Carotenoids Research Articles

Microbial-Derived Carotenoids and Their Health Benefits

Natural carotenoids (CARs) such as β-carotene, astaxanthin, lutein, norbixin, bixin, capsanthin, lycopene, β-Apo-8-carotenal, canthaxanthin, β-apo-8-carotenal-ester, and zeaxanthin are being explored for possible applications in feed, food, cosmeceuticals, and nutraceuticals. Three primary areas of carotenoid research are emerging: (1) encapsulations for improved chemical and physical properties; (2) natural source carotenoid manufacturing; and (3) preclinical, epidemiological, and clinical studies of carotenoids’ potential health benefits. The recent advancements in research on the chemistry and antioxidant activity, marketing strategies, dietary sources, bioavailability, and bioaccessibility, extraction, dietary consumption, encapsulating techniques, and health advantages of carotenoids are all extensively discussed in this review. Carotenoids are pigments found naturally in most fruits and vegetables, algae, plants, and photosynthetic bacteria. Carotenoids cannot be synthesized by humans and must be consumed in the form of food or supplements. There are several roles for carotenoids in human health. Although individual carotenoids may function in different ways, their main action is to act as antioxidants. There are validated techniques for separating and purifying carotenoids, yet, industrial production requires the development of economically viable techniques for larger-scale implementation. Carotenoids have been shown to boost cognitive performance and cardiovascular health, as well as help prevent some types of cancer. Despite evidence for carotenoids’ health benefits, major population-based supplementation trials have yielded conflicting outcomes for several carotenoids. This review includes recent developments in carotenoid metabolism and nutritional and health advantages. It also offers an outlook on future directions in these areas.

Methyl jasmonate elicitation improves the growth performance and biosynthesis of antioxidant metabolites in Portulaca oleracea through ROS modulation

The application of elicitors is regarded as one of the most efficient strategies for augmenting secondary metabolite contents in medicinal plants. There are numerous reports documenting the impact of methyl jasmonate (meJA) on plant growth and biosynthesis of secondary metabolites. However, the underlying physiological response of the plants towards meJA elicitation is understudied. Thus, the current study focused on evaluating the influence of meJA on growth performance, reactive oxygen species (ROS)/antioxidants crosstalk, and expression of bioactive metabolites in Portulaca oleracea. The seeds of P. oleracea were sown, and the plants were cultivated in pots in nursery settings. P. oleracea plants were sprayed with meJA (ranging from 0.1 to 1.0 mM) on the 35th day after sowing (DAS). The plants were harvested on the 60th DAS. The P. oleracea plants elicited with 1.0 mM meJA exhibited the highest plant height (PH), number of leaves (LN), root length (RL), fresh (FW-P), and dry weights of whole plants (DW-P). The highest increase in total anthocyanin (TAC), total chlorophyll (Total Chl), and total carotenoid (CAR) were observed in plants elicited with 0.4 mM meJA. Meanwhile, the highest increase in total phenolic content (TPC) occurred in plants elicited with 0.6 mM meJA, whereas the highest increase in total flavonoid (TFC) and ascorbic acid content (AsA) was noted in plants elicited with 0.8 mM meJA. The lowest decrease in the stress indicators, malondialdehyde (MDA) and hydrogen peroxide (H2O2) was observed in plants elicited with 0.6 mM meJA. Pearson's analysis and Partial Least Squares Regression (PLSR) were employed in exploring the relationships among all essential parameters. It was found that the antioxidant metabolites and enzymes, particularly the total soluble sugar (TSS), proline, chlorophyll a/chlorophyll b ratio (Chl a/Chl b), and superoxide dismutase (SOD) served as the most essential factors in influencing the growth performance of P. oleracea by modulating the total antioxidant activity (Total AOX) and acting as ROS scavengers. Moreover, meJA elicitation led to the distinct expression of various bioactive compounds, amplifying the medicinal properties of P. oleracea. Overall, this research indicates that meJA enhances growth performance and boosts the production of metabolites possessing medicinal values in P. oleracea.

Exploring somatic embryogenesis in Ajuga multiflora Bunge: Profiling lipophilic metabolites via HPLC, GC-FID, and GCMS– analysis

The present study aims to assess the effect of different concentrations of auxins and combinations of plant growth regulators (PGRs), specifically auxin and cytokinin, on somatic embryogenesis in Ajuga multiflora. We also aim to compare the lipophilic metabolite profiles, such as carotenoids (CAs), fatty acids (FAs), phytosterols (PSs), and tocopherols (TPs), in globular somatic embryos (SEs), germinated SEs, and shoots of SEs derived plantlets. This assessment is carried out utilizing high performance liquid chromatography, gas chromatography-flame-ionization detection, and gas chromatography–mass spectrometry techniques. The results reveal that the application of 2,4-dichlorophenoxyacetic acid (2,4-D) had the most significant impact on somatic embryogenesis, inducing both SE initiation (34.4%) and the number of SEs (3.5) per explant. Among the explants used, leaf explants were found to be the most effective for SE induction (SEI). Additionally, the study explores the combined effect of 2,4-D and cytokinins (N6-benzyladenine, N6-BA, or 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea, TDZ) on somatic embryogenesis, highlighting optimal conditions for SEI percentages and the number of SEs per explant. The maximum SE induction rate (100%) and the number of SEs (45.9) per leaf explant were obtained on an SEI medium with 30 µM of 2,4-D and 2.3 µM of TDZ. The maturation and conversion of SEs were also examined, emphasizing the role of GA3 in achieving the highest conversion percentage (94.0 ± 2.7 at 0.8 µM GA3). Furthermore, the study details the biochemical composition during various stages of somatic embryogenesis, including CAs, TPs, PSs, and FAs. Globular SEs displayed comparatively lower concentrations of CAs than their germinated counterparts and shoots from SE-derived plantlets, while the total PSs content remained relatively consistent across all stages. Conversely, fatty acids tended to accumulate more in globular SEs, with the exception of α-Linolenic acid. These findings provide valuable insights into the optimization of somatic embryogenesis protocols in A. multiflora, with implications for plant tissue culture, regeneration and lipophilic metabolites production.

The main nutritional components in colored rice grains

Colored rice grains contain rich nutrients. To investigate the differences in nutrient composition among different colored rice varieties, LC-MS non-targeted lipidomics and targeted amino acid profiling were used to study the lipid and amino acid composition in four colored rice grains. The study analyzed the relationship between amino acids, mineral elements, crude protein (CP), crude fat (CF), carotenoids (CAROT), vitamin C (ASA), ATP, total sugar (TS), soluble protein (SP), and metabolites. A total of 505 lipid metabolites were identified. The results depicted that YZ6H had the highest levels of Arg, Asn, Met, Orn, and Try. HN had the highest levels of GABA, His, Lys, Thr, Tyr, Val, and Tau, which were significantly higher than those in YZ6H, YJN818, and YCN1H. PC (16:0/16:1,16:1/18:2,18:1/14:1,18:1/14:0,18:1/18:1,18:0/18:1), TG (16:0/18:3/22:2,22:4/18:2/18:2,16:0/20:2/20:4), and PE(20:4e/15:0) were significantly negatively correlated with GABA, Leu, Lys, Thr, Tyr, Val, Gln, His, and Ile. TG(18:2/17:1/18:2,15:0/18:2/18:2,15:0/18:2/18:3,15:0/16:0/18:2,15:0/18:1/18:2,18:1/17:1/18:2,18:1/17:1/18:1,18:1/10:1/18:1) was significantly positively correlated with Pro and Tau. YZ6H had the highest levels of ASA, SP, TS, CAROT, and ATP content. PG(28:0/18:1), MLCL(14:2/16:0/16:0), Cer(t18:0/26:0+O,d18:2/16:0,t18:0/26:0), and LPC(16:0) TG(20:4e/18:3/20:1) were significantly negatively correlated with SP, CAROT. Hex1Cer(t18:1/24:0+O), MLCL(14:2/16:0/16:0), Cer(t18:0/26:0+O,d18:2/16:0,t18:0/26:0), LPC(16:0), TG(16:0/20:2/20:4,20:4e/18:3/20:1), and DG(18:1/14:0), which are key lipid metabolites involved in the synthesis of nutritional components in colored rice grains.

Assessment of acute toxicity of crude extract rich in carotenoids from Cantaloupe melon (Cucumis melo L.) and the gelatin-based nanoparticles using the zebrafish (Danio rerio) model

Cantaloupe melon is known for its carotenoid-rich orange pulp. However, carotenoids are sensitive to oxygen, light, and heat, potentially reducing their benefits. Nanoencapsulation can preserve these benefits but raises concerns about toxicity. We aimed to assess the safety and bioactive potential of crude extract-rich carotenoids (CE) and nanoparticles based on gelatin loaded with CE (EPG) by investigating parameters such as cardio or neurotoxicity, especially acute toxicity. EPG was obtained by O/W emulsification and characterized by different methods. Zebrafish embryos were exposed to CE and EPG at 12.5 mg/L and 50 mg/L for 96h and were investigated for survival, hatching, malformations, and seven days post fertilization (dpf) larvae's visual motor response. Adult fish underwent behavioral tests after acute exposure of 96h. CE and EPG showed no acute toxicity in zebrafish embryos, and both improved the visual motor response in 7dpf larvae (p = 0.01), suggesting the potential antioxidant and provitamin A effect of carotenoids in cognitive function and response in the evaluated model. Adult fish behavior remained with no signs of anxiety, stress, swimming pattern changes, or sociability that would indicate toxicity. This study highlights the safety and potential benefits of carotenoids in zebrafish. Further research is needed to explore underlying mechanisms and long-term effects.

The Essential Role of H2S-ABA Crosstalk in Maize Thermotolerance through the ROS-Scavenging System.

Hydrogen sulfide (H2S) and abscisic acid (ABA), as a signaling molecule and stress hormone, their crosstalk-induced thermotolerance in maize seedlings and its underlying mechanism were elusive. In this paper, H2S and ABA crosstalk as well as the underlying mechanism of crosstalk-induced thermotolerance in maize seedlings were investigated. The data show that endogenous levels of H2S and ABA in maize seedlings could be mutually induced by regulating their metabolic enzyme activity and gene expression under non-heat stress (non-HS) and HS conditions. Furthermore, H2S and ABA alone or in combination significantly increase thermotolerance in maize seedlings by improving the survival rate (SR) and mitigating biomembrane damage. Similarly, the activity of the reactive oxygen species (ROS)-scavenging system, including enzymatic antioxidants catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and superoxide dismutase (SOD), as well as the non-enzymatic antioxidants reduced ascorbic acid (AsA), carotenoids (CAR), flavone (FLA), and total phenols (TP), was enhanced by H2S and ABA alone or in combination in maize seedlings. Conversely, the ROS level (mainly hydrogen peroxide and superoxide radical) was weakened by H2S and ABA alone or in combination in maize seedlings under non-HS and HS conditions. These data imply that the ROS-scavenging system played an essential role in H2S-ABA crosstalk-induced thermotolerance in maize seedlings.

Application of nitrogen for mitigating the adverse effects of flooding stress in lettuce

Global warming and the subsequent climate change increase the severity and frequency of floods day by day. Therefore, there is a need to develop new strategies to prevent the negative effects of flooding stress and to determine the changes that may occur in the plant under extreme water stress. Thus, in this study, changes in agronomic, physiological, and biochemical properties of lettuce plants exposed to flooding stress under greenhouse conditions were analyzed. In this study, two different irrigation regimes, including full irrigation (I100) and flooding stress (I150) and three different nitrogen doses, including no-nitrogen (N0), 100 kg ha−1 (N10), and 200 kg ha−1 (N20), were applied. The results revealed that while flooding stress caused significant decreases in above-ground fresh and dry weights, membrane damage (MD), contents of carotenoid (CT), proline (PL), and protein (PT), as well as catalase activity (CAT), leaf relative water content (RWC) and peroxidase (POX) content showed significant increases. Increasing nitrogen doses caused the increase in the pigment contents (Cl a, Cl b, and CT) and PL, superoxide dismutase (SOD) of the lettuce. In addition, RWC content and the uptake of Fe and Mn elements increased under flooded conditions. It has been revealed that the application of at least 100 kg of nitrogen fertilizers per hectare to prevent the negative effects of flooding stress in the regions where lettuce cultivation was carried out supported the plant growth both under full irrigation and flooded conditions.

Alleviation of Shade Stress in Chinese Yew (Taxus chinensis) Seedlings with 5-Aminolevulinic Acid (ALA).

5-aminolevulinic acid (ALA) is a novel regulator that can promote plant growth, nitrogen uptake, and abiotic stress tolerance. Its underlying mechanisms, however, have not been fully investigated. In this study, the effects of ALA on morphology, photosynthesis, antioxidant systems, and secondary metabolites in two cultivars of 5-year-old Chinese yew (Taxus chinensis) seedlings, 'Taihang' and 'Fujian', were examined under shade stress (30% light for 30 days) using different doses of ALA (0, 30, and 60 mg/L). The findings from our study show that shade stress significantly reduced plant height, stem thickness, and crown width and increased malondialdehyde (MDA) levels. However, the application of 30 mg/L ALA effectively mitigated these effects, which further induced the activity of antioxidant enzymes under shade stress, resulting in the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) being increased by 10%, 16.4%, and 42.1%, and 19.8%, 20.1%, and 42% in 'Taihang' and 'Fujian', respectively. It also promoted their role in the absorption, conversion, and efficient use of light energy. Additionally, the use of 30 mg/L ALA caused a significant increase in the concentration of secondary metabolites, including polysaccharide (PC), carotenoid (CR), and flavonoids (FA), with increases of up to 46.1%, 13.4%, and 35.6% and 33.5%, 7.5%, and 57.5% in both yew cultivars, respectively, contributing to nutrient uptake. With ALA treatment, the yew seedlings showed higher chlorophyll (total chlorophyll, chlorophyll a and b) levels and photosynthesis rates than the seedlings that received the shade treatment alone. To conclude, the application of 30 mg/L ALA alleviated shade stress in yew seedlings by maintaining redox balance, protecting the photorespiratory system, and increasing organic metabolites, thus increasing the number of new branches and shoots and significantly promoting the growth of the seedlings. Spraying with ALA may be a sustainable strategy to improve the shade-resistant defense system of yew. As these findings increase our understanding of this shade stress response, they may have considerable implications for the domestication and cultivation of yew.

Biochemical Characterization and Responses of Two Contrasting Genotypes of Chenopodium quinoa Willd. to Salinity in a Hydroponic System

Chenopodium quinoa is a promising species for future food security and combating climate change due to its nutritional content and halophytic nature. This study focuses on the temporal differential responses of the salt-tolerant (Chadmo) and the salt-sensitive (Kankolla) under control (CK) and 400 mM NaCl arranged under the randomised block designed (RBD). Biochemical features assessed and results indicate a significant difference (p<0.05) being identified by ANOVA and Tukey analyses in total chlorophyll (CHL), carotenoids (CAR), proline, glycine betaine (GB), soluble sugars, K+, Na+, K+/Na+ ratio, Mg2+ and Ca2+ in both genotypes between the CK and 400 mM NaCl. Na+ increased while K+ and the bivalent ions Mg2+ and Ca2+ decreased progressively with time points (CK and 24 h) in both genotypes but more pronounced in Kankolla. Proline increased by 24.45 and 18.63% between the CK and 24 h after exposure to 400 mM NaCl in Chadmo and Kankolla, respectively. Similarly, significant increases were observed in ABA, glycine betaine and soluble sugars from the CK to 24 h after exposure to 400 mM NaCl in both genotypes. Using these biochemical responses to salinity, Chadmo proved to be the better-performing genotype when exposed to 400 mM NaCl and hence identified as the salt-tolerant genotype.

Phenology, yield, and phytochemicals of Capsicum spp. in response to shading

Background: Capsicum spp. grow in environments with different incident radiation, that could modify the plant growth and the concentration of phytochemicals in fruits.
 Hypothesis: Shading positively affects phenology and fruit yield, decreases the total contents of phenols (TPC), flavonoids (FLV), proanthocyanidins (PAN) and carotenoids (CAT) in fruits of wild Capsicum species.
 Studied species: Capsicum annuum var. glabriusculum: amashito (AMA) and garbanzo (GAR), and C. frutescens (Pico Paloma, PIP)
 Study site and dates: Huimanguillo, Tabasco, Mexico; 2020 and 2021.
 Methods: Seeds were treated with gibberellic acid (GA3) (500 mg L-1) for 24 h prior to seeding. The seedlings were transplanted in an open field and under two levels of shade (35 and 70 %) under a subsplit plot design with four replicates. TPC, FLV, PAN and CAT were determinate in immature and ripe fruits by UV-vis spectrophotometry.
 Results: Shade accelerated the phenological processes from the first bifurcation of the stem, and decreased the fruits ripening time from anthesis of the genotypes studied. Shade only increased the yield of the AMA genotype and reduced the contents of TPC, FLV, and CAT; however, these metabolites increased under open field conditions.
 Conclusions: The shade reduced the duration of phenological stages including the ripening period of fruits, and increased the plant height of the Capsicum spp. The increase in yield by shading effect only was observed in AMA genotype. The content of phytochemicals in Capsicum fruits is reduced by shading levels.

Chlorophyll Pigment and Leaf Macronutrient Trait Variation of Four Salix Species in Elevated CO2, under Soil Moisture Stress and Fertilization Treatments

Leaf chlorophyll pigment and macronutrient concentrations were quantified for four willow species (Salix cordata (COR), S. discolor (DIS), S. eriocephala (ERI) and S. interior (INT)) while growing under 2 × 2 factorial of ambient and elevated CO2 and well-watered and drought-stressed soil moisture treatments (Expt. 1). After the first year, we saw no difference in stem biomass between CO2 treatments. In the following year, a second experiment was conducted on a subset of well-watered willows as a 2 × 2 factorial of atmospheric CO2 and soil fertilization (FERT). For both years of Expt. 1, chlorophyll a, b, a + b (TCC) and carotenoids (CAR) significantly downregulated in response to elevated CO2 (eCO2) and upregulated in response to drought (DRT). In Expt. 2, FERT mitigated CO2 downregulation of TCC and CAR, and upregulated TCC and CAR. Across species, ERI had the greatest pigment concentrations followed by either COR or DIS. Except for one case, INT had the lowest pigment concentrations. A significant species x FERT interaction was due to magnitude effects. The CHLa:b ratio was not affected by CO2 or DRT but did increase in response to FERT. INT had the greatest CHLa:b ratio followed by DIS, then either ERI or COR. In the second year, TCC:CAR ratio decreased in response to eCO2 and increased in response to DRT and FERT. In Expt. 1, leaf N was the only nutrient to significantly downregulate in response to eCO2; whereas all other nutrient levels remained unchanged. In response to DRT, leaf N and Mg upregulated; whereas leaf P, K, and Ca were downregulated. In response to eCO2 in Expt. 2, again only leaf N downregulated; whereas all other nutrients remained unchanged. All leaf nutrients upregulated in response to FERT. Of the four species, INT had the greatest leaf N and K, and the lowest Ca. Species variation was important, but so to was clonal variation in response to change. Indeed, INT leaf chlorophyll and macronutrients are significantly different or segregated from the other three willow species and this may be related to the evolutionary origins of INT, and other species of the taxonomic section Longifoliae, in the arid southwest USA and Mexico. Furthermore, under low nutrient conditions, it may be necessary to fertilize the plants to see a biomass response to eCO2.

Morpho-Physiological and Biochemical Responses Of Salt-Sensitive and Salt-Tolerant Potato Varieties To Salinity Stress

A pot experiment was conducted with three potato varieties [‘BARI Alu-72’ (salt-tolerant), ‘BARI Alu-25’ (relatively salt-tolerant) and ‘BARI Alu-13’ (saltsensitive)] under three levels of salinity stress (control; 0.2, moderate; 6-8 and severe; 10-12 dSm-1) for evaluating their morphological, physiological and biochemical changes during rabi season of 2018-19. Salinity treatment was imposed from 10 days after emergence (DAE) to maturity stage by adding NaCl solution. Salinity stress caused higher reduction in chlorophyll (Chl), carotenoids (CAR), cell membrane stability index (CMSI), biomass and tuber yield plant-1 but increase in contents of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR) activities in all potato varieties and at all the salinity levels. The reduction of Chl, CAR, CMSI, biomass and yield plant-1 were lower in ‘BARI Alu-72’ as compared to other two varieties. Moreover, ‘BARI Alu-72’ showed higher activities of CAT, POD, APX, GPX, GR and GST as well as contents of K+ and lower malondialdehyde (MDA), lipoxygenase (LOX) and Na+ contents in comparison with those of ‘BARI Alu-25’ and ‘BARI Alu-13’. Activities of antioxidants were found moderate in ‘BARI Alu-25’. ‘BARI Alu-13’ showed higher Na+ and Na+/K+ ratio. The results showed that salinity tolerance in potato was manifested by lower decrease in biomass and yield plant-1 with higher antioxidant activities and K+ contents, and lower MDA, LOX and Na+ content than salinity sensitive genotype.
 Bangladesh J. Agril. Res. 45(3): 315-333, September 2020

Enzymatic and non-enzymatic response of grafted and ungrafted young European pear (Pyrus communis L.) trees to drought stress

The optimization and selection of the scion-rootstock combination are commonly based on its physiological and biochemical alterations capacity, especially in the rootstock, which is significant to elucidate the mechanisms associated with water stress tolerance. To verify the antioxidant defense systems under drought stress, two ungrafted rootstocks, `Dargazi᾿ seedling (D) and `Pyrodwarf᾿ clonal (P), and two pear scion cultivars including `Dargazi᾿ (D) and `Louise Bonne᾿ (L), that were grafted on the studied rootstocks were examined. We considered growth and chlorophyll fluorescence traits, some oxidative stress markers, and non-enzymatic and enzymatic antioxidant parameters in plants subjected to different soil water regimes. Treatments were, well-watered as control (100% FC), moderate (60% FC), and severe drought (30% FC) under greenhouse conditions. Drought stress influenced chlorophyll fluorescence contents and limited the quantum yield of PSII (Fv/Fm), mainly in P rootstock. In contrast, the highest specific leaf area (SLA), and lowest leaf mass area (LMA) was observed in the P rootstock, which indicated that the P rootstock was more sensitive to drought stress. Physiological and biochemical alterations and the main components of multivariate analysis showed that hydrogen peroxide (H2O2) and malondialdehyde (MDA) were accumulated under water deficit conditions, and P and D rootstocks showed a higher level of H2O2. We found a reduction in chlorophyll pigments, carotenoid (CAR), and ascorbic acid (AA), by drought stress, which had the highest amount in P and D rootstocks. Water stress directly influenced anthocyanin (ANT), total phenolic content (TPC), total flavonoid content (TFC), catalase (CAT), guaiacol peroxidase (GPOX), and ascorbate peroxidase (APOX) activity, especially under severe stress levels, and there was a high activity of GPOX in grafted combinations. In general, rootstocks showed more oxidative stress than grafted combinations because of the high increase in H2O2 and MDA, and response to stress by the accumulation of some enzymatic and non-enzymatic factors. However, grafted combinations mostly showed better tolerance with the enzymatic antioxidant defense system, which can be the result of resistance induced by rootstocks and the cultivar's capacity to minimize the negative effects of drought stress.

Comparative morphological, physiological and molecular analyses of drought-stressed strawberry plants affected by SiO2 and SiO2-NPs foliar spray

Drought stress impairs plant growth leading to depression in yield. This experiment aimed to elucidate the substantial impact of silicon (Si) [in forms of SiO2 and SiO2-nanoparticles (SiO2-NPs)] on modulating adverse effects of drought stress on strawberry plants. The plants grown in the greenhouse were exposed to drought stress simulating 25% field capacity (FC) (severe stress), 50% FC (moderate stress), and 100% FC (control). The strawberry plants were then sprayed with suspensions containing SiO2 or SiO2-NPs (50 mg L−1). The SiO2 treatment improved morphological parameters (number of plant leaves and length of petiole). Under drought stress, application of foliar SiO2 and SiO2-NPs increased osmolytes such as proline and total soluble sugar and improved chlorophylls (Chl a, Chl b, and total Chl) and carotenoids (CARs) as well as Chl fluorescence in strawberry plants as compared to non-treated ones. Moreover, treatment by SiO2 raised tolerance to drought by promoting the activity of antioxidant enzymes such as peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and phenylalanine ammonia lyase (PAL) as well as reduced hydrogen peroxide (H2O2) and malondialdehyde (MDA) activity in strawberry plants. Drought stressed strawberry plants treated by Si exhibited the recovery in antioxidant activity and phenolic compounds as non-enzymatic antioxidants. The modifications of abscisic acid and phenolic compounds occurred following up-regulation of some responsive genes as a beneficiary response to drought stress when SiO2 and SiO2-NPs were applied. This application of SiO2 and SiO2-NPs can contribute to protect strawberry plants against damaging effects of drought stress.

Confirmatory assessments of putative quality and nutritional properties of branded and unbranded commercial edible oils

Dietary associated non-communicable diseases have become a major concern and consumption of branded and unbranded vegetables oils may be one out of many probable contributing factors. Thus, the objective of this preliminary study was to access the nutritional qualities and trans-fat contents of 28 randomly selected three commonly consumed vegetable oils (crude palm oil CPO, soybean oil SBO, and peanut oil PNO) from cross-sectional area of the country. CPOs samples exhibited an upper limit of 5.18% for acidity, which is slightly outside minimum standard requirement for crude oil (<5.00%). Similarly, both SBOs and PNOs were above tolerant limit for acidity (>0.30%). Six of the nine CPOs had peroxide value > 8.0 meqO2/kg, while none of the refined oils was <1.63 meqO2/kg – an indication of oxidative instability. Although, moisture content, conjugated trienes and dienes were significantly higher in CPOs, but the oils exhibited lower trans-fat content with a range 0 – 6.27% compared to SBOs (3.73 – 9.72%) and PNOs (0.72 – 7.14%). CPOs were higher in total phenol (TPC), tocopherol (TFR), and carotenoid (CAR) contents, that could make up for the low oxidative stability indices. Among the variables predicting trans-fat contents of the oils using variable important projection (VIP) model, saturated, polyunsaturated (PUFA) fatty acids, acidity, PV and conjugated trienes had positive influence, while TPC, TFR, CAR, monounsaturated fatty acid (MUFA), and MUFA/PUFA ratio showed negative contributions. Thus, only few samples satisfied the ideal quality and nutritional requirements of edible oils.

Hydrogen Peroxide Variation Patterns as Abiotic Stress Responses of Egeria densa.

In vegetation management, understanding the condition of submerged plants is usually based on long-term growth monitoring. Reactive oxygen species (ROS) accumulate in organelles under environmental stress and are highly likely to be indicators of a plant’s condition. However, this depends on the period of exposure to environmental stress, as environmental conditions are always changing in nature. Hydrogen peroxide (H2O2) is the most common ROS in organelles. The responses of submerged macrophytes, Egeria densa, to high light and iron (Fe) stressors were investigated by both laboratory experiments and natural river observation. Plants were incubated with combinations of 30–200 μmol m–2 s–1 of photosynthetically active radiation (PAR) intensity and 0–10 mg L–1 Fe concentration in the media. We have measured H2O2, photosynthetic pigment concentrations, chlorophyll a (Chl-a), chlorophyll b (Chl-b), carotenoid (CAR), Indole-3-acetic acid (IAA) concentrations of leaf tissues, the antioxidant activity of catalase (CAT), ascorbic peroxidase (APX), peroxidase (POD), the maximal quantum yield of PSII (Fv Fm–1), and the shoot growth rate (SGR). The H2O2 concentration gradually increased with Fe concentration in the media, except at very low concentrations and at an increased PAR intensity. However, with extremely high PAR or Fe concentrations, first the chlorophyll contents and then the H2O2 concentration prominently declined, followed by SGR, the maximal quantum yield of PSII (Fv Fm–1), and antioxidant activities. With an increasing Fe concentration in the substrate, the CAT and APX antioxidant levels decreased, which led to an increase in H2O2 accumulation in the plant tissues. Moreover, increased POD activity was proportionate to H2O2 accumulation, suggesting the low-Fe independent nature of POD. Diurnally, H2O2 concentration varies following the PAR variation. However, the CAT and APX antioxidant activities were delayed, which increased the H2O2 concentration level in the afternoon compared with the level in morning for the same PAR intensities. Similar trends were also obtained for the natural river samples where relatively low light intensity was preferable for growth. Together with our previous findings on macrophyte stress responses, these results indicate that H2O2 concentration is a good indicator of environmental stressors and could be used instead of long-term growth monitoring in macrophyte management.

CHANGES IN PHOTOSYNTHETIC PIGMENT CONTENTS AND SPAD INDEX IN RELATION TO WATERLOGGING IN SUGARCANE

Waterlogging is a major abiotic factor in tropics and subtropics India affecting plant productivity by creating anoxia, aerial rooting, mineral deficiency and toxicity, physiological and biochemical alterations. In present study, an effort was made to evaluate changes in photosynthetic pigments, chlorophyll a (Chl a), chlorophyll b (Chl b), total Chl (Chl a+Chl b), carotenoids (CAR), the ratio of Chl a and Chl b (Chl a/b) and total Chl/CAR ratio and Soil plant analysis development (SPAD) index in plants grown under waterlogged conditions (WL) along with untreated control (C) using four sugarcane cultivars; CoLk 94184, BO 91, CoS 767 and CoJ 64. The results obtained indicated variation in Chl a, b, total Chl contents (mg/g fresh wt.) among different cultivars and relatively less in waterlogged plants. Chl ranged between 1.277-2.300 (mean: 1.949 in control) and 1.057- 2.150 (mean: 1.716 in waterlogged), Chl b, 0.319- 0.607 (mean: 0.518) in control and 0.290- 0.571 (mean: 0.453) in waterlogged plants, respectively. Chl a/b ratio is slightly higher in waterlogged (3.640-3.957, mean: 3.794) as compared to control (3.610-3.997, mean: 3.789) plants except in CoJ 64, while total Chl/ CAR ratio was comparatively lesser in waterlogged plants as compared to untreated control. SPAD index was relatively higher in control (30.1 - 35.3, mean: 34.0) than waterlogged plants (22.4-34.1, mean: 29.6) similar to destructive analysis of chlorophyll contents. Carotenoids contents ranged from 0.477- 0.787 in control and 0.467-0.797 mg/g fresh wt in waterlogging treatment; BO91 and CoS767 cultivars showed slightly higher value in waterlogged. Correlation among different attributes indicated significant positive relationship except chlorophyll a/b ratio showing negative association. Cultivar CoJ 64 showed highest decrease in Chl a/b, total Chl/CAR ratio and CAR contents reflecting highly sensitive to waterlogging stress as compared to other cultivars studied.

The Effects of Silveroxide on mRNA Level of Key Genes Involved In the Biosynthesis of Rebaudioside-A in Stevia Rebaudiana

Stevia rebaudiana bertoni is a plant with sweetening properties. This medicinal plant is perennial and from Asteraceae family. Its leaves contain glycoside compounds of a sugar part and non-sugar sectors. One of the glycosides compounds is Rebaudioside¬A which has a greater importance in market. Several key regulating genes including copalyl diphosphate synthase (CPPS) (AF034545.1), geranylgeranyl diphosphate synthase (GGDPS) (DQ432013.3), (E)-4-hydroxy-3-methylbut-2-enyl diphosphate synthase (HDS) (FJ755689.1), UDP glucosyltranserase 85C2(UGT85C2)(AY345978.1), UDPglucosyltranserase–74G1 (UGT74G1) (AY345982.1) and UDP glucosyltranserase–76G1 (UGT76G1) (KC631816.1) are involved in the biosynthesis Rebaudioside A. This experiment was conducted to evaluate the effect of silver oxide Ag2O on the mRNA level of these genes in the stevia rebaudiana. The experiments repeated 3 times and with concentrations of 50, 100 and 200 µM. Increasing concentrations of 50 micromoles of silver oxide up to 100 micromoles leads to an increase in the expression levels of all the studied genes. Also according to the expression profile of these genes and the results of HPLC there is a significant increase on the expression level of the genes and production of Rebaudioside¬A under Ag2O treatment. In general, it was found that increasing the concentration of Ag2O can lead to an increase in the level of mRNA for the chosen genes. On the other hand, the low expression of the genes studied under control conditions (No Treatment), compared to the treatment with Ag2O, revealed that the treatment can lead to higher sweetener glycoside components in the Stevia leaves. The physiological assay showed that Ag2O treatment in concentrations of 100 and 200 µM have more positive effect on chlorophyll, protein, carbohydrates and carotenoids in Stevia.

Carotenoids: Dietary Sources, Extraction, Encapsulation, Bioavailability, and Health Benefits-A Review of Recent Advancements.

Natural carotenoids (CARs), viz. β-carotene, lutein, astaxanthin, bixin, norbixin, capsanthin, lycopene, canthaxanthin, β-Apo-8-carotenal, zeaxanthin, and β-apo-8-carotenal-ester, are being studied as potential candidates in fields such as food, feed, nutraceuticals, and cosmeceuticals. CAR research is advancing in the following three major fields: (1) CAR production from natural sources and optimization of its downstream processing; (2) encapsulation for enhanced physical and chemical properties; and (3) preclinical, clinical, and epidemiological studies of CARs’ health benefits. This review critically discusses the recent developments in studies of the chemistry and antioxidant activity, marketing trends, dietary sources, extraction, bioaccessibility and bioavailability, encapsulation methods, dietary intake, and health benefits of CARs. Preclinical, clinical, and epidemiological studies on cancer, obesity, type 2 diabetes (T2D), cardiovascular diseases (CVD), osteoporosis, neurodegenerative disease, mental health, eye, and skin health are also discussed.

Influence of cultivar and season on carotenoids and phenolic compounds from red lettuce influence of cultivar and season on lettuce

This paper presents complete HPLC profiles and MS spectrometric data of bioactive compounds from four cultivars of red lettuce produced in winter and summer and their antioxidant capacity. The experiment was carried out in a greenhouse, where red curly lettuce was cultivated: Mila, Maira, Carmin and Scarlet. The cultivar and season have not influenced the qualitative profile of carotenoids (CAR) and phenolic compounds (PC) of red lettuce. Instead, the season influenced the concentration of these components in all cultivars. The levels of phenolic compounds were significantly higher in winter, while the levels of carotenoids were higher in summer. Ten anthocyanins were identified (cyanidins and delphinidins). The main carotenoid found was the all-trans-β-carotene (45–48%), followed by lutein (13–20%) and zeaxanthin (11–15%). Major phenolic compounds include 5-caffeoylquinic acid, rutin and amentoflavone. Red lettuce cultivars have their main bioactive compounds described and compared within the variety and within the growing season. Different season and different lettuce cultivars may differ in the content of their bioactive compounds and in their antioxidant capacity.