Sunflower (Helianthus annuus L.) biochemical properties and seed components affected by potassium fertilization under drought conditions

Detection of chlorine in potassium chloride and potassium sulfateusing chemical imaging and artificial neural network

Chlorine in potassium chloride and potassium sulfate must be detected due to its negative effect on soil. Although the laboratory-based chlorine measurement tests are reliable, they are time-consuming, expensive, and requires chemical agents and highly skilled operators. Therefore, the novelty of the present research is developing a fast, accurate, and cheap machine-based method to measure the amount of chlorine. The purpose of this research was to apply hyperspectral imaging and machine learning techniques to detect chlorine content in potassium chloride and potassium sulfate. Different percentages of chlorine in potassium chloride and potassium sulfate products were prepared with ranges of 53.1-50.05 and 1.47-2.13 %, respectively. Hyperspectral images were captured from the sample at the range of 400-950 nm. Mean, minimum, maximum, median, variance, and standard deviation features were extracted from the image channels corresponding to the effective wavelengths. The extracted features were classified using artificial neural network method and highest accuracy of the best models for potassium chloride and potassium sulfate were 95.6 and 94.4, respectively. The combination of hyperspectral imaging and machine learning promises reliable detection of chlorine content in potassium chloride and potassium sulfate in industrial systems with high speed and low cost.

Manifold roles of potassium in mediating drought tolerance in plants and its underlying mechanisms

Drought stress (DS) is a major devastating factor affecting plant growth and development worldwide. Potassium (K) is considered a vigorous moiety and stress alleviator, which crop cultivars need for better yield. It is also helpful in alleviating the DS-induced negative consequences by regulating various morphological, physiological, biochemical, and molecular mechanisms in plants. Particularly, the K application improves plant tolerance against DS by improving plant growth parameters, photosynthetic pigments, cell turgor pressure, osmotic pressure, nutritional balance, compatible solutes, and the plant's antioxidant defense system. Apart from its role as a constituent of the plant structure, biochemical processes such as protein synthesis, carbohydrate metabolism, and enzyme activation are also regulated by K. However, the exact K-mediated molecular mechanisms of DS tolerance are still unclear and require more investigation. The present review aims to provide insight into the role of K in regulating various morphological and physico-chemical aspects under DS. It also emphasizes the crosstalk of K with other nutrients and phytohormones, as well as molecular mechanisms for K homeostasis under DS. We have also shed light on genomics analysis to discover K transporter's novel genes in different plant species.

Functional and biotechnological cues of potassium homeostasis for stress tolerance and plant development

Potassium (K+) is indispensable for the regulation of a plethora of functions like plant metabolism, growth, development, and abiotic stress responses. K+ is associated with protein synthesis and entangled in the activation of scores of enzymes, stomatal regulation, and photosynthesis. It has multiple transporters and channels that assist in the uptake, efflux, transport within the cell as well as from soil to different tissues, and the grain filling sites. While it is implicated in ion homeostasis during salt stress, it acts as a modulator of stomatal movements during water deficit conditions. K+ is reported to abate the effects of chilling and photooxidative stresses. K+ has been found to ameliorate effectively the co-occurrence of drought and high-temperature stresses. Nutrient deficiency of K+ makes leaves necrotic, leads to diminished photosynthesis, and decreased assimilate utilization highlighting the role it plays in photosynthesis. Notably, K+ is associated with the detoxification of reactive oxygen species (ROS) when plants are exposed to diverse abiotic stress conditions. It is irrefutable now that K+ reduces the activity of NADPH oxidases and at the same time maintains electron transport activity, which helps in mitigating the oxidative stress. K+ as a macronutrient in plant growth, the role of K+ during abiotic stress and the protein phosphatases involved in K+ transport have been reviewed. This review presents a holistic view of the biological functions of K+, its uptake, translocation, signaling, and the critical roles it plays under abiotic stress conditions, plant growth, and development that are being unraveled in recent times.

Exploring the anti-gout potential of sunflower receptacles alkaloids: A computational and pharmacological analysis

Gout, a painful condition marked by elevated uric acid levels often linked to the diet's high purine and alcohol content, finds a potential treatment target in xanthine oxidase (XO), a crucial enzyme for uric acid production. This study explores the therapeutic properties of alkaloids extracted from sunflower (Helianthus annuus L.) receptacles against gout. By leveraging computational chemistry and introducing a novel R-based clustering algorithm, "TriDimensional Hierarchical Fingerprint Clustering with Tanimoto Representative Selection (3DHFC-TRS)," we assessed 231 alkaloid molecules from sunflower receptacles. Our clustering analysis pinpointed six alkaloids with significant gout-targeting potential, particularly emphasizing the fifth cluster's XO inhibition capabilities. Through molecular docking and the BatchDTA prediction model, we identified three top compounds-2-naphthylalanine, medroxalol, and fenspiride-with the highest XO affinity. Further molecular dynamics simulations assessed their enzyme active site interactions and binding free energies, employing MM-PBSA calculations. This investigation not only highlights the discovery of promising compounds within sunflower receptacle alkaloids via LC-MS but also introduces medroxalol as a novel gout treatment candidate, showcasing the synergy of computational techniques and LC-MS in drug discovery.

Plant growth regulators affecting canola (Brasica Napus L.) biochemistry including oil yield under drought stress

The objective was to test the effects of PGR on canola (Brassica napus L.) biochemistry including oil yield under drought stress. A two-year (Y1 and Y2) split plot field experiment on the basis of a randomized complete block design with three replications was conducted. The main factor was, drought stress levels, including irrigation after a reduction of 40 (D1), 60 (D2) and 80% (D3) of field capacity (FC) moisture, and the sub-factor was PGR including control (S1), soil application of humic acid (S2), foliar applications of amino acid (S3), fulvic acid (S4) or seaweed extract (S5), and the combination of all PGR (S6). Although drought stress significantly decreased plant chlorophyll contents (a, b and total), oil percentage and oil yield, PGR significantly increased them. The D3 treatment, compared with control, decreased crop oil yield by 48.67 and 35.29% in the first and second year, respectively. However, treatment Y2D3S6 significantly increased oil percentage (43.10%) compared with control (40.97%). The PGR increased seed oil yield, in D3, by a maximum of 254 kg ha-1. The PGR numerically (p ≤ 0.0886) increased proline to 6.14 mg  g-1 LFW (Y1D3S6) compared with control (4.79 mg g-1 LFW). The PGR also significantly increased sugar content to 17.05 mg g-1 LFW, significantly different from the control (12.95 mg g-1 LFW). In conclusion, the tested PGR can improve the biochemical properties (quality) including oil yield of canola in drought stress conditions, which is of economic and health significance.

Exogenous plant growth regulator and foliar fertilizers for phytoextraction of cadmium with Boehmeria nivea [L.] Gaudich from contaminated field soil

As a enrichment plant, ramie can be used for the phytoremediation of cadmium (Cd)-contaminated soil. However, it is worth exploring the role of plant growth regulators and foliar fertilizers in the process of plant growth and development and Cd adsorption. By measuring the agronomic traits, Cd content of aboveground and underground ramie, calculating the Cd transfer coefficient (TF) and Cd bioconcentration factors (BCF), and the correlation between various indicators. This study examined the effects of plant growth regulators and foliar fertilizers on ramie's capacity for Cd accumulation and transportation. Plant growth regulators and foliar fertilizers increased the Cd content of the aboveground ramie, reduced the Cd content of the underground ramie, and increased the TF. Among them, GA-1 increased the Cd content of the aboveground ramie to 3 times more than that of the control and reduced the Cd content of the underground ramie by 54.76%. Salicylic acid (SA) increased the Cd content of the aboveground ramie to three times more than that of the control. The combination of GA and foliar fertilizer reduced the Cd content of the aboveground and underground ramie and the TF and BCF of the underground ramie. After the hormones were sprayed, the TF of ramie had a significant positive correlation with the Cd content of the aboveground ramie; the BCF of the aboveground ramie had a significant positive correlation with the Cd content and TF of the aboveground ramie. The results indicate that Brassinolide (BR), gibberellin (GA), ethephon (ETH), polyamines (PAs), and salicylic acid (SA) have different effects on the enrichment and transport of Cd in ramie. This study provided an effective method to improve the capacity for ramie to adsorb heavy metals during cultivation.

Clustering Analysis, Structure Fingerprint Analysis, and Quantum Chemical Calculations of Compounds from Essential Oils of Sunflower (Helianthus annuus L.) Receptacles

Sunflower (Helianthus annuus L.) is an appropriate crop for current new patterns of green agriculture, so it is important to change sunflower receptacles from waste to useful resource. However, there is limited knowledge on the functions of compounds from the essential oils of sunflower receptacles. In this study, a new method was created for chemical space network analysis and classification of small samples, and applied to 104 compounds. Here, t-SNE (t-Distributed Stochastic Neighbor Embedding) dimensions were used to reduce coordinates as node locations and edge connections of chemical space networks, respectively, and molecules were grouped according to whether the edges were connected and the proximity of the node coordinates. Through detailed analysis of the structural characteristics and fingerprints of each classified group, our classification method attained good accuracy. Targets were then identified using reverse docking methods, and the active centers of the same types of compounds were determined by quantum chemical calculation. The results indicated that these compounds can be divided into nine groups, according to their mean within-group similarity (MWGS) values. The three families with the most members, i.e., the d-limonene group (18), α-pinene group (10), and γ-maaliene group (nine members) determined the protein targets, using PharmMapper. Structure fingerprint analysis was employed to predict the binding mode of the ligands of four families of the protein targets. Thence, quantum chemical calculations were applied to the active group of the representative compounds of the four families. This study provides further scientific information to support the use of sunflower receptacles.

Enhancing drought stress tolerance in Camelina (Camelina sativa L.) through exogenous application of potassium

The current study was performed under controlled conditions to study the effects of exogenous potassium application on carotenoid contents and drought tolerance in Camelina. Water deficit levels such as 100% FC (control) and 40% FC (drought stress) were imposed after germination of Camelina plants grown to maturity, and different treatments of exogenous K+ were applied at the vegetative stage. We have reported 17 traits of plant growth, physiology, antioxidant enzyme activity, focusing on carotenoids in Camelina to explore their potential yield and yield components. For this purpose, we used multivariate analysis techniques (descriptive statistics, correlation matrix, analysis of variance [ANOVA] and principal components analysis [PCA] to determine the best relation between potassium and studied traits). The results showed a large number of variations in the studied trait under control and water deficit condition. Plant fresh weight (g) was negatively correlated with shoot length and SOD insignificantly correlated with plant fresh weight (g) under water deficit conditions. Potassium loading predicted that foliar application (3 mM K₂ SO₄ ), foliar application (6 mM KNO₃ ), foliar application (12 mM KNO₃ ) and foliar application (12 mM K₂ SO₄ ) are the important doses that contribute the most to enhance the growth, physiological and biochemical activities and carotenoids to improve the Camelina yield under water deficit condition. These doses should be considered in the future to improve the Camelina yield under semi-arid conditions with increased genetic diversity (varietal selection).

Influence of water stress on engineering characteristics and oil content of sunflower seeds

Knowing some physical and mechanical characteristics and oil percentage of sunflower seeds could be useful for harvesting and processing equipment and activities such as transportation, storage, food production processes and establishing database of this seed. The main aim of this research was to study the effect of water stress during irrigation on seed's properties and quality. For this purpose, a field experiment was done under four deficit irrigation treatments [80%, 60%, 100-80 (100% irrigation requirement ETc to seed formation, and then reduced to 80% until harvesting) and 100-60% (100% ETc to seed formation, and then reduced to 60% until harvesting)] in comparable with full irrigation (100%). Geometrical, gravimetrical and mechanical characteristics as well as oil seed content and yield of sunflower seed were estimated. Result showed that there was no significant effect of low (100-80%) and medium (80%) irrigation deficit treatments on geometrical, gravimetrical and mechanical characteristics, while applying 60% of irrigation requirement (ETc) showed a significant effect on them. On the other hand, low and medium irrigation stress treatments improved the oil yield and seed oil content. The highest increase was 8.54% and 5.6% for oil yield and oil content respectively, considering T_100-80 followed by applying 80% ETc, but with high water stress (60% ETc) oil yield and seed oil content significantly decreased.

Bioremediation of potentially toxic elements of sewage sludge using sunflower (Heliantus annus L.) in greenhouse and field conditions

The bioremediation of sewage sludge, containing potentially toxic elements (heavy metals), by the hyperaccumulator sunflower (Helianthus annus L.), was determined in greenhouse (G) and field (F) conditions in Isfahan, Iran. The soil pots, mixed with dried sewage sludge at 0, 15, 30, 45, and 60 mg/kg, were planted with sunflower seedlings and kept in the greenhouse (G) and in the field (F). Different soil physicochemical and plant biochemical properties including heavy metal uptake of nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd) were determined. In contrast with the soil pH, soil salinity, organic matter, nitrogen, and not soil CaCO₃, were significantly enhanced by increasing sewage sludge. Sewage sludge was significant on plant uptake of Ni (2.27-4.25 mg/kg), Cr (3.27-4.75 mg/kg), Cd (13.85-15.27 mg/kg), and total chlorophyll (1.69-1.99 mg/g) in the greenhouse, and plant uptake of Ni (1.75-2.75 mg/kg) and Cd (1.37-2.25 mg/kg), and chlorophyll b (0.06-0.26 mg/g), total chlorophyll (0.57-1.16 mg/g), and carotenoids (1.10-1.61 mg/g) in the field. Although Pb was not significantly affected by sewage sludge, it showed the highest bioaccumulation factor of 0.96 at 15 mg/kg. Interestingly, the heavy metals were all positively and significantly correlated with each other and with plant carotenoids, similar to the positive and significant correlations between Pb with chlorophyll a and b. Accordingly, the increased levels of carotenoids, acting as antioxidant, may be an indicator of oxidative stress. Sunflower plants can be used as an efficient method for the bioremediation of the soils polluted with sewage sludge including Ni, Cr, and Cd.

Molecular Interactions Associated with Coagulation of Organic Pollutants by 2S Albumin of Plant Proteins: A Computational Approach

The removal of organic pollutants is a major challenge in wastewater treatment technologies. Coagulation by plant proteins is a promising technique for this purpose. The use of these proteins has been experimentally investigated and reported in the literature. However, the determination of the molecular interactions of these species is experimentally challenging and the computational approach offers a suitable alternative in gathering useful information for this system. The present study used a molecular dynamic simulation approach to predict the potentials of using Moringa oleifera (MO), Arachis hypogaea, Bertholletia excelsa, Brassica napus, and Helianthus annuus plant proteins for the coagulation of organic pollutants and the possible mechanisms of coagulation of these proteins. The results showed that the physicochemical and structural properties of the proteins are linked to their performance. Maximum coagulation of organic molecules to the proteins is between 50-100%. Among five proteins studied for coagulation, Brassica napus and Helianthus annuus performed better than the well-known MO protein. The amino acid residues interacting with the organic molecules play a significant role in the coagulation and this is peculiar with each plant protein. Hydrogen bond and π-interactions dominate throughout the protein-pollutants molecular interactions. The reusability of the proteins after coagulation derived from their structural quality analysis along with the complexes looks promising and most of them are better than that of the MO. The results showed that the seed proteins studied have good prediction potentials to be used for the coagulation of organic pollutants from the environment, as well as the insights into their molecular activities for bioremediation.

Potassium in plants: Growth regulation, signaling, and environmental stress tolerance

Potassium (K) is an essential element for the growth and development of plants; however, its scarcity or excessive level leads to distortion of numerous functions in plants. It takes part in the control of various significant functions in plant advancement. Because of the importance index, K is regarded second after nitrogen for whole plant growth. Approximately, higher than 60 enzymes are reliant on K for activation within the plant system, in which K plays a vital function as a regulator. Potassium provides assistance in plants against abiotic stress conditions in the environment. With this background, the present paper reviews the physiological functions of K in plants like stomatal regulation, photosynthesis and water uptake. The article also focuses upon the uptake and transport mechanisms of K along with its role in detoxification of reactive oxygen species and in conferring tolerance to plants against abiotic stresses. It also highlights the research progress made in the direction of K mediated signaling cascades.

Potassium fertilization improves growth, yield and seed quality of sunflower (Helianthus annuus L.) under drought stress at different growth stages

Water scarcity is a major concern for sunflower production in the semi-arid and arid regions of the world. Potassium (K) application has been found effective to alleviate the influence of drought stress; however, the impact of drought stress on seed quality of sunflower has not been reported frequently. Therefore, a field experiment was performed to determine the optimum K requirement for mitigating the adverse effects of water stress and improving growth and seed quality of spring-planted sunflower. Sunflower plants were exposed to water stress at different growth stages, i.e., I_o = no stress (normal irrigation), I₁ = pre-anthesisi stress (irrigation skipped at pre-anthesis stage), I₂ = anthesis stress (irrigation skipped at anthesis stage) and I₃ = post-anthesis stress (irrigation skipped at post-anthesis stage). Potassium was applied at four different rates, i.e., K_o = 0, K₁ = 50, K₂ = 100 and K₃ = 150 kg ha^-1. The results revealed that water stress at pre- and post-anthesis stages significantly reduced plant height, head diameter, number of achenes, oleic acid contents, and phosphorus (P) uptake. However, pre-anthesis stress improved linoleic acid contents. Treatment I_oK₃ (stress-free with 150 kg ha^-1 K) was optimum combination for 1000-achene weight, biological and achene yields, oil contents, protein contents, and N and P uptake. Results indicated that a higher amount of K and irrigation resulted in higher yield, whereas yield and yield components decreased with early-stage water stress. Nevertheless, potassium application lowered the impacts of waters stress compared to no application. Keeping in view these results, it is recommended that sunflower must be supplied 150 kg ha^-1 K in arid and semi-arid regions to achieve higher yield and better seed quality.

The biological approaches of altering the growth and biochemical properties of medicinal plants under salinity stress

Due to their interesting properties for human health, medicinal plants are of worldwide interest, including Iran. More has yet to be investigated and analyzed on the use of methods affecting medicinal plant growth and biochemical properties under stress. The important question about medicinal plants is the purpose of their plantation, determining their growth conditions. The present review article is about the effects of salinity stress on the growth and production of secondary metabolites (SM) in medicinal plants. In stressful conditions including salinity, while the growth of medicinal plants decreases, the production of secondary metabolites (SM) may increase significantly affecting plant medicinal properties. SMs are self-protective substances that medicinal plants quickly accumulate to resist changes in the external environment. Although previous research has indicated the effects of salt stress on the growth and yield of medicinal plants, more has yet to be indicated on how the use of biological methods including plant growth regulators (PGR) and soil microbes (mycorrhizal fungi and plant growth-promoting rhizobacteria, PGPR) may affect the physiology of medicinal plants and the subsequent production of SM in salt stress conditions. The use of modern omics has become significantly important for the identification and characterization of new SM, transcriptomics, genomics, and proteomics of medicinal plants, as well as for the high production of plant-derived medicines. Accordingly, the possible biological mechanisms, which may affect such properties, have been presented. Future research perspectives for the production of medicinal plants in saline fields, using biological methods, have been suggested. KEY POINTS: • The important question about medicinal plants is the purpose of their plantation. • Secondary metabolites (SM) may significantly increase under salinity stress. • Biological methods, affecting the production of SM by stressed medicinal plants.

Mayten Tree Seed Oil: Nutritional Value Evaluation According to Antioxidant Capacity and Bioactive Properties

The Mayten tree (Maytenus boaria Mol.), a native plant of Chile that grows under environmentally limiting conditions, was historically harvested to extract an edible oil, and may represent an opportunity to expand current vegetable oil production. Seeds were collected from Mayten trees in north-central Chile, and seed oil was extracted by solvent extraction. The seed oil showed a reddish coloration, with quality parameters similar to those of other vegetable oils. The fatty acid composition revealed high levels of monounsaturated and polyunsaturated fatty acids. Oleic and linoleic acids, which are relevant to the human diet, were well represented in the extracted Mayten tree seed oil. The oil displayed an antioxidant capacity due to the high contents of antioxidant compounds (polyphenols and carotenoids) and may have potential health benefits for diseases associated with oxidative stress.

Pepermint (Mentha piperita L.) growth and biochemical properties affected by magnetized saline water

Due to the limitation of suitable water for crop production in the world, recycling water is among the most proper methods enhancing water efficiency and availability. One modern method, which is of economic, health, and environmental significance, and may improve water properties for plant use is water magnetization. Medicinal plants are of nutritional, economic and medical values and their growth decreases under salinity stresses. This research was hypothesized and conducted because there is not any data, to our knowledge, on the use of magnetized salty water affecting the growth and biochemical properties of peppermint (Mentha piperita L.). The experiment was a split plot design with three replicates. The main plots consisted of magnetic fields at control (M1), 100 mT (M2), 200 mT (M3), and 300 mT (M4), the sub-plots consisted of salinity treatments (NaCl) at control (S1), 4 dS/m (S2), 8 dS/m (S3), and 12 dS/m (S4), and the growth media including cocopeat (X1), palm (X2), cocopeat + perlite (V/V = 50, X3) and palm + perlite (V/V = 50, X4) were located in the sub-sub-plots. Different plant growth and biochemical properties including plant fresh and dry weight, plant menthol, menthone, chlorophyll and proline contents were determined. Analysis of variance indicated the significant effects of experimental treatments and their interactions on the growth and biochemistry of peppermint. Different magnetic fields significantly increased plant growth, and interestingly with increasing the salinity level the alleviating effects of magnetic field on salinity stress became more clear (significant interaction between salinity and magnetic field treatments). Cocopeat was the most efficient growth medium. At the third level of salinity (8 dS/m) just the two levels of 100 and 200 mT increased plant menthol concentration. Treatments M3S2X4 and M1S1X1 resulted in the highest (38%) and the least menthol percentage (13%), respectively. Treatments S2 and M2 and M3 significantly increased plant menthone concentration, especially in the growth media of X1 and X3. However, at the third level of salinity, M3 and M4 were the most effective treatments. The highest (25.8%) and the least (1.2%) concentrations of menthone were related to treatments M3S2X4 and M2S4X1, respectively. The results indicated that it is possible to alleviate the stress of salinity on peppermint growth and improve its biochemical (medicinal) properties using magnetized salty water, although proline concentration was not much affected by the magnetic field.

Safflower (Carthamus tinctorius) Biochemical Properties, Yield, and Oil Content Affected by 24-Epibrassinosteroid and Genotype under Drought Stress

The steroid hormones, including brassinosteroids, regulate plant growth under stress. It is hypothesized that 24-epibrassinosteroids (24-EBR) can affect safflower (Carthamus tinctorius) biochemical properties, crop yield, and oil content under drought stress. The objective of our study was to determine the response of three safflower genotypes (Goldasht, Faraman, and Sina) to exogenous 24-EBR (0 and 10^-7 M) under drought stress, including 85, 65, and 45% of field capacity in 2015. Stress decreased chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, relative water content (RWC), seed yield, and oil percentage. The activities of superoxide dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), and proline contents increased in response to either drought stress or 24-EBR. Genotypes behaved significantly different under stress. 24-EBR significantly increased plant chlorophyll contents and oil percentage, and it significantly reduced the malondialdehyde (MDA) content via increasing the proline and carotenoid contents under stress. 24-EBR can increase safflower oil and seed yield under drought stress.