Optimized production of gibberellic acid via Box-Behnken design and artificial neural networks: a sustainable approach for enhancing paddy crop growth.

Influence of CCC on the content of gibberellic acid in cerealsIn green cereal plants from pot and seedling experiments the effect of CCC‐treatment upon the plants' contents of gibberellic acid (GA3) respectively upon gibberellic acid synthesis was examined. Methanol extracts were extracted at pH 2.6–2.8 with ethyl acetate and with n‐butanol. Gibberellic acid was identified and isolated from both extracts by thin‐layer chromatography. Its biological activity was examined by means of the dwarf pea test (kleine Rheinländerin). The results may be summarized as follows: CCC treatment decreased the content of gibberellic acid in all cereals tested. Together with the decrease of stalk length the gibberellic acid contents diminished. Treatment of cereals with authentic gibberellic acid (GA3) increased stalk length even after CCC‐treatment. Thus the physiological effect of added gibberellic acid was not influenced by CCC. Cancelling of CCC effects by treatment with gibberellic acid suggests, that between both compounds does not exist a competitive inhibition. CCC‐treatment decreased the content of gibberellic acid (GA3) in all experiments, however the gibberellic acid synthesis was probably not completely stopped under the conditions of this experiment (50 to 150 mg CCC per pot). Gibberellic acid (GA3) was rarely found in n‐butanol extracts but mainly in ethyl acetate extracts.

Paecilomyces sp. ZB is a cell factory for the production of gibberellic acid using a cheap substrate in solid state fermentation.

Biosynthesis of gibberellic acid from milk permeate in repeated batch operation by a mutant Fusarium moniliforme cells immobilized on loofa sponge

The effect of temperature on alpha-amylase synthesis and secretion from barley (c.v. Himalaya) half-seeds and aleurone layers is reported. Barley half-seeds incubated at 15 C in gibberellic acid (GA) concentrations of 0.5 and 5 micromolar for 16 hours do not release alpha-amylase. Similarly, isolated aleurone layers of barley do not release alpha-amylase when incubated for 2 or 4 hours at temperatures of 15 C or below following 12 hours incubation at 25 C at GA concentrations from 50 nanomolar to 50 micromolar. There is an interaction between temperature and GA concentration for the process of alpha-amylase release from aleurone layers; thus, with increasing GA concentration, there is an increase in the Q(10) of this process. A thermal gradient bar was used to resolve the temperature at which the rate of alpha-amylase release changes; thermal discontinuity was observed between 19 and 21 C. The time course of the response of aleurone tissue to temperature was determined using a continuous monitoring apparatus. Results show that the effect of low temperature is detectable within minutes, whereas recovery from exposure to low temperature is also rapid. Although temperature has a marked effect on the amount of alpha-amylase released from isolated aleurone layers, it does not significantly affect the accumulation of alpha-amylase within the tissue. At all GA concentrations above 0.5 nanomolar, the level of extractable alpha-amylase is unaffected by temperatures between 10 and 28 C. It is concluded that the effect of temperature on alpha-amylase production from barley aleurone layers is primarily on the process of enzyme secretion.

Auxin and GA signaling play important roles in the maize response to phosphate deficiency

Gibberellic acid production using Fusarium moniliforme, isolated from wilted sugarcane plant has been investigated by solid state fermentation (SSF). The gibberellic acid production of 154mgm/gm was obtained on commercial wheat bran (CWB) mineral salt acid bed in 500 ml flasks after 168 h incubation. The gibberellic acid production rate was about 0.6 to 0.9 mgm/gm/hr during 96 to 168 h. Different carbon sources namely sucrose, lactose, maltose, soluble starch, glycerol, wheat flour and maize flour were tested as an additional substrate along with CWB at the concentration of 25% w/w or v/w base to observe its effects on gibberellic acid production. Soluble starch has been proved the best additional carbon source for gibberellic acid production, which yielded 1160mgm/gm of gibberellic acid after 168 h. Similarly, various nitrogen sources namely NH4Cl, NH4NO3, (NH4)2SO4, (NH4)MoO4 and urea were tested as an additional substrate at the concentration of 0.07% w/w of CWB. Urea was proved as the best nitrogen source which yielded 532 mgm/gm of gibberellic acid after 168 h incubation. We have observed about 7.5-fold and 3.5-fold increase in gibberellic acid production upon addition of soluble starch and urea respectively, in CWB using Fusarium moniliforme.Int J Appl Sci Biotechnol, Vol 4(3): 402-407

Control of seed germination in the shade

Tulip (Tulipa gesneriana L.) is an important and highly valuable flower of the cut flower industry. The most critical step in its cultivation is to break dormancy in order to initiate the growth, especially in tropical and sub-tropical areas of the world. Therefore, the current research was conducted to break bulb dormancy and foster the growth of tulip in Potohar region with the help of different primers. The objective of this study was the selection of best primer at appropriate concentration level to enhance growth, yield and vase life of the flower. Tulip bulbs were treated with different primers: T0 (distilled water), T1 (chitosan @ 5 g/L), T2 (gibberellic acid @ 0.15 g/L), T3 (humic acid 160 g/L), T4 (imidacloprid 19 g/L) and T5 (salicylic acid 0.1 g/L) for 24 hours, respectively. The experiment was laid out using Complete Randomized Design (CRD) with three replications. Statistical results revealed that characteristics including early germination, plant height, number of leaves, stalk length, fresh and dry weight of flower, weight of bulbs, diameter of bulbs and number of daughter bulbs were significantly increased in T2. Whereas, leaf area, diameter of stem and flower was maximum in T0. Plants under T3 showed an increase in chlorophyll content of leaves. While floral characteristics like early formation and opening of flower bud, more number of flowers and vase life were improved in T1. Thus, statistical results showed that priming can effectively help to improve morpho-physiological attributes of tulip.

To examine the production of gibberellic acid by selected morphological mutants of Gibberella fujikuroi in liquid cultures. Mutants of G. fujikuroi having different morphological characteristics were selected after UV irradiation. The production of gibberellic acid by mutants that had different hyphal lengths was examined in shake flasks in media with different concentrations of nutrients as well as different volumes of the medium. Fed-batch fermenter study was performed to evaluate the mutant Mor-25 for growth and production of gibberellic acid. The broth was analysed by high performance liquid chromatography for fusaric acid, the common mycotoxin produced by strains of Fusarium. A variety of morphological mutants having different mycelial and soluble pigmentation as well as colony morphologies were generated from G. fujikuroi upon exposure to UV radiation. A nonpigmented mutant (Car-1) was selected as intermediate parent and later, mutants Mor-1 and Mor-25 were selected based on their distinct morphology. The colonies on regeneration agar plates were small, compact and dry. In liquid medium, mutant Mor-25 grew in a micro-pelleted form and the mycelium had short, highly branched hyphae, curly at tips with thick, swollen cells. Mutant Mor-25 grew rapidly in a low-cost medium containing defatted groundnut flour, sucrose and salts. In media with higher nutrient concentrations as well as larger volumes, it produced twofold more gibberellic acid than the parent. Fusaric acid, the common mycotoxin, was absent in the fermentation broth of mutant Mor-25. The mutants have been deposited in National Collection of Industrial Microorganisms (NCIM), National Chemical Laboratory, Pune, India under following culture collection numbers (Car-1, NCIM 1323; Mor-1, NCIM 1322; and Mor-25, NCIM 1321). Growth of unpigmented, morphological mutants of G. fujikuroi that led to lower viscosity in fermentation broth resulted in increased production of gibberellic acid. The use of morphological mutants that have lower viscosity in liquid cultures for gibberellic acid production is not reported earlier. Similar mutants can be useful for other types of fungal fermentations also.

Two local strains of Fusarium moniliforme, were isolated from leaves and roots of maize plant. The two strains were compared for gibberellic acid production. The production of gibberellic acid by the local strain (1) was higher than strain (2). The strain (1) of F. moniliforme was chosen for the later experiments. The effects of culture components and conditions were studied at aiming to improve gibberellic acid production by the local strain (1). The optimum incubation period for the highest production of gibberellic acid was 9 days. The glucose, as a carbon source, gave the highest production of gibberellic acid reached 91.13 mg/liter especially at the concentration 2%. Ammonium nitrate, as a nitrogen source, gave the higher production of gibberellic acid reached 94.55 mg/liter and at the concentration 3 gm/liter. The technology of the spectrophotometer was used for the quantitative evaluation for gibberellic acid in the samples and at the wase longitude of 254 nanometer.

Using high performance liquid chromatography, the content of gibberellic acid (GA) and abscisic acid (ABA) was examined in white ash seeds (Fraxinus americana) ranging in age from 1 to 10 years. The youngest seeds exhibited the highest level of GA, after which the GA content decreased rapidly. The greatest concentration of ABA was found in 4-yrold seed. Germination tests showed that germination rate could be enhanced in older seeds with lower concentrations of exogenous GA. Furthermore, the germination of seeds receiving no exogenous GA showed a high positive correlation to fluctuations in the endogenous GA:ABA ratio. Thus, the initiation of germination in white ash seeds appears to be affected by the relative concentrations of these two hormones.

Changes in plant hormones and metabolites in long-shoot stems of interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) during cone induction by gibberellic acid (GA) treatment were analyzed by high performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple reaction monitoring mode. A mixture of GA(4) and GA(7), including small amounts of GA(3) and GA(1), was stem-injected into each tree in amounts of 0, 4, 40 or 400 mg. One week after injection, concentrations of GA(4), GA(7) and GA(3) were elevated in all GA-treated samples. The ratio of GA(4) to GA(7) decreased significantly at Week 3. Absolute concentrations of all gibberellins declined sharply at Week 3 after GA application. After 5 weeks, GA(1) and GA(4) were below detection limits in all samples, and GA(7) and GA(3) were found only in the samples from trees treated with 40 or 400 mg of GA. Endogenous indole-3-acetic acid (IAA) concentrations increased following GA injection, and peaked at Week 2 or Week 3 in the trees treated with 40 or 400 mg GA, respectively. Injection of 400 mg of GA brought about a twofold increase in IAA concentration compared with control values. Injection of 40 and 400 mg of GA caused significant increases in stem dry mass in Week 5. Seed orchard data revealed that injection of either 40 or 400 mg GA enhanced female cone formation, whereas male cone formation was enhanced only by 400 mg GA. Slight decreases in concentrations of abscisic acid (ABA) and isopentenyl adenosine were observed after GA application. No significant changes were detected in the concentrations of ABA metabolites except for a slight decrease in the concentration of 7'-hydroxy ABA. The concentration of ABA declined during the growing season and the concentration of ABA glucose ester increased correspondingly.

Kinetic of the gibberellic acid and bikaverin production in an airlift bioreactor

Three‐month‐old sugarcane (Saccharum officinarum) plants were raised from single‐eye cuttings and grown in aerated nutrient solution for an additional 28 days at an air temperature fluctuating between 21.5 C (night) and 30.5 C (day). The nutrient solutions in which the roots were immersed were kept at eight different temperatures ranging from 12.5 C to 33.5 C. Half the number of plants in each temperature treatment were treated weekly with gibberellic acid (GA). The GA (100 µg) was applied in 0.1 ml of water per plant in the folded leaves above the top visible dewlap.A loss in mean dry weight of the plants at a root temperature of 12.5 C indicated a higher respiratory than photosynthetic activity. Above 15.5 C an increase in root temperature resulted in an almost linear increase in dry matter production up to 30.5 C. The effect of GA on dry matter production was more pronounced at 18.5 C than at 27.5 C to 30.5 C. There was very little response to GA application at intermediate temperatures. Tiller production was reduced by root temperature below 24.5 C, above which there was an increase in the mean number and mean dry weight of tillers with increasing temperature. GA caused a reduction in tiller dry weight at 27.5 C; however, the effect decreased above that temperature.It is suggested that GA production in the roots, or translocation from the roots, or both, are inhibited by root temperatures below 18.5 C, which would explain the high response to applied GA at 18.5 C. At temperatures of 27.5 C and 30.5 C a positive response to exogenous GA might be the result of depletion, through consumption of endogenous GA due to the rapid growth rate of the plants at these temperatures. The growth of the GA‐treated plants was maximum at a root temperature of 30.5 C under the conditions of the experiment. for the control plants maximum growth was attained at the root temperature of 33.5 C. However, the maximum response to GA, compared to the controls at the same temperature, occured at 18.5 C.

Endophytic fungi are a significant group of fungi found in various ecosystems, producing significant secondary metabolites with economic applications. The study aims to extract gibberellic acid from endophytic fungi, optimize its production using low-cost agriculture residues, and apply it to plants. Endophytic fungi were isolated from onion leaves, screened for gibberellic acid production, and the highest producer was identified by morphological and molecular tools. The production was optimized using three levels Box–Behnken design, and the hormone was applied to maize seeds at concentrations of 0, 50, and 100 ppm. Fusarium solani, F. oxysporum, F. incarnatum, and F. camptoceras produced gibberellic acid at concentrations from 3.04 to 36.33 mg/l, with the highest production by F. incarnatum-ASU19 (MK387876). The optimal parameters increased the production significantly (R2 0.9974) to 166.81 mg/l using 20 g/l sugarcane bagasse, 35 °C incubation temperature, and seven days of incubation. Increased gibberellic acid concentrations induced morphological characteristics, chlorophyll, flavonoids, and total antioxidants in maize compared to controls without GA3 addition. In conclusion, the endophytic fungus Fusarium incarnatum demonstrates significant potential for gibberellic acid production from low-cost agricultural residues. This bioprocess not only promotes a cleaner environment but also enhances plant tolerance to abiotic stress and positively influences agricultural productivity.