indole-3-acetic acid (IAA), hydrogen cyanide (HCN), ammonia (NH3), and exopolysaccharides (EPS). Wheat seeds of two genotypes, Inqilab-91 (drought tolerant) and Shahkar-2013 (drought sensitive), which differed in terms of their sensitivity to drought stress, were soaked for three hours prior to sowing in 24-hour old cultures of the bacterial strains Planomicrobium chinense strain P1 (accession no. MF616408) and Bacillus cereus strain P2 (accession no. MF616406). SA was applied (150 mg/L), as a foliar spray on one-month-old wheat seedlings. A significant reduction in the physiological parameters was noted in the plants grown in rainfed conditions but the PGPR and SA treatment effectively ameliorated the adverse effects of moisture stress. The wheat plants treated with PGPR and SA showed significant increases in leaf protein and sugar contents and maintained higher chlorophyll content, chlorophyll fluorescence (fv/fm) and performance index (PI) under rainfed conditions. Leaf proline content, lipid peroxidation, and antioxidant enzyme activity were higher in the non-inoculated plants grown in rainfed conditions but significantly reduced in the inoculated plants of both genotypes. Integrative use of a combination of PGPR strains and SA appears to be a promising and eco-friendly strategy for reducing moisture stress in plants.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Plant-growth-promoting microorganisms are beneficial microbes that reside in the rhizosphere and roots of plants, direct their developmental process and induce systemic resistance ...
Nanotechnology has shown promising potential tools and strategies at the nanometer scale to improve food production and meet the future demands of agricultural and food security. However, considering ...nanotechnology’s potential benefits to date, their applicability has not yet reached up to field conditions. Increasing concerns regarding absorption, translocation, bioavailability, toxicity of nanoparticles, and impropriety of the regulatory framework restrict the complete acceptance and inclination of the agricultural sector to implement nanotechnologies. The biological function of nanoparticles depends on their physicochemical properties, the method of application, and concentration. The effects of the various types of nanoparticles (NPs) on plants were determined to increase seed germination and biomass or grain yield. The NPs also increased the plant’s resistance to various biotic and abiotic stresses. The plant’s biological functions depend on the events that occur at the molecular level. However, little progress has been made at the molecular level influenced by nanoparticles, which is an important step in evaluating potential mechanisms and plants’ effects. Therefore, it is important to understand plants’ underlying mechanism and response towards nanoparticles, and the gene expression changes through molecular approaches. The associations of nanomaterials with plant cells, the process of internalization, and the distribution of biomolecules using nanoparticles as a carrier are studied but not well understood. The transmission of biomolecules, such as nucleic acids, is a major obstacle due to cell walls, limiting the application of nanomaterials in crop enhancement mediated by genetic engineering. Recently, the use of different nanomaterials for nucleic acid delivery in plant cells has been published. Here, we aim to update researchers on the absorption and translocation of nanoparticles and elaborate on the importance of nanoparticles in agriculture and crop stress tolerance.
Plant growth regulators (PGRs) and plant growth promoting rhizobacteria (PGPRs) play an important role in mitigating abiotic stresses. However, little is known about the parallel changes in ...physiological processes coupled with metabolic changes induced by PGRs and PGPRs that help to cope with drought stress in chickpeas. The present investigation was carried out to study the integrative effects of PGRs and PGPRs on the physiological and metabolic changes, and their association with drought tolerance in two chickpea genotypes. Inoculated seeds of two chickpea genotypes, Punjab Noor-2009 (drought sensitive) and 93127 (drought tolerance), were planted in greenhouse condition at the University of Florida. Prior to sowing, seeds of two chickpea varieties were soaked for 3 h in 24 h old cultures of PGPRs (Bacillus subtilis, Bacillus thuringiensis, and Bacillus megaterium), whereas, some of the seeds were soaked in distilled water for the same period of time and were treated as control. Plant growth regulators, salicylic acid (SA) and putrescine (Put), were applied on 25 days old seedlings just prior to the induction of drought stress. Drought stress was imposed by withholding the supply of water on 25-day-old seedlings (at the three-leaf stage) and continued for the next 25 days until the soil water content reached 14%. Ultrahigh-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) analysis concomitant with physiological parameters were carried out in chickpea leaves at two-time points i.e. 14 and 25 d after imposition of drought stress. The results showed that both genotypes, treated with PGRs and PGPRs (consortium), performed significantly better under drought condition through enhanced leaf relative water content (RWC), greater biomass of shoot and root, higher Fv/FM ratio and higher accumulation of protein, sugar and phenolic compounds. The sensitive genotype was more responsive than tolerant one. The results revealed that the accumulation of succinate, leucine, disaccharide, saccharic acid and glyceric acid was consistently higher in both genotypes at both time points due to PGRs and PGPRs treatment. Significant accumulation of malonate, 5-oxo-L-proline, and trans-cinnamate occurred at both time points only in the tolerant genotype following the consortium treatment. Aminoacyl-tRNA, primary and secondary metabolite biosynthesis, amino acid metabolism or synthesis pathways, and energy cycle were significantly altered due to PGRs and PGPRs treatment. It is inferred that changes in different physiological and metabolic parameters induced by PGRs and PGPRs treatment could confer drought tolerance in chickpeas.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Non-invasive remote health monitoring plays a vital role in epidemiological situations such as SARS outbreak (2003), MERS (2015) and the recently ongoing outbreak of COVID-19 because it is extremely ...risky to get close to the patient due to the spread of contagious infections. Non-invasive monitoring is also extremely necessary in situations where it is difficult to use complicated wired connections, such as ECG monitoring for infants, burn victims or during rescue missions when people are buried during building collapses/earthquakes. Due to the unique characteristics such as higher penetration capabilities, extremely precise ranging, low power requirement, low cost, simple hardware and robustness to multipath interferences, Impulse Radio Ultra Wideband (IR-UWB) technology is appropriate for non-invasive medical applications. IR-UWB sensors detect the macro as well as micro movement inside the human body due to its fine range resolution. The two vital signs, i.e., respiration rate and heart rate, can be measured by IR-UWB radar by measuring the change in the magnitude of signal due to displacement caused by human lungs, heart during respiration and heart beating. This paper reviews recent advances in IR- UWB radar sensor design for healthcare, such as vital signs measurements of a stationary human, vitals of a non-stationary human, vital signs of people in a vehicle, through the wall vitals measurement, neonate's health monitoring, fall detection, sleep monitoring and medical imaging. Although we have covered many topics related to health monitoring using IR-UWB, this paper is mainly focused on signal processing techniques for measurement of vital signs, i.e., respiration and heart rate monitoring.
During the last two decades the world has experienced an abrupt change in climate. Both natural and artificial factors are climate change drivers, although the effect of natural factors are lesser ...than the anthropogenic drivers. These factors have changed the pattern of precipitation resulting in a rise in sea levels, changes in evapotranspiration, occurrence of flood overwintering of pathogens, increased resistance of pests and parasites, and reduced productivity of plants. Although excess CO
2
promotes growth of C
3
plants, high temperatures reduce the yield of important agricultural crops due to high evapotranspiration. These two factors have an impact on soil salinization and agriculture production, leading to the issue of water and food security. Farmers have adopted different strategies to cope with agriculture production in saline and saline sodic soil. Recently the inoculation of halotolerant plant growth promoting rhizobacteria (PGPR) in saline fields is an environmentally friendly and sustainable approach to overcome salinity and promote crop growth and yield in saline and saline sodic soil. These halotolerant bacteria synthesize certain metabolites which help crops in adopting a saline condition and promote their growth without any negative effects. There is a complex interkingdom signaling between host and microbes for mutual interaction, which is also influenced by environmental factors. For mutual survival, nature induces a strong positive relationship between host and microbes in the rhizosphere. Commercialization of such PGPR in the form of biofertilizers, biostimulants, and biopower are needed to build climate resilience in agriculture. The production of phytohormones, particularly auxins, have been demonstrated by PGPR, even the pathogenic bacteria and fungi which also modulate the endogenous level of auxins in plants, subsequently enhancing plant resistance to various stresses. The present review focuses on plant-microbe communication and elaborates on their role in plant tolerance under changing climatic conditions.
Both the plant growth promoting rhizobacteria (PGPR) and plant growth regulators (PGR) exert beneficial effects on plant growth even under stress, but combined effect of both of them has not been ...evaluated yet. Present investigation was aimed to determine the responses of 2 chickpea varieties (differing in drought tolerance) to 3 PGPR viz. Bacillus subtilis, Bacillus thuringiensis and Bacillus megaterium and PGR (SA and Putrescine) on physiology of chickpea grown in sandy soil. The PGR, Salicylic acid (SA) and Putrescine (Put) were sprayed on the seedling 20 days after germination. Results revealed, synergistic effects of PGPR and PGR on chlorophyll, protein and sugar contents. Addition of PGR to PGPR inoculated plants assisted the plant in osmoregulation and amelioration of oxidative stresses and in induction of new proteins. Combined application of PGR and PGPR decreased lipid peroxidation more effectively but increased the leaf area. It is inferred that PGPR and PGR work synergistically to promote growth of plants under moisture and nutrient deficit condition of sandy soil. Since, SA induces Systemic Acquired Resistance (SAR) in plants hence the addition of SA along with PGPR may render the plant more productive and better tolerant to diseases/pathogen attack.
Textile industries use dyes to color their products and release waste water containing dyes, causing water pollution which is a serious problem for survival of human life on earth. The decolorization ...of basic turquise blue X-GB (BTB X-GB) 250% and basic blue X-GRRL (BB X GRRL) 250% dyes was examined by advanced (Fenton process) oxidation process. The effects of different parameters (initial dye concentration, pH, concentrations of hydrogen peroxide (H
) and reaction time) have been examined and optimum conditions were determined. It has been noted that percentage decolorization of both dyes (50 mg/L) increases with increase in concentration of H
. At optimum conditions (pH=3.0, H
=4.8 mM, temperature=50°C, time=80 min of BTB X-GB, and pH=5.0, H
=5.6 mM, temperature=40°C, time=60 min of BB X-GRRL) the decolorization obtained by Fenton process was 85.83% of BTB X-GB and 74.98% for BB X-GRRL. 1
order, 2
order and BMG kinetic models were used to analyze the data. BMG model gives us the higher values of correlation coefficients for all data. Results showed that Fe
/H
are most effective for oxidation treatment of waste water effluents containing dyes as main pollutants.
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