Levels Of Photosynthetic Pigments Research Articles

Mitigating Effect of Trans-Zeatin on Cadmium Toxicity in Desmodesmus armatus.

Phytohormones, particularly cytokinin trans-zeatin (tZ), were studied for their impact on the green alga Desmodesmus armatus under cadmium (Cd) stress, focusing on growth, metal accumulation, and stress response mechanisms. Using atomic absorption spectroscopy for the Cd level and high-performance liquid chromatography for photosynthetic pigments and phytochelatins, along with spectrophotometry for antioxidants and liquid chromatography-mass spectrometry for phytohormones, we found that tZ enhances Cd uptake in D. armatus, potentially improving phycoremediation of aquatic environments. Cytokinin mitigates Cd toxicity by regulating internal phytohormone levels and activating metal tolerance pathways, increasing phytochelatin synthase activity and phytochelatin accumulation essential for Cd sequestration. Treatment with tZ and Cd also resulted in increased cell proliferation, photosynthetic pigment and antioxidant levels, and antioxidant enzyme activities, reducing oxidative stress. This suggests that cytokinin-mediated mechanisms in D. armatus enhance its capacity for Cd uptake and tolerance, offering promising avenues for more effective aquatic phycoremediation techniques.

Silica nanoparticles improve growth, chemical bioactive, and antioxidant enzyme activity of Dianthus caryophyllus L., plant

Background Nanotechnology has provided innovative use of various materials with unique properties. These substances may react positively in plants, and the induction of bioactive compounds and antioxidant activity is particularly remarkable. Ornamental plant production is a positive economic activity of great interest, especially Carnation (Dianthus caryophyllus L.). This plant is more attractive for its various colors, but the flower quality and its longevity can diminish very fast. Thus, examining methods capable of improving flower quality and vase life is crucial. Additionally, carnation can be used to treat coronary and nervous disorders. Carnation contains compounds that calm the nervous system and minimize swelling and inflammation. Objective This research aimed to evaluate the effect of silica nanoparticles (SiO2 NPs) on the growth, bioactive chemical analysis, enzyme activity, and antioxidant accumulation. Material and methods The different rates of SiO2 NPs (0, 150, and 300 ppm) were used in two ways: foliar spray and soil drench; it was applied 3 times. The first application was after 3 weeks of transplanting and repeated with 21-day intervals. Results and conclusion The results showed that foliar application of SiO2 NPs increased all morphological and flowering traits compared with drench and the control, higher levels of photosynthetic pigments and anthocyanin, greater total phenols, total sugars, and total free amino acids were obtained from plants treated with foliar spray 300 ppm followed than 150 ppm. In addition, the greatest levels of enzyme activity were recorded with plants treated with foliar spray of SiO2 NPs at a rate of 300 ppm, as well as improved anatomical structure of the stem and stomata properties compared with the drench method and control. Similarly, SiO2 NPs application method is more critical than their concentration. Therefore, it is recommended that foliar spraying of SiO2 NPs at 300 ppm can enhance plant growth, flowering, bioactive compounds, enzyme activity, and anatomical structure of the stem of carnation plants while adding SiO2 NPs drench at a rate of 150 ppm had rather acceptable findings.

Effectiveness of light-emitting diodes for arsenic and mercury accumulation by Ceratophyllum demersum L.: An innovative advancement in phytoremediation technology

Light Emitting Diodes (LEDs) have emerged as a tool with great potential in the field of phytoremediation, offering a novel approach to enhance the efficiency of plant-based remediation techniques. In this work investigated the influence of LEDs on the phytoremediation of arsenic (As) and mercury (Hg) by Ceratophyllum demersum L., propagated using tissue culture methods. In addition, the biochemical properties of the plants exposed to metal toxicity were examined. Phytoremediation experiments employed concentrations of As (0.01-1.0 mg/L) and Hg (0.002-0.2 mg/L), with application periods set at 1, 7, 14, and 21 days. In addition to white, red and blue LEDs, white fluorescent light was used for control purposes in the investigations. A positive correlation was observed between higher metal concentrations, extended exposure times, and increased metal accumulation in the plants. Red LED light yielded the highest level of heavy metal accumulation, while white fluorescent light resulted in the lowest accumulation level. Examination of the biochemical parameters of the plants, including photosynthetic pigment levels, protein quantities, and lipid peroxidation, revealed a pronouncedly enhanced performance in specimens subjected to red and blue LED illumination, surpassing outcomes observed in other light treatments. The findings of this study introduce innovative avenues for the effective utilization of red and blue LED lights in the realm of phytoremediation research. Thus, the interaction between LEDs, tissue culture, and the phytoremediation process could lead to synergistic effects that contribute to more effective and sustainable remediation strategies.

Laccase-induced decontamination and humification mechanisms of estrogen in water-crop matrices.

Enzymatic humification plays a crucial biogeochemical role in eliminating steroidal estrogens and expanding organic carbon stocks. Estrogenic contaminants in agroecosystems can be taken up and acropetally translocated by crops, but the roles of laccase-triggered rhizospheric humification (L-TRH) in pollutant dissipation and plant uptake remain poorly understood. In this study, the laccase-induced decontamination and humification mechanisms of 17β-estradiol (E2) in water-crop media were investigated by performing greenhouse pot experiments with maize seedlings (Zea mays L.). The results demonstrated that L-TRH effectively dissipated E2 in the rhizosphere solution and achieved the kinetic constants of E2 dissipation at 10 and 50 μM by 8.05 and 2.75 times as much as the treatments without laccase addition, respectively. The copolymerization of E2 and root exudates (i.e. phenols and amino acids) consolidated by L-TRH produced a larger amount of humified precipitates with the richly functional carbon architectures. The growth parameters and photosynthetic pigment levels of maize seedlings were greatly impeded after a 120-h exposure to 50 μM E2, but L-TRH motivated the detoxication process and thus mitigated the phytotoxicity and bioavailability of E2. The tested E2 contents in the maize tissues initially increased sharply with the cultivation time but decreased steadily. Compared with the treatment without laccase addition, the uptake and accumulation of E2 in the maize tissues were obviously diminished by L-TRH. E2 oligomers such as dimer, trimer, and tetramer recognized in the rhizosphere solution were also detected in the root tissues but not in the shoots, demonstrating that the acropetal translocation of E2 oligomers was interrupted. These results highlight a promising strategy for decontaminating estrogenic pollutants, boosting rhizospheric humification, and realizing low-carbon emissions, which would be beneficial for agroenvironmental bioremediation and sustainability.

Effects of Biochar and Arbuscular Mycorrhizal Fungi on Soil Health in Chinese Kale (Brassica oleracea var. alboglabra L.) Cultivation

Biochar and arbuscular mycorrhizal fungi (AMF), a promising environmentally friendly soil enhancer and biostimulant, play a crucial role in sustainable agriculture by influencing soil properties and plant growth. This research investigates the chemical properties of three biochar types [bamboo (BB-char), corn cob (CC-char), and coffee grounds (CG-char)] derived from different biomass sources and their impact on soil quality and Chinese kale growth. The results reveal significant differences in chemical properties among different types of biochar. Particularly, CG-char showed the greatest pH value and phosphorus content, with an average of 10.05 and 0.44%, respectively. On the other hand, CC-char had the highest potassium content, with an average of 2.16%. Incorporating biochar into degraded soil enhances soil structure, promoting porosity and improved texture, as evidenced by scanning electron microscope images revealing distinct porous structures. Soil chemistry analyses in treatment T2–T14 after a 42-day cultivation demonstrate the impact of biochar on pH, electrical conductivity, organic matter, and organic carbon levels in comparison to the control treatment (T1). Furthermore, the research assesses the impact of biochar on Chinese kale growth and photosynthetic pigments. Biochar additions, especially 5% BB-char with AMF, positively influence plant growth, chlorophyll content, and photosynthetic pigment levels. Notably, lower biochar concentrations (5%) exhibit superior effects compared to higher concentrations (10%), emphasizing the importance of optimal biochar application rates. The study also delves into the total phenolic content in Chinese kale leaves, revealing that the synergistic effect of biochar and AMF enhances phenolic compound accumulation. The combination positively influences plant health, soil quality, and nutrient cycling mechanisms. Overall, the research indicates the multifaceted impact of biochar on soil and plant dynamics, emphasizing the need for tailored application strategies to optimize benefits in sustainable agriculture.

Alteration of growth, phenology, and yield of lily flowers through the synergetic effect of light spectra and endophytic bacterial priming

The production of ornamental flowers in controlled environment agriculture (CEA) has gained significant attention due to its potential for efficient cultivation. This study aimed to evaluate the influence of light quality (red, blue, red+blue, and white) after priming bulbs with Bacillus subtilis (Bs) on lily plant growth, phenology, yield, ornamental attributes, and pigmentation. Both light quality and Bs treatment significantly affected vegetative and generative organ development and overall plant growth. Bulbs primed with Bs and grown under blue light exhibited the earliest budding and flowering phases, along with an extended flowering period. The highest flower yield and productivity were achieved in Bs-primed bulbs under blue light. Regarding qualities, the best scores were obtained for Bs-primed bulbs grown under blue or red+blue light, compared to control plants grown under red light. The combined effects of Bs treatment and light quality also impacted photosynthetic pigment content in lily leaves. Throughout the growing season, the highest levels of photosynthetic pigments were detected under white light. Although the ratio between Chl a with other photosynthetic pigments were decreased during the flowering period, Bs treatment positively influenced those rations during the flowering phase when plants grown under monochromatic lights (red and blue). In summary, to achieve high-quality lily flowers in CEAs, the most promising approach involves utilizing a red+blue light spectrum in combination with Bs priming. This research highlights the importance of optimizing growing conditions and understanding the interplay between light quality and biological treatments for enhancing ornamental flower production in CEA systems.

Protective role of endophytic fungi and salicylic acid as therapeutic nutrients to improve immune responses of tomato plants against fusarial wilt disease

The exacerbation of climatic changes helped to increase the risk of plant diseases in the world. Based on this concept, we suggest Endophytic fungi (EF) and Salicylic acid (SA) alternatives to reduce the spread of Fusarium wilt disease, which is one of the most important agricultural crops globally. Therefore, this study aims to isolate endophytic fungi and test their ability to stimulate plant resistance against Fusarium wilt disease and study the possibility of combining these isolates with salicylic acid as a therapeutic nutrient for tomato plants. Two fungal endophytes were isolated from Vigna unguiculata seeds (VUS) and identified as Aspergillus oryzae and Aspergillus tubingensis according to morphological and molecular identification. Under pot circumstances, the influence of these two fungal endophytes as tomato fusarial wilt depressants and as plant stimulants was evaluated. The combination of A. oryzae and A. tubingensis exhibited a simultaneous efficacy of 80% in conferring protection against Fusarium wilt, while simultaneously resulting in a notable decreasing diseases index to 16.66%. Treatment of infected plants with A. oryzae and A. tubingensis (single or mixed) and salicylic acid not only deterioration influence of Fusarium wilt on plant fitness, but also showed a significant improvement in the levels of photosynthetic pigments, sugars, proteins and phenols, and enhancement in the activity of antioxidant enzymes. The analysis of variability among endophytic fungi revealed the presence of 17 distinct bands exhibiting polymorphism, accounting for approximately 35.294% of the observed genetic variation. In conclusion, endophytic A. oryzae and A. tubingensis work well as stimuli for tomato plant growth and as a means of boosting the plants’ resistance to Fusarium wilt. Further, A. oryzae and A. tubingensis act synergistically with SA toward improving plant growth and fusarial wilt disease resistance.

Wheat Drought Tolerance: Morpho-Physiological Criteria, Stress Indexes, and Yield Responses in Newly Sand Soils

AbstractDrought presents a major risk to wheat growth and productivity under changing climates. During the last few years, various morphological and physiological approaches were used to overcome drought stress-associated problems. Cultivation of tolerant wheat cultivars can serve as a sustainable choice to raise wheat yield under water stress. Herein, field trials were carried out at the experimental farm of Ismailia Agricultural Research Station, Egypt, in two successive growing seasons (2020/2021 and 2021/2022) to investigate the response of four Egyptian bread wheat cultivars (Misr 1, Misr 3, Giza 171, and Sakha 95) to drought stress according to morpho-physiological characteristics, yield, and stress indices. Irrigation treatments and cultivars were assigned to the main and sub-plots, consequently, in a split-plot design with three replicates. The findings revealed that in both the first and second seasons, drought drastically revoked growth vigor of shoot, growth vigor of flag leaf, relative water content (%), membrane stability index (%), photosynthetic pigments, heading (days), maturity (days), as well as yield and yield attributes: spike length, number of spikes/m2, spike weight, grain number/spike, 100-kernel weight, grain yield/m2, straw yield/m2, biological yield/m2, and harvest index of all four wheat cultivars. Conversely, drought caused a marked increase in saturation water deficit (%), carotenoids content, and NKP uptake of all four wheat cultivars in both study seasons. The current study found that all four of the wheat cultivars were drought-tolerant plants. These cultivars exhibited similar drought-tolerant behaviors, which included decreased loss in relative water content, membrane stability, and photosynthetic pigment levels, consequently reducing wheat grain yield loss under water stress. Additionally, the drought tolerance indices of Sakha 95 > Giza 171 > Misr 1 > Misr 3 were revealed by the stress sensitivity index (SSI), mean productivity (MP), stress tolerance index (STI), and yield stability index (YSI). In conclusion, Misr 3 was the least tolerant wheat cultivar and Sakha 95 was the most tolerant. These results can be applied to breeding programs by plant breeders.

Sulfur-Oxidizing Bacteria Alleviate Salt and Cadmium Stress in Halophyte Tripolium pannonicum (Jacq.) Dobrocz.

The aim of this study was to investigate how introducing halophilic sulfur-oxidizing bacteria (SOB) Halothiobacillus halophilus to the growth substrate affects the physiological and biochemical responses of the halophyte Tripolium pannonicum (also known as sea aster or seashore aster) under salt and cadmium stress conditions. This study assessed the plant's response to these stressors and bacterial inoculation by analyzing various factors including the accumulation of elements such as sodium (Na), chloride (Cl), cadmium (Cd) and sulfur (S); growth parameters; levels of photosynthetic pigments, proline and phenolic compounds; the formation of malondialdehyde (MDA); and the plant's potential to scavenge 2,2-Diphenyl-1-picrylhydrazyl (DPPH). The results revealed that bacterial inoculation was effective in mitigating the deleterious effect of cadmium stress on some growth criteria. For instance, stem length was 2-hold higher, the growth tolerance index was 3-fold higher and there was a 20% increase in the content of photosynthetic pigments compared to non-inoculated plants. Furthermore, the SOB contributed to enhancing cadmium tolerance in Tripolium pannonicum by increasing the availability of sulfur in the plant's leaves, which led to the maintenance of an appropriate, about 2-fold-higher level of phenolic compounds (phenylpropanoids and flavonols), as well as chloride ions. The level of MDA decreased after bacterial application in all experimental variants except when both salt and cadmium stress were present. These findings provide novel insights into how halophytes respond to abiotic stress following inoculation of the growth medium with sulfur-oxidizing bacteria. The data suggest that inoculating the substrate with SOB has a beneficial effect on T. pannonicum's tolerance to cadmium stress.

The effect of chelating agents on the Zn-phytoextraction potential of hemp and soil microbial activity

BackgroundHemp (Cannabis sativa) is a crop with a wide range of uses, from the production of fiber and seeds to the secondary metabolites for medicinal purposes. In addition, it is characterized by high biomass yield and the ability to accumulate heavy metals, which makes this plant convenient for phytoremediation purposes. In this study, the effect of applying exogenous biodegradable chelating agents, citric acid (CA) and nitrilotriacetic acid (NTA), to zinc-contaminated soil on zinc (Zn) uptake by two industrial hemp varieties ‘Felina 32’ and ‘Monoica’ was studied. The effect of CA and NTA on available Zn in soils was investigated using an ‘in pot’ experiment under controlled conditions. The effect of both tested compounds on soil microbial activity was simultaneously evaluated.ResultsAfter the application of NTA at a concentration of 5 mmol L−1, a > threefold increased accumulation of Zn in the above-ground parts was recorded in the ‘Felina 32’ variety. In the ‘Monoica’ variety, the levels of Zn in the above-ground parts were increased > twofold. NTA affected the soil microbiome negatively, causing decreased enzyme activity (in ‘Monoica’ planted soil) and induced respiration (in ‘Monoica’ and especially in ‘Felina 32’ planted soil). On the other hand, CA application did not lead to significantly increased Zn levels in any of the studied hemp varieties. Together with CA’s negative effects on some soil enzymes, CA enhanced urease activity, dehydrogenase and several respiration types for the ‘Felina 32’ variety and exerted less detrimental effect on the soil microbiome. No toxic effects from increased Zn uptake and accumulation in experimental plants were detected, accounting for the unchanged physiological stress markers (levels of photosynthetic pigments and proline in leaves, chlorophyll fluorescence parameters) and selected growth traits of the above-ground organs and root system.ConclusionsFrom the studied varieties, ‘Felina 32’ seems to be more suitable for Zn-phytoextraction because of its higher tolerance to increased Zn levels, higher biomass production and Zn accumulation capacity. Our results indicate the potential of using the ‘Felina 32’ variety in NTA-assisted Zn phytoextraction from contaminated soils.Graphical

Phytohormone Supplementation for Nutrient Removal from Mariculture Wastewater by Oocystis borgei in Sequential Batch Operation

To enhance the nutrient removal efficiency of Oocystis borgei for mariculture wastewater (MW), the effects and processes of three phytohormones on nitrogen and phosphorus removal from synthetic mariculture wastewater (SMW) by O. borgei under sequential batch operation were compared. The findings revealed that the supplementation with 10−6 M 3-indoleacetic acid (IAA), gibberellic acid (GA3), and zeatin (ZT) resulted in the most effective elimination, while there was no appreciable difference among them. The nitrogen and phosphorus indices of the effluent dramatically reduced (p < 0.01) upon the supplementation of phytohormones, and the removal effects were ranked as NO3−-N > PO43−-P > NH4+-N > NO2−-N. The removal rates for NH4+-N and PO43−-P were 0.72–0.74 mg·L−1·d−1 and 1.26–1.30 mg·L−1·d−1, respectively. According to physiological studies, phytohormones enhanced the levels of photosynthetic pigments and chlorophyll fluorescence parameters (Fv/Fm and φPSII), thereby improving photosynthetic activity. Additionally, they stimulated Nitrate Reductase (NR) and Glutamine Synthetase (GS) activities to promote nitrogen metabolism and increased Superoxide Dismutase (SOD), Catalase (CAT), and carotenoid contents to mitigate oxidative stress damage caused by abiotic stress. These activities contribute to the proliferation of O. borgei, which in turn resulted in an increase in the assimilation of nitrogen and phosphorus from SMW. In conclusion, phytohormone supplementation significantly increased nutrient removal from SMW by O. borgei in a sequential batch reactor, which has potential application in MW treatment.

Differential responses of Brassica napus cultivars to dual effects of magnesium oxide nanoparticles.

Magnesium oxide nanoparticles (MgO NPs) have great potential to enhance the crop productivity and sustainability of agriculture. Still, a thorough understanding is lacking about its essentiality or toxicity and precise dose for the safe cultivation of oilseed crops. Thus, we assessed the dual effects of MgO NPs (control, 5, 10, 20, 40, 80, and 200mg/L) on the seed germination, growth performance, photosynthesis, total soluble protein, total carbohydrates, oxidative stress markers (hydrogen peroxide as H2O2 and superoxide anion as O2•‒), lipid peroxidation as MDA, and antioxidant defence machinery (SOD, CAT, APX, and GR activities, and GSH levels) of seven different oilseeds (Brassica napus L.) cultivars (ZY 758, ZD 649, ZD 635, ZD 619, GY 605, ZD 622, and ZD 630). Our findings revealed that low doses of MgO NPs (mainly at 10mg/L) markedly boosted the seed germination, plant growth (shoot and root lengths) (15‒22%), and biomass (fresh and dry) (11‒19%) by improving the levels of photosynthetic pigments (14‒27%), net photosynthetic rate, stomatal conductance, photosynthetic efficiency (Fv/Fm), total soluble protein and total carbohydrates (16‒36%), antioxidant defence, and reducing the oxidative stress in B. napus tissues. Among all B. napus cultivars, these beneficial effects of MgO NPs were pronounced in ZD 635. ile, elevated levels of MgO NPs (particularly at 200mg/L) induced oxidative stress, impairedantioxidant scavenging potential, photosynthetic inhibition, protein oxidation, and carbohydrate degradation and lead to inhibit the plant growth attributes. These inhibitory effects were more pronounced in ZD 622. Collectively, low-dose MgO NPs reinforced the Mg contents, protected the plant growth, photosynthesis, total soluble carbohydrates, enzyme activities, and minimized the oxidative stress. While, the excessive MgO NP levels impaired the above-reported traits. Overall, ZD 622 was highly susceptible to MgO NP toxicity and ZD 635 was found most tolerant to MgO NP toxicity.

Regeneration of African Violet in Response to Light Quality

Light-emitting diode (LED) technology is a form of artificial lighting that offers precise control over spectral composition, creating specific conditions for plant growth and development. However, the influence of various LED wavelengths on the regeneration characteristics in African violet (AV) has not been extensively explored. This study aims to investigate the changes in the regeneration traits of AV when exposed to different LED light colors within controlled conditions. In this study, AV leaf cuttings were prepared and subjected to white, red, blue, and red + blue light colors for a period of three months in a growth chamber. Afterward, they were transferred to the laboratory for further analysis. The results indicated that the AVs treated with red + blue colors exhibited the most significant improvement in several morpho-physiological traits of both the roots and shoots. The highest total biomass (2.96 g), shoot fresh weight (1.76 g), root dry weight (0.14 g), root volume (3.10 cm3), and shoot length (1.60 cm) were observed in this treatment group. Furthermore, the highest levels of photosynthetic pigments, such as chlorophyll a, chlorophyll b, and carotenoids (0.14, 0.12, and 3.80 mg g−1 f.w., respectively), were predominantly observed in the red + blue treatment group. In conclusion, this study introduces a novel methodology for optimizing lighting conditions to enhance the regeneration of African violets, shedding light on the potential for improving AV regeneration practices.

Impact of Argemone mexicana L. on tomato plants infected with Phytophthora infestans.

Fungal diseases can cause significant losses in the tomato crop. Phytophthora infestans causes the late blight disease, which considerably affects tomato production worldwide. Weed-based plant extracts are a promising ecological alternative for disease control. In this study, we analyzed the plant extract of Argemone mexicana L. using chromatography-mass spectrometry analysis (GC-MS). We evaluated its impact on the severity of P. infestans, as well as its effect on the components of the antioxidant defense system in tomato plants. The extract from A. mexicana contains twelve compounds most have antifungal and biostimulant properties. The findings of the study indicate that applying the A. mexicana extract can reduce the severity of P. infestans, increase tomato fruit yield, enhance the levels of photosynthetic pigments, ascorbic acid, phenols, and flavonoids, as well as decrease the biosynthesis of H2O2, malondialdehyde (MDA), and superoxide anion in the leaves of plants infected with this pathogen. These results suggest that using the extract from A. mexicana could be a viable solution to control the disease caused by P. infestans in tomato crop.

Effect of Fluoride Toxicity on Physiological and Biochemical Parameters of Wheat (Triticum aestivum)

Wheat is the second most important cereal crop next to rice. Fluoride toxicity effects on physiological (relative water content, chlorophyll and carotenoids) and biochemical (soluble sugar, starch, free amino acid, proline and malondialdehyde (MDA) contents parameters of wheat plants from their germination to maturity and ultimately reduces the yield.A pot experiment was conducted to investigate the effect of different concentrations [0 (T1 ), 50 (T2 ), 100 (T3 ), 200 (T4 ), 250 (T5 ) and 300 (T6 ) mg fluoride kg-1 soil] of fluoride in wheat variety HUW-234. Observation was recorded at 30, 60 and 90 DAS. The results indicate that increased level of fluoride decline RWC, chlorophyll, carotenoids, starch, soluble protein, free amino acid while chlorophyll a: b ratio, soluble sugar, proline and MDA contents increased. The present study revealed that fluoride increased concentrations of soluble sugars, proline and MDA indicated that like other stresses fluoride also caused oxidative stress in wheat. Chlorophyll a : chlorophyll b ratio also increased in plant leaves exposed to fluoride. It is noted that fluoride caused more reduction in level of accessory photosynthetic pigments (chlorophyll b and carotenoids) than in the level of main photosynthetic pigments.

Analysis of Morpho-physiological and Biochemical Responses in Brassica Varieties under Salt Stress

Abiotic stresses like salinity, water stress, high light intensity, heavy metals, etc. have a significant influence on the morphology, biochemical characteristics, and crop productivity, of Brassica species. Among these numerous abiotic stresses, stress from salinity is a significant issue, that demands immediate attention and resolution. Therefore, in this study, the tolerance of Brassica carinata and five different varieties of Brassica campestris including Agrani, Shafal, BINA Sharisha-6, BARI Sharisha-15 and Tori-7 were examined at varying concentrations of NaCl (0, 50, 100, 150, 200 mM). Different morpho-physiological and biochemical properties including seed germination parameters, root/shoot ratio, proline content, H2O2 and MDA level, photosynthetic pigments, and Na+/K+ ion accumulation were measured and showed varying responses to the inhibitory impacts of NaCl. B. carinata, BINA Sharisha-6, Tori-7 and Shafal, with increasing NaCl concentrations resulted in the loss of germination percentages, root/shoot ratio, levels of photosynthetic pigments, proline, levels of H2O2 and MDA and the Na+/K+ ion accumulation in comparison to the other Brassica varieties. Among these varieties, Shafal, showed the lowest values of the salt tolerant indicators. In contrast, variety Agrani and BARI Sharisha-15 exhibited high proline content, a good level of H2O2 and MDA and photosynthetic pigments, in response to salt stress, which enhanced their hydration status, enzyme activities and cellular functions. Plant Tissue Cult. & Biotech. 33(2): 167-180, 2023 (December)

Stable Colloidal Iron Oxide Nanoparticles: A New Green Nanofertilizer and Therapeutic Nutrient for Eggplant Immune Response Against Fusarium Wilt Disease

Cultivating crops often presents numerous challenges, including resource loss such as water, fertilizers, and pesticides, as well as the spread and escalation of infections. Nanotechnology offers promising solutions to enhance plant immunity and resolve agricultural issues. In this study, in order to prevent Fusarium-wilt disease in eggplants, we concentrated on the simple manufacture of colloidal ferric oxide nanoparticles (Fe2O3 NPs) as a promising nanofertilizers. To evaluate the effectiveness of systemic resistance (SR) development, we evaluated markers of metabolic resistance, photosynthetic pigments, plant protection, and disease index (DI). Positively, Fe2O3 NPs exhibit significant antifungal activity against Fusarium oxysporum. However, when applied at a concentration of 20 µg/mL, Fe2O3 NPs proved to be the most effective treatment, reducing the  percent disease index (PDI) from 82.5% in infected control plants to 22.5%. Similar results were observed with a concentration of 10 µg/mL Fe2O3 NPs. In both healthy and diseaseed plants, Fe2O3 NP treatments also showed beneficial effects on the activity of antioxidant enzymes, osmolytes, and photosynthetic pigments. Notably, compared to untreated Fusarium-infected plants, the application of Fe2O3 NPs at a concentration of 20 µg/mL significantly increased the levels of osmolyte, comprising soluble sugar, proline, and soluble protein, by 32.88%, 47.09%, and 31.34%, respectively. Furthermore, in both healthy and diseased eggplants, Fe2O3 NPs at a concentration of 20 µg/mL increased the levels of photosynthetic pigments, osmolytes, peroxidase, polyphenol oxidase, catalase, and superoxide dismutase enzymes. Overall, our research findings indicates that Fe2O3 NPs can successfully decreased the harmful effects that F. oxysporum causes to infected eggplants. With their promising therapeutic potential, these nanoparticles provide a secure and effective substitute for chemical fungicides in the management of Fusarium wilt disease.

The physiological responses of celery (Apium graveolens L.) and its ability to accumulate selenium when inoculated with Funneliformis mosseae

Celery (Apium graveolens L.) has a strong capacity to enrich selenium (Se) and is a good system for research on Se enrichment in vegetables. Arbuscular mycorrhizal fungi (AMF) are commonly used plant symbionts that affect plant growth and their effectiveness is plant species specific. However, there is little research on the effects of AMF inoculation on the accumulation and translocation of Se in celery. The treatments in this study included inoculation with AMF (+AMF) and the application of different types and concentrations of exogenous Se. We evaluated the growth, root mycorrhizal colonization, photosynthetic pigment content, ascorbate-glutathione cycle (ASA-GSH cycle), the accumulation and translocation of Se and the combination of AMF + Se compared with an untreated control. The application of low concentrations of Se (≤10 mg kg−1) stimulated celery growth, while high concentrations (>20 mg kg−1) had the opposite effect. The inhibition of celery growth was more severe with Se6+ than Se4+ when applied at the same concentration. The accumulation of Se improved in all the organs of celery as the supply increased. AMF had a significant positive effect on the accumulation and translocation of Se. In addition, +AMF significantly increased the shoot height and root fresh weight of celery and reduced the inhibitory effect of Se on growth. However, +AMF had slight effects on the levels of photosynthetic pigments and the ASA-GSH cycle. +AMF combined with 10 mg kg−1 sodium selenite (Se4+) is an effective way to produce Se-rich celery.

Novel Bioformulations with Trichoderma lixii to Improve the Growth Dynamics and Biocontrol of the Cowpea Damping-Off Disease

Because agricultural wastes are abundant in biologically active substances, they can be used as a substitute source to produce highly valuable products while lowering pollution levels in the environment. Therefore, we aimed at determining the best agricultural wastes to increase the biomass production rate and the effectiveness of the biocontrol strain Trichoderma lixii SARS 111 in a solid-state fermentation system. The potential for its use in enhancing growth dynamics and controlling the Fusarium oxysporum NCAIM-F-00779-caused damping-off disease of cowpea plants grown in greenhouse conditions was also studied. Using a one-factor-at-a-time experiment, five cheap agricultural waste substrates (faba bean, cowpea, sweet potato, pumpkin, and cassava) were studied using the Plackett–Burman design (PBD) and the central composite design (CCD) to optimize the nutritional and growth conditions to maximize the production of Trichoderma conidia. The findings demonstrated that increasing Candida production quantitatively required the use of 3 g of sweet potato, 3 g of cassava, pH 6, 25 °C, and pre-treatment with dH2O. The shelf life and viability of T. lixii strain were measured as log10 CFU g−1 per substrate at room temperature (RT, 25 °C) at the beginning of month 0 and subsequently at 2-month intervals for 12 months. Data showed that the fungal counts increased with the use of 4 g of sweet potato + 2 g of cassava up to 7 months and then sharply decreased, lasting up to 12 months. Additionally, this bioformulation was applied to cowpea plants in a greenhouse experiment, where a significantly higher level of plant growth traits, photosynthetic pigments, antioxidant enzymes, and chemical content in the leaves, as well as lower incidence of the damping-off disease, were noted. Accordingly, it is possible to suggest 4 g of sweet potato and 2 g of cassava as a suitable bioformulation for the industrial-scale production of the T. lixii strain, which may be a potential biocontrol agent for preventing the cowpea damping-off disease caused by F. oxysporum and improving the growth dynamics.

The Adaptive Role of Carotenoids and Anthocyanins in Solanum lycopersicum Pigment Mutants under High Irradiance.

The effects of high-intensity light on the pigment content, photosynthetic rate, and fluorescence parameters of photosystem II in high-pigment tomato mutants (hp 3005) and low-pigment mutants (lp 3617) were investigated. This study also evaluated the dry weight percentage of low molecular weight antioxidant capacity, expression patterns of some photoreceptor-regulated genes, and structural aspects of leaf mesophyll cells. The 3005 mutant displayed increased levels of photosynthetic pigments and anthocyanins, whereas the 3617 mutant demonstrated a heightened content of ultraviolet-absorbing pigments. The photosynthetic rate, photosystem II activity, antioxidant capacity, and carotenoid content were most pronounced in the high-pigment mutant after 72 h exposure to intense light. This mutant also exhibited an increase in leaf thickness and water content when exposed to high-intensity light, suggesting superior physiological adaptability and reduced photoinhibition. Our findings indicate that the enhanced adaptability of the high-pigment mutant might be attributed to increased flavonoid and carotenoid contents, leading to augmented expression of key genes associated with pigment synthesis and light regulation.