Exogenous nitric oxide alleviates sulfur deficiency-induced oxidative damage in tomato seedlings.

Despite numerous reports on the role of nitric oxide (NO) in regulating plants growth and mitigating different environmental stresses, its participation in sulfur (S) -metabolism remains largely unknown. Therefore, we studied the role of NO in S acquisition and S-assimilation in tomato seedlings under low S-stress conditions by supplying NO to the leaves of S-sufficient and S-deficient seedlings. S-starved plants exhibited a substantial decreased in plant growth attributes, photosynthetic pigment chlorophyll (Chl) and other photosynthetic parameters, and activity of enzymes involved in Chl biosynthesis (δ-aminolevulinic acid dehydratase), and photosynthetic processes (carbonic anhydrase and RuBisco). Also, S-deficiency enhanced reactive oxygen species (ROS) (superoxide and hydrogen peroxide) and lipid peroxidation (malondialdehyde) levels in tomato seedlings. Contrarily, foliar supplementation of NO to S-deficient seedlings resulted in considerably reduced ROS formation in leaves and roots, which alleviated low S-stress-induced lipid peroxidation. However, exogenous NO enhanced proline accumulation by increasing proline metabolizing enzyme (Δ1-pyrroline-5-carboxylate synthetase) activity and also increased NO, hydrogen sulfide (a gasotransmitter small signaling molecule) and S uptake, and content of S-containing compounds (cysteine and reduced glutathione). Under S-limited conditions, NO improved S utilization efficiency of plants by upregulating the activity of S-assimilating enzymes (ATP sulfurylase, adenosine 5-phosphosulfate reductase, sulfide reductase and O-acetylserine (thiol) lyase). Under S-deprived conditions, improved S-assimilation of seedlings receiving NO resulted in improved redox homeostasis and ascorbate content through increased NO and S uptake. Application of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxy l-3-oxide (an NO scavenger) invalidated the effect of NO and again caused low S-stress-induced oxidative damage, confirming the beneficial role of NO in seedlings under S-deprived conditions. Thus, exogenous NO enhanced the tolerance of tomato seedlings to limit S-triggered oxidative stress and improved photosynthetic performance and S assimilation.

Potential roles of melatonin and sulfur in alleviation of lanthanum toxicity in tomato seedlings.

Owing to the active use of rare-earth elements in many areas, it is necessary to study their behavior in the environment and their biological impact on plants. Despite the role of melatonin and sulfur in plant growth, development and abiotic stress tolerance; it is still not clear how they have a strong regulatory influence and synergistic effect on growth, physiological and biochemical characteristics of plants under different environmental stresses. Therefore, this study highlights how melatonin and sulfur together potentially involved in a reversal of lanthanum-inhibited photosynthetic and growth responses in tomato seedlings. Here, we reported that seedlings grown in a medium containing 150 µM lanthanum exhibited increased overproduction of reactive oxygen species (ROS) and lipid peroxidation together with increased Chlorophyll degradation, and activity of chlorophyllase, proline dehydrogenase and glycolate oxidase (GOx), and decreased photosynthesis and growth. However, the application of melatonin and sulfur showed significant responses on tomato seedlings, although the response of their combined treatment was more effective by further increasing photosynthesis and growth under lanthanum toxicity. Melatonin supplied with sulfur suppressed ROS formation, lipid peroxidation and activity of GOx, and increased photosynthesis by upregulating activities of carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase. Also, sulfur supplementation with melatonin to seedlings resulted in an elevation in the accumulation of Chl and proline by increasing δ-aminolevulinic acid and activity of δ-aminolevulinic acid dehydratase and Δ1-pyrroline-5-carboxylate synthetase activity. The administration of melatonin with sulfur substantially induced upregulation of enzymes (superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase) activities involved in the antioxidant system, thereby mitigating ROS-induced oxidative damage. Thus, this study provides strong evidence that melatonin and sulfur have strong regulatory influence and synergistic role in alleviating the adverse effect of lanthanum-toxicity by increasing photosynthesis and growth.

The value of ultrasound and magnetic resonance imaging in diagnostics and prediction of morbidity in cases of placenta previa with abnormal placentation.

BACKGROUND: The purpose of the study was to evaluate the role of ultrasound (US) and magnetic resonance imaging (MRI) in the diagnostics and management of abnormal placentation in women with placenta previa and to compare the morbidity associated with that to placenta previa alone. MATERIAL/METHODS: The study includes 100 pregnant women with placenta previa with and without abnormal placentation. The results of MRI and US in abnormal placentation were compared with post-operative data. The patients' files were reviewed for assessment of operative and post-operative morbidity. The results of our statistical analysis were compared with data from the literature. RESULTS: US and MRI showed no significant difference in sensitivity and specificity in diagnosing abnormal placentation (97-100% and 94-100%, respectively). MRI was more sensitive than US for the detection of myometrial invasion and the type of abnormal placentation (73.5% and 47%, respectively). The difference between pre- and post-operative hemoglobin values and estimated blood loss were the most significant risk factors for abnormal placentation, added to risk factors known for placenta previa. Post-partum surgical complications and prolonged hospital stay were more common in the cases of placenta previa with abnormal placentation, however statistically insignificant. CONCLUSIONS: US and MRI are accurate imaging modalities for diagnosing abnormal placentation. MRI was more sensitive for the detection of the degree of placental invasion. The patient's morbidity increased in cases with abnormal placentation. There was no significant difference in post operative-complications and hospitalization time due to pre-operative planning when the diagnosis was established with US and MRI.

Effects of Zinc Oxide and Silicon Dioxide Nanoparticles on Physiological, Yield, and Water Use Efficiency Traits of Potato Grown under Water Deficit.

Water deficit is a major challenge for sustainable global food security, especially, in arid and semi-arid regions. Nanotechnology is regarded as an effective tool for managing a wide range of environmental stresses by providing novel and practical solutions. A field experiment was conducted to assess the effects of zinc oxide nanoparticles 'ZnO NPs' (0, 50, 100 ppm) and silicon dioxide nanoparticles 'SiO2 NPs' (0, 25, 50 ppm) as an exogenous application on the physiological indices, total yield and water use efficiency (WUE) of potato under water deficit conditions (50%, 75%, and 100% of crop evapotranspiration (ETc) water requirements). Water deficit significantly decreased most physiological indices and yield traits of potato, but increased proline content and WUE. In contrast, exogenous application of ZnO NPs and SiO2 NPs to plants grown under different water deficit treatments resulted in an increase in leaf gas exchange, leaves relative water contents (LRWC), photosynthetic pigments, and leaf green index. Under different water deficit treatments, the highest total yield and harvest index traits were obtained from plants treated with ZnO-NPs-100 ppm followed by 50 ppm of ZnO and SiO2 NPs, respectively. The highest WUE was recorded when the potato plants were irrigated with 50% ETc and exogenous treated with 100 ppm of ZnO NPs compared with fully irrigated plants. In conclusion, the exogenous application of ZnO NPs (100 ppm) can significantly mitigate the water deficit stress and improve the physiological, yield, and WUE of potato grown in arid regions under water deficit conditions.

The Effect of LED Light Spectra on the Growth, Yield and Nutritional Value of Red and Green Lettuce (Lactuca sativa).

Controlled Environment Agriculture (CEA) is a method of increasing crop productivity per unit area of cultivated land by extending crop production into the vertical dimension and enabling year-round production. Light emitting diodes (LED) are frequently used as the source of light energy in CEA systems and light is commonly the limiting factor for production under CEA conditions. In the current study, the impact of different spectra was compared with the use of white LED light. The various spectra were white; white supplemented with ultraviolet b for a week before harvest; three combinations of red/blue lights (red 660 nm with blue 450 nm at 1:1 ratio; red 660 nm with blue 435 nm 1:1 ratio; red 660 nm with blue at mix of 450 nm and 435 nm 1:1 ratio); and red/blue supplemented with green and far red (B/R/G/FR, ratio: 1:1:0.07:0.64). The growth, yield, physiological and chemical profiles of two varieties of lettuce, Carmoli (red) and Locarno (green), responded differently to the various light treatments. However, white (control) appeared to perform the best overall. The B/R/G/FR promoted the growth and yield parameters in both varieties of lettuce but also increased the level of stem elongation (bolting), which impacted the quality of grown plants. There was no clear relationship between the various physiological parameters measured and final marketable yield in either variety. Various chemical traits, including vitamin C content, total phenol content, soluble sugar and total soluble solid contents responded differently to the light treatments, where each targeted chemical was promoted by a specific light spectrum. This highlights the importance of designing the light spectra in accordance with the intended outcomes. The current study has value in the field of commercial vertical farming of lettuce under CEA conditions.

Utilizing spectral vegetation indices for yield assessment of tomato genotypes grown in arid conditions.

Tomato is among important vegetable crops cultivated in different climates; however, heat stress can greatly affect fruit quality and overall yield. Crop reflectance measurements based on ground reflectance sensor data are reliable indicators of crop tolerance to abiotic stresses. Here, we report on using non-destructive spectral vegetation indices to monitor yield traits of 10 tomato genotypes transplanted on three different dates (Aug. 2, Sept. 3 and Oct. 1) during 2019 growing season in the Riyadh region. The ten genotypes comprised six commercial cultivars-(Pearson Improved, Strain B, Valentine, Marmande VF, Super Strain B, and Pearson early) --and four local Saudi cultivars (Al-Ahsa, Al-Qatif, Hail and Najran). Spectral reflectance data were utilized using a FieldSpec 3 spectroradiometer in the range of 350-2500 nm to calculate nine vegetation indices (VIs): Normalized Water Band Index (NWBI), Difference Water Index (NDWI), Photochemical Reflectance Index (PRI), Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Red Edge Normalized Difference Vegetation Index, Soil Adjusted Vegetation Index (SAVI), Red Edge Normalized Difference Vegetation Index (RENDVI), Renormalized Difference Vegetation Index (RDVI), and Normalized Difference Nitrogen Index (NDNI). VIs and yield parameters (total fruit yield, harvest index) revealed that second transplanting date was optimal for all the genotypes. Valentine showed the best growth performance followed by Najran, Hail, Super Strain B and finally Pearson early. For all the three transplanting dates, Valentine recorded the highest total fruit yield. Additionally, some genotypes had no significant differences in the VIs values or the total fruit yield between the second and third transplanting dates. This study indicated that yield parameters could be linked to rapid, non-destructive hyperspectral reflectance data to predict tomato production under heat stress.

Assessment of Morpho-Physiological, Biochemical and Antioxidant Responses of Tomato Landraces to Salinity Stress.

Understanding salt tolerance in tomato (Solanum lycopersicum L.) landraces will facilitate their use in genetic improvement. The study assessed the morpho-physiological variability of Hail tomato landraces in response to different salinity levels at seedling stages and recommended a tomato salt-tolerant landrace for future breeding programs. Three tomato landraces, Hail 548, Hail 747, and Hail 1072 were tested under three salinity levels: 75, 150, and 300 mM NaCl. Salinity stress reduced shoots' fresh and dry weight by 71% and 72%, and roots were 86.5% and 78.6%, respectively. There was 22% reduced chlorophyll content, carotene content by 18.6%, and anthocyanin by 41.1%. Proline content increased for stressed treatments. The 300 mM NaCl treatment recorded the most proline content increases (67.37 mg/g fresh weight), with a percent increase in proline reaching 61.67% in Hail 747. Superoxide dismutase (SOD) activity decreased by 65% in Hail 548, while it relatively increased in Hail 747 and Hail 1072 treated with 300 mM NaCl. Catalase (CAT) activity was enhanced by salt stress in Hail 548 and recorded 7.6%, increasing at 75 and 5.1% at 300 mM NaCl. It revealed a reduction in malondialdehyde (MDA) at the 300 mM NaCl concentration in both Hail 548 and Hail 1072 landraces. Increasing salt concentrations showed a reduction in transpiration rate of 70.55%, 7.13% in stomatal conductance, and 72.34% in photosynthetic rate. K+/Na+ ratios decreased from 56% for 75 mM NaCl to 85% for 300 mM NaCl treatments in all genotypes. The response to salt stress in landraces involved some modifications in morphology, physiology, and metabolism. The landrace Hail 548 may have better protection against salt stress and observed protection against reactive oxygen species (ROS) by increasing enzymatic "antioxidants" activity under salt stress.

Non-destructive assessment of flesh firmness and dietary antioxidants of greenhouse-grown tomato (Solanum lycopersicum L.) at different fruit maturity stages.

Non-destructive methods have been widely recognized for evaluating fruit quality traits of many horticultural crops and food processing industry. Destructive (analytical) test, and non-destructive evaluation of the quality traits were investigated and compared for 'Red Rose' tomato (Solanum lycopersicum L.) fruit grown under protected environment. Fresh tomato fruit at five distinctive maturity stages namely; breaker (BK), turning (TG), pink (PK), light-red (LR), and red (RD) were labeled and scanned using the handheld near infra-red (NIR) enhanced spectrometer at a wavelength range of 285-1200 nm. The labeled tomato samples were then measured analytically for flesh firmness, lycopene, ß-carotene, total phenolic content (TPC) and total flavonoids content (TFC). The results revealed that quality traits could be estimated using NIR spectroscopy with a relatively high coefficient of determination (R2): 0.834 for total phenolic content, 0.864 for lycopene, 0.790 for total flavonoid content, 0.708 for ß-carotene; and 0.679 for flesh firmness. The accumulation of Lyco and ß-Car rapidly increased in tomatoes harvested between the TG and the LR maturity stages. Harvesting tomatoes at BK maturity stage resulted in significantly higher flesh firmness than harvesting at the later maturity stages. Tomato fruits had the lowest TPC and TFC contents at the earliest maturity stage (BK), while they had intermediate TPC and TFC levels at LR and RD maturity stages. NIR spectroscopic measurements of fruit firmness and lipophilic antioxidants in tomato fruit at various maturity stages were partially in accordance with those estimated by destructive (analytical) methods. Based on these findings, we recommend using non-destructive NIR spectroscopy as an effective tool for predicting tomato fruit quality during harvest stage and postharvest processing.

Interaction Effects of Nitrogen Source and Irrigation Regime on Tuber Quality, Yield, and Water Use Efficiency of Solanum tuberosum L.

Two field experiments were conducted to investigate the effects of three drip irrigation regimes (G1: 120% crop evapotranspiration (ETc), G2: 100% ETc, and G3: 80% ETc) and four nitrogen (N) source treatments (S0: non-fertilized; S1: urea, S2: ammonium nitrate, and S3: ammonium sulfate on water consumption use, water utilization efficiency, chlorophyll, yield and tubers quality of potato (Solanum tuberosum L.; cv Diamond) under a drip irrigation system during two successive winter seasons (2015/16 and 2016/17)). Nitrogen fertilization was applied at 380 kg ha-1 as standard application for potato in the investigated area. The highest tubers yield was obtained from potato grown with G1 S2 (65.8 Mg ha-1), G1 S3 (63.6 Mg ha-1), G2 S2 (64.1 Mg ha-1), and G2 S3 (62.4 Mg ha-1), while the lowest tubers yield was obtained from potato grown with G3 S0 (10.1 Mg ha-1) and G2S0 (17.4 Mg ha-1). Different treatments of N source resulted in a significant increase for water use efficiency (WUtE) compared with unfertilized treatment. For the interaction effect, the highest WUtE was obtained from potato grown with G3 S2 (18.1 kg m-3), followed by G3 S3 (17.6 kg m-3), while the lowest WUtE was obtained from plants grown with G3S0 (3.0 kg m-3). However, the highest chlorophyll content was obtained from plants grown with G1 and any N source, followed by G2S1-3, while the lowest chlorophyll content was obtained from those grown with G3S0. The highest N, S, protein, and P contents in tubers were obtained from plants grown with G3S3, G3S2, and G2S2, while the highest K content in tubers was obtained from plants grown with G1S1 and G1S2. In concussion, the integrative effects of G1 or G2 with S2 or S3 is recommended for high productivity, while the integrative effects of G3S3 and G3S2 are recommended for high quality tubers.

Improved functional and nutritional properties of tomato fruit during cold storage.

The use of synthetic antioxidants has been associated with serious concerns for human and environmental health. During ripening stages, tomato fruit is exposed to different abiotic stresses which not only influence its nutritional, mechanical, and functional properties at harvest, but also affect the quality and shelf life of the fruit during storage. This study investigated the pattern of changes in dietary antioxidants during various ripening stages of tomato fruit (cv. Red Rose) and their impact on storage behavior of the fruit during cold storage. Tomato fruits were harvested at mature green, breaker, turning, pink, light-red and red stages of maturity. Then, they were analysed for flesh firmness, soluble solids content, titratable acidity, total sugars, pH, dry matter content, lipophilic (lycopene, ß-carotene, and total carotenoids), and hydrophilic (ascorbic acid, phenolic and flavonoids) antioxidants. Additional fruits were harvested at each maturity stage and divided into three equal lots, then were subjected to low-temperature (10 ± 1 °C) storage with 80 ± 5% RH, for 7, 14, and 21 days. Flesh firmness, and the levels of dietary antioxidants were analysed following the subsequent storage periods. The results revealed that the peak of hydrophilic antioxidants such as ascorbic acid, phenolic compounds, and flavonoids was between the 'pink' and the 'light-red' stages of fruit maturity. Whereas tomatoes harvested at the 'red' stage of maturity had the highest levels of lycopene and ß-carotene. Both the stage of fruit maturity at harvest and duration of cold storage influenced flesh firmness, organoleptic and functional properties of 'Red Rose' tomato fruit. In conclusion, the results of the current investigation have practical implications in formulating foods with improved functional properties at processing industries.

Comparison of maternal and fetal outcomes, in epileptic and non-epileptic women.

OBJECTIVE: To assess maternal and fetal outcomes, in epileptic and non-epileptic pregnant women. METHODS: A retrospective case-control study was conducted from January 2005 - December 2006 at Riyadh Military Hospital, Riyadh, Kingdom of Saudi Arabia. A total of 16508 live birth charts were reviewed. Maternal, obstetrical, and fetal outcomes were compared between women with epilepsy Group 1 (n = 53) and women who did not have epilepsy (controls) Group 2 (n = 60). RESULTS: There were no significant differences between either group in total length of labor, labor induction and oxytocin augmentation, need for labor analgesia, total blood loss and the need for blood transfusion, mode of delivery, and the length of hospital stay. There were no significant differences in all maternal complications between either group (p=0.8, 95% CI: 0.3-2.1). There was an increase in the mean dose of the antiepileptic medications needed during pregnancy. However, 4 women (7.5%) in the epileptic group had major seizures during pregnancy. All of these women needed addition of a second antiepileptic medication. Major congenital malformations occurred in 2 newborns (3.8%) of epileptic women, and none occurred in the control group. Both newborns were from women who received polytherapy. CONCLUSION: Women with epilepsy are not at increased risk for obstetric and neonatal complications, provided there is a combined team management approach by a neurologist and an obstetrician.