Ethanolic extract of Betel (Piper betle L.) and Chaphlu (Piper sarmentosum Roxb.) dechlorophyllized using sedimentation process: Production, characteristics, and antioxidant activities

Sedimentation process was used to remove chlorophyll from betel leaf ethanolic extracts (BLEE) and chaphlu leaf ethanolic extracts (CLEE). The influence of water quantity on chlorophyll content, total phenolic content (TPC), and antioxidant activity of the extracts was studied. The sedimentation process showed a remarkable reduction in chlorophyll A, chlorophyll B, and total chlorophyll contents of both extracts. Nevertheless, no differences in chlorophyll content, TPC, and antioxidant activities were observed between dechlorophyllized fractions in both extracts (p > .05). Liquid Chromatography-Mass Spectrometry (LC/MS) profiling showed that the BLEE dechlorophyllized using the extract/water ratio of 1:1 (BLEE-DC1) had higher phenolic compounds than CLEE-DC1. Isovitexin was the most abundant compound identified in the BLEE-DC1 while vitexin 4'-O-galactoside was the most prevalent in CLEE-DC1. When thermal and pH stabilities of the dechlorophyllized extracts were tested, BLEE-DC1 exhibited more heat stability (at 60-100°C for 0-60 min) than CLEE-DC1. Both dechlorophyllized extracts showed optimum antioxidant activities at pH 5.0. PRACTICAL APPLICATIONS: Oxidation process is associated with the numerous human diseases as well as it induces the deteriorative changes in foods, especially those rich in fat or lipid containing high polyunsaturated fatty acids. Numerous synthetic antioxidants have been employed but they may not be safe. Natural antioxidants have gained attention, particularly those from several leaves rich in polyphenols. However, due to the green color caused by chlorophylls, the extract is limited for further applications. Betel leaf ethanolic extract possessing high antioxidant activity could be dechlorophyllized using sedimentation process with the appropriate proportion of water. This green process not only showed the effective removal of chlorophyll, but also increased the proportion of polyphenol in the extract. Greenless betel leaf extract with augmented antioxidant activity can be used as natural additive to replace synthetic counterpart.

Albinism in plants - far beyond the loss of chlorophyll: Structural and physiological aspects of wild-type and albino royal poinciana (Delonix regia) seedlings

The partial or complete loss of chlorophylls, or albinism, is a rare phenomenon in plants. In the present study, we provide the first report of the occurrence in albino Delonix regia seedlings and describe the morpho-physiological changes associated with albinism. Wild-type (WT) and albino seedlings were characterized. Leaflets samples were processed following common procedures for analysis with light, scanning and transmission electron microscopy. The chlorophyll a fluorescence parameters and the carbohydrate, lipid and soluble protein content were also determined in leaf and cotyledon samples of both albino and WT seedlings. Albino seedlings showed reduced growth. They also had lower chlorophyll and protein content in foliar tissues than WT seedlings, in addition to lower concentrations of lipids and carbohydrates stored in cotyledons. The chloroplasts of albino seedlings were poorly developed, with an undefined internal membrane system and the presence of plastoglobules. Wild-type seedlings had a uniseriate and hypoestomatic epidermis. The mesophyll was dorsiventral, consisting of a layer of palisade parenchyma and two to four layers of spongy parenchyma. In albino seedlings, the spongy parenchyma was compact, with few intercellular spaces, and the thickness of the mesophyll was larger, resulting in increased thickness of the leaf blade. Albino seedlings had higher stomatal density and number of pavement cells, although the stomata had smaller dimensions. In addition to the partial loss of chlorophylls, albino D. regia showed changes at physiological and structural levels, demonstrating the crucial nature of photosynthetic pigments during the development and differentiation of plant leaf tissues/cells.

Spatial Variation of Leaf Chlorophyll in Northern Hemisphere Grasslands

Chlorophyll is the molecular basis for the function of photosystems and is also a promising tool for ecological prediction. However, the large-scale patterns of chlorophyll variation in grasslands remain poorly understood. We performed consistent measurements of chlorophyll a, b, a+b, and the a:b ratio (chlorophyll a/b) for 421 species across northern hemisphere grassland transects, recorded their distributions, variations, and influencing factors, and examined their relationships with leaf nitrogen. The results showed that the distributional ranges were 0.52-28.33 (mean 5.49) mg·g^-1 dry weight, 0.15-12.11 (mean 1.83) mg·g^-1 dry weight, 0.67-39.29 (mean 7.32) mg·g^-1 dry weight, and 1.28-7.84 (mean 3.02) for chlorophyll a, b, a+b, and a/b, respectively. The chlorophyll averages differed among regions (higher in the Loess Plateau and the Mongolian Plateau than in the Tibetan Plateau), grassland types (desert grasslands > meadow > typical grasslands), life forms, life spans, and taxonomies. In the entire northern hemisphere grassland, chlorophyll concentrations and chlorophyll a/b were negatively correlated to photosynthetically active radiation and the soil N:P ratio, and positively correlated to the mean annual temperatures. These results implied that chlorophyll in grasslands was shaped by the layered structure of grasses, distinct plateau environments, and phylogeny. The allocation patterns of leaf nitrogen to chlorophyll differed among regions and grassland types, showing that caution is required if simply relating single leaf N or chlorophyll to productivity separately. These findings enhance our understanding of chlorophyll in natural grasslands on a large scale, as well as providing information for ecological predictive models.

Stage-dependent concomitant microbial fortification improves soil nutrient status, plant growth, antioxidative defense system and gene expression in rice

Stage-dependent concomitant fortification of rice (Oryza sativa L.) varieties PB1612 and CO51 with microbial inoculants Trichoderma asperellum and Pseudomonas fluorescens as seed coating, seedling root inoculation and soil application enhanced growth, activated antioxidant enzymes and modulated defence-related genes in plants. Microbial inoculants improved shoot height, tiller numbers, fresh weight and dry biomass. Co-inoculation was more impactful in enhancing plant growth and development as compared to single inoculation. Single and co-inoculation improved organic carbon (OC) and N, P and K content in the soil substantially. Mean values between control and co-inoculation varied significantly for OC in PB1612 (p0.001) and CO51 (p0.019) and phosphorus content in PB1612 (p0.044) and CO51 (p0.021). Microbial inoculation enhanced soil nutrients and increased their bioavailability for the plants. Total polyphenolics, flavonoids and protein content increased in the leaves following microbial inoculation. Enhanced non-enzymatic antioxidant parameters (ABTS, DPPH, Fe-ion reducing power and Fe-ion chelation) was found in microbe inoculated rice reflecting high free radical scavenging activity in polyphenolics-rich leaf extracts. Increased enzyme activity of superoxide dismutase (SOD), glutathione reductase (GR), phenylalanine ammonia-lyase (PAL), peroxidase (PO), glutathione peroxidase (GPX), ascorbate peroxidase (APX) and catalase (CAT) showed improved ROS scavenging in rice plants having co-inoculation. Over-expression of PAL, cCuZn-SOD and CAT genes in microbial inoculated rice plants was recorded. The study concludes that plant stage-wise concomitant fortification by microbial inoculants could play multi-pronged manifestations at physiological, biochemical and molecular level in rice to positively influence growth, development and defense attributes in plants.

Investigating the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the composition and ultrastructure of green leafy vegetables with important nutritional values

The global presence of pharmaceuticals in the environment has been particularly considered a concerning problem with unknown consequences. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed drugs in the world, and as a result, they are commonly found in different environmental compartments. In the present work, we studied the effects of NSAIDs (diclofenac, ibuprofen, and naproxen) on the composition and ultrastructure of Atriplex patula L., S. oleracea, and Lactuca sativa L., three green leafy vegetables with significant nutritional value. Contaminant solutions of NSAIDs were applied every two days using concentrations of 0.1 mg L^-1, 0.5 mg L^-1, and 1 mg L^-1. After eight weeks of exposure of the green leafy vegetables to the selected NSAIDs, the chlorophylls (a + b), carotenoids (zeaxanthin, lutein, and ß-carotene), total polyphenol and total flavonoid contents, antioxidant capacity, and the ultrastructural modifications were determined. The obtained results indicated a moderate reduction in the assimilating pigments, total polyphenol and flavonoid contents. In addition, ultrastructural damages of the chloroplasts and cell walls were observed in the leaves of the selected vegetables, which were exposed to abiotic stress-induced by NSAIDs. All data collectively suggest that this group of drugs induced harmful effects on plants, and implicitly they may also negatively affected human health on the long term.

p-Aminobenzoate Organic Salts as Potential Plant Growth Regulators for Tomatoes

The discovery of environmentally friendly and inexpensive plant growth regulators (PGRs) for agronomically important crops is a necessity and must be considered a priority worldwide. This study provides the synthesis, structure determination and the biological evaluation of two binary organic salts as potential PGRs. New compounds have dual biological activity and are based on natural metabolite p-aminobenzoic acid (pABAH) and different alkanolamines. Studied compounds exhibit hydrogen-bonded 3D supramolecular architectures with different crystal packing due to the formation of one homosynthon and various heterosynthons. The biological profile of new compounds was investigated in laboratory and greenhouse on Solanum lycopersicum L., revealing the efficiency in promoting plant rooting and plant productivity. The results may have a positive impact on agricultural economics, developing new sustainable PGRs for tomatoes.

Peroxidases from an invasive Mesquite species for management and restoration of fertility of phenolic-contaminated soil

Phenolics drive the global economy, but they also pose threats to soil health and plant growth. Enzymes like peroxidase have the potential to remove the phenolic contaminants from the wastewater; however, their role in restoring soil health and improving plant growth has not yet been ascertained. We fractionated efficient peroxidases (MPx) from leaves of an invasive species of Mesquite, Prosopis juliflora, and demonstrated its superiority over horseradish peroxidase (HRP) in remediating phenol, 3-chlorophenol (3-CP), and a mixture of chlorophenols (CP-M), from contaminated soil. MPx removes phenolics over a broader range of pH (2.0-9.0) as compared with HRP (pH: 7.0-8.0). In soil, replacing H₂O₂ with CaO₂ further increases the phenolic removal efficiency of MPx (≥90% of phenol, ≥ 70% of 3-CP, and ≥90% of CP-M). MPx maintains ~4-fold higher phenolic removal efficiency than purified HRP even in soils with extremely high contaminant concentration (2 g phenolics/kg of soil), which is desirable for environmental applications of enzymes for remediation. MPx treatment restores soil biological processes as evident by key enzymes of soil fertility viz. Acid- and alkaline-phosphatases, urease, and soil dehydrogenase, and improves potential biochemical fertility index of soil contaminated with phenolics. MPx treatment also assists the Vigna mungo test plant to overcome toxicant stress and grow healthy in contaminated soils. Optimization of MPx for application in the field environment would help both in the restoration of phenolic-contaminated soils and the management of invasive Mesquite.

Application of PROSPECT for estimating total petroleum hydrocarbons in contaminated soils from leaf optical properties

Recent advances in hyperspectral spectroscopy suggest making use of leaf optical properties for monitoring soil contamination in oil production regions by detecting pigment alterations induced by Total Petroleum Hydrocarbons (TPH). However, this provides no quantitative information about the level of contamination. To achieve this, we propose an approach based on the inversion of the PROSPECT model. 1620 leaves from five species were collected on a site contaminated by 16 to 77 g.kg^-1 of TPH over a 14-month period. Their spectral signature was measured and used in PROSPECT model inversions to retrieve leaf biochemistry. The model performed well for simulating the spectral signatures (RMSE < 2%) and for estimating leaf pigment contents (RMSE ≤ 2.95 μg.cm^-2 for chlorophylls). Four out of the five species exhibited alterations in pigment contents when exposed to TPH. A strong correlation was established between leaf chlorophyll content and soil TPH concentrations (R² ≥ 0.74) for three of them, allowing accurate predictions of TPH (RMSE =3.20 g.kg^-1 and RPD = 5.17). The accuracy of predictions varied by season and improved after the growing period. This study demonstrates the capacity of PROSPECT to estimate oil contamination and opens up promising perspectives for larger-scale applications.

Geographic location and food availability offer differing levels of influence on the bacterial communities associated with larval sea urchins

Determining the factors underlying the assembly, structure, and diversity of symbiont communities remains a focal point of animal-microbiome research. Much of these efforts focus on taxonomic variation of microbiota within or between animal populations, but rarely test the proportional impacts of ecological components that may affect animal-associated microbiota. Using larvae from the sea urchin Strongylocentrotus droebachiensis from the Atlantic and Pacific Oceans, we test the hypothesis that, under natural conditions, inter-population differences in the composition of larval-associated bacterial communities are larger than intra-population variation due to a heterogeneous feeding environment. Despite significant differences in bacterial community structure within each S. droebachiensis larval population based on food availability, development, phenotype, and time, variation in OTU membership and community composition correlated more strongly with geographic location. Moreover, 20-30% of OTUs associated with larvae were specific to a single location while less than 10% were shared. Taken together, these results suggest that inter-populational variation in symbiont communities may be more pronounced than intra-populational variation, and that this difference may suggest that broad-scale ecological variables (e.g., across ocean basins) may mask smaller scale ecological variables (e.g., food availability).