Search Results (34)

Foliar fertilization, an effective strategy for enhancing crop yields, is relatively uncommon in bamboo cultivation. To investigate the impact of potassium fertilizer applied directly to bamboo leaves, we applied K₂CO₃ on the fresh leaves of 1-year-old Neosinocalamus affinis culms. The results indicated that potassium fertilization significantly promoted leaf growth and development, evidenced by thicker leaf and epidermal and mesophyll cells and increased areas of bulliform and fusoid cells. Additionally, the chlorophyll content rose, while the moisture levels declined. Notably, the soluble sugar, starch, and non-structural carbohydrate (NSC) contents in the leaves also increased. Further analysis of the sugar metabolism revealed that the exogenous potassium application boosted the activities of key enzymes involved in sucrose metabolism, including soluble acid convertase (SAI), cell wall invertase (CWI), sucrose synthase (SuSy), and sucrose phosphate synthetase (SPS). The foliar application of K₂CO₃ also promoted starch synthesis in the leaves by elevating the activities of ADPG pyrophosphorylase (AGPase), soluble starch synthase (SSS), and granular-bound starch synthase (GBSS), while simultaneously diminishing the activities of starch phosphorylase (STP), α-amylase, and β-amylase. Moreover, the targeted application of K₂CO₃ significantly reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) and significantly enhanced the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), thereby improving the stress resistance of bamboo leaves. This study suggested that the foliar application of potassium fertilizer promoted leaf growth, enhanced bamboo’s sugar metabolism and storage, and increased the stress resistance of bamboo leaves. Full article

Plant small molecules, such as nitric oxide (NO) and melatonin (MN) as natural and human health-friendly compounds, play important roles in the mitigation of abiotic stresses in plants. Heavy metals such as chromium (Cr) are hazardous for the survival of ornamentals, especially edible flowers. This study evaluated the effects of NO (50 µM; sourced as sodium nitroprusside) and MN (50 µM) applied two times through foliar spraying at 1-week intervals on alleviating Cr (120 µM; K₂Cr₂O₇)-induced oxidative stress in edible flowers of Calendula officinalis cv. Orange King. Cr stress decreased plant dry mass, leaf SPAD values, net photosynthetic rates, and the maximum photochemical quantum yield (F_v/F_m), and increased the oxidative stress markers. The individual application of NO or MN significantly mitigated the adverse effects, and the combined application of NO and MN synergistically enhanced plant tolerance to Cr stress, including increased activities of antioxidant enzymes in plants and concentrations of carbohydrate, ascorbic acid, sugar, total protein, as well as ash contents of edible flowers. The co-application also significantly elevated the concentrations of total phenolics, flavonoids, free reducing power, antioxidant capacity DPPH, and total carotenoids in Cr-treated plants compared with those in Cr-stressed plants. Additionally, the essential oil contents in flowers increased in response to the signaling molecule treatment under Cr stress. Compared with individual applications, the co-application of NO and MN had more significant effects. Our results indicate that the combination of signaling molecules, such as MN and NO, can not only increase the biomass of edible calendula plants but also improve flower quality for use as a novel food. Full article

Although rice is highly sensitive to salinity, it is considered one of the best crops to grow in salt-affected mudflat soils to alleviate the salinity problem. Applying chemical compounds for an increase in leaf CO₂ and nutrient levels can help mitigate the negative impact of salinity on plants in a cost-effective manner. To identify the benefits of using lithovit (Liv), ethanol (Eth), and potassium carbonate (KC) as a source of CO₂ and K to enhance rice production in salt-affected soils, a field study was conducted to assess the effects of these compounds on the agro-physiological parameters of two rice genotypes (Giza178 and Giza179) in saline soils. The compounds were applied as a foliar spray at a concentration of 30 mM each before and after the heading growth stage. The results indicated that the genotype, application time, compounds, and their potential two-way interactions significantly influenced all agro-physiological parameters, with only a few exceptions. The genotype Giza 179 exhibited higher pigment contents, photosynthetic capacity, relative water content (RWC), grain yield, and most yield components compared to Giza 178, with increases ranging from 2.1% to 37.9%. Foliar application of different compounds resulted in a 9.7–37.9% increase in various parameters and a 34.6–43.2% decrease in the number of unfilled grains (NUFG) per panicle compared to untreated treatment. Foliar application of different compounds before heading resulted in an increase in various parameters by 4.8–16.1% and a decrease in the NUFG per panicle by 22.9% compared to those applied after heading. Heatmap clustering analysis revealed that foliar application of Liv before heading was the most effective treatment in enhancing various parameters for both genotypes and mitigating the negative effects of salinity stress on the NUFG. This was followed by Eth and KC before heading for Giza 179. Applying Eth and KC to the leaves after heading had a moderate positive impact on most parameters for Giza 179, outperforming the application after heading for Giza 178. Overall, our findings indicate that spraying readily available compounds that elevate CO₂ and K levels in rice leaves can help alleviate the negative impacts of salt stress and improve rice production in salt-affected soils in a cost-effective manner. Full article

Nanotechnology has been increasingly used in plant sciences, with engineered nanoparticles showing promising results as fertilizers or pesticides. The present study compared the effects in the foliar application of Se nanoparticles (SeNPs) or sodium selenite-Se(IV) on rice seedlings. The degree of plant growth, photosynthetic pigment content, and concentrations of Se, Na, Mg, K, Ca, Mn, Co, Cu, Zn, As, Cd, and Pb were evaluated. The results showed that the application of SeNPs at high concentrations (5 mg L⁻¹), as well as the application of Se(IV), inhibited plant growth and increased the root concentrations of As and Pb. The application of SeNPs at 0.5 mg L⁻¹ significantly increased Se accumulation in the aerial part from 0.161 ± 0.028 mg kg⁻¹ to 0.836 ± 0.097 mg kg⁻¹ without influencing physiological, chemical, or biochemical parameters. When applied to leaves, SeNPs tended to remain in the aerial part, while the application of Se(IV) caused a higher Se translocation from the shoots to the roots. This study provides useful information concerning the uptake, accumulation, and translocation of different Se formulations in rice seedlings and their effect on plant ionomic profiles, thus showing that the foliar application of SeNPs at low concentrations can be an effective and safe alternative for rice biofortification. Full article

Dihydrochalcones (DHCs) constitute a specific class of flavonoids widely known for their various health-related advantages. Melatonin (MLT) has received attention worldwide as a master regulator in plants, but its roles in DHC accumulation remain unclear. Herein, the elicitation impacts of MLT on DHC biosynthesis were examined in Lithocarpus litseifolius, a valuable medicinal plant famous for its sweet flavor and anti-diabetes effect. Compared to the control, the foliar application of MLT significantly increased total flavonoid and DHC (phlorizin, trilobatin, and phloretin) levels in L. litseifolius leaves, especially when 100 μM MLT was utilized for 14 days. Moreover, antioxidant enzyme activities were boosted after MLT treatments, resulting in a decrease in the levels of intracellular reactive oxygen species. Remarkably, MLT triggered the biosynthesis of numerous phytohormones linked to secondary metabolism (salicylic acid, methyl jasmonic acid (MeJA), and ethylene), while reducing free JA contents in L. litseifolius. Additionally, the flavonoid biosynthetic enzyme activities were enhanced by the MLT in leaves. Multiple differentially expressed genes (DEGs) in RNA-seq might play a crucial role in MLT-elicited pathways, particularly those associated with the antioxidant system (SOD, CAT, and POD), transcription factor regulation (MYBs and bHLHs), and DHC metabolism (4CL, C4H, UGT71K1, and UGT88A1). As a result, MLT enhanced DHC accumulation in L. litseifolius leaves, primarily by modulating the antioxidant activity and co-regulating the physiological, hormonal, and transcriptional pathways of DHC metabolism. Full article

Tillage conservation practices (CA), traditional agriculture (TA), and liming influence soil properties and crop yield. However, it is essential to demonstrate which tillage and liming practices improve soil properties and forage corn yield. This study compared soil properties and forage corn production in two tillage systems with the addition of dolomite and lime, which formed four treatments. The tillage in the first three days surpassed the TA soil CO₂ emission, with 64.8% more CO₂ than in the CA soil, and the TA hydraulic conductivity and bulk density were more suitable than those in the CA soil. The CA soil had 233 earthworms m⁻² more than in TA. The TA green forage corn yielded 6.45 t ha⁻¹ more than in CA, with a higher P, Ca, and Mg foliar content than in CA, but in the CA, the foliar N and K were higher than in TA. The liming increased soil cations (except K), highlighting the lime on dolomite with—52% Al and + 4.85 t ha⁻¹ of forage corn compared to the control. Soil CO₂ emission was far lower in CA than in TA, with a slightly lower forage yield, and other soil properties were improved, meaning lower land preparation costs and time savings than in TA. Lime improved acidic soil faster than dolomite, generating higher forage yields. Full article

Salinity is considered to be a global problem and a severe danger to modern agriculture since it negatively impacts plants’ growth and development at both cellular- and whole-plant level. However, cobalt (Co) and titanium (Ti), multifunctional non-essential micro-elements, play a crucial role in improving plant growth and development under salinity stress. In the current study, Co and Ti impact on the morphological, biochemical, nutritional, and metabolic profile of Pennisetum divisum plants under three salinity levels which were assessed. Two concentrations of Co (Co-1; 15.0 mg/L and Co-2; 25.0 mg/L), and two concentrations of Ti (Ti-1; 50.0 mg/L and Ti-2; 100.0 mg/L) were applied as foliar application to the P. divisum plants under salinity (S1; 200 mM, S2; 500 mM, and S3; 1000 mM) stress. The results revealed that various morphological, biochemical, and metabolic processes were drastically impacted by the salinity-induced methylglyoxal (MG) stress. The excessive accumulation of salt ions, including Na⁺ (1.24- and 1.21-fold), and Cl⁻ (1.53- and 1.15-fold) in leaves and roots of P. divisum, resulted in the higher production of MG (2.77- and 2.95-fold) in leaves and roots under severe (1000 mM) salinity stress, respectively. However, Ti-treated leaves showed a significant reduction in ionic imbalance and MG concentrations, whereas considerable improvement was shown in K⁺ and Ca²⁺ under salinity stress, and Co treatment showed downregulation of MG content (26, 16, and 14%) and improved the antioxidant activity, such as a reduction in glutathione (GSH), oxidized glutathione (GSSG), Glutathione reductase (GR), Glyoxalase I (Gly I), and Glyoxalase II (Gly II) by up to 1.13-, 1.35-, 3.75-, 2.08-, and 1.68-fold under severe salinity stress in P. divisum roots. Furthermore, MG-induced stress negatively impacted the metabolic profile and antioxidants activity of P. divisum’s root and leaves; however, Co and Ti treatment considerably improved the biochemical processes and metabolic profile in both underground and aerial parts of the studied plants. Collectively, the results depicted that Co treatment showed significant results in roots and Ti treatment presented considerable changes in leaves of P. divism under salinity stress. Full article

Inoculation with Azospirillum brasilense has promisingly increased plant yield and nutrient acquisition. The study aimed to estimate the dose of A. brasilense that increases yield, gas exchange, nutrition, and foliar nitrate reduction. The research was carried out in a greenhouse at Ilha Solteira, in a hydroponic system in randomized blocks with four replicates. The treatments consisted of doses of inoculation with A. brasilense strains AbV5 and AbV6 via nutrient solution (0, 8, 16, 32, and 64 mL 100 L⁻¹). Inoculation with A. brasilense at calculated doses between 20 and 44 mL provided the highest fresh and dry mass of shoots and roots, number of leaves, and leaf yield. In addition, the calculated doses of inoculation with A. brasilense increased the accumulation of N, P, K, Ca, Mg, S, B, Fe, Mn, and Zn in shoots and roots, except the accumulation of Ca in roots. It also increased cell membrane integrity index (15%), relative water content (13%), net photosynthesis rate (85%), intracellular CO₂ concentration (15%), total chlorophyll (46%), stomatal conductance (56%), transpiration (15%), and water use efficiency (59%). Hence, inoculation with A. brasilense at doses between 20 and 44 mL 100 L⁻¹ is considered the best approach for increasing the growth, yield, accumulation of nutrients, and gas exchange of hydroponically grown iceberg lettuce. Full article

The relationships of selenium (Se) with other elements in plants is important for producing functional food with high Se contents and a predicted quality. To unveil the peculiarities of the element interactions, eight botanical varieties of Brassica oleracea L. were grown in similar conditions with or without foliar application of sodium selenate. High varietal differences, elicited by the Se supply, were recorded with regard to the accumulation of the elements examined, except for Mg, P and Si. Cabbage florets (broccoli and cauliflower) were characterized by both the lowest total mineral content and number of elements showing content changes under the Se supply (7–8 out of 25), whereas in Savoy cabbage, the highest number of minerals displayed content changes (13–14 from 25). The Se treatment did not significantly interfere with the high correlation coefficients recorded between Sr–Ca, Co–Ni and Zn–Mg (0.824–0.952). The selenium biofortification value varied from 12 to 138 depending on the species and was inversely correlated with the Si accumulation in the control plants (r = −0.872, p < 0.001). A significant decrease in the correlation coefficients occurred due to the Se supply regarding Zn with P and Co, Ca with Co and Li, Li and V, and Na and Sn, while the V–Pb relationship was significantly enhanced. Among the 25 elements studied, Cr demonstrated the highest number of significant correlation coefficient changes (with K, Na, P, Si, Zn, Cu, Co, I, As, Pb, and V). The results of this research prove the variability of the element interactions under foliar Se treatments in Brassica oleracea plants and reveal, for the first time, an inverse correlation between the Se biofortification level and Si content in untreated plants. Full article

The matrix effect refers to the change in the analytical signal caused by the matrix in which the sample is contained, as well as the impurities that are co-eluted with the target analyte. In crop sample analysis using LC–MS/MS, the matrix effect can affect the quantification results. Chinese chives are likely to exhibit a strong matrix effect when co-extracted with bifenthrin and butachlor due to the presence of phytochemicals and chlorophyll. A novel analytical method was developed to reduce the matrix effects of bifenthrin and butachlor to a negligible level in Chinese chives. The established method had a limit of quantitation of 0.005 mg/kg and correlation coefficients greater than 0.999 within the range of 0.005–0.5 mg/kg. Matrix effects were found to be negligible, with values ranging from −18.8% to 7.2% in four different sources of chives and two leafy vegetables. Compared to conventional analytical methods for the LOQ and matrix effect, the established method demonstrated improved performances. The analytical method was further applied in a residual study in chive fields. The active ingredient of butachlor 5 granule (GR) was not detected after soil admixture application, while that of bifenthrin 1 emulsifiable concentrate (EC) showed a range from 1.002 to 0.087 mg/kg after foliar spraying. The dissipation rate constant (k) of bifenthrin was determined to be 0.115, thus its half-life was calculated to be 6.0 days. From the results, PHI and safety use standards of both pesticides were suggested. The developed analytical method can be applied to accurately determine bifenthrin and butachlor residues in Chinese chives and provides a foundation for further research on the fate and behavior of these pesticides in the environment. Full article

Potassium (K) is an essential element, which is often supplied to horticultural crops via foliar spraying. Some studies have investigated the effect of different foliar-applied K compounds; however, most studies have focussed on crop quality and yield parameters, or were performed with isolated leaf cuticles. The aim of this study was to evaluate the rates of the foliar ion penetration and leaf surface deposition of 130 mM K sprays of compounds with markedly different point of deliquescence (POD) and efflorescence (POE) values, the rates having been previously estimated in climate chamber trials. Shoots of field-grown, commercial olive trees were sprayed with K-nitrate (KNO₃), K-sulphate (K₂SO₄), K-chloride (KCl), K-phosphate (K₃PO₄), K-carbonate (K₂CO₃) and K-bicarbonate (KHCO₃), and leaf samples were collected after 3 and 24 h. Cation and anion concentrations were determined in the leaf tissues, and in a preliminary leaf water wash for estimating surface-deposited ion concentrations. No significant leaf tissue K increments were recorded between the K sprays. Olive tissue anion concentrations showed different patterns, and a chloride (Cl⁻) increase was detected 3 h after the foliar KCl supply. On the other hand, the foliar K applications led to leaf nitrate changes regardless of the K source supplied. High amounts of K and accompanying ions were recovered in the washing liquid of the foliar K-supplied leaves. Some foliar K treatments increased the leaf surface concentration of sulphate and chloride, suggesting a potential effect on leaf cell anion extrusion. Hence, despite no evidence of foliar K uptake, an effect of leaf anion concentrations was observed, indicating that foliar nutrient sprays may influence leaf and leaf surface anion balance. Full article

Spermine (SPM) and salicylic acid (SA) are plant growth regulators, eliciting specific responses against salt toxicity. In this study, the potential role of 30 mgL⁻¹ SPM and/or 100 mgL⁻¹ SA in preventing salt damage was investigated. Wheat plants were grown under non-saline or saline conditions (6.0 and 12.0 dS m⁻¹) with and without SA and/or SPM foliar applications. Exogenously applied SA and/or SPM alleviated the inhibition of plant growth and productivity under saline conditions by increasing Calvin cycle enzyme activity. Foliage applications also improved ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase activities, which effectively scavenged hydrogen peroxide and superoxide radicals in stressed plants. Furthermore, foliar treatments increased antioxidants such as ascorbate and glutathione, which effectively detoxified reactive oxygen species (ROS). Exogenous applications also increased N, P, and K⁺ acquisition, roots’ ATP content, and H⁺-pump activity, accompanied by significantly lower Na⁺ accumulation in stressed plants. Under saline environments, exogenous SA and/or SPM applications raised endogenous SA and SPM levels. Co-application of SA and SPM gave the best response. The newly discovered data suggest that the increased activities of Calvin cycle enzymes, root H⁺-pump, and antioxidant defense machinery in treated plants are a mechanism for salt tolerance. Therefore, combining the use of SA and SPM can be a superior method for reducing salt toxicity in sustainable agricultural systems. Full article

Climate change is aggravating soil salinity, causing huge crop losses around the globe. Multiple physiological and biochemical pathways determine the ability of plants to tolerate salt stress. A pot experiment was performed to understand the impact of proline levels, i.e., 0, 10, 20 mM on growth, biochemical and yield attributes of two pea (Pisum sativum L.) cultivars (cv. L-888 and cv. Round) under salt stress (150 mM) along with control (0 mM; no stress). The pots were filled with river-washed sand; all the plants were irrigated with full-strength Hoagland’s nutrient solution and grown for two weeks before application of salt stress. Foliar spray of proline was applied to 46-day-old pea plants, once a week till harvest. Data for various growth and physio-biochemical attributes were collected from 70-day-old pea plants. Imposition of salt stress significantly checked growth, gas exchange characteristics [net CO₂ assimilation rate (A), transpiration rate (E), stomatal conductance (g_s)], total soluble proteins, concentration of superoxide dismutase (SOD), shoot and root K⁺ and Ca²⁺ contents, while sub-stomatal CO₂ concentration (Ci), coefficient of non-photochemical quenching (_qN), non-photochemical quenching (NPQ), concentration of catalase (CAT) and peroxidase (POD), free proline, and shoot and root Na⁺ contents increased substantially. Foliar application of proline significantly improved growth, yield, A, g_s, activity of POD, and shoot and root K⁺ and Ca²⁺ contents, while decreased NPQ values in both pea cultivars under stress and non-stress conditions. Moreover, both pea cultivars showed significant differences as cv. Round exhibited a higher rate of growth, yield, gas exchange, soluble proteins, CAT activity, free proline, shoot and root K⁺ and Ca²⁺ contents compared to L-888. Hence, the outcomes of this study pave the way toward the usage of proline at 20 mM, and cv. Round may be recommended for saline soil cultivation. Full article

Southern corn leaf blight is one of the most widespread foliar diseases in maize-producing areas worldwide and can seriously reduce the yield and quality of sweet corn. However, the molecular mechanisms underlying the disease in sweet corn have not been widely reported. In this study, two sweet corn inbred lines, resistant K13 (RK13) and susceptible K39 (SK39), were used to explore the disease resistance mechanism of southern leaf blight. We observed morphological characteristics and assessed the changes in protective enzymatic activity in sweet corn leaves after inoculation of C. heterostrophus. RNA-seq was performed to elucidate the transcriptional dynamics and reveal the key pathways involved in southern leaf blight resistance without pathogens (Mock) and at 1 and 3 days post inoculation (1 and 3 dpi). Differentially expressed genes (DEGs) were identified in the SK39 group (including three pairwise combinations: SK39−0d_vs_SK39−1d, SK39−1d_vs_SK39−3d and SK39−1d_vs_SK39−3d), the RK13 group (including three pairwise combinations: RK13−0d_vs_RK13−1d, RK13−1d_vs_RK13−3d and RK13−1d_vs_RK13−3d), and the SK39_vs_RK13 group (including three pairwise combinations: SK39−0d_vs_RK13−0d, SK39−1d_vs_RK13−1d, and SK39−3d_vs_RK13−3d). In our study, 9455 DEGs from the RK13 group, 9626 from the SK39 group, and 9051 DEGs from the SK39_vs_RK13 group were obtained. Furthermore, 2775, 163, and 185 DEGs were co-expressed at SK39_vs_RK13, RK13, and SK39, respectively. A functional analysis of the DEGs revealed that five pathways—i.e., photosynthesis, plant hormone signal transduction, MAPK signaling pathway, phenylpropanoid biosynthesis, and biosynthesis of secondary metabolites—and transcription factor families play crucial roles in disease resistance. The results from the present study enabled the identification of the JA and SA signaling pathways, which are potentially involved in the response to southern leaf blight in maize. Our findings also highlight the significance of ZIM transcription factors and pathogenesis-related (PR) genes during pathogen infection. This study preliminarily explored the molecular mechanisms of the interaction between sweet corn and C. heterostrophus and provides a reference for identifying southern leaf blight resistance genes in the future. Full article

Beneficial plant–microbe interaction for enhancing crop yield and quality is a sustainable way to achieve eco-friendly, desirable agricultural productions. The main objective of this experiment was to evaluate the individual and combined effects of an arbuscular mycorrhizal fungus (AMF) strain (Funneliformis mosseae) and a seaweed extract (SWE) derived from Ascophyllum nodosum, on the growth and physiological responses of lettuce (Lactuca sativa L.). Lettuce plants were inoculated with commercial AMF inoculum (5 g kg⁻¹ soil), and SWE foliar application was done at three levels (0.5, 1.5, and 3 g L⁻¹). The findings revealed that AMF along with SWE generated the greatest impact. In fact, co-application of AMF inoculation and 3 g L⁻¹ SWE considerably enhanced root colonization, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and mineral content in the shoots and roots (N, P, K, Ca, Fe, Zn, and Mn content) of lettuce plants. This combination improved initial fluorescence (F₀), photochemical efficiency of PSII (F_V/F_m) and Y(NO) and total antioxidant activity (TAA), whereas the maximum fluorescence, (F_m) and Y(II), showed the highest increase in lettuce plants treated with AMF and 1.5 g L⁻¹ SWE. Furthermore, AMF inoculation along with SWE, at concentrations 1.5 and 3 g L⁻¹, considerably enhanced variable fluorescence (F_V) and the activity of water decomposition in electron donor photosystem II (F_V/F₀). As a result of these findings, it can be stated that the co-application of AMF and SWE positively improves the growth and development of lettuce plants. Full article