Total Soluble Phenolics Research Articles

Effect of Pediococcus acidilactici and mango seed polyphenols on the fermentative profile of the indigestible fraction of yam bean

Yam bean is an important source of dietary fiber and other components that comprise the total indigestible fraction (TIF), which can be fermented by the colonic microbiota and produce metabolites with beneficial health effects. Therefore, the objective of this study was to evaluate the in vitro colonic fermentation of yam bean TIF and the changes caused by the addition of a polyphenolic extract of mango seed and the lactic acid bacteria Pediococcus acidilactici. The mango seed extract was obtained by ultrasound-assisted extraction, and the microbial growth rate and viability of P. acidilactici were determined using a Neubauer chamber. Yam bean TIF was isolated by triple enzymatic hydrolysis and subjected to in vitro colonic fermentation in combination with treatments with mango seed extract and P. acidilactici suspensions. Changes in pH, total soluble phenols (TSP), and antioxidant capacity (AOX) were evaluated. Furthermore, the production of metabolites was quantified by HPLC-DAD-MS and GC–MS. The Growth rate of P. acidilactici was 0.1097 h−1 with 97.5 % viability at 7 h of incubation. All TIF treatments showed a high capacity of fermentation, and the addition of mango seed extract increased the TSP content and AOX in DPPH and FRAP assays. A total of Forty-six volatile metabolites were detected, with highlighting the presence of esters, benzenes, aldehydes, and short-chain fatty acids. Five phenolic compounds associated with mango by-products were quantified during all fermentation process, despite the concentration of the extract. P. acidilactici did not substantially modify the fermentative profile of TIF. However, further studies such as the evaluation of the abundance of microbial communities may be necessary to observe whether it can generate changes during colonic fermentation.

1‐MCP combined with laser microporous film packaging maintains the quality and prolongs the storage period of Xiahei grapes

SummaryThe effects of a 1‐methylcyclopropene (1‐MCP) treatment combined with laser microporous film (LMF) packaging on the quality of postharvest Xiahei grapes during storage at 4 ± 1 °C were investigated. Compared with the control group, the 1‐MCP + LMF treatment significantly decreased the weight loss and respiration rate of the grapes (P < 0.05). Additionally, the combination of 1‐MCP and LMF maintained relatively high titratable acid, ascorbic acid, and total soluble phenol contents, as well as low levels of soluble solids. The combined application of 1‐MCP and LMF also reduced the accumulation of superoxide anions, hydrogen peroxide, and malondialdehyde. Except in a few samples, the superoxide dismutase, ascorbic peroxidase, and catalase activities were higher under 1‐MCP + LMF treatment. Conversely, lipoxygenase, polyphenol oxidase, peroxidase, and cellulase activities were lower than in the control. The results suggested that the combined application of 1‐MCP and LMF significantly mitigated water evaporation, retarded nutrient consumption, induced catabolism, and minimised oxidative damage of grapes during storage. These changes prolonged the shelf life of Xiahei grapes to 60 days at 4 ± 1 °C.

Enhancing salinity tolerance in cucumber through Selenium biofortification and grafting

BackgroundSalinity stress is a major limiting factor for plant growth, particularly in arid and semi-arid environments. To mitigate the detrimental effects of salinity stress on vegetable production, selenium (Se) biofortification and grafting onto tolerant rootstocks have emerged as effective and sustainable cultivation practices. This study aimed to investigate the combined effects of Se biofortification and grafting onto tolerant rootstock on the yield of cucumber grown under salinity stress greenhouse conditions. The experiment followed a completely randomized factorial design with three factors: salinity level (0, 50, and 100 mM of NaCl), foliar Se application (0, 5, and 10 mg L-1 of sodium selenate) and grafting (grafted and non-grafted plants) using pumpkin (Cucurbita maxima) as the rootstock. Each treatment was triplicated.ResultsThe results of this study showed that Se biofortification and grafting significantly enhanced salinity tolerance in grafted cucumbers, leading to increased yield and growth. Moreover, under salinity stress conditions, Se-Biofortified plants exhibited increased leaf relative water content (RWC), proline, total soluble sugars, protein, phenol, flavonoids, and antioxidant enzymes. These findings indicate that Se contributes to the stabilization of cucumber cell membrane and the reduction of ion leakage by promoting the synthesis of protective compounds and enhancing antioxidant enzyme activity. Moreover, grafting onto pumpkin resulted in increased salinity tolerance of cucumber through reduced Na uptake and translocation to the scion.ConclusionIn conclusion, the results highlight the effectiveness of Se biofortification and grafting onto pumpkin in improving cucumber salinity tolerance. A sodium selenate concentration of 10 mg L-1 is suggested to enhance the salinity tolerance of grafted cucumbers. These findings provide valuable insights for the development of sustainable cultivation practices to mitigate the adverse impact of salinity stress on cucumber production in challenging environments.

Enhancing Protoplast Isolation and Early Cell Division from Cannabis sativa Callus Cultures via Phenylpropanoid Inhibition.

De novo regeneration of Cannabis sativa L. (cannabis) using tissue culture techniques remains unreliable and infrequent. Conventional methods for the regeneration and transformation of cannabis have not achieved the reliability and replicability that need to be integrated into research and breeding programs. Protoplast systems are effective for gene expression studies and transformation and genome-editing technologies and open the possibility of somatic hybridization to create interspecific hybrids. To date, leaf-derived protoplasts have been isolated for transient gene expression studies, but protoplast-to-plant regeneration has not been reported. The present study aims to evaluate the efficacy of using a callus culture system as an abundant tissue source for protoplast isolation and lays the groundwork for a protoplast-to-plant regeneration system. Using hypocotyl-derived callus cultures, which are known to have relatively greater regenerative potential, the efficacy of protoplast isolation and initial cell division were assessed. In this study, the effect of 2-aminoindane-2-phosphonic acid (AIP), a competitive inhibitor of phenylalanine ammonia lyase (PAL), in callus culture media and the effect of subculture frequency on protoplast yield were assessed. This study found that inclusion of AIP at 1 mM resulted in a 334% increase in protoplast yield compared with AIP-free medium, representing the first known use of AIP in cannabis tissue culture. Inclusion of AIP led to a 28% decrease in total soluble phenolics and 52% decrease in tissue browning compared with the control medium. Lastly, a two-phase culture system for protoplast regeneration was tested. At a concentration of 2.0 × 105 protoplasts per mL, cell wall reconstitution and cell division were observed, providing one of the first know reports of cell division from cannabis protoplasts and setting the stage for the future development of a protoplast-to-plant regeneration system.

Study of sugar, Carotenoid, Antioxidant, Mineral and Biomass Content of Mango, Water Apple, and Banana

Mango, water apple, and banana fruits are the staple fruit crops in Asia, Europe, America, and also all over the world. Fruits are mainly used as fruit, juice, and a source of different food products. These are traditional and common fruits with health benefits and nutritional, pharmaceutical, and medicinal value. The study evaluated the carbohydrate content represented by glucose, fructose, total soluble solids, carotenoids, flavonoids, antioxidants, and phenolics. pH and minerals are micro-macro nutrient content in mango, water apple, and banana. 48 fruits were collected: mango, water apple, and banana. Samples were collected randomly following the completely randomized design. An atomic emission (AE) spectroscopic multi-element analyzer was used for minerals, and GC-FID was used for sugar analysis. Fruit fructose and glucose were higher in bananas and mangoes than in water apples. pH content was found higher in apples than in mango and banana. In addition, total soluble solids (TSS) content was the highest in mango. Potassium content was higher in bananas and mangoes than in mangoes. However, Phosphorus and calcium content were the highest in bananas. Moreover, magnesium (Mg) content was higher in water apples than in bananas and mango. Comparatively, more micronutrients were found in bananas and water apples than in mangoes. Fe, Zn, Na, and Mn were higher in water apples and mangoes than in bananas. The highest fiber and moisture were found in bananas. Flavonoids and carotenoids were found higher in water apples than in other fruits. Antioxidant and phenolic content were higher in mangos compared to the others. The results conclude that banana and water apples contain better biochemical (glucose, TSS, and pH) content than mango, and bioactive compound (flavonoid, phenolic, and carotenoids) was found higher in mangos and water apples, which can be used in the pharmaceutical industry for biomedicine production.

Assessment of agronomic crops-based residues for growth and nutritional profile of Pleurotus eryngii.

Among edible mushrooms, Pleurotus eryngii is unique due to its flavor, admirable medicinal and nutritional profiling. Pakistan is an agricultural country diverse in various crops. However, the residues of the horticultural and agronomic crops are wasted without utilization in the food chain. Hence, a study was performed to assess the performance of relatively low-cost, easily available crops residues i.e. cotton, rice, wheat, mustard and water chestnut for yield and nutrition enhancement of Pleurotus eryngii strains P9 (China) and P10 (PSU-USA). The results revealed that morphological attributes i.e. mycelium run, fruit development, yield and biological efficiency were significantly higher by using cotton waste as compared to other substrates. Regarding biochemical attributes i.e. total soluble solids (12.67 °Brix), phenolics (259.6 mg/100g), moisture (92.3%) and ascorbic acid contents (2.9 mg/100ml) were also significantly higher by using cotton waste. Whereas, acidity (0.30%), reducing sugar (7.67%), non-reducing (4.33%) and total sugars contents (12%) were found highest by using mustard straw. Nutrient analysis of substrates showed that nutrient levels were increased after harvesting of crop as compared to before harvesting levels. Overall results revealed that cotton waste and mustard straw are promising substrates for Pleurotus eryngii better growth and have potential in yield and nutrition enhancement. Moreover, P10 strain performed better as compared to P9.

Nanoparticle-assisted removal of EBT dye from textile wastewater: Towards sustainable Green gram seedling cultivation

Background: Wastewater refers to water of substandard quality that originates from urban and suburban regions. The water in question is used for cultivation in regions where there is a limited water supply for agricultural activities. The utilisation of marginal quality water for farming spans about 20 million hectares of land globally, with around 10% of the global population consuming food crops that have been irrigated with this kind of water. Methods: The CuONPs wassynthesizedby a chemical method, followed by their characterization using many methods including UV-Vis spect., FTIR, DLS, XRD, and SEM.The photocatalytic degradation of EBT dye and its adsorption kinetic studies were performed. Furthermore, impact of CuONPs, and wastewater on green gram seedlings under in-vitro conditions.Findings: The chemical methods effectively synthesized CuONPs as well as under ideal phytocatalytic condition CuONPsdegraded the EBT dye up to 51.09% in 5h of treatment.The inclusion of CuONPsat a dosage of 100 mg L−1 in the wastewater proceeded in a notable improvement in the green gram seed germination by 50%, and notable biometric profile as well as essential biomolecule (chlorophyll a&b, total soluble phenolics, and lycopene) profiles.

Preharvest Foliar Spraying Combined with Postharvest Salicylic Acid Treatment Regulates Panzao (Ziziphus jujuba Mill. cv. ‘Jingcang1’) Fruit Quality and Softening during Storage

Panzao (Ziziphus jujuba Mill. cv. ‘Jingcang1’) have a short shelf-life, which hampers their marketability. To investigate effects of combined pre- and postharvest treatments on quality and softening during storage, preharvest Guomantian foliar fertilizer (FF) spray and postharvest salicylic acid (SA) dip were applied to panzao. By day 63 of storage, fruit firmness responded to treatment in the order of FF+SA treatment > FF or SA treatments > Control. All treatments inhibited fruit reddening during storage and, compared with those of the control, alleviated the decline in total soluble solids, ascorbic acid, and phenol contents and decreased the oxidative aging process, which was consistent with the change in firmness. The FF+SA treatment reduced the activities of amylase, cellulase, polygalacturonase, and β-glucosidase, which decreased the degradation of macromolecules including starch, cellulose, and pectin. Principal component analysis showed that FF+SA exhibited a synergistic effect and was the most effective treatment for maintaining fruit quality during storage. FF increased accumulation of nutrients during growth and improved quality, while SA delayed the decline in fruit quality and reduced softening. These results provide the theoretical basis and technical knowledge for improving the shelf-life of panzao during storage and long-distance transportation.

Modification of TEMPO-oxidized cellulose nanofibers as a source of potassium and its impact on onion plant

This research study aims to improve the productivity and vegetative growth characteristics of onion to meet local demands and the volume of exports. This was done by the application of foliar nano-fertilizers based on cellulose nanofibers (CNF). TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) -oxidized cellulose nanofibers (TO-CNFs) were fabricated using the TEMPO-oxidized method in the presence of sodium or potassium hydroxide to obtain sodium carboxylate TO-CNFs (N-CNF) and potassium carboxylate TO-CNFs (K-CNF), respectively. Also, potassium acrylate was used in grafting N-CNF to get potassium polyacrylate-g-sodium carboxylate TO-CNFs (G-CNF). The prepared CNFs were described via various techniques such as FTIR, SEM, TGA, and XRD. X-ray analysis demonstrated that N-CNF, K-CNF, and G-CNF consisted of a crystalline domain of crystallinity index 0.45, 0.41, and 0.55, respectively. K-CNF showed marginally lower thermal stability than N-CNF influenced by its crystalline properties. The vegetative growth and the yield of onion plants, plus the content of photosynthetic pigments, minerals, cellulose, hemicellulose, and lignin, as well as total phenols, flavonoids, and indoles, were studied. The results showed that the application of K-CNF as a foliar nano-fertilizer improved the onion yield and the content of elements, protein, total soluble solid, phenols, and indoles as well as the content of cellulose and lignin

Influence of the Growing Region on the Phytochemical Composition and Antioxidant Properties of North American Cranberry Fruit (Vaccinium macrocarpon Aiton).

The impact of the growth environment on the production of health-promoting phytochemicals in cranberry fruit (Vaccinium macrocarpon Aiton) is not well established despite increased production worldwide. We investigated the secondary metabolite composition among the cranberry fruit of nine cultivars produced in two major coastal North American growing regions that differ in climate. Using 1H NOESY NMR to generate metabolic fingerprints, principal component analysis revealed variation between the two regions and identified likely contributing metabolites. Triterpenoids ursolic and oleanolic acid, as well as citric and malic acids, were quantified using 1H qNMR, and anthocyanins and flavonols were determined by HPLC-DAD. Total proanthocyanidins (PACs), total soluble phenolics, and DPPH free-radical scavenging antioxidant activity were also evaluated. Across all cultivars, anthocyanins, flavonols, and total phenolic content were significantly higher in West Coast fruit than East Coast fruit, correlating with a regional trend of higher antioxidant activity in fruit grown on the West Coast. The opposite trend was observed for triterpenoids and organic acids, which were significantly higher across cultivars in East Coast fruit. These trends persisted over two growing seasons. The study demonstrates that climate plays an important role in the production of antioxidant and anti-inflammatory phytochemicals in cranberry plants.

28-Homobrassinolide Primed Seed Improved Lead Stress Tolerance in Brassica rapa L. through Modulation of Physio-Biochemical Attributes and Nutrient Uptake.

Brassinosteroids (BRs) influence a variety of physiological reactions and alleviate different biotic and abiotic stressors. Turnip seedlings were grown with the goal of further exploring and expanding their function in plants under abiotic stress, particularly under heavy metal toxicity (lead stress). This study's objective was to ascertain the role of applied 28-homobrassinolide (HBL) in reducing lead (Pb) stress in turnip plants. Turnip seeds treated with 1, 5, and 10 µM HBL and were grown-up in Pb-contaminated soil (300 mg kg-1). Lead accumulation reduces biomass, growth attributes, and various biochemical parameters, as well as increasing proline content. Seed germination, root and shoot growth, and gas exchange characteristics were enhanced via HBL treatment. Furthermore, Pb-stressed seedlings had decreased total soluble protein concentrations, photosynthetic pigments, nutrition, and phenol content. Nonetheless, HBL increased chlorophyll a and chlorophyll b levels in plant, resulting in increased photosynthesis. As a result, seeds treated with HBL2 (5 µM L-1) had higher nutritional contents (Mg+2, Zn+2, Na+2, and K+1). HBL2-treated seedlings had higher DPPH and metal tolerance indexes. This led to the conclusion that HBL2 effectively reduced Pb toxicity and improved resistance in lead-contaminated soil.

Optimization of ultrasonic extraction for enhanced polyphenol profile and antioxidant capacity in mango seeds: A comparative study with thermal extraction

The mango seed (MS) is a by-product with a high content of bioactive compounds and antioxidant capacity (AOX). Ultrasound-assisted extraction (UAE) has been recognized as an efficient technology for the extraction of bioactive compounds in plant materials. Nonetheless, it is essential to optimize the process conditions and compared with conventional technologies. The objective of this study was to compare the profile of bioactive compounds and AOX in an optimized ultrasound extract with a thermal extract. The optimized parameters for UAE included exposure to light, 1 s ultrasound pulse, 8 min extraction, 40 % amplitude, 60 °C extraction temperature, 20 % (v/v) ethanol, 35:1 (v/w) liquid-to-solid, and 850 µm particle size and showed gallic acid content of 1.97 mg/g MS. The thermal extract had a higher total soluble phenol content, mainly composed of gallates and gallotannins. Nevertheless, specific compounds, such as maclurin galloyl glucoside and quercetin xyloside, were uniquely identified in the UAE-optimized extract. DPPH and ABTS values were higher in the thermal extract. The half-maximal inhibitory concentration for the thermal treatment was 15.93 mg, while for UAE, it was 19.77 mg GAE/mL. Both thermal and ultrasound mango seed extracts exhibit significant potential as functional ingredients due to their high content of polyphenols and AOX.

Bio-Chemical Factors Associated with Resistance to Aphid, Hyadaphis coriandari (Das) in Fennel at Bikaner, Rajasthan, India

Fennel (Foeniculum vulgare Miller) is a significant spice crop from the Apiaceae family, often referred to as 'saunf,'. Aphid, Hyadaphis coriandari (Das) remained chief constraints in realising potential production and productivity of fennel in arid region. The biochemical characters viz., free amino acids, total soluble sugar and phenol content in different genotypes of fennel were responsible for resistance. The experiment was conducted using a randomized block design and involved ten different fennel varieties with three replications. The plot size was 2.4 x 3.0 meter and inter row and inter plant distance were 40 cm x 20 cm, respectively. The biochemical characters of varieties/entries viz., total soluble sugar, total phenols and free amino acids were estimated during peak aphid population on the crop. The free amino acids content in different varieties varied from 1.05 to 2.93 per cent. The variety RF-205 contained lowest per cent of free amino acid, harbored minimum aphid population and the RF-145 contained highest per cent of free amino acids and had highest aphid population. The RF-205 variety lowest content of TSS (0.90 mg/100g) harbored lowest aphid population (44.40 aphids/plant) and variety AF-2 contained highest 1.14 mg/100g of TSS. That shows least susceptibility against this pest. The total phenol content ranged from 2.33 to 4.55 per cent being minimum in RF-145 and maximum in variety RF-205. Total phenol (r= -0.99) were significantly negatively correlated with peak aphid population.

Characterization and antioxidant capacity of phenolic compounds of jackfruit genotypes from Nayarit, Mexico

Jackfruit is a rich source of phytochemicals, thus offering a broad perspective in developing value-added healthy nutritional foods. This research compares the content of phenolic compounds and antioxidant capacity in different jackfruit genotypes. In the results of total soluble phenols (TSP), the genotype "Agüitada" showed the highest values at the end of storage life (1.43 mg of gallic acid equivalent (GAE)/g in dry weight (DW)), as well as in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with 7.82 mmol of trolox equivalent (TE)/g DW. The "Licenciada" genotype obtained the highest ferric reducing antioxidant power (FRAP) and 2,2′-Azino-bis-(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS•+) assays values, with 244.29 and 12.08 mmol TE/g DW, respectively. Phenolic profiling by high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) quantified 28 phenolic compounds, with shikimic acid being the most abundant in all genotypes; flavonoids were also identified, with epigallocatechin standing out. The results obtained in phenolic profile, TSP and antioxidant capacity showed sufficient evidence of differences among all genotypes. This information will generate interest among consumers and will revalue this developing crop.

Effect of different types of ethylene scavengers used in different combinations, on the post-harvest quality and phytochemicals retention of tomatoes (Solanum lycopersicum L.)

BackgroundRipening of climacteric vegetable, tomato, is a complicated process that results in numerous physiological and biochemical changes, and role of ethylene in this phenomenon is very crucial. Use of different ethylene scavengers can control the post-harvest ripening and quality of tomatoes. In current study, combinations of chemicals as 2% CaCl2 and KMnO4 (T1), 1 mM salicylic acid and KMnO4 (T2), 2% CaCl2 and K2Cr2O7 (T3) and 1 mM salicylic acid and K2Cr2O7 (T4), were tested to study their effect on pH, acidity, total soluble solids (TSS), vitamin C, lycopene, phenolics, flavonoids and antioxidant activity of treated tomatoes, after 30 and 40 days of storage.ResultsWeight loss and titratable acidity were significantly reduced in treated tomatoes, even after 40 days, which were high in untreated tomatoes. Total phenolic contents (TPC), total flavonoid contents (TFC) and vitamin C, were significantly lesser in untreated tomatoes after 30 and 40 days of storage, but use of ethylene scavengers caused increment in these phytochemicals during post-harvest storage, with more prominent results of T1. Highest lycopene was found in T0 (9.76 ± 0.2 mg/100 g), due to fully ripened and spoiled tomatoes, as compared to treated samples, while the lowest value was found in T1 (4.82 ± 0.20 mg/100 g). Highest antioxidant activity was detected in T1 (33.80 ± 0.52%), whereas the lowest antioxidant activity was noticed in T0 (22.00 ± 0.2%).ConclusionFindings revealed that during the storage period, the 50 g KMnO4 sachet + 2% CaCl2 exerted most superior effects than the other treatments, and extended the shelf-life of tomato fruits for up to 40 days, with no quality and phytochemicals deterioration. Therefore, tomatoes could be harvested at breaker stage, to optimize the ripening process during storage, through application of ethylene scavengers.Graphical abstract

Effect of 1-methylcyclopropene on jackfruit with marketing simulation at 8°C

Jackfruit is a tropical fruit and competes with traditional crops such as mango, banana, and pineapple with regard to the quantity exported from the state of Nayarit, Mexico. Because jackfruit is a climacteric fruit with a high respiration rate and ethylene production, it has a limited market due to its short shelf life. The effect of the application of 1-methylcyclopropene (1-MCP) post-harvest to extend the shelf life of jackfruit was studied. Physiologically mature fruits were used and 1-MCP was applied at concentrations of 300, 600, and 1000 nL·L−1; control fruit without treatment was also evaluated. The fruits were stored for 5 days at 8°C and then were stored at 25°C to simulate the commercialization of the fruit. An absolute control group stored permanently at 25°C was used. The following analyses were carried out: physiologic and physicochemical factors, antioxidant capacity, vitamin C, total carotenoids, total soluble phenols, and sensory evaluation of the fruits when ripe. The climacteric peak for the absolute controls and fruit treated with 1-MCP (300, 600, and 1000 nL·L−1) occurred on days 3, 14, 17, and 17 respectively, prolonging the climacteric peak by an average of 13 days. The maximum rates of ethylene production were reported on days 3, 15, 17, and 17 in the same order, prolonging this by an average of 13 days. The treatment with 1-MCP (600 nL·L−1) extended the shelf life of jackfruit by 9 days compared with the absolute control, preserving the physicochemical, phytochemical, and sensory characteristics for up to 17 days of storage, confirming that the application of 1-MCP post-harvest is effective, providing the opportunity to increase the export destinations of Mexican jackfruit.
 Keywords: Jackfruit; 1-Methylcyclopropene; Marketing conditions; Physiologic and physicochemical parameters; Total soluble phenols; Antioxidant capacity

A halotolerant plant growth promoting consortium of Bacillus sp. RB3 and Pseudomonas sp. EB3 primes banana, Musa acuminata cv. Berangan, against salinity and Foc-TR4 stresses

A plant-growth promoting bacterial consortium of halotolerant Bacillus sp. and Pseudomonas sp. was evaluated for the ability to prime banana (Musa acuminata cv. Berangan) plants against abiotic (salinity) and biotic (Foc-TR4) stress challenges. PGPB consortium-primed banana plants showed better growth (plant height, root length and root biomass) and improved physiological parameters (relative water content, chlorophyll, and carotenoid contents) in both stressed conditions compared to non-primed banana plants. In addition, primed banana plants showed a reduction in lipid peroxidation and an increase in proline and antioxidant enzymatic activities (superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and glutathione reductase). In salt-stress conditions (sea salt at 100 mM NaCl equivalent), primed plants showed higher levels of K+, Ca2+, and Mg2+ and lower levels of Cl- and Na+ compared to non-primed salt-stressed plants. Under Foc-TR4 stress, the primed plants showed significant enhancement in the levels of total soluble phenolics, lignin content and defense-related enzyme activities (β-1, 3-glucanase, phenylalanine ammonia lyase, chitinase, polyphenol oxidase, and lipoxygenase). Expression analysis of nine stress-responsive MaWRKY genes (MaWRKY4, MaWRKY23, MaWRKY24, MaWRKY25, MaWRKY28, MaWRKY45, MaWRKY65, MaWRKY89 and MaWRKY145) showed significant upregulation in primed banana plants under salt and Foc-TR4 stresses compared to non-primed plants. These results demonstrate that inoculation with the PGPB consortium improved banana plant growth characteristics and primed WRKY-mediated protection against abiotic and biotic stresses.

Influence of 4-CPA and GA3 on physiological, biochemical and yield attributes of tomato under high-temperature conditions

The present research investigated the impact of plant growth regulators in mitigating the effects of heat stress in tomato (Solanum lycopersicum L.) genotype LST-6 and cultivar Punjab Varkha Bahar-4. In north India, the temperature in the summer season ranges between 25-45 ?C and temperature above 28?C leads to heat stress in plants and negatively affects the reproductive stage of plants. Considering this, we subjected the plants to varying concentrations of GA3 (10, 20, 30 µg/mL) and 4-CPA (15, 45, 75 µg/mL). GA3 application took place three weeks after transplanting, while 4-CPA was administered during the anthesis stage. We recorded observations from both control and treated plants, with a 10-day gap between each spray treatment. The application of plant growth regulators (PGRs) enhanced the plants’ ability to withstand high temperatures by improving photosynthetic efficiency, as evidenced by increased chlorophyll and carotenoid levels in the leaves. The level of different biochemical constituents (total protein, starch, total soluble sugars, phenol and proline content) also increased in PGRs treated plants. Application of GA3 and 4-CPA also enhanced the membrane thermostability and reduced lipid peroxidation. The PGRs treated plants exhibited increased plant height, leaf area, pollen viability, fruit set, number of fruits per plant and fruit weight, ultimately improving yield. GA3 and 4- CPA application also increased the total soluble solids, lycopene content and titratable acidity in tomato fruits. Thus, overall improvement was observed with the application of PGRs; however, 75µg /mL 4-CPA was most effective in imparting thermo tolerance.

Biostimulants as a Means to Alleviate the Transplanting Shock in Lettuce

When transplanting vegetable plants in the field, the transplants undergo a small or large setback in growth, known as transplanting shock. Various practices are commonly applied to reduce the transplanting shock. In the past two decades, several studies have shown that the application of microbial and non-microbial biostimulants can enhance plant tolerance against abiotic stresses. However, there is no information on the effect of applying biostimulants at the time of transplanting in mitigating the transplanting shock of lettuce transplants in the field. Lettuce seedlings transplanted into the soil of an unheated plastic greenhouse were treated with two biostimulants, one microbial (Bactiva®) and one non-microbial (Isabion®), on the day of transplanting and after 14 and 21 days. During production, plant growth, and development, chlorophyll fluorescence and compositional parameters were determined. According to the results, the application of the non-microbial biostimulant had a significant effect on some measured parameters, with the leaves of the treated plants having a higher chlorophyll index (CCI) by 8%, as well as higher fluorescence parameters Fm/Fo, Fv/Fo, and Fv/Fm and area by 7, 10, 3, and 27%, respectively, but fewer total soluble phenols and lower fluorescence parameter ABS/RC by 7 and 26%, respectively, compared to the control untreated ones. The above may constitute some effects on the transplanting shock, without, however, being accompanied by significant effects on the number of leaves/plant, the leaf color parameters (L*, a*, b*, C*, and ho), and the chlorophyll (a, b, a + b), total carotenoid, dry matter, and nitrate content, along with the antioxidant capacity and plant fresh weight at harvest. However, a notable effect was that a greater percentage of plants at harvest had a fresh weight in the 351–400 class, while the greatest percentage of the control plants had a fresh weight in the 301–350 g class. In contrast, the application of the microbial biostimulant had no significant effect on any of the parameters determined compared to the control. Therefore, under the conditions of the present study, the effectiveness of biostimulant application at the time of transplanting on lettuce transplants is questionable.

Aspergillus nomiae and fumigatus Ameliorating the Hypoxic Stress Induced by Waterlogging through Ethylene Metabolism in Zea mays L.

Transient and prolonged waterlogging stress (WS) stimulates ethylene (ET) generation in plants, but their reprogramming is critical in determining the plants' fate under WS, which can be combated by the application of symbiotically associated beneficial microbes that induce resistance to WS. The present research was rationalized to explore the potential of the newly isolated 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing fungal endophytic consortium of Aspergillus nomiae (MA1) and Aspergillus fumigatus (MA4) on maize growth promotion under WS. MA1 and MA4 were isolated from the seeds of Moringa oleifera L., which ably produced a sufficient amount of IAA, proline, phenols, and flavonoids. MA1 and MA4 proficiently colonized the root zone of maize (Zea mays L.). The symbiotic association of MA1 and MA4 promoted the growth response of maize compared with the non-inoculated plants under WS stress. Moreover, MA1- and MA4-inoculated maize plants enhanced the production of total soluble protein, sugar, lipids, phenolics, and flavonoids, with a reduction in proline content and H2O2 production. MA1- and MA4-inoculated maize plants showed an increase in the DPPH activity and antioxidant enzyme activities of CAT and POD, along with an increased level of hormonal content (GA3 and IAA) and decreased ABA and ACC contents. Optimal stomatal activity in leaf tissue and adventitious root formation at the root/stem junction was increased in MA1- and MA4-inoculated maize plants, with reduced lysigenous aerenchyma formation, ratio of cortex-to-stele, water-filled cells, and cell gaps within roots; increased tight and round cells; and intact cortical cells without damage. MA1 and MA4 induced a reduction in deformed mesophyll cells, and deteriorated epidermal and vascular bundle cells, as well as swollen metaxylem, phloem, pith, and cortical area, in maize plants under WS compared with control. Moreover, the transcript abundance of ethylene-responsive gene ZmEREB180, responsible for the induction of the WS tolerance in maize, showed optimally reduced expression sufficient for induction in WS tolerance, in MA1- and MA4-inoculated maize plants under WS compared with the non-inoculated control. The existing research supported the use of MA1 and MA4 isolates for establishing the bipartite mutualistic symbiosis in maize to assuage the adverse effects of WS by optimizing ethylene production.