Application Of Gibberellic Acid Research Articles

Exogenously Applied Gibberellic Acid Alters Cannabinoid Profile in Cannabis sativa L.

Cannabis sativa (C. sativa L.) has garnered significant attention worldwide due to its widespread use as a pharmaceutical agent. With the increasing clinical application of C. sativa and cannabinoid therapeutics, there is strong interest in the development of superior plant varieties and optimisation of growth conditions to enhance secondary metabolite yield. Our RNA sequencing analysis revealed differential expression of hormone-related transcripts in developing C. sativa trichomes, suggesting the involvement of hormone signalling pathways in cannabinoid production. Leveraging the potency of exogenous hormones on plants, this study sought to determine if the application of cytokinin (CK), gibberellic acid (GA) and jasmonic acid (JA) modified trichome morphology and the cannabinoid profile over an 8-week period following the induction of flowering. Exogenous hormone application led to alterations in trichome morphology, with each treatment significantly reducing trichome head width by the final week of assessment. Interestingly, GA application also resulted in a significant reduction in the concentration of Δ-9-tetrahydrocannabinol (THC), Δ-9-tetrahydrocannabinolic acid (THCA), cannabidiol (CBD) and cannabidiolic acid (CBDA) by week 8 post floral induction, however, JA and CK treatment did not consistently modulate the accumulation of these cannabinoids. The minor cannabinoids, cannabidivaranic acid (CBDVA), cannabicyclolic acid (CBLA), cannabicyclol (CBL), cannabichromene (CBC), cannabigerolic acid (CBGA) and cannabigerol (CBG), were also affected by hormone treatments, with varying degrees of accumulation observed. These findings underscore the intricate interplay between phytohormones and secondary metabolite biosynthesis in C. sativa. Our study highlights the potential of hormone modulation as a strategy to enhance cannabinoid yield and offers some insights into the regulatory mechanisms governing cannabinoid biosynthesis in C. sativa trichomes.

Efficiency of paclobutrazol and gibberellic acid in wheat (Triticum aestivum L.) under different doses of nitrogen fertilization

Application of growth regulators like paclobutrazol and gibberellic acid is a suitable way to prevent excessive nitrogen consumption. Therefore, this 2-year research was conducted in Karaj, Iran. This research was laid out in a randomized complete block design with three replications in a split-plot arrangement in 2019–2021. Treatments included nitrogen at three levels: (60, 105 and 150 kg ha−1) which were placed in the main plots. The second factor was the foliar application of growth regulators at three levels: [gibberellic acid (100 ppm), paclobutrazol (200 ppm) and control]. The results showed that application of paclobutrazol and gibberellic acid raised super wheat yield and quality compared to control. The highest biological yield (27.67 ton ha−1), was observed in the interaction of nitrogen 150 kg ha−1 + gibberellic acid in the second year, which was the same with nitrogen 150 kg ha−1 + gibberellic acid in the first year and also interaction of nitrogen 150 kg ha−1 + paclobutrazol in the second year. The highest grain protein (14.69%) was seen in nitrogen 150 kg ha−1 + gibberellic acid in the second year and nitrogen 150 kg ha−1 + gibberellic acid in the first year. Growth regulators usage and increasing the nitrogen content (150 kg ha−1), improved the yield and grain quality of wheat. Therefore, the interaction of nitrogen 150 kg ha−1 + gibberellic acid and nitrogen 150 kg ha−1 +paclobutrazol, were the best treatments of this study, due to the creation of suitable environmental conditions for wheat, and these treatments can be suggested to the farmers.

Determination of the Effects of Aminoethoxyvinilglycine (AVG) and Gibberellic Acid (GA3) Applications on Pre-Harvest Fruit Drop Amount and Fruit Quality in Hakko Pear Cultivar

This study was conducted to determine the effects of pre-harvest Aminoethoxyvinylgylcine (AVG) and Gibberellic acid (GA3) applications on the pre-harvest fruit drop amount and fruit quality in the 'Hakko' pear (Pyrus pyrifolia) cultivar grafted on BA29 rootstock in a private orchard in the Bala district of Ankara in 2021-2022. It was conducted in an orchard belonging to a producer. 50-100-150 mg/l AVG and 25-50-75 mg/l GA3 were applied 4 weeks before the estimated harvest date. Fruits are harvested at full maturity date; Pomological properties such as cumulative drop percentage, yield, fruit weight, fruit width and length, fruit stem width and length, fruit flesh firmness, fruit color, and chemical properties such as soluble solids content (SSC), pH and titratable acidity (TA) were evaluated. It was observed that all doses of AVG and GA3 during the harvest period reduced the cumulative casting rate compared to the control application (6.78%). In general, the yield per tree was found to be high in GA3 applications. In both AVG and GA3 applications, its effects on fruit weight, fruit width and length, fruit flesh firmness, SSC and pH were found to be statistically significant. It was observed that in both AVG and GA3 applications, the amount of fruit drop pre-harvest decreased and fruit quality characteristics were better than the control.

Foliar application of IAA and GA3 on growth and yield attributes of mungbean (Vigna radiata L. R. Wilczek)

A field experiment was conducted to assess the effects of foliar application of Indole acetic acid (IAA) and Gibberellic acid (GA3) on the growth and yield of mungbean (BARI Mung-6) plants. Nine treatments were administered, including various concentrations of IAA and GA3, applied individually and in combination. The experiment followed a randomized complete block design (RCBD) with three replications, data were recorded on growth and yield parameters at 30 days after sowing (DAS) and at harvest. Results indicated that treatment T8 (IAA 50 mg/l + GA3 50 mg/l) significantly enhanced growth and yield attributes. Notably, T8 exhibited the highest values for plant height (57.50 cm), number of leaves per plant (47.33), number of branches per plant (7.67), chlorophyll content (55, SPAD value), shortest duration to 80% flowering (27.33) with 80% pod maturity (55.33), number of pods per plant (37.67), pod length (14.99 cm), number of seeds per pod (13.78), weight of 1000 seeds (54.95 g), seed yield (1.68 t/ha), biological yield (3.52 t/ha), and harvest index (47.73%). Conversely, the untreated control (T0) exhibited the lowest performance across all parameters. Therefore, foliar application of IAA and GA3, particularly at 50 mg/l concentration each, demonstrated significant improvements in growth, yield, and related attributes of mungbean. Bangladesh J. Bot. 53(3): 459-464, 2024 (September)

Effect of D-mannitol and Gibberellic Acid on Physiological Parameters, Early Seedling Growth Characteristics, and Some of the Most Important Chemical Components of Barberry (Berberis vulgaris L.)

Background: One of the important medicinal plants and agricultural products in Asia, particularly in Iran, is barberry, and both salinity and drought can cause osmotic or ionic imbalance in plant cells. In order to study the impacts of D-Mannitol and gibberellic acid on seed germination, physiological parameters, early seedling growth characteristics, and some of the most important chemical ingredients of barberry, one experiment is designed. Methods: The experimental design was Completely Randomized Design (CRD) with three replicates, and drought stress was done by D-mannitol at various stress levels, namely, 0 MPa, 40 MPa, and 80 MPa, and the reaction of studied cultivar was assessed on the basis of experimental characteristics associated to germination and seedling growth, and Gibberellic acid treatments were 0 mgL-1, 300 mgL-1, 600 mgL-1, and 900 mgL-1. Results: The effects of D-mannitol were significant in germination percentage, germination rate, seedling vigor index, chlorophyll a, total chlorophyll, leaf dry weight and total sugar. Experimental treatments such as germination percentage, germination rate, and total chlorophyll were also influenced by the application of gibberellic acid. The interaction between D-mannitol and gibberellic acid had significant effect on peroxidase activity. The highest germination percentage, germination rate, seedling vigor index, catalase activity, peroxide activity, and Chlorophyll a were obtained for 0 MPa application of D-Mannitol, followed by usage of 40 MPa, and 80 Mpa, respectively. The maximum total chlorophyll, relative water content, and leaf dry weight were also related to control treatment (0 MPa D-Mannitol), while the higher values of proline content, carotenoids and total sugar were obtained for 80 MPa application of D-Mannitol. The maximum values of germination rate, germination percentage, seedling vigor index, peroxidase activity, and chlorophyll a were related to control treatment (0 mgL-1 gibberellic acid), and the highest CAT activity was related to the application of 300 mgL-1 gibberellic acid. The highest total chlorophyll content and relative water content were related to 0 mgL-1 gibberellic acid, while the maximum praline content and leaf dry weight were obtained for the application of 600 mgL-1 and 0 mgL-1 gibberellic acid. There was not any significant difference in carotenoids between gibberellic acid treatments, while the application of 900 mgL-1 gibberellic acid obtained the highest value of total sugar of barberry. Conclusion: Conclusively, on the basis of the results, the application of 80 MPa D-Mannitol and 600 mgL-1 could be recommended as they can increase the absorption of nutrients and water.

The crosstalk interaction of ethylene, gibberellins, and arbuscular mycorrhiza improves growth in salinized tomato plants by modulating the hormonal balance

Ethylene (ET) and gibberellins (GAs) play key roles in controlling the biotic and abiotic interactions between plants and environment. To gain insights about the role of ET and GAs interactions in the mycorrization and response to salinity of tomato (Solanum lycopersicum L.) plants, the ET-insensitive (Never-ripe, Nr), and the ET-overproducer (Epinastic, Epi) mutants and their wild type cv. Micro-Tom (MT), were inoculated or not with the arbuscular mycorrhizal fungi (AMF) Rhizophagus irregularis and exposed to control (0 mM NaCl) and salinity (100 mM NaCl) conditions, with and without gibberellic acid (10−6 M GA3) application during four weeks. Exogenous GA3 enhanced plant growth irrespective of the genotype, AMF, and salinity conditions, while an additional effect on growth by AMF was only found in the ET-overproducer (Epi) mutant under control and salinity conditions. Epi almost doubled the AMF colonization level under both conditions but was the most affected by salinity and GA3 application compared to MT and Nr. In contrast, Nr registered the lowest AMF colonization level, but GA3 produced a positive effect, particularly under salinity, with the highest leaf growth recovery. Foliar GA3 application increased the endogenous concentration of GA1, GA3, and total GAs, more intensively in AMF-Epi plants, where induced levels of the ET-precursor ACC were also found. Interestingly, GA4 which is associated with AMF colonization, registered the strongest genotype x GA x AMF × salinity interactions. The different growth responses in relation to those interactions are discussed.

Sexual and Asexual Propagation of Wild Lime (Zanthoxylum fagara L. Sarg.), a Native Florida Plant with Ornamental and Ecological Value

Abstract A series of four propagation studies were implemented to better understand the seed biology of wild lime (Zanthoxylum fagara L. Sarg. [Rutaceae]) and its adventitious rooting response to auxin treatments. Plant origin (north central vs south Florida ecotypes) did not affect initial seed viability but significantly influenced germination response to seasonal temperatures. Fifty-five days after sowing north central Florida seeds, germination was similar among spring, summer and fall treatments (28.9 to 41.1%), but was reduced by the winter temperature (10.7%). South Florida seeds showed greatest germination under the fall temperature (71.2%), and the least germination under the summer temperature (30.2%). Additional seed treatments including applications of gibberellic acid (GA3) with kinetin nominally improved germination by 1.2 times compared to non-treated seed. Seeds tolerated cryopreservation treatments, including combinations of a plant vitrification solution, liquid nitrogen, phloroglucinol and precooling, suggesting long-term storage capability. As an alternative to seed propagation, cutting propagation was found to be a reliable means of reproducing wild lime with 91.0% rooting success when softwood cuttings were treated with 8,000 mg·kg−1 (0.13 oz·lb−1) indole-butyric acid (IBA), compared to 3,000 mg·kg−1 (0.05 oz·lb−1) IBA (86.3%) or the non-treated control (71.2%). Species used in this study: Wild lime, Zanthoxylum fagara (L. Sarg). Chemicals used in this study: 2,3,5-triphenyl-2H-tetrazolium chloride (TZ); sodium hypochlorite solution (Clorox bleach); gibberellic acid (GA3); kinetin (kinetin), plant vitrification solution 2 (PVS2); liquid nitrogen (LN); phloroglucinol (phloroglucinol); glycerol (glycerol); dimethyl sulfoxide (DMSO); MS media (Murashige and Skoog media), sucrose (sucrose); 15N-5P-15K liquid fertilizer (Peters Excel Cal-Mag Special); indole-3-butyric acid (IBA); 14N-14P-14K slow-release fertilizer (Osmocote).

Mitigation of salinity-induced adverse effects through exogenous application of gibberellic acid in turnip ( Brassica rapa L.)

Mitigation of salinity-induced adverse effects through exogenous application of gibberellic acid in turnip ( <i>Brassica rapa</i> L.)

Effect of foliar application of plant growth regulators on incidence of insect-pests and diseases in autumn planted seed potato (Solanum tuberosum)

A field experiment was conducted during 2019–20 and 2020–21 at Punjab Agricultural University, Ludhiana, Punjab to study the effect of foliar application of plant growth regulators on insect-pest and disease incidence in potato (Solanum tuberosum L.) under subtropical conditions. A total of 11 treatments including control were tested in a randomized complete block design (RCBD) with three replications on the potato cv. Kufri Pukhraj. The results indicated that plant growth regulators, like GA3, IBA, NAA, ethrel, jeevamrit and waste decomposer were not producing any significant effect on the incidence of aphid, jassid and whitefly population in comparison to untreated control. However, diseases such as scab and scurf did not reveal any significant differences among the plant growth regulator’s treatments except in late blight. Foliar application of gibberellic acid (200 ppm) at 45 and 60 days after sowing (DAS) significantly reduced the late blight incidence and severity in seed potato cv. Kufri Pukhraj.

Advances in Gibberellic Acid Application in Cropping

Advances in Gibberellic Acid Application in Cropping

Morphological Changes to Fruit Development Induced by GA3 Application in Sweet Cherry (Prunus avium L.).

Cherry (Prunus avium) fruits are important sources of vitamins, minerals, and nutrients in the human diet; however, they contain a large stone, making them inconvenient to eat 'on the move' and process. The exogenous application of gibberellic acid (GA3) can induce parthenocarpy in a variety of fruits during development. Here, we showed that the application of GA3 to sweet cherry unpollinated pistils acted as a trigger for fruit set and permitted the normal formation of fruit up to a period of twenty-eight days, indicating that gibberellins are involved in the activation of the cell cycle in the ovary wall cells, leading to fruit initiation. However, after this period, fruit development ceased and developing fruit began to be excised from the branch by 35 days post treatment. This work also showed that additional signals are required for the continued development of fully mature parthenocarpic fruit in sweet cherry.

Effects of Kinetin and Gibberellic Acid on Growth and Ion Transport of Rice Under Cadmium Stress

An experiment was conducted to analyze the effects of kinetin and gibberellic acid on growth, and ion transport of rice (Oryza sativa var. BRRI-80) under cadmium stress. Exogenous application of both kinetin (2 µM) and gibberellic acid (1 µM) alleviated the negative effects of cadmium (Cd) on growth parameters by enhancing the length of both root and shoot, and biomass of Cd stressed rice plants grown on sand culture. Kinetin and GA3 caused decrease in Na+ accumulation while increasing K+ accumulation in both root and shoot. Accumulation of NO3- and PO43- were improved under cadmium stress by kinetin and GA3 in cadmium stressed rice plants. In addition to this, kinetin and GA3 reduced Cd accumulation in the root and shoot of cadmium stressed rice plants. Both kinetin and gibberellic acid were found effective in improving relative water contents in shoots of cadmium stressed rice plants. Bangladesh J. Bot. 53(2): 209-216, 2024 (June)

Interacting effects of phytohormones and fruit pruning on the morpho-physiological and biochemical attributes of bell pepper

Several factors, such as pruning and phytohormones, have demonstrated an influence on both the quantity and quality in the bell pepper. A factorial experiment using a completely randomized design was conducted on the Lumos yellow bell in a greenhouse. Treatments were the fruit pruning (0, 10, and 30%) and foliar application of phytohormones auxin (AUX) and gibberellic acid (GA3) at concentrations of 10 µM AUX, 10 µM GA3, 10 µM AUX + 10 µM GA3+, and 20 µM AUX + 10 µM GA3 along with controls. The plants were sprayed with phytohormones in four growth stages (1: flowering stage when 50% of the flowers were on the plant, 2: fruiting stage when 50% of the fruits were the size of peas, 3: fruit growth stage when 50% of the fruits had reached 50% of their growth, and 4: ripening stage when 50% of the fruits were at color break). The results of the present investigation showed that pruning rate of 30% yielded the highest flesh thickness and vitamin C content, decreased seed count and hastened fruit ripening. The use of GA3 along with AUX has been observed to augment diverse fruit quality characteristics. According to the results, the application of 10% pruning in combination with 20 µM AUX and 10 µM GA3 demonstrated the most significant levels of carotenoids, chlorophyll, and fruit length. The experimental group subjected to the combined treatment of 30% pruning and 10 µM AUX + 10 µM GA3 showed the most noteworthy levels of vitamin C, fruit weight, and fruit thickness. The groups that received the 10 µM GA3 and 20 µM AUX + 10 µM GA3 treatments exhibited the most favorable fruit flavor. According to the research results, the implementation of hormonal treatments 10 µM AUX and 10 µM AUX + 10 µM GA3 in combination with a 30% pruning strategy resulted in the most advantageous yield of bell peppers.

Improving growth of Solanum melongena L. exposed to lead (Pb) stress using gibberellic acid in combination with Agrobacterium fabrum

Lead (Pb), as heavy metal, poses substantial threats to plant health, impeding growth, disrupting nutrient uptake, and inducing oxidative stress. Its interference with crucial processes such as photosynthesis and water uptake, combined with its capacity to accumulate in plant tissues, results in stunted development and compromised overall productivity. To address this issue, the application of gibberellic acid (GA3) emerges as an effective amendment, promoting seed germination, stem elongation, and flowering. Additionally, the inoculation of rhizobacteria, specifically Agrobacterium fabrum (A. fabrum), offers resistance, improved nutrient uptake, and enhanced growth under conditions of heavy metal toxicity. Therefore, the present study was designed to investigate the impact of GA3 and A. fabrum on Solanum melongena L. cultivated under Pb toxicity. The experiment comprised four treatments: control, A. fabrum, 30 mg/L GA3 (30GA3), and A. fabrum + 30GA3, applied in four replications following a completely randomized design. Results indicated that A. fabrum + 30GA3 significantly enhanced Solanum melongena L. shoot and root length, fresh and dry weight over the control under Pb stress. Furthermore, a notable increase in Solanum melongena L. chlorophyll contents, stomatal conductance, transpiration rate, and photosynthetic rate over the control under Pb stress validated the effectiveness of A. fabrum + 30GA3. Additionally, improvements in N, P, and K concentration in roots and shoots confirmed the efficacious functioning of A. fabrum + 30GA3 from the control under Pb stress. In conclusion, A. fabrum + 30GA3 is recommended as an amendment for the mitigation of Pb stress in Solanum melongena L.

Effect of methyl jasmonate and GA3 on canola (Brassica napus L.) growth, antioxidants activity, and nutrient concentration cultivated in salt-affected soils

Salinity stress is a significant challenge in agricultural production. When soil contains high salts, it can adversely affect plant growth and productivity due to the high concentration of soluble salts in the soil water. To overcome this issue, foliar applications of methyl jasmonate (MJ) and gibberellic acid (GA3) can be productive amendments. Both can potentially improve the plant’s growth attributes and flowering, which are imperative in improving growth and yield. However, limited literature is available on their combined use in canola to mitigate salinity stress. That’s why the current study investigates the impact of different levels of MJ (at concentrations of 0.8, 1.6, and 3.2 mM MJ) and GA3 (0GA3 and 5 mg/L GA3) on canola cultivated in salt-affected soils. Applying all the treatments in four replicates. Results indicate that the application of 0.8 mM MJ with 5 mg/L GA3 significantly enhances shoot length (23.29%), shoot dry weight (24.77%), number of leaves per plant (24.93%), number of flowering branches (26.11%), chlorophyll a (31.44%), chlorophyll b (20.28%) and total chlorophyll (27.66%) and shoot total soluble carbohydrates (22.53%) over control. Treatment with 0.8 mM MJ and 5 mg/L GA3 resulted in a decrease in shoot proline (48.17%), MDA (81.41%), SOD (50.59%), POD (14.81%) while increase in N (10.38%), P (15.22%), and K (8.05%) compared to control in canola under salinity stress. In conclusion, 0.8 mM MJ + 5 mg/L GA3 can improve canola growth under salinity stress. More investigations are recommended at the field level to declare 0.8 mM MJ + 5 mg/L GA3 as the best amendment for alleviating salinity stress in different crops.

The effect of pre-harvest salicylic acid and gibberellic acid applications on-tree storability in ‘Satsuma’ mandarins (Citrus unshiu Marc.)

Objective: Satsuma mandarin (Citrus unshiu Marc.), an important export product for Türkiye, is kept on the tree until the beginning of January. This study aimed to determine the effects of single and co-application of salicylic acid (SA) and gibberellic acid (GA3) on the storability of Satsuma mandarin on trees. &#x0D; Material and Methods: For this purpose, 20 ppm GA₃ two weeks before the color break period, 2 mM SA, and 1.5 ml/L Rezist at the color break period were applied alone and together to Satsuma mandarin fruit. Those without treatment were accepted controls. Various measurements and analyses were made in the samples taken at monthly intervals during storage on the tree. &#x0D; Results: It was harvested in three periods at approximately one-month intervals from the beginning of November. The applications of SA or GA₃ alone or together limited the fruit drop rate during on-tree storage, the increase in the shell thickness, and the decrease in the specific gravity. Applications involving GA₃ delayed the coloration of fruits. The maturity index of the fruits treated with Resist and GA₃ in the first harvest was lower. &#x0D; Conclusion: The results showed that the pre-harvest applications of Satsuma mandarin would have positive contributions to the storage of fruits on the tree until the beginning of January by preventing fruit drop, and delaying the peel and fruit aging.

Exogenous application of gibberellic acid reduces antioxidant capacity of leaves, resulting in increased Tipburn damages in Lisianthus cultivars

Tipburn (calcium (Ca) deficiency disorder of new leaf tips) is a severe problem in horticultural crop production. Studies have focused on the fact that tipburn commonly occurs during bolting and shown that plants exhibited greater tipburn damage than the control when bolting was induced using exogenous gibberellic acid (GA). However, why exogenous GA application enhances tipburn damage and why tipburn occurs during bolting remains unclear. To address this knowledge gap, we investigated the occurrence of tipburn, Ca concentrations in each organ, antioxidant capacity (superoxide dismutase (SOD) and catalase activity), and gene expression in three lisianthus cultivars (‘Umihonoka’ (UH), ‘Reina White’ (RW), and ‘Voyage Peach’ (VP)), where bolting was induced through exogenous active GA application (GA treatment) and discussed the cause of tipburn occurring during bolting. The incidence and severity of tipburn in the GA treatment were significantly higher than those in the control group in all cultivars. The Ca concentrations in the top leaves of the GA treatment were similar to or higher than those in the control treatment for all cultivars. In contrast, SOD activity in VP was significantly lower in GA treatment than that in the control, which was consistent with the results of SOD-CuZn expression. Additionally, significantly lower catalase activity at GA treatment were detected in the UH and RW than at the control. Recent studies have reported that reactive oxygen species and antioxidants significantly affect the appearance of blossom-end rot. Therefore, exogenous GA application decreased the antioxidant capacity of the upper leaves, resulting in increased tipburn damage. In addition, it is known that a decrease in antioxidant capacity and an increase in H2O2 concentration in leaves of Arabidopsis is a trigger for the initiation of bolting. Our findings provide important insight into the causes and ecological implications of tipburn during bolting.

Exogenously applied gibberellic acid and benzylamine modulate growth and chemical constituents of dwarf schefflera: a stepwise regression analysis

Ornamental foliage plants that have a dense appearance are highly valued. One way to achieve this is by using plant growth regulators as a tool for plant growth management. In a greenhouse with a mist irrigation system, a study was conducted on dwarf schefflera, an ornamental foliage plant, which was exposed to foliar application of gibberellic acid and benzyladenine hormones. The hormones were sprayed on dwarf schefflera leaves at 0, 100, and 200 mg/l concentrations, at 15-day intervals in three stages. The experiment was conducted as a factorial based on a completely randomized design, with four replicates. The combination of gibberellic acid and benzyladenine at 200 mg/l concentration had a significant effect on leaf number, leaf area, and plant height. The treatment also resulted in the highest content of photosynthetic pigments. Furthermore, the highest soluble carbohydrate to reducing sugars ratio was observed in treatments of 100 and 200 mg/l benzyladenine, and 200 mg/l gibberellic acid + benzyladenine. Stepwise regression analysis showed that root volume was the first variable to enter the model, explaining 44% of variations. The next variable was root fresh weight, and the two-variable model explained 63% of variations in leaf number. The greatest positive effect on leaf number was related to root fresh weight (0.43), which had a positive correlation with leaf number (0.47). The results showed that 200 mg/l concentration of gibberellic acid and benzyladenine significantly improved morphological growth, chlorophyll and carotenoid synthesis, and reducing sugar and soluble carbohydrate contents in dwarf schefflera.

Mitigation of cadmium-induced stress in maize via synergistic application of biochar and gibberellic acid to enhance morpho-physiological and biochemical traits

Cadmium (Cd), being a heavy metal, tends to accumulate in soils primarily through industrial activities, agricultural practices, and atmospheric deposition. Maize, being a staple crop for many regions, is particularly vulnerable to Cd contamination, leading to compromised growth, reduced yields, and potential health risks for consumers. Biochar (BC), a carbon-rich material derived from the pyrolysis of organic matter has been shown to improve soil structure, nutrient retention and microbial activity. The choice of biochar as an ameliorative agent stems from its well-documented capacity to enhance soil quality and mitigate heavy metal stress. The study aims to contribute to the understanding of the efficacy of biochar in combination with GA3, a plant growth regulator known for its role in promoting various physiological processes, in mitigating the adverse effects of Cd stress. The detailed investigation into morpho-physiological attributes and biochemical responses under controlled laboratory conditions provides valuable insights into the potential benefits of these interventions. The experimental design consisted of three replicates in a complete randomized design (CRD), wherein soil, each containing 10 kg was subjected to varying concentrations of cadmium (0, 8 and 16 mg/kg) and biochar (0.75% w/w base). Twelve different treatment combinations were applied, involving the cultivation of 36 maize plants in soil contaminated with Cd (T1: Control (No Cd stress; T2: Mild Cd stress (8 mg Cd/kg soil); T3: Severe Cd stress (16 mg Cd/kg soil); T4: 10 ppm GA3 (No Cd stress); T5: 10 ppm GA3 + Mild Cd stress; T6: 10 ppm GA3 + Severe Cd stress; T7: 0.75% Biochar (No Cd stress); T8: 0.75% Biochar + Mild Cd stress; T9: 0.75% Biochar + Severe Cd stress; T10: 10 ppm GA3 + 0.75% Biochar (No Cd stress); T11: 10 ppm GA3 + 0.75% Biochar + Mild Cd stress; T12: 10 ppm GA3 + 0.75% Biochar + Severe Cd stress). The combined application of GA3 and BC significantly enhanced multiple parameters including germination (27.83%), root length (59.53%), shoot length (20.49%), leaf protein (121.53%), root protein (99.93%), shoot protein (33.65%), leaf phenolics (47.90%), root phenolics (25.82%), shoot phenolics (25.85%), leaf chlorophyll a (57.03%), leaf chlorophyll b (23.19%), total chlorophyll (43.77%), leaf malondialdehyde (125.07%), root malondialdehyde (78.03%) and shoot malondialdehyde (131.16%) across various Cd levels compared to the control group. The synergistic effect of GA3 and BC manifested in optimal leaf protein and malondialdehyde levels indicating induced tolerance and mitigation of Cd detrimental impact on plant growth. The enriched soils showed resistance to heavy metal toxicity emphasizing the potential of BC and GA3 as viable strategy for enhancing maize growth. The application of biochar and gibberellic acid emerges as an effective means to mitigate cadmium-induced stress in maize, presenting a promising avenue for sustainable agricultural practices.

Exogenous gibberellin improves the yield and quality of basil (Ocimum basilicum L.) and chervil (Anthriscus cerefolium L.) plants grown under salinity stress conditions

Gibberellins play a crucial role as plant hormones in the regulation of various aspects of plant growth and development. They are involved in processes such as seed germination, breaking plant and bud dormancy, and counteracting the effects of auxin. Additionally, gibberellins promote leaf expansion, stimulate stem elongation, and contribute to flower development and fruit set. The objective of this study was to investigate the effects of gibberellic acid (GA3) treatments (T0: 0 ppm, T1: 1 ppm, and T2: 10 ppm) on the growth regulation and physiological parameters of basil and chervil plants under salinity stress conditions (150 mM NaCl). The study explored various growth outcomes and biochemical parameters, including chlorophyll, proteins, soluble sugars, proline, and nitrate. The results indicate that the application of gibberellic acid alleviated the adverse effects of high salinity and resulted in enhanced biomass production. In comparison to the control treatment, foliar surface values for basil and chervil increased by 15% and 35%, respectively, in T2. Moreover, root lengths of basil and chervil reached their highest values in T2, showing a 16% increase for basil and a 33% increase for chervil. Carotenoid levels were positively influenced by GA3 treatments, reaching high concentrations in T2, exceeding T0 levels by 41% for basil and 83% for chervil. Additionally, under T2 treatment, protein and glucose levels increased by factors of 2.7 and 1.7, respectively, in basil plants and by factors of 2.1 and 1.7, respectively, in chervil plants. The application of gibberellic acid led to a 33% reduction in proline content for basil and a 27% reduction for chervil compared to the T0 treatment.