Pea Seedlings Research Articles

Impact of PGRS Priming on Germination and Seedling Parameters of Pea And Plantago under Artificial Magnetism

Seed priming is widely recognized as a significant phenomenon for synchronizing germination and enhancing the vigor of seeds. Seeking the importance of priming, the influence of magnetic treatments in overall performance of plants cannot be undermined as well. In the present study, seeds of Pisum sativum L. and Plantago ovata Forssk. were primed with essential Plant Growth Regulators (PGRs) such as; Gibberellic acid (GA3), Potassium nitrate (KNO3), Salicylic acid (SA), Ascorbic acid (AsA), Hydrogen peroxide (H2O2) in combination with different artificial magnetic treatment (North, South and N/S) to document morpho-physiological attributes. A lab experiment was conducted under Complete Randomized Design (CRD) which consisted of 6 seed priming treatment along with control (no-priming) each with three replications. Seeds were primed with water (H2O) and PGRs for 12 hours and the final harvest of seedlings was obtained for morpho-physiological analysis after 20 days of germination. Results portrayed statistically significant (p < 0.05) data by increasing the morphological characteristics (root/shoot length, number of leaves, root/shoot fresh weight and root/shoot dry weight). Similarly, photosynthetic pigments i.e., chl a and carotenoids recorded significant variations under artificial magnetism except chl b which showed non-significant (p > 0.05) variations. Results concluded that hydro priming and pre-soaking of seeds with essential PGRs are highly recommended to maximize the early germination, morpho-physiological performance in pea and plantago seedlings under artificial magnetism.

Portable Electrochemical Sensing of Indole‐3‐acetic Acid Based on Self‐assembled MXene and Multi‐walled Carbon Nanotubes Composite Modified Screen‐printed Electrode

AbstractAs a typical plant hormone, indole‐3‐acetic acid (IAA) can regulate the biological activities including division, growth and differentiation of plant cells. In this paper, a MXene and multi‐walled carbon nanotubes composite was prepared by self‐assembly procedure, which was modified on screen‐printed electrode (SPE) to construct a wireless portable electrochemical sensor. Electrochemical investigations of IAA were studied by cyclic voltammetry and an irreversible oxidation process could be observed. The excellent electroanalytical method of IAA was realized on the modified SPE with the detection range as 0.05–125.0 μmol/L and the detection limit as 16.7 nmol/L. The sensor was used for IAA content analysis in different part of pea seedlings with satisfactory results.

Comparative Physiology and Antioxidant Response of Grasspea (Lathyrus sativus L.) Seedlings under the Iso-osmotic Potential of Salinity and Drought Stress

Aims: This study's objective was to determine how early-stage grass pea seedlings will respond to salinity and drought stress with iso-osmotic potential, emphasising ROS-scavenging enzymes.
 Study Design: Completely randomized design.
 Place and Duration of Study: Laboratory studies on the grass pea varieties BK-14 and Pratik were carried out in the academic years 2017–2018 and 2018–2019 at the Department of Plant Physiology, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, West Bengal, India.
 Methodology: Sodium chloride and PEG 6000 solutions with iso-osmotic potentials of -0.2, -0.4, and -0.8 MPa were used to study salinity's effects and drought stress. The experiment was conducted in sand culture using modified Hoagland solution under diffused light, at a temperature of 22°C and an approximate relative humidity (R.H.) of 80±1%.
 Results: Results indicated that drought stress was found to produce more adverse effects on seedling dry weight and lipid peroxidation in comparison with iso-osmotic potential of salinity stress. Variety BK-14 was found to be more tolerant than Pratik for seedling dry weight at the highest intensity of drought stress. The data further indicated that drought- induced more accumulation of phenol in the leaf as well than iso-osmotic salinity stress. The activities of four ROS scavenging enzymes (viz, superoxide dismutase, guaiacol peroxidase, ascorbate peroxidase and catalase) in leaves mostly showed a sigmoidal pattern of changes under varying levels of both stresses. Comparative analysis indicated that Pratik registered higher activities of two peroxidases, viz, GPOX and APX, under higher levels of drought stress while BK 14 registered higher activities under salinity stress. However, BK-14 was found to register a higher increase in SOD activity at the most intense level of salinity and drought stress as compared to Pratik.
 Conclusion: In the present experiment, it was discovered that BK-14 was generally more tolerant than Pratik for seedling growth under the utmost level of stress. This may be explained by the stronger antioxidative mechanism it exhibited in the present experiment under the conditions of the maximum stress, as generated by both enzymatic and non-enzymatic components.

Bacterioplankton Associated with Toxic Cyanobacteria Promote Pisum sativum (Pea) Growth and Nutritional Value through Positive Interactions.

Research on Plant Growth-Promoting Bacteria (PGPB) has focused much more on rhizospheric bacteria. However, PGPB associated with toxic cyanobacterial bloom (TCB) could enter the rhizosphere through irrigation water, helping plants such as Pisum sativum L. (pea) overcome oxidative stress induced by microcystin (MC) and improve plant growth and nutritional value. This study aimed to isolate bacteria associated with toxic cyanobacteria, test PGPB properties, and inoculate them as a consortium to pea seedlings irrigated with MC to investigate their role in plant protection as well as in improving growth and nutritional value. Two bacterioplankton isolates and one rhizosphere isolate were isolated and purified on a mineral salt medium supplemented with 1000 μg/L MC and identified via their 16S rRNA gene. The mixed strains were inoculated to pea seedlings in pots irrigated with 0, 50, and 100 μg/L MC. We measured the morphological and physiological parameters of pea plants at maturity and evaluated the efficiency of the plant’s enzymatic and non-enzymatic antioxidant responses to assess the role and contribution of PGPB. Both bacterioplankton isolates were identified as Starkeya sp., and the rhizobacterium was identified as Brevundimonas aurantiaca. MC addition significantly (p < 0.05) reduced all the growth parameters of the pea, i.e., total chlorophyll content, leaf quantum yield, stomatal conductance, carotenoids, and polyphenol contents, in an MC concentration-dependent manner, while bacterial presence positively affected all the measured parameters. In the MC treatment, the levels of the pea’s antioxidant traits, including SOD, CAT, POD, PPO, GST, and ascorbic acid, were increased in the sterile pots. In contrast, these levels were reduced with double and triple PGPB addition. Additionally, nutritional values such as sugars, proteins, and minerals (Ca and K) in pea fruits were reduced under MC exposure but increased with PGPB addition. Overall, in the presence of MC, PGPB seem to positively interact with pea plants and thus may constitute a natural alternative for soil fertilization when irrigated with cyanotoxin-contaminated water, increasing the yield and nutritional value of crops.

Phytotoxicity of VO2 nanoparticles with different sizes to pea seedlings

Vanadium dioxide nanoparticles (VO2 NPs) have been massively produced due to their excellent metal-insulator transition characteristics for various applications. Pilot studies indicated the toxicity of VO2 NPs to bacteria and mammalian cells, but the environmental hazards of VO2 NPs to plants have been unrevealed to date. In this study, we reported the inhibitive effects of VO2 NPs to the growth and photosynthesis of pea seedlings. Laboratory synthesized monoclinic VO2 NPs (N-VO2), commercial nanosized VO2 NPs (S-VO2), and commercial microsized VO2 particles (M-VO2) were carefully characterized for environmental toxicity evaluations. VO2 particles were supplemented to culture medium for seed germination and seedling growth. All three VO2 samples did not affect the germination rates of pee seeds, while serious growth inhibition of pea seedlings was observed at 10 mg/L for S-VO2 and N-VO2, and 100 mg/L for M-VO2. VO2 particles had no impact on the chlorophyll contents, but the photosynthesis of leaf was significantly decreased following the consequence of N-VO2 > S-VO2 > M-VO2. The inhibition of photosynthesis was attributed to the damage of acceptor side of photosystem II by VO2 particles at high concentrations. Abundant bioaccumulations of vanadium in roots aroused oxidative damage and changed the root structure. Our results collectively indicated that the phytotoxicity of VO2 NPs was related to the concentration, size and crystalline degree.

THE EFFECT OF BACTERIAL AND STIMULATING DRUGS ON THE GERMINATION OF SPRING PEA SEEDS

The effect of the bacterial drug Rhizoactive and the stimulator Regoplant, as well as their combined use on the laboratory germination of seeds and the beginning growth stages of spring pea plants Oplot, were studied.Regoplant and the mixture Rhizoactive + Regoplant had the greatest influence on the processes of seed germination of spring peas during heterotrophic nutrition. Decrease in the crude mass of cotyledons was detected during the phase of transition of pea seedlings to autotrophic nutrition using the stimulant drug Regoplant and its combination with a bacterial preparation. It was accompanied by the activation of growth processes in the aboveground and underground parts of the seedling, in particular, an in crease in linear size and mass.The best indicators of sowing qualities of spring pea seeds were found when using a combined treatment of seeds with stimulant drug Regoplant and bacterial preparation Rhizoactive. There was an increase in germination energy by 3.0%, general germination by 2.0%, and germination simultaneity by 3.9% compared to control in this variant.

Phytotoxic Effects of Bisphenol a on Growth Indicants And Chlorophyll Content of Pisum Sativum L.

In the environment, Bisphenol A (BPA) is an emerging universal pollutant and it disrupts endocrine system and is substantially toxic for living beings and significantly harmful to the plants as well. Toxicologic effects of BPA on plants is not fairly documented. In the present study, effects of BPA on growth and chlorophyll content were studied in Pisum sativum L. (pea) seedlings. After treatment of pea seeds with varying concentrations of BPA (2, 5, 10, 15, 20, and 25 mg/l) for 3 hrs at room temperature (21°C), they were sown in pots and growth viz., height of plants, fresh and dry weights of stems and leaves and chlorophyll content were recorded after 15 and 30 days from sowing. The current study confirmed that BPA can affect the growth and chlorophyll content in a dose related manner. BPA at lower concentration (2 mg/l) increased the growth in pea seedlings whereas BPA at higher concentration exhibited a significant inhibitory effect on the growth of pea seedlings. Consequently, the results of this study may be applied in future researches of environmental hazards linked to soil due to BPA as well as managing of BPA in relation to soil. Bangladesh J. Bot. 51(2): 237-245, 2022 (June)

Selection of Carrier Materials to Formulate Bioinoculant Package for Promoting Seed Germination

Biofertilizers are a novel technique for Indian agriculture that has the potential to address many of the shortcomings of chemical-based technology. Plant growth-promoting (PGP) traits such as IAA, P-solubilization, ACC deaminase, NH3, HCN, EPS, siderophore synthesis, and biofilm formation have been demonstrated in two salt-tolerant PGPR, BST YS1 42 (Bacillus cereus) and CHR JH203 (Bacillus marisflavi). They are most commonly utilized to make carrier-based compositions. This study aimed to evaluate how different carrier-based formulations of salt-tolerant PGPR performed in seedlings of pea and maize plants. The chosen PGPR was mass replicated in the lab and put into seedlings via a variety of carriers, including charcoal powder, dry pea peel powder, tea leaf powder, hay+2%peptone, and cowdung powder. The influence of bio inoculants on seedling growth of Pisum sativum and Zea mays seedlings was investigated. There was a substantial variation in seedling germination in both pea and maize. The result was different depending on the type of carrier materials utilized in the bioformulation process. The results showed that seedling germination was better with the bioformulation made with charcoal and tea leaf powder. As a result, we believe it might be used to alleviate abiotic stresses in a cost-effective and environmentally friendly manner.

Appraisal of foliar spray of iron and salicylic acid under artificial magnetism on morpho-physiological attributes of pea (Pisum sativum L.) plants.

The appraisal of foliar treatment of iron (Fe) and salicylic acid (SA) on plant under artificial magnetism is very crucial in understanding its impact on growth and development of plants. The present study was designed to document the potential role of Fe and SA on pea (Pisum sativum L.) Matore variety exposed to different magnetism treatments (geomagnetism and artificial magnetism). Thus a pot experiment was conducted using Completely Randomized Design under factorial with three replicates. Various artificial magnetic treatment were applied in pots prior to sowing. Further, 15 days germinated pea seedlings were foliarly supplemented with 250 ppm Fe and 250μM SA, moreover after 20 days of foliar fertilization plants were harvested to analyze and record various morpho-physiological attributes. Data elucidate significant variations in pea plants among different treatments. Artificial magnetism treatments in combination with foliar application of Fe and SA significantly improved various growth attributes (root and shoot length, fresh and dry weights of root and shoot, leaf area), photosynthetic pigments (Chl a, b and carotenoids) and the contents of soluble sugars. However, oxidative stress (H2O2 and MDA) enhanced under different magnetism treatment but foliar application of Fe and SA hampered the production of reactive oxygen species thereby limiting the concentration of H2O2 and MDA in plant tissues. Furthermore the accumulation of nutrients (iron, potassium and nitrate) profoundly increased under artificial magnetism treatment specifically under Fe and SA foliar treatment excluding nitrate where Fe foliar treatment tend to limit nitrate in plant. Consequently, the present research interestingly highlights progressive role of Fe and SA foliar treatment on pea plants under artificial magnetism. Thus, foliar supplementation may be suggested for better growth and development of plants combined with magnetic treatments.

Evaluation of ACC deaminase and indole acetic acid production by Streptomyces hydrogenans DH16 and its effect on plant growth promotion

Environmental degradation caused by the unabated and indiscriminate use of agrochemicals, employed to increase the crop yields, and thus resulting in incrementing the public concern by every passing year, has invited the interest of researchers to find ever safe alternatives for enhancing the crop productivity. In the light of this, the present study undertook the research objective to explore the plant growth promoting activities of Streptomyces hydrogenans DH16, a soil actinobacterium possessing broad spectrum antifungal activity. Optimization of IAA production by S. hydrogenans DH16 using one variable at a time approach resulted in 2.24 fold (from 36 μg/ml to 80.06 μg/ml) increase in yield of IAA. S. hydrogenansDH16 completely utilized 1-aminocyclopropane-1-carboxylate on fourth day of incubation and showed 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of 363 nano molesα-ketobutyrate/mg protein/h. This streptomycete also demonstrated in vitro ability to colonize plant roots, fix atmospheric nitrogen and inhibit fungal phytopathogens viz.Alternaria solani and Pyricularia oryzae. The influence of S. hydrogenansDH16 on growth of pea seedlings (Pisum sativum) was evaluated in which it significantly enhanced seed germination, shoot length, root length, fresh and dry weights and lateral roots. Similarly, treatment of seeds with culture broth containing IAA (50 μg/ml) showed positive impact on growth of pea seedlings with 39.45–58.04% increase in various growth parameters. These results demonstrate that S. hydrogenans strain DH16 and extracellular metabolites (antifungal and plant growth promoting substances) produced by it can be exploited as soil amendment as biofungicide and biofertilizer with many advantages over the chemical fungicides and fertilizers.

Characteristics of Antimony Migration and Transformation and Pollution Evaluation in a Soil-Crop System Around a Tin Mine in Hunan Province

This study used 193 sets of farmland soil and agricultural product samples collected from around a tin mine in Hunan Province, China, to explore the antimony (Sb) content characteristics and pollution status of soil and agricultural products and to provide a scientific basis for the prevention and control of soil antimony pollution in antimony mining areas and the safe use of farmland. We analyzed the amount of antimony in the soil, basic physical and chemical properties, and antimony content in agricultural products; studied the characteristics of antimony migration and transformation in the soil-agricultural product system; and conducted safety assessments on soil and agricultural products. The results showed that the soil ω(Sb) in the central area of the mine, the southern area of the mine, the central township area, the urban-rural transfer area, and the northern area of the mine reached (2348±2165), (1298±884.1), (311.8±526.5), (302.5±355.9), and (215.6±183.2) mg·kg-1, and the exceeding multiples reached 65.22, 36.06, 8.66, 8.40, and 5.99 times, respectively. The antimony enrichment coefficients of lettuce, scallion, cabbage, water spinach, garlic, and pea seedlings in agricultural products were 0.01-0.1, which indicated good antimony absorption capacity. The antimony enrichment coefficients of loofah, asparagus lettuce, pepper, carrot, bitter gourd, corn, eggplant, cowpea, and celery were less than 0.01, and the antimony absorption capacity was relatively poor. The safety assessment results showed that roots, allium, and garlic vegetables had a high risk of antimony pollution; leafy vegetables and legumes had a higher risk of antimony pollution; and solanaceous vegetables, melons, and fruit vegetables and corn (cereals) had a high risk of antimony pollution. Therefore, it is urgent to take soil antimony pollution control measures in the mining area. At the same time, in order to realize the safe use of agricultural land in the mining area, the farmland far away from the low antimony content of the soil in the central area of the mine should be selected as the planting area, and the agricultural products with weak antimony absorption capacity should be planted first.

GREEN SYNTHESIS OF ZINC OXIDE NANOPARTICLES USING SCHREBERA SWIETENIOIDES ROXB., AQUEOUS LEAF EXTRACT AND INVESTIGATION OF ITS EFFECT ON SEED GERMINATION AND PLANT GROWTH ON PIGEON PEA (CAJANUS CAJAN LINN.)

Objective: The present work intended to green and eco-friendly synthesis of Zinc oxide (ZnO) nano particles (NPs) using aqueous leaf extract of Schrebera swietenioides and the synthesised NPs were applied for enhancement of seed germination and plant growth in pigeon pea (Cajanus cajan Linn.). Methods: The Zinc acetate was utilised as metal source and metal was reduced using aqueous leaf extract of S. swietenioides as green reducing agent. The synthesised NPs were characterized using various techniques such as SEM-EDS, TEM, XRD, FT-IR and UV-visible spectrophotometer. The seed germination study as well as plant growth promotion activity, was performed on pigeon pea seeds. Results: The result achieved in characterization of NPs confirms that he NPs were hexagonal wurtzite form having a spherical shape with irregular surfaces. The average size was found to be 68 nm with the metal composition of 73.7 %. The NPs were studied for seed germination and growth promotion activity on pigeon pea seeds and the mean germination time was observed to be 38.60±0.56, 28.53±0.59 and 37.53±0.40 h whereas the final germination percentage was found as 91.33±0.58, 98.00±1.00, and 92.67±1.15 h for control, NPs treated and zinc acetate treated seeds respectively. The NPs treated plants grow more rapidly than the untreated as well as Zn acetate-treated pigeon pea plants. The pigeon pea seeds treated with ZnO NPs shows the high activity of enzyme activities such as amylases, protease, catalase than the untreated as well as Zn acetate treated seeds. Conclusion: The aqueous leaf extract of S. swietenioides mediated ZnO NPs can augment the growth of pigeon pea seedlings, and the NPs treatment shows a stimulatory effect on the enzymes associated with the growth of seedlings.

Pengenalan Bunga Telang (Clitoria ternatea L.) di Desa Wisata Alam Sungai Masjid Kabupaten Dumai sebagai upaya membantu peningkatan Hospitality

Kelompok Sadar Wisata or Tourism Awareness Group (POKDARWIS) Desa Wisata Sungai Masjid Kabupaten Dumai have been improving their rural tourism. One of their services for tourists or guests is providing welcome drinks. Therefore, the objective of our program was to introduce butterfly pea, how to plant and how to utilize the flowers particularly for improving hospitality such as welcome drink and welcome kit. Butterfly pea (Clitoria ternatea L.) plants are known relatively easy to grow and possess chemical properties good for human health. We delivered our program to POKDARWIS Desa Wisata Sungai Masjid ss our partner through the oral presentation and demonstrated video. We also gave seeds and seedlings of butterfly pea to the participants. Our partners did not know about butterfly pea flower before participating in our program. They showed their enthusiasm and curiosity, particularly during the discussion session. Results of the questionnaire indicated that our program was useful to enhance their knowledge and provide inspiration to improve their life. One week later, after the training, the POKDARWIS had their program which adopted our program such as sowing and planting butterfly pea seeds and seedlings. Based on the results, we conclude that we have conveyed our program successfully and inspired our partners to produce butterfly pea-based food and beverages.

Influence of Burning-Induced Electrical Signals on Photosynthesis in Pea Can Be Modified by Soil Water Shortage.

Local damage to plants can induce fast systemic physiological changes through generation and propagation of electrical signals. It is known that electrical signals influence numerous physiological processes including photosynthesis; an increased plant tolerance to actions of stressors is a result of these changes. It is probable that parameters of electrical signals and fast physiological changes induced by these signals can be modified by the long-term actions of stressors; however, this question has been little investigated. Our work was devoted to the investigation of the parameters of burning-induced electrical signals and their influence on photosynthesis under soil water shortage in pea seedlings. We showed that soil water shortage decreased the amplitudes of the burning-induced depolarization signals (variation potential) and the magnitudes of photosynthetic inactivation (decreasing photosynthetic CO2 assimilation and linear electron flow and increasing non-photochemical quenching of the chlorophyll fluorescence and cyclic electron flow around photosystem I) caused by these signals. Moreover, burning-induced hyperpolarization signals (maybe, system potentials) and increased photosynthetic CO2 assimilation could be observed under strong water shortage. It was shown that the electrical signal-induced increase of the leaf stomatal conductance was a potential mechanism for the burning-induced activation of photosynthetic CO2 assimilation under strong water shortage; this mechanism was not crucial for photosynthetic response under control conditions or weak water shortage. Thus, our results show that soil water shortage can strongly modify damage-induced electrical signals and fast physiological responses induced by these signals.

Decoding the Plant Growth Promotion and Antagonistic Potential of Bacterial Endophytes From Ocimum sanctum Linn. Against Root Rot Pathogen Fusarium oxysporum in Pisum sativum.

The present study demonstrates plant growth promotion and induction of systemic resistance in pea (Pisum sativum) plant against Fusarium oxysporum f.sp. pisi by two bacterial endophytes, Pseudomonas aeruginosa OS_12 and Aneurinibacillus aneurinilyticus OS_25 isolated from leaves of Ocimum sanctum Linn. The endophytes were evaluated for their antagonistic potential against three phytopathogens Rhizoctonia solani, F. oxysporum f. sp. pisi, and Pythium aphanidermatum by dual culture assay. Maximum inhibition of F. oxysporum f. sp. pisi was observed by strains OS_12 and OS_25 among all root rot pathogens. Scanning electron microscopy of dual culture indicated hyphal distortion and destruction in the case of F. oxysporum f. sp. pisi. Further, volatile organic compounds (VOCs) were identified by gas chromatography–mass spectrometry (GC-MS). The GC-MS detected eight bioactive compounds from hexane extracts for instance, Dodecanoic acid, Tetra decanoic acid, L-ascorbic acid, Trans-13-Octadecanoic acid, Octadecanoic acid. Both the endophytes exhibited multifarious plant growth promoting traits such as indole acetic production (30–33 μg IAA ml–1), phosphate solubilization, and siderophore and ammonia production. Pot trials were conducted to assess the efficacy of endophytes in field conditions. A significant reduction in disease mortality rate and enhancement of growth parameters was observed in pea plants treated with consortium of endophytes OS_12 and OS_25 challenged with F. oxysporum f.sp. pisi infection. The endophytic strains elicited induced systemic resistance (ISR) in pathogen challenged pea plants by enhancing activities of Phenylalanine ammonia lyase (PAL), peroxidase (PO), polyphenol oxidase (PPO), ascorbate oxidase (AO), catalase (CAT) and total phenolic content. The endophytes reduced the oxidative stress as revealed by decrease in malondialdehyde (MDA) content and subsequently, lipid peroxidation in host plant leaves. Robust root colonization of pea seedlings by endophytes was observed by scanning electron microscopy (SEM) and fluorescence microscopy. Thus, plant growth promoting endophytic P. aeruginosa and A. aneurinilyticus can be further exploited through bio-formulations for sustainable protection of crops against root rot diseases as bio-control agents.

Utjecaj magnetnih polova na svojstva sjemena krmnog graška (Pisum sativum L.) različite starosti

The study on the influence of magnetic poles on field pea seed of the 'Bera' variety of different ages was carried out under laboratory conditions in a growing chamber. Field pea seed were exposed to a neodymium magnet's positive and negative magnetic poles with a magnetic flux density of 250 mT for 24 hours. Germination of untreated as well as magnetically poled treated seed was carried out according to ISTA rules. Seed characteristics, germination energy, and germination were determined by counting. The root and stem length of the seedlings were measured, and the total length of the field pea seedlings was added up. The total mass of the seedlings was determined by weighing. On average, seed age and magnetic poles significantly (p&amp;lt;0.05) increased the traits: stem length, total length, and seedling weight. On average, significant differences (p&amp;lt;0.05) were found for untreated and magnetic poles treated seed for all the studied traits except seedling stem length. Significant interaction (p&amp;lt;0.05) between magnetic pole treatment and seed age was found for all the traits studied.

Preparation of humic acid water‐retaining agent‐modified polyurethane sponge as a soilless culture material

AbstractBased on the structural characteristics of the polyfunctional groups of humic acid (HA), a HA water‐retaining agent (HAA) was prepared by the polymerization of an aqueous solution using potassium humate, acrylic acid, sodium carboxymethyl cellulose, and bentonite. HAA was obtained by the polymerization of an aqueous solution using an assembly ligand, and a polyurethane (PU) sponge was used as a carrier to mix HAA in the foaming process of the PU sponge to obtain the HAA‐modified PU (HAA‐PU) sponge matrix. The HAA‐PU sponge prepared with the HAA‐to‐PU mass ratio of 1:4 had the strongest foaming volume and water absorption. Fourier transform infrared spectrometry, scanning electron microscopy, and thermal stability analysis showed the successful preparation of the HAA‐PU sponge substrate, which allowed for the slow entry or storage of moisture and nutrients. The results of the pea seedling growth test on the HAA‐PU sponge and soil CK (control check) group showed that the emergence rate of the HAA‐PU group was&gt;60%. It was not affected by the amount of watering and provided plants with long‐term water and nutrition. The chlorophyll, and vitamin C content of pea seedlings grown in the HAA‐PU sponge group were higher than the soil CK group.

Nitric Oxide Alleviates Photochemical Damage Induced by Cadmium Stress in Pea Seedlings

Cadmium (Cd), a life threatening hazardous heavy metal is abundant in nature. Cd amounts are greater in leaves than other plant parts, and it shows considerable effects on photosynthesis. Nitric oxide (NO), a free radical present in living organisms, is now known as an important signaling molecule playing various physiological processes in plants. In this study, the possible ameliorative effect of NO on photosynthesis was examined on pea seedlings grown under Cd stress. Results showed that chlorophyll, net photosynthetic rate, transpiration rate, stomatal conductance, photochemical efficiency of Photosystem II and Photosystem I decreased, and Fo and non-photochemical parameters for PSII and PSI significantly increased due to Cd stress. This suggests that Cd affects the photochemistry efficiency at both the PSII and PSI levels. Nitric oxide supplementation through SNP ameliorated Cd stress by enhancing all the above mentioned parameters but causing a reduction in the Fo, and non-photochemical parameters of PSII and PSI in pea plants. These data indicate that the exogenous application of NO was useful in mitigating Cd-induced damage to photosynthesis in pea seedling.

Polyethylene Gycol (PEG) Induced Water Stress in Four Different Genotypes of Pea Seedlings and Evaluation of The Induced Defense Mechanism

The present work was undertaken on artificially induced water stress on pea seedlings under in vitro conditions in order to select the drought tolerant line. Artificial water stress was induced with PEG-6000 on 15-day old seedlings of four varieties for 4, 8 and 12 days. The activities of antioxidative enzymes like peroxidase, catalase, ascorbate peroxidase, glutathione reductase and superoxide dismutase were assayed in the stressed and control plants. POX activity was increased in the initial stages of stress, but its activity was decreased significantly on the 12th day in all the varieties. APOX also showed a similar trend but the maximum activity was noted in Var 3 on the 8th day. CAT activity decreased in var 1 and var 2 when compared with the control, which, however, increased significantly in var 3 and var 4. A slight increase in the GR activity was observed in var 1 and var 2 at the initial stages of the drought stress but its activity decreased significantly on the 12th day in both these varieties when compared with control plants. However, its activity also increased steadily in var 3 and var 4. Maximum SOD activities were noted on the 4th day of drought stress in all four varieties but its activities decreased steadily on the subsequent 8th and 12th days when compared with control. When antioxidative activities were compared among the four varieties, var 3 and var 4 showed maximum increase in antioxidant activity during the period of drought stress. Among the four varieties, var 3 and var 4 showed greater accumulation of H2O2 during the stress days and were maximum at 12th day. Lipid peroxidation also increased in the same varieties. Maximum proline content was noted in both the root and leaf of var 3, followed by var 4. It was further noted that the chlorophyll content decreased significantly in all four varieties in subsequent longer drought stresses. The accumulation of proline content was steadily higher with an increase in the stress length in all the four varieties. During the drought stress, all the varieties showed an increase in ascorbate content but, it was maximum in var 4 followed by var 3 and the least ascorbate was noted in var 1. The present findings indicate that water stress induces oxidative stress in all the four varieties. However, antioxidative mechanisms were found to be more pronounced in var 4 which, therefore, may be considered as the most tolerant to drought stress.

Nitric oxide alleviates cadmium-impeded growth by limiting ROS accumulation in pea seedlings

Cadmium (Cd) causes oxidative stress, which leads to the oxidation of various biomolecules by the production of reactive oxygen species (ROS) to facilitate programmed cell death (PCD). The antioxidant defense system fails to detoxify ROS when it is produced in excess. Nitric oxide (NO), a gaseous free radical and a phytohormone, regulates various physiological processes of plants. Therefore, this work was undertaken to study the effects of the application of exogenous sodium nitroprusside (SNP, a NO donor) on growth parameters, oxidative stress, accumulation of secondary metabolites, and activities of antioxidant enzymes under Cd stress. Mild (50 µM) and severe (200 µM) Cd stress were applied to hydroponically grown pea (Pisum sativum L.) plants with or without 50 µM SNP. Severe Cd stress had a substantial impact on the plants. The effectiveness of NO in reducing Cd-induced negative effects on plant height, fresh weight, dry weight, protein content, nitrite content, nitrate reductase (NR) activity, catalase activity, and peroxidase activity were investigated. Seedling development, protein content, nitrite content, nitrate reductase (NR) activity, antioxidant defense systems disruption, overproduction of reactive oxygen species, and oxidative damage were observed. The antioxidant defense system (catalase and peroxidase activities) was activated by NO, which resulted in lower lipid peroxidation and lower hydrogen peroxide (H2O2) levels in Cd-exposed plants. SNP treatment boosted endogenous NO levels and NR activity in Cd-stressed plants while also enhanced proline levels to preserve osmotic equilibrium. The presence of total phenols and flavonoids increased after SNP treatment, indicating that SNP enhanced stress recovery and boosted plant development in Cd-stressed plants.