Soybean (Glycine max (L.) Merrill) is a globally important crop, providing oil and protein. Diaporthe/Phomopsis complex includes seed-borne pathogens that affect this legume. Non-thermal plasma ...treatment is a fast, cost-effective and environmental-friendly technology. Soybean seeds were exposed to a quasi-stationary (50 Hz) dielectric barrier discharge plasma operating at atmospheric pressure air. Different carrying gases (O2 and N2) and barrier insulating materials were used. This work was performed to test if the effects of non-thermal plasma treatment applied to healthy and infected seeds persist throughout the entire cycle of plants. To this aim, lipid peroxidation, activity of catalase, superoxide dismutase and guaiacol peroxidase, vegetative growth and agronomic traits were analysed. The results here reported showed that plants grown from infected seeds did not trigger oxidative stress due to the reduction of pathogen incidence in seeds treated with cold plasma. Vegetative growth revealed a similar pattern for plants grown from treated seeds than that found for the healthy control. Infected control, by contrast, showed clear signs of damage. Moreover, plasma treatment itself increased plant growth, promoted a normal and healthy physiological performance and incremented the yield of plants. The implementation of this technology for seeds treatment before sowing could help reducing the use of agrochemicals during the crop cycle.
•UV-B affects plant growth and development.•Nitric oxide protects against UV-B-induced oxidative stress.•Nitric oxide up-regulates antioxidant enzymes transcript levels.•Specific isoforms of ...antioxidant enzymes are involved in plant acclimation to UV-B.
Antioxidant enzymes play a key role in plant tolerance to different types of stress, including ultraviolet-B (UV-B) radiation. Here we report that nitric oxide (NO) enhances antioxidant enzymes gene expression and increases the activity of specific isoforms protecting against UV-B radiation. Pre-treatments with sodium nitroprussiate (SNP), a NO-donor, prevented lipid peroxidation, ion leakage and H2O2 and superoxide anion accumulation in leaves of UV-B-treated soybean plants. Transcripts levels of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were significantly induced by SNP. These data correlated with the enhancement of particular antioxidant enzyme isoforms, such as one CAT isoform and two APX isoforms. Moreover, SNP induced the expression of three new isoforms of SOD, identified as Mn-SOD subclass. Further results showed that total activities of SOD, CAT and APX significantly increased by 2.2-, 1.8- and 2.1-fold in SNP-treated plants compared to controls, respectively. The protective effect of SNP against UV-B radiation was negated by addition of the specific NO scavenger cPTIO, indicating that NO released by SNP mediates the enhancement of antioxidant enzymes activities. In conclusion, NO is involved in the signaling pathway that up-regulates specific isoforms of antioxidant enzymes protecting against UV-B-induced oxidative stress.
BACKGROUND: Serotoninergic (5-HT) neurons are suggested to regulate estrous cycle in animal models. In the present study we evaluated whether a relationship exists between the serotoninergic ...precursors in the central nervous system and the gonadotrophin–ovarian cyclic function. METHODS: We measured 5-HT precursors free (FT) and total (TT) tryptophan and LH, FSH and 17β-estradiol (E2) levels in the serum of 15 fertile women with normal menstrual cycles during the follicular (cycle days 1–5, 7–11), mid-cycle (cycle days 14–16) and luteal (cycle days 17–19, 22–24) phases. RESULTS: TT and FT were significantly increased in the 7–11 and 17–19 cycle days and were decreased at mid-cycle (P<0.01), with a cyclic and opposite behaviour when compared to that of FSH and LH. Indeed, correlation analysis through the matrix of mean values showed that LH was negatively correlated to TT (r=−0.636) and FT (r=−0.574), as well as FSH (TT, r=−0.655; FT, r=−0.663), and that TT and FT were positively correlated to each other (r=0.801; P<0.001). Furthermore, whilst the two FT peaks reached approximately the same levels in the follicular and luteal phase, TT levels were ∼30% higher in the luteal than in the follicular phase of the cycle: thus in the first (follicular) phase FT peak was relatively higher than that of TT, whereas the contrary occurred in the second (luteal) phase of the cycle. CONCLUSIONS: Both TT and FT levels have cyclic variations throughout the menstrual cycle, being lowest at mid-cycle (14–16 cycle days), concomitant with the highest LH and FSH concentrations, and higher before and after mid-cycle phase, coinciding with the lowest circulating LH/FSH levels. Since TT and FT levels in the plasma have cyclic changes, our study: (i) suggests that a consumption of serum serotonin precursors takes place concomitant with gonadotrophin release during menstrual cycle; (ii) may represent an in vivo model to investigate this relationship in women in different physiopathological conditions.
•HO activity is not the main source of CO in soybean plants.•Total CO production in leaves and roots is induced by 200mM NaCl treatment.•CO production is not the best parameter to measure HO activity ...in soybean plants.•Endogenous CO levels significantly vary in different plant species.
The exogenous application of carbon monoxide (CO) is a valuable strategy which enables study of the effects under different stress conditions. However, in this experimental model a true endogenous CO production by plants cannot be measured. In this work, so as to achieve an elevated sensitivity and to avoid invasive techniques, we quantify the endogenous CO production by tissues in salt-treated soybean plants through gas chromatography coupled to a reduction gas detector. This technique allows short and room temperature incubation of intact tissues and homogenates. We found that a 200mM NaCl treatment induces total CO production in leaves and roots. The sensitivity of the technique offers no correlation between this increment and heme oxygenase (HO) activity measured as a function of CO production. We also found that untreated soybean plants continue to produce significant CO levels up to 7 days post planting, after which CO content decreases to a third and remains constant in the next days. However, HO activity does not change throughout these days. The data here reported shows that HO activity is not the main source of CO in soybean plants. We discuss alternative sources that could be implicated in this production. Taking our own results and data reported by other colleagues, we propose lipid peroxidation and ureide metabolism as potential sources of CO.
We examined the biocontrol and the differential production of H2O2 and Formula omitted. in the relationship Macrophomina phaseolina - PGPR in soybean seedling. Fungal colonisation was efficiently ...prevented by inoculation with Pseudomonas fluorescens 9. Its ability to improve ROS production and gene expression of antioxidant enzymes could be related to its capacity to control the disease.
The behaviour of enzymes involved in nitrogen metabolism, as well as oxidative stress generation and heme oxygenase gene and protein expression and activity, were analysed in soybean (
Glycine max ...L.) nodules exposed to 50, 100 and 200
mM NaCl concentrations. A significant increase in lipid peroxidation was found with 100 and 200
mM salt treatments. Moreover, superoxide dismutase, catalase and peroxidase activities were decreased under 100 and 200
mM salt. Nitrogenase activity and leghemeoglobin content were diminished and ammonium content increased only under 200
mM NaCl. At 100
mM NaCl, glutamine synthetase (GS) and NADH-glutamate dehydrogenase (GDH) activities were similar to controls, whereas a significant increase (64%) in NADH-glutamate synthase (GOGAT) activity was observed. GS activity did not change at 200
mM salt treatment, but GOGAT and GDH significantly decreased (40 and 50%, respectively). When gene and protein expression of GS and GOGAT were analysed, it was found that they were positively correlated with enzyme activities. In addition, heme oxygenase (HO) activity, protein synthesis and gene expression were significantly increased under 100
mM salt treatment. Our data demonstrated that the up-regulation of HO, as part of antioxidant defence system, could be protecting the soybean nodule nitrogen fixation and assimilation under saline stress conditions.
Recent full-scale experimental tests performed on steel and composite structures have demonstrated that the presence of tensile forces in axially-restrained beams during the cooling phase of a fire ...could lead to bolt failures. In order to understand this observation and design structures that are not prone to such a failure mode, it is essential to have a deep knowledge of the material behaviour of all the components, including bolts, during both the heating and cooling phase.
In the present article, the test set-ups and the results of the tensile and shear tests performed at the Centro Sviluppo Materiali (Italy) on Grade 8.8 bolts under heating–cooling cycles are described.
Then, material laws are defined for characterising the mechanical behaviour of Grade 8.8 bolts under heating and cooling phases. These laws account for the non-reversibility of the mechanical properties of Grade 8.8 bolts.
► The behaviour of Grade 8.8 bolts is not reversible after heating up to
50
0
∘
C
. ► The loss of bolts resistance after a complete heating–cooling cycle can be 40%. ► The ductility of bolts is clearly increased when the peak temperature of the cycle is
80
0
∘
C
.
We have previously demonstrated that the induction of haem oxygenase-1 (EC 1.14.99.3) plays a protective role for soybean plants against cadmium and UV-B stress. Here, we have investigated the ...possible signal transduction pathways involved in haem oxygenase-1 induction in leaves of soybean plants subjected to salt stress. Treatment with 100 mM NaCl during 48 h increased thiobarbituric acid reactive substances by 30%, whereas GSH decreased by 50%, with respect to controls. These effects were prevented by pre-incubation with diphenyleneiodonium (DPI; an NADPH oxidase inhibitor), 1,2,4oxadiazolo-4,3-aquinoxalin-1-one (ODQ; a guanylate cyclase inhibitor) or LaCl
3
(calcium channel blocker). NaCl at 100 mM produced in situ accumulation of H
2
O
2
and O
2
*−
, which were also prevented by DPI, ODQ or LaCl
3
. Moreover, salt-induced haem oxygenase-1 activity was also totally abolished by pretreatment with the different inhibitors. These results clearly demonstrated that the signal transduction pathways involved in oxidative stress triggered by salt stress were similar to those implicated in haem oxygenase-1 induction, and provide additional information suggesting that haem oxygenase might play a key role in the antioxidative protection machinery of higher plants.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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