Major Macronutrients Research Articles

Serum Magnesium concentration in normal and preeclamptic pregnancy: A tertiary center experience

Preeclampsia and maternal mortality are more prevalent in underdeveloped nations. Preeclampsia has an estimated 16% incidence rate in Bangladesh, which is extremely high. One of the body's major macronutrients is magnesium. It also serves a multitude of enzymes as a cofactor. This cross-sectional study was done in the department of Biochemistry of Mymensingh Medical College, Mymensingh, from July 2016 to June 2017. This study involved a total of 100 individuals, where 50 preeclamptic patients and 50 healthy pregnant women served as the case and control groups, respectively. The results were shown as mean ±SD. For both the case and control groups, the mean ±SD of serum magnesium levels were 1.75 ±0.22 mg/dl and 1.63 ±0.21, respectively. Comparison of the mean ±SD of serum magnesium in the case and control groups revealed a highly significant difference (P<0.001). Students' unpaired ‘t’ test was used to compute the statistical difference. Mediscope 2024;11(2): 73-76

Analysis of Selected Macro- and Microelement Components in the Indigenous Soybean Cultivars from Regions of the Western Himalaya in India

The need to focus on traditional crops for food security has been realized across the globe. ‘Bhat’ is an indigenous soybean variety from the Indian Himalayan Region that has been neglected in recent times due to changing agricultural choices. The present study was conducted on 52 indigenous soybean accessions collected from different villages of Uttarakhand, a hilly state in Northern India, to determine the concentrations of various macro- and microelements in the crop. The analysis used the HHXRF (handheld X-ray fluorescence) spectroscopic technique and atomic absorption spectroscopy (AAS). The findings reveal that the ‘bhat’ is an extremely nutrient-rich crop with calcium being the most significant macronutrient (highest concentration of 27,300 ppm), followed by phosphorus, potassium, and sulphur found in the bhat seeds. The study suggests that samples from Pauri Garhwal (Gwad Khirsu, Bironkhal, Sripur), Tehri (PratapNagar, Singoli), Chamoli (Paini, and Agastyamuni) villages were rich in all the major macronutrients. Among the micronutrients, silicon was found to be the most dominant with the highest concentration of 1920 ppm. This was followed by the dominance of iron, zinc, and manganese in descending order of abundance. Tipri, Chandola Rai Goonth, Chopdiun, and Paini villages were found to have the highest concentrations of microelements. The statistical data analysis confirms that seed samples from different regions are significantly similar in terms of nutrient concentrations, except for Si and Fe, thereby indicating that ‘bhat’ from any of the villages is equally good for consumption. However, seed samples from certain regions were found to be contaminated with heavy metals, indicating soil pollution, which demands attention towards current agricultural practices. The findings show that the crop is an exceptional source of essential and quasi-essential elements and should be promoted to benefit the hill populations.

Влияние предварительной биоконверсии пшеничной соломы в модельной природоподобной системе на продуктивность растений

Studies focused on maintaining high productivity and stability of artificial ecosystems that reproduce the processes of natural cenoses are relevant and interesting. It seems to be effective to include decomposers, detritivores and vegetative waste in model systems aimed at obtaining products. The use of earthworms as detritivores is promising because they utilize the organic matter as well as enrich the substrates with microflora including those with antagonistic and growth-stimulating activities. The aim of this study was to assess the prospects of preliminary bioconversion of wheat straw by basidiomycetes (Lentinus tigrinus and Pleurotus ostreatus) to increase the productivity of lettuce plants. The work was carried out in laboratory conditions with model systems consisting of a substrate (peat, cattle manure and wheat straw with and without bioconversion), earthworms (Eisenia fetida) and lettuce (Lactuca sativa var. crispa cultivar Credo). The leaf area, the weight of each plant (wet and dry), the productivity of lettuce plants, and the content of the main biogenic elements in the plant tissue and substrate were evaluated. The number and weight of adult worms at the beginning and at the end of the experiment, and the number of juvenile worms at the end of the experiment, the number of cocoons, as well as coprolite weight and yield were considered. A significant phytotoxic effect when straw was added into the substrate was found. The addition of straw processed by basidiomycetes (10%) in the substrate had a favorable effect on the earthworm population. Growing lettuce on substrates with bioconverted straw and with the earthworm introduction increases the content of major macronutrients (nitrogen, phosphorus, potassium) in plants. The introduction of earthworms contributed to a significant decrease in the phytotoxicity of substrates. Thus, it is possible to recommend the inclusion of fungiculture wastes (such as substrates after fruiting bodies obtaining) in green crop production systems together with the introduction of earthworms into substrates.

Nitrogen Nutrition-Induced Changes in Macronutrient Content and Their Indirect Effect on N-Metabolism Via an Impact on Key N-Assimilating Enzymes in Bread Wheat (Triticum aestivum L.)

Judicious application of nitrogen (N) fertilizers in crop production is critical for reducing the nitrate pollution of groundwater and greenhouse gas emissions. It is, thus, important to improve the nitrogen use efficiency under the reduced application of nitrogen. A genotypic variation in N-uptake and N-use efficiency particularly under low N-input conditions exists across crops that can be deciphered and exploited for environmentally sustainable farming without any significant penalty of yield and quality. The present research conducted under the nutrient solution culture aimed to explore the inherent variability in the growth response of ten genetically diverse wheat varieties to low fertilizer N-application (N-, 10 μM N) in comparison to N sufficient control (N+, 8.5 mM N) viz., a viz., the activity of various key N-assimilating enzymes and to delineate the indirect effect of low N on uptake and partitioning of other major macronutrients viz., P, K, S, which may indirectly regulate the N-use efficiency. A notable increase in sulfur, potassium, and phosphorus content was observed under nitrogen-deficient conditions. Varieties such as Carnamah and HD 2824 exhibit a significant increase in shoot phosphorus content, emphasizing their potential to optimize phosphorus acquisition and utilization efficiency under nutrient-limited conditions. The findings highlight the complex interplay between nutrient availability and plant responses, showcasing varietal-specific adaptations to nitrogen limitations.

The contribution of commonly consumed edible insects to nutrition security in the Eastern D.R. Congo

Edible insects are perceived as an incredible opportunity to mitigate the major challenge of sustainably producing healthy foods for a growing world population in the face of climate change uncertainties over the coming decade. In this study, we assessed the nutrient composition and sensory properties of Acheta domesticus, Apis mellifera, Gnathocera trivittata, Gryllotalpa africana, Imbrasia epimethea, Imbrasia oyemensis, Locusta migratoria, Macrotermes subhylanus, Nomadacris septemfasciata, Rhyncophorus phoenicis, Ruspolia differens and Rhynchophorus ferrugineus consumed in Eastern D. R. Congo. The investigated edible insects are highly appreciated and nutritious, with proteins (20.67–43.93 g/100 g) and fats (14.53–36.02 g/100 g) being the major macro-nutrients, proving their potential to improve diets through food enrichment. The high potassium (24–386.67 mg/100 g), sodium (152–257.82 mg/100 g), magnesium (32–64 mg/100 g), iron (5.3–16.13 mg/100 g), calcium (25–156.67 mg/100 g) and zinc (11–19.67 mg/100 g) content make the assessed edible insects a useful mineral-containing ingredient for preventing undernutrition in countries which are plagued by micronutrient deficiencies. A scatter plot of matrices and Pearson’s correlations between sensory attributes and nutritional composition showed a negative correlation (r = − 0.45) between protein and appearance. While no strong correlation was observed between nutritional attributes and sensory acceptance, a positive correlation was observed between potassium and aroma (r = 0.50), after-taste (r = 0.50) and acceptability (r = 0.52). Principal component analysis results indicated that the two axes accounted for up to 97.4% of the observed variability in the nutrient composition and sensory attributes of commonly consumed edible insects in the Eastern D. R. Congo. Given the significant delicacy and nutritional potential of edible insects highlighted in this paper, households can rely on the latter to meet their nutritional needs rather than conventional livestock, thus contributing to environmental and financial security through local business opportunities.

Longitudinal Relationship between the Percentage of Energy Intake from Macronutrients and Overweight/Obesity among Chinese Adults from 1991 to 2018.

To investigate the prospective relationship between macronutrient intake and overweight/obesity, data were collected in the China Health and Nutrition Survey (CHNS) from 1991 to 2018. Adults who participated in at least two waves of the survey and were not obese at baseline were selected as the study subjects. A total of 14,531 subjects were finally included with complete data. Overweight/obesity was defined as a body mass index (BMI) ≥ 24.0 kg/m2. The generalized estimating equation (GEE) was used to analyze the relationship between the percentage of energy intake from macronutrients and BMI and overweight/obesity. The percentages of energy intake from protein and fat showed an increasing trend (p < 0.01), and the percentage of energy intake from carbohydrate showed a decreasing trend (p < 0.01) among Chinese adults between 1991 and 2018. Adjusting for covariates, the energy intake from fat was positively correlated with BMI, while the energy intake from carbohydrates was negatively correlated with BMI. The percentage of energy intake from non-high-quality protein and polyunsaturated fatty acids (PUFA) were positively correlated with overweight/obesity. In contrast, monounsaturated fatty acids (MUFA) and high-quality carbohydrates were negatively correlated with overweight/obesity. In short, fat, non-high-quality protein, saturated fatty acids (SFA), and PUFA were positively correlated with the risk of obesity, whereas higher carbohydrate, MUFA, and high-quality carbohydrate intake were associated with a lower risk of obesity. Obesity can be effectively prevented by appropriately adjusting the proportion of intake from the three major macronutrients.

Tomato Seed (Solanum lycopersicum) Meal Derived From Agrifood Waste as Functional Ingredient: Nutritional Value, Antioxidant and Antimicrobial Activities, and Functional Properties

Agrifood wastes derived from fruits and vegetables are a major source of valuable bioactive compounds. They are therefore a potential functional ingredient that can be used for improving the physicochemical, and sensory, properties; health benefits; and shelf life of food. This study was aimed at evaluating the antioxidant and antimicrobial potential of tomato seed (Solanum lycopersicum) meal derived from agrifood waste to be used as a functional ingredient for food preservation. To this end, proximate composition, bioactive compounds, antioxidant activity, antimicrobial ability, and functional properties were evaluated using relevant methods. The seeds are the most nutrient‐rich part of the tomato. They contain major macronutrients such as proteins (29.97%, dw), lipids (28.32%, dw), carbohydrates (17.19%, dw), and dietary fibers (20.93%, dw). They are rich in minerals (3.57%, dw), and bioactive molecules include total phenolic (4.8 mg/100 g) and carotenoids (with 43.65 μg/g for lycopene and 23.62 μg/g for β‐carotene). Owing to their content of biomolecules, tomato seed meal extracts inhibited the growth of certain food‐borne pathogens and food spoilage microorganisms with inhibition diameters of up to 25 cm. Methanolic extracts of these meals showed significant antioxidant activity (25.03% inhibition percentage of diphenyl‐picryl‐hydrazyl). Our findings highlight the importance of making better valorization of tomato seeds. Tomato seed meal has interesting potential as a functional ingredient, capable of improving the physicochemical properties, enriching the nutritional quality, and extending the shelf life of foods.

Larval nutritional effects on male and female survival and fecundity in Anastrepha ludens

AbstractThe three major macronutrients – proteins (P), carbohydrates (C), and lipids (L) – constitute the fundamental nutrient niche. In order to meet their nutritional requirements, organisms need to assess their nutritional state, select suitable foods, and regulate the amount of food eaten. The objective of this study was to determine whether larval nutrition could have a differential effect on female and male survival and fecundity by manipulating the P:C:L ratios in diet environments. We manipulated food availability during the larval stages, subjecting the larvae to food regimes with different P:C:L ratios. Upon adult emergence, we examined the fecundity, fertility, survival, and longevity of the various larval nutrition treatments. We then assessed the reproductive performance (fecundity and egg hatching) under an ad libitum food regime. We found that the concentration of macronutrients in the larval hemolymph indicates that the P:C:L ratio in the larval diet affects the assignment of macronutrients, and this effect is carried over to males and females differently. A larval diet with high carbohydrate content affects the carryover of macronutrients and male and female fitness. According to the life‐history traits, an adult that emerged from a larva with high lipid content in the hemolymph could suggest better health status. Insects with high cold tolerance have high body lipids content. Interactions between lipids, carbohydrates, and proteins suggest that their relative ratios must be taken into consideration in the design and improvement of artificial diets.

Effects of Blanching, Freezing and Canning on the Carbohydrates in Sweet Corn.

Sweet corn is frequently consumed in the US and contains carbohydrates as major macronutrients. This study examined the effects of blanching, freezing, and canning on carbohydrates in sweet corn. Fresh bi-color sweet corn was picked in the field and processed immediately into frozen and canned samples. Simple sugars, starch, and dietary fiber (DF) (including total DF (TDF), insoluble DF (IDF) and two fractions of soluble DF (SDF)) were measured according to the AOAC methods. Additional glycomic analysis including oligosaccharides, monosaccharide composition of total polysaccharides (MCTP) and glycosidic linkage of total polysaccharides (GLTP) were analyzed using UHPLC-MS. Sucrose is the major simple sugar, and IDF is the main contributor to TDF. Sucrose and total simple sugar concentrations were not altered after blanching or freezing but were significantly reduced in canned samples. Kestose was the only oligosaccharide identified in sweet corn and decreased in all heat-treated or frozen samples. Starch content decreased in frozen samples but increased in canned samples. While two SDF fractions did not differ across all samples, blanching, freezing and canning resulted in increases in TDF and IDF. Six monosaccharides were identified as major building blocks of the total polysaccharides from MCTP analysis. Glucose and total monosaccharide concentrations increased in two canned samples. GLTP was also profoundly altered by different food processing methods. This study provided insights into the changes in the content and quality of carbohydrates in sweet corn after food processing. The data are important for accurate assessment of the carbohydrate intake from different sweet corn products.

Nutritional and functional potentials of germinated rice: A systematic review

The cereal food group contributes significant amounts of the major macronutrients and micronutrients, making it an essential part of a healthy diet. The primary food for nutrition, energy, and nourishment in India, especially in North Eastern India, is rice. It is rich in dietary fiber, vitamin B including niacin, riboflavin, and thiamin, in addition to minerals like phosphorus, potassium, and magnesium. Germination as a biochemical process has the ability to enhance the nutritional value of whole brown rice grains and bioactive properties of rice. It is a time-honored, cost-effective way to prepare sprouted seeds. Since, high molecular proteins break down into low molecular proteins during germination, this process impacts on product qualities including odor, bioactivity and digestibility, which is advantageous for baby nutrition. Varying steeping time or water pH causes changes in reducing sugar, free GABA, and amylase activity, however, there is a decrease in total starch content. Gamma-aminobutyric acid (GABA) inhibits leukemia cell proliferation and stimulates cancer cell Apoptosis. Therefore, the aim of this present review is to highlight the biochemical changes that occur in rice due to germination and its health benefits.

Leaf yield and mineral content of mizuna in response to cut-and-come-again harvest, substrate particle size, and fertilizer formulation in a simulated spaceflight environment

The Veggie plant-growth unit deployed onboard the International Space Station (ISS) grows leafy vegetables to supplement crew diets. “Cut-and-come-again” harvests are tested to maximize vegetative yield while minimizing crew time. Water, oxygen, and fertilizer delivery to roots of leafy greens growing in microgravity have become the center of attention for Veggie. Current Veggie technology wicks water into particulate root substrates incorporating controlled-release fertilizer (CRF). Mizuna mustard (Brassica rapa) was grown under ISS-like environments in ground-based Veggie-analogue units comparing crop response to combinations of two different substrate particle sizes, two different fertilizer formulations, and three leaf-harvest times from each plant. Fine-particle porous ceramic substrate (Profile©) was compared with a 40:60 mix of fine-particle porous ceramic Profile© + coarse porous ceramic Turface© substrate. Identical 18-6-8 (NPK) CRF formulations consisting of [50% fast-release (T70) + 50% intermediate-release (T100) prills] vs. [50% fast-release (T70) + 50% slow-release (T180) prills] were incorporated into each substrate, and leaf tissues were harvested from each treatment combination at 28, 48, and 56 days after sowing. The combination of T100 CRF in 100% Profile© substrate gave the highest fresh mass (FM) and leaf area (LA) across harvests, whereas T180 CRF in 40% Profile© gave the lowest. Dry-mass (DM) yields varied with effects on leaf area. Tissue nitrogen (N) and potassium (K) specific contents declined across harvests for all treatment combinations but tended to be highest for T100 CRF/100% Profile©, and lowest for T180 CRF/40% Profile©. These major macronutrients were taken up faster by roots growing in small particle-size substrate incorporating intermediate-rate CRF, but also were depleted faster from the same treatment combination, suggesting it may not continue to be the best combination for additional harvests. Micronutrients did not decline in tissue specific content across treatment combinations, but manganese (Mn) accumulated in leaf tissue across treatments and apparently comes mainly from the ceramic substrate, regardless of particle size. Substrate leachate analysis following final harvest indicated that pH remained in the range for nominal availability of mineral nutrients for root uptake, but electro-conductivity measurements suggested depletion of fertilizer salts from root zones, especially from the treatment combination supporting the highest yields and major macronutrient contents. Although 100% Profile© was the better growth substrate for mizuna in combination with intermediate-rate CRF and three cut-and-come-again harvests in ground-based studies, mixed-particle-size substrates may be a better choice for plant growth under microgravity conditions, where capillary forces predominant and tend to cause saturation of a fine medium with water. Since there were no statistically significant interactions between substrate and fertilizer in this study, our ground-based findings for CRF choice should translate to the best substrate choice for microgravity, but if NASA wants to consider additional cut-and-come-again harvests from the same mizuna plants, more complex CRF formulations likely will have to be investigated.

Enhancing sustainability through microalgae cultivation in urban wastewater for biostimulant production and nutrient recovery

Microalgae can produce biostimulants in form of phytohormones, which are compounds that, even if applied in low concentrations, can have stimulant effects on plants growth and can enhance their quality and their resistance to stress. Considering that microalgal biomass can grow recovering nutrients from wastewater, this circular approach allows to use residues for the production of high added value compounds (such as phytohormones) at low cost. The interest on biostimulants production from microalgae have recently raised. Scientists are focused on the direct application of these cellular extracts on plants, while the number of studies on the identification of bioactive molecules, such as phytohormones, is very scarce. Two cyanobacteria strains (Synechocystis sp. (SY) and Phormidium sp. (PH)) and a chlorophyte (Scenedesmus sp. (SC)) were cultured in laboratory-scale PBRs with a working volume of 2.5 L in secondary urban wastewater varying N:P ratio in the cultures to obtain the highest productivity. The variation of N:P ratio affects microalgae growth, and SY and PH presented higher productivities (73 and 48 mg L−1 d, respectively) under higher N:P ratio (> 22:1). Microalgal biomass was freeze-dried and phytohormones content was measured with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The three microalgae showed similar phytohormones profiles, being the auxin (indole-3-acetic acid, IAA) the most abundant (72 ng g−1DW in SY). Proteins were major macronutrient for all strains, reaching 48 %DW in PH culture. To optimize the biostimulants production, a balance between the production of such compounds, biomass productivity and nutrients removal should be taken into consideration. In this sense, SC was the most promising strain, showing the highest N and P removal rates (73 % and 59 %, respectively) while producing phytohormones.

Responce of European Wheat to Weed Competitiveness as Affected by Potassium Fertilizer Levels

Purpose: The significance of potassium has been well documented as one of the major macronutrients for many crops, particularly wheat. Herbicide resistance in weeds and other environmental issues in the wheat crop has encouraged researchers to find alternative methods for weed management.Research methods: A field experiment was conducted during the winter season 2021-2022 at a private farm in North Samawah city, Iraq to examine the competitive ability of two European wheat cultivars against weeds as affected by potassium (K) levels. Treatments included two wheat cultivars (Milano and Pick-row), and three K fertiliser levels (0, 200 and 400 Kg K2O/ha).Findings: The results showed that Pick-row was a superior cultivar in terms of crop competitive ability with weeds compared with Milano. Pick-row was taller, produced the largest number of spikes, had the greatest grain yield, greatest crop biomass and least weed biomass about 61.5 cm, 70 spike/m2, 0.66 t/ha, 2.29 t/ha, and 52.5 g/m2 respectively. The increased K fertiliser level has a positive effect on crop production and weed biomass reduction, especially with Pick-row cultivar.Originality/ Value: It is implicated that Pick-row can be useful as a competitive cultivar under Al-Muthanna Province environments. Potassium K fertiliser is better to be increased and split into a number of equal doses and applied at different growth stages of wheat to avoid critical competitive timing risks.

Nutritional, chemical, and antioxidant screening of selected varieties of lentils (Lens culinaris spp.) from organic and conventional agriculture.

Lentils are an ancient legume established worldwide for direct consumption and with great potential for application in food processing. In addition, it is a sustainable crop owing to its ability to scavenge nitrogen and carbon, and it improves the nutrient status of the soil. A diet rich in lentils has been linked to significant health benefits. However, the composition of lentils can be influenced by both the lentil variety and the growing conditions. The aim of this work was to evaluate the nutritional profiles and antioxidant potential, as well as the impact that the type of cultivation (conventional or organic) and the variety could have on these parameters, in different lentil varieties. Overall, carbohydrates are the major macronutrients in all varieties, with notable amounts of fibre (11.62-27.36%) and starch (41.98-50.27%). High amounts of protein and ash were also identified, particularly in the Beluga variety, with 21.9-23.3 and 1.38-1.82 g 100 g-1 fresh weight, respectively. Fructose and sucrose were detected (high-performance liquid chromatography (HPLC) with refraction index detection), along with oxalic, quinic, malic, and shikimic acids (ultra-fast liquid chromatography with photodiode array detection), and α- and γ-tocopherol isoforms (HPLC with fluorescence detection). Fatty acid methyl ester assessment showed the prevalence of polyunsaturated fatty acids (33.5-46.3%). Good antioxidant capacity (thiobarbituric acid reactive substances and oxidative haemolysis inhibition assay) was also noted. The results obtained showed that all the varieties analysed are an excellent source of fibre and have a good antioxidant capacity. Lentil variety has a greater influence on its nutritional composition than the type of cultivation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Post-nursing early life macronutrient balance promotes persistent and malleable biometric and metabolic traits in mice.

It is known that dietary factors within the gestational and nursing period affect early life and stably affect later life traits in animals. However, there is very little understanding of whether dietary factors within the early life period from post-nursing to adulthood affect traits in adulthood. To address this, we conducted studies on male C57Bl/6J mice fed from 3weeks (immediately post-nursing) until 12weeks (full maturity) using nine different diets varying in all three major macronutrients to parse out the effects of individual macronutrients. Early life macronutrient balance affected body composition and glucose homeostasis in early adulthood, with dietary protein and fat showing major effects. Despite this, mice showed rapid reversal of the effects on body composition and glucose homeostasis of early life diet feeding, upon standard diet feeding in adulthood. However, some traits were persistent, with early life low dietary protein levels stably affecting lean and muscle mass, and early life dietary fat levels stably affecting serum and liver triglyceride levels. In summary, macronutrient balance in the post-nursing early life period does not stably affect adiposity or glucose homeostasis but does impact muscle mass and lipid homeostasis in adulthood, with prominent effects of both protein and fat levels. KEY POINTS: Early life dietary low protein and high fat levels lowered and heightened body mass, respectively. These effects did not substantially persist into adulthood with rapid catch-up growth on a normal diet. Early life protein (negative) and fat (positive) levels affected fat mass. Early life low protein levels negatively affected lean mass. Low protein effects on lower lean and muscle mass persisted into adulthood. Early life macronutrient balance effects did not affect later life glucose homeostasis but early life high fat level affected later life dyslipidaemia. Effects of dietary carbohydrate levels in early and later life were minor.

The Role of Submarine Groundwater Discharge to the Input of Macronutrients Within a Macrotidal Subpolar Estuary

The major sources of macronutrients (nitrate, ammonium, phosphate, and silicic acid) in Jakolof Bay, Alaska are submarine groundwater discharge (SGD), rivers, and offshore water. We estimated SGD using natural geochemical tracers (radon and radium), a salt mass balance, and a two-component salinity mixing equation based on the change in groundwater salinity on falling lower low tide. Previous studies have hypothesized that the major macronutrient input into Jakolof Bay is offshore water. This study challenges that assumption by determining the relative contribution of macronutrients from SGD relative to offshore water and rivers. Here, SGD is tidally driven and, as the Northern Gulf of Alaska experiences some of the largest tidal ranges in the world, the SGD fluxes from this region are high relative to the global average regardless of local sediment type. The fluxes ranged from 596 ± 85 cm day−1 at low tide to 97 ± 83 cm day−1 at high tide and are predominantly composed of recirculated seawater (89%) rather than freshwater (11%). The major macronutrients in seawater had different input mechanisms into the semi-enclosed bay. SGD and offshore waters contend as the primary sources of nitrate, which is shown to be the limiting nutrient in this coastal area, while SGD dominates the input of silicic acid. Conversely, the aquifer is found to be a sink for phosphate, indicating that the nutrient is primarily sourced from offshore water.

Response of Medical Cannabis to Magnesium (Mg) Supply at the Vegetative Growth Phase.

Recent studies demonstrated a significant impact of some major macronutrients on function and production of medical cannabis plants, yet information on the effect of most nutrients, including Mg, is scarce. Magnesium is required for major physiological functions and metabolic processes in plants, and in the present study we studied the effects of five Mg treatments (2, 20, 35, 70, and 140 mg L-1 Mg), on plant development and function, and distribution of minerals in drug-type (medical) cannabis plants, at the vegetative growth phase. The plants were cultivated in pots under controlled environment conditions. The results demonstrate that plant development is optimal under Mg supply of 35-70 mg L-1 (ppm), and impaired under lower Mg input of 2-20 mg L-1. Two mg L-1 Mg resulted in visual deficiency symptoms, shorter plants, reduced photosynthesis rate, transpiration rate, photosynthetic pigments and stomatal conduction in young-mature leaves, and a 28% reduction of total plant biomass compared to the optimal supply of 35 mg L-1 Mg. The highest supply level of 140 mg L-1 Mg induced a small decrease in physiological function, which did not affect morphological development and biomass accumulation. The low-deficient Mg supply of 2 mg L-1 Mg stimulated Mg uptake and accumulation of N, P, K, Ca, Mn, and Zn in the plant. Increased Mg supply impaired uptake of Ca and K and their root-to-shoot translocation, demonstrating competitive cation inhibition. Mg-deficiency symptoms developed first in old leaves (at 2 mg L-1 Mg) and progressed towards young-mature leaves, demonstrating ability for Mg in-planta storage and remobilization. Mg toxicity symptoms appeared in old leaves from the bottom of the plants, under 140 mg L-1 Mg. Taken together, the findings suggest 35-70 mg L-1 Mg as the optimal concentration range for cannabis plant development and function at the vegetative growth phase.

Effect of spring nitrogen fertilization on bearing and branching behaviors of young apple trees.

The total aboveground biomass production, nutritional status, bearing and branching behaviors of the central leader and one year old shoots of young apple trees have been analyzed. The shoots were further characterized according to the length, shoot demography, and the production of terminal and lateral flowers. All the characteristics are described in connection with nitrogen supply and cultivar. Nitrogen represents one of the major macronutrients involved in the growth and development of the fruit trees. The understanding of the effect of nitrogen supply for flower bud formation can be further improved by detailed analyses of tree architecture. While the biomass production was cultivar specific, the trees within particular cultivar were characterized by almost similar growth with respect to the nitrogen supply. Cultivar ´Rubinola´ exhibited similar branching pattern, but higher vigor than ´Topaz´. As a result of higher apical dominance, ´Rubinola´ produced higher proportion of long shoots, but a lower quality of short shoots than ´Topaz´. Consequently, cultivar ´Rubinola´ produced only few terminal flowers on short shoots and lateral flowers dominantly in the distal zone, while ´Topaz´ was characterized by intensive terminal flowering, but the lateral flowers were more abundant in the median zone. Even a lower dose of spring nitrogen improved the flower bud formation on both terminal and lateral positions extending the flowering zone on one-year-old shoots. This further changed the branching and bearing behavior of the apple trees, which particularly allows to optimize their fertilization management. However, this effect appears to be further regulated by mechanism connected with apical dominance.

Comparative transcriptome analyses under individual and combined nutrient starvations provide insights into N/P/K interactions in rice

Crops often suffer from simultaneous limitations of multiple nutrients in soils, including nitrogen (N), phosphorus (P) and potassium (K), which are three major macronutrients essential for ensuring growth and yield. Although plant responses to individual N, P, and K deficiency have been well documented, our understanding of the responses to combined nutrient deficiencies and the crosstalk between nutrient starvation responses is still limited. Here, we compared the physiological responses in rice under seven kinds of single and multiple low nutrient stress of N, P and K, and used RNA sequencing approaches to compare their transcriptome changes. A total of 13,000 genes were found to be differentially expressed under all these single and multiple low N/P/K stresses, and 66 and 174 of them were shared by all these stresses in roots and shoots, respectively. Functional enrichment analyses of the DEGs showed that a group of biological and metabolic processes were shared by these low N/P/K stresses. Comparative analyses indicated that DEGs under multiple low nutrient stress was not the simple summation of single nutrient stress. N was found to be the predominant factor affecting the transcriptome under combined nutrient stress. N, P, or K availability exhibited massive influences on the transcriptomic responses to starvation of other nutrients. Many genes involved in nutrient transport, hormone signaling, and transcriptional regulation were commonly responsive to low N/P/K stresses. Some transcription factors were predicted to regulate the expression of genes that are commonly responsive to N, P, and K starvations. These results revealed the interactions between N, P, and K starvation responses, and will be helpful for further elucidation of the molecular mechanisms underlying nutrient interactions.

Linking Rhizosphere Soil Aggregates with Belowground and Aboveground Plant Traits

Rhizosphere soil ecosystems are represented by the diversity of different soil aggregate-size classes, such as large macroaggregates, small macroaggregates, mesoaggregates, and microaggregates. Though these aggregate-size classes represent distinct biological, chemical, and physical properties, little is known about their dynamics and relationships with belowground and aboveground plant traits. In this study, we examined the relationships of various soil aggregate-size classes and their organic carbon contents with many aboveground and belowground soybean plant traits. Our study revealed several novel and interesting relationships between soil structural properties and plant traits. Notably, small macroaggregates represented a major portion of the rhizosphere soil ecosystem of soybean plants while organic carbon contents decreased with decreasing size of soil aggregates. Only microaggregates showed a significant relationship with root architectural traits, such as length and surface area. Among all soil aggregate size classes, the abundance of small macroaggregates and the organic carbon contents of microaggregates were better correlated with plant traits. In general, organic carbon contents of different soil aggregate-size classes showed positive correlations with leaf trichome density (defense traits) and major macronutrients, such as root P, K, and S contents; while there were mostly negative correlations with some micronutrient (Ca, Mn, Zn, Cu, B, and Mg) contents of roots and shoots. However, the abundance of small macroaggregates mostly positively correlated with the mineral contents of plant roots and shoots. Collectively, the positive and negative correlations of organic carbon contents of different soil aggregate-size classes with trichomes (defense) and physiological traits (micro-mineral contents) suggest their significance in plant nutrition and defense. Though our results suggest the relationships of soil aggregate properties with aboveground and belowground traits, further research is needed to discern the role of soil structural traits in mediating plant growth, development, defense, and physiology.