Showing papers on "Gibberellic acid published in 2005"
TL;DR: The results showed that Pb and Zn significantly delayed and impeded the germination of chickpea seeds and the negative effect of Pb on germination was higher than that of Zn.
Abstract: The present work describes the changes that take place in phytohormone contents in germinating chickpea (Cicer arietinum cv. Aziziye-94) seeds in response to heavy metal stress. For this aim, endogenous abscisic acid (ABA), gibberellic acid (GA3), zeatin (Z) and zeatin riboside (ZR) contents were followed for 24, 48 and 72 h in chickpea seeds germinating at the concentrations of 0.1, 1.0 and 5.0 mM Pb or 0.1, 1.0 and 10 mM Zn. The results showed that Pb and Zn significantly delayed and impeded the germination of chickpea seeds. The negative effect of Pb on germination was higher than that of Zn. Further, Pb increased ABA and Z contents while decreased GA3 content in the germinating seeds. The high concentrations of Zn (1.0 and 10 mM) decreased contents of Z, ZR and GA3 while 0.1 mM Zn increased the content of the same hormones. The ABA content was enhanced by Zn in all concentrations used.
172 citations
TL;DR: Micropropagated plants established in garden soil, farmyard soil, and sand were uniform and identical to the donor plant with respect to growth characteristics as well as floral features.
Abstract: An efficient rapid and large-scale in vitro clonal propagation of the valuable medicinal herb Eclipta alba (Asteraceae) by enhanced axillary shoot proliferation in cotyledonary node segments was designed. The medium type, various carbon sources, plant growth regulators, and coconut water markedly influenced in vitro propagation of Eclipta alba. An in vitro plantlet production system has been investigated on Murashige and Skoog (MS) medium with the synergistic combination of benzyladenine (4.4μM), kinetin (4.6μM), 2-isopentenyladenine (4.9μM), gibberellic acid (1.4μM), 5% coconut water, and 3% sucrose which promoted the maximum number of shoots as well as beneficial shoot length: Subculturing of cotyledonary node segments on a similar medium enabled continuous production of healthy shoots with similar frequency. Rooting was highest (94.3%) on full strength. MS medium containing 9.8 μM indolebutyric acid. Micropropagated plants established in garden soil, farmyard soil, and sand (2∶1∶1) were uniform and identical to the donor plant with respect to growth characteristics as well as floral features. These plants grew normally without showing any morphological variation.
132 citations
TL;DR: Investigation of the effects of nitric oxide and gibberellic acid on the responses of amylases in wheat seeds showed that SNP might play an interesting role in the dissociation of free β-amylase from small homopolymers or heteropolymers, and SNP directly induced the release of bound β-amide from glutenin and its crude enzyme preparation.
Abstract: The effects of nitric oxide (NO) and gibberellic acid (GA3) on the responses of amylases in wheat (Triticum aestivum L.) seeds (caryopses) were investigated during the first 12 h of germination. GA3 had no effects on the activities of α-amylase (EC 3.2.1.1) or β-amylase (EC 3.2.1.2), either in intact seeds or embryoless halves within 12 h. In contrast, addition of sodium nitroprusside (SNP), an NO donor, was able to induce a rapid increase in β-amylase activity without affecting α-amylase. Furthermore, the rapid response of β-amylase to SNP in wheat seeds could be attributed to NO and was approximately dose-dependent. Some other aspects of SNP induction of amylase isozymes were also characterized. Further investigations showed that SNP might play an interesting role in the dissociation of free β-amylase from small homopolymers or heteropolymers. Furthermore, SNP also directly induced the release of bound β-amylase from glutenin and its crude enzyme preparation. However, the slight increase in protease also induced by SNP might not be responsible for this action. Interestingly, based on the fact that the rapid response of β-amylase to NO also existed in seeds of other species, such as barley, soybean, rice and watermelon, it might be a universal event in early seed germination.
78 citations
01 Jan 2005
TL;DR: In this article, a pot experiment was conducted in the screen of the National Research Centre during two successive seasons to study the response of periwinkle plants to foliar spray with tryptophan or putrescine at the concentrations 10 M, 10 M or 10 M.
Abstract: A pot experiment was conducted in the screen of the National Research Centre during two successive seasons to study the response of periwinkle plants to foliar spray with tryptophan or putrescine at the concentrations 10 M, 10 M or 10 M. The obtained data indicated that exogenous application of tryptophan or putrescine on periwinkle transplants considerably increased plant growth at successive developmental stages. The effect was more pronounced with 10 M tryptophan or putrescine. Photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids), soluble and total insoluble sugars, total proteins and total alkaloids in the leaves of periwinkle plants were increased as a result of application of tryptophan or putrescine, more so with 10 M each. Tryptophan at 10 or 10 M increased gibberellic acid (GA3), IAA and ABA contents, while low concentration (10 M) of tryptophan decreased their endogenous levels. Tryptophan at 10 M or 10 M decreased cytokinins, while application of tryptophan at 10 M increase the endogenous cytokinins. Foliar application of putrescine at used concentrations caused obvious increases in the quantitative amounts of endogenous GA3, IAA, cytokinins and ABA.
74 citations
Journal Article•
TL;DR: In this paper, Czern and Coss cv. Varuna investigated the response of mustard (Brassica juncea) seeds to presowing seed treatment with sodium chloride (NaCl).
Abstract: The response of mustard (Brassica juncea (L.) Czern & Coss cv. Varuna) to presowing seed treatment with sodium chloride (NaCl) was investigated. The plants raised from treated seeds were sprayed with water or 10-6 M GA3 at the 30- day stage. The seeds imbibed in 1 or 10 mM of NaCl resulted in a decrease in dry mass, leaf chlorophyll content, carbonic anhydrase activity (E.C. 4.2.1.1), nitrate reductase activity (E.C. 1.6.6.1) and net photosynthetic rate at the 60-day stage, and pod number and seed yield at harvest. However, spray application of GA3 neutralized the ill effect of soaking treatment in NaCl (1 or 10 mM).
59 citations
TL;DR: An efficient and reproducible protocol for mass propagation of Eclipta alba (L.) Hassk, an important medicinal plant, was standardized by culturing shoot tips and nodal segments taken from in vitro raised plants.
Abstract: An efficient and reproducible protocol for mass propagation of Eclipta alba (L.) Hassk, an important medicinal plant, was standardized by culturing shoot tips and nodal segments taken from in vitro raised plants. Maximum shoot proliferation occurred when the explants were cultured on Murashige and Skoog (MS) medium supplemented with 1 mg l−1 benzylaminopurine (BAP). The shoot buds formed were further multiplied and maintained on medium containing BAP (0.5 mg l−1) and gibberellic acid (0.5 mg l−1). Rooting was best achieved on MS medium supplemented with 1 mg−1 indole-3-butyric acid. Rooted plantlets attained maturity and flowered normally in the field.
57 citations
TL;DR: The direct induction of adventitious shoots from leaf explants obtained from adult plants of Zhanhua winter jujube, an elite variety of Zizyphus jujuba Mill, is reported.
Abstract: The direct induction of adventitious shoots from leaf explants obtained from adult plants of Zhanhua winter jujube, an elite variety of Zizyphus jujuba Mill., is reported. The percentage of leaf explants producing shoots and the average number of shoots per explant were significantly improved when 10-day-old leaves were explanted onto Woody Plant Medium and maintained initially in the dark. The plant growth regulator thidiazuron (TDZ) was effective in stimulating shoot regeneration from leaf explants of Zhanhua winter jujube. The highest efficiency of shoot formation was observed with a 20-day culture in the dark on WPM containing 4.54 μM TDZ and 2.85 μM indoleacetic acid (IAA). The regenerated shoots were transferred to MS medium containing 0.89 μM benzyladenine and 5.77 μM gibberellic acid for growth. When the shoots were about 2 cm in height, they were transferred to Nitsch medium supplemented with 1.14 μM IAA and 2.46 μM indolebutyric acid to induce rooting. This system of adventitious shoot production from leaf explants of adult plants could be useful for the genetic engineering and polyploidization of winter jujube.
55 citations
TL;DR: RT-PCR shows that LEP transcript accumulates in wild-type seeds during imbibition and germination, and the transcript levels of REPRESSOR of ga1-3-LIKE2 (RGL2, a negative regulator of GA signaling during germination), is unaffected in lep-1, suggesting LEP is a positive regulator ofGA-induced germination acting independently of RGL2.
Abstract: Gibberellic acid (GA) promotes germination, stem/hypocotyl elongation, and leaf expansion during seedling development. Using activation-tagging mutagenesis, we identified a mutation, sob2-D (for suppressor of phytochromeB-4 [phyB-4]#2 dominant), which suppresses the long-hypocotyl phenotype of a phyB missense allele, phyB-4. This mutant phenotype is caused by the overexpression of an APETALA2 transcription factor, SOB2, also called DRN-like. SOB2/DRN-like transcript is not detectable in wild-type seedling or adult tissues via RT-PCR analysis, suggesting that SOB2/DRN-like may not be involved in seedling development under normal conditions. Adult sob2-D phyB-4 plants have curled leaves and club-like siliques, resembling plants that overexpress a closely related gene, LEAFY PETIOLE (LEP). Hypocotyls of a LEP-null allele, lep-1, are shorter in the light and dark, suggesting LEP involvement in seedling development. This aberrant hypocotyl phenotype is due at least in part to a delay in germination. In addition, lep-1 is less responsive to GA and more sensitive to the GA biosynthesis inhibitor paclobutrazol, indicating that LEP is a positive regulator of GA-induced germination. RT-PCR shows that LEP transcript accumulates in wild-type seeds during imbibition and germination, and the transcript levels of REPRESSOR OF ga1-3-LIKE2 (RGL2), a negative regulator of GA signaling during germination, is unaffected in lep-1. These results suggest LEP is a positive regulator of GA-induced germination acting independently of RGL2. An alternative model places LEP downstream of RGL2 in the GA-signaling cascade.
54 citations
TL;DR: Ovaries and anthers showed different degrees of embryogenic competence and callus frequency depended on genotype, explant type and the culture medium used.
Abstract: Somatic embryos and plants from immature anthers or ovaries were obtained from the Vitis vinifera cvs Sugraone, Crimson Seedless, Italia and Don Mariano. Explants were cultured on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (4, 7 or 10 μM) and 6-benzyladenine (0.7, 1 or 1.3 μM) for callus induction. Callus frequency depended on genotype, explant type and the culture medium used. Calli were transferred to half strength MS without growth regulators for embryo differentiation. The presence of activated charcoal (AC, 0.25 %) in this medium was essential to obtain somatic embryos in the case of Crimson Seedless, Italia and Don Mariano and to increase the frequency of embryogenic calli in Sugraone (from 5.8 % without AC to 99.5 % with AC). Ovaries and anthers showed different degrees of embryogenic competence. When somatic embryos were placed in a medium with indole-3-acetic acid (10 μM), gibberellic acid (1 μM) and 0.25 % AC, embryo germination was normal, i.e. embryos turned green, the hypocotyls and cotyledons started to grow and the apical root axis developed. The percentage of germinated embryos was 100 % for Sugraone and 27.5 %, 38.1 % and 54.5 % for Don Mariano, Italia and Crimson Seedless, respectively. When the germinated embryos were transferred to half strength MS medium in test tubes, 100 % of Crimson, Italia and Don Mariano and 68.3 % of Sugraone embryos developed into normal plants.
50 citations
TL;DR: A single medium-based protocol able to achieve more than 160000 seedlings within 21 wk, starting from a single capsule, sufficient for both large-scale propagation and in vitro conservation of this threatened orchid is described.
Abstract: The effect of 3-indoleacetic acid (IAA), 6-furfurylaminopurine (kinetin), and gibberellic acid (GA3) on germination of the orchid Comparettia falcata was evaluated in a factorial experiment (4×4×4) with Murashige and Skoog (1962) basal medium. It was established that seeds of this orchid could be maintained under aseptic conditions as long as the necessary nutrients and appropriate concentrations of growth regulators were provided. Of the three growth regulators used, IAA significantly decreased seed germination of Comparettia falcata. There was a synergistic effect in the kinetin:GA3 combination that produced a positive response in both percentage seed germination and development of seedlings. This study describes a single medium-based protocol able to achieve more than 160 000 seedlings within 21 wk, starting from a single capsule, sufficient for both large-scale propagation and in vitro conservation of this threatened orchid.
49 citations
TL;DR: In vitro direct multiple shoot formation from seedling explants of Indian high pungent varieties of Capsicum annuum cv.
TL;DR: The role of cytokinins in the promotion of flowering in the endangered species Kniphofia leucocephala Baijnath was investigated using shoots maintained in culture for 3 years, with high concentrations of BA inhibiting flower formation.
Abstract: The role of cytokinins in the promotion of flowering in the endangered species Kniphofia leucocephala Baijnath. was investigated using shoots maintained in culture for 3 years. The highest percentage flowering (65%) was obtained on media containing 20 μM benzyladenine (BA). The inclusion of isopentenyladenine and zeatin in the media also resulted in flowering, but these treatments were less effective than BA in inducing flowering. The effect of cytokinins on flowering was dose-dependent, with high concentrations of BA inhibiting flower formation. Treatments that resulted in rooting of explants produced no flowers. The resulting inflorescences in all treatments did not mature and senesced prematurely, even when gibberellic acid (GA3) was applied post-flower-emergence.
TL;DR: In this paper, the evolution of water activity during solid-state cultivation of Gibberella fujikuroi was followed and a non-linear model based on neural networks was proposed to represent the sorption curves of the substrate during the fermentation process.
TL;DR: An α-amylase gene from cassava tuberous roots is isolated and the predicted structural model of MEamy2 contains three domains, active sites and starch-binding domain that are common with other plant α-AMylases.
TL;DR: It is demonstrated that significant genotypic differences for seedling emergence and vigour are demonstrated and not all cultivars responded to the treatment with GA(3) and GB, under low temperature.
Abstract: Prevalence of low temperature at sowing results in poor rice seed germination, seedling establishment and vigour in several temperate rice growing countries around the world Rice seed of four cultivars (Sasanishiki, H433, HSC-55 and Doongara) was soaked in various combinations of gibberellic acid(3) (GA(3)) and glycinebetaine (GB) in petri dishes placed in a low temperature glasshouse (18/13 degrees C; day/night) for 2 days After the 2 days soak, 10 treated seed were transferred into plastic pots filled with soil and seedlings were grown in the same glasshouse, where seed was treated Seedling emergence was least affected by low temperature in cold tolerant cultivar, HSC-55, while other three cultivars showed reduced seedling emergence However, seedling emergence increased significantly in some cultivars in response to seed treatment with GA(3) and/or GB Seedlings emerged faster even in the cold tolerant cultivar, HSC-55, as measured by reduced mean emergence time (MET), in response to GB Seedling height and seedling dry matter also increased in response to both GA(3) and GB Combined treatment of both GA(3) and GB was more beneficial in increasing seedling emergence and vigour than the treatment with only GA3 or GB We demonstrated significant genotypic differences for seedling emergence and vigour and not all cultivars responded to the treatment with GA(3) and GB, under low temperature
Journal Article•
TL;DR: Application of 1000 mg/l GA3 proved more effective than any of the other concentrations of GA3 applied and the relationships between GA3 concentration and seed germination of black mulberry were linear.
Abstract: Experiments were done to determine the effects of cold stratification (0, 20, 40, 60, 80 or 100 days), application of gibberelic acid (GA3) (0, 250, 500, 1000 or 2000 mg/l) and the combination (GA3 + stratification) on seed germination of black mulberry. Application of 1000 mg/l GA3 proved more effective than any of the other concentrations of GA3 applied. Seeds stratified for 100 days showed 88% germination. The combined treatment of 250 mg/l GA3 and 100 days of stratification yielded 96% germination of seeds. The relationships between GA3 concentration and seed germination (r = 0.93), and between stratification duration and seed germination (r = 0.91) of black mulberry were linear.
TL;DR: In this article, a plump Pleurotus sajor-caju was grown under submerged condition in deproteinized whey supplemented with diammonium hydrogen phosphate and plant growth hormones, viz. indole-3-acetic acid (IAA), gibberellic acid (GA3), and kinetin (KIN).
TL;DR: Gibberellic acid could be also counteracted the adverse effects of heavy metals on mitotic index and some metabolic mechanisms of broad bean plants.
Abstract: The influence of gibberellic acid, two heavy metals (cadmium and lead) and their interactions on mitotic activity and biochemical constituents of Vicia faba yielded seeds was studied. The results showed that different concentrations of cadmium (Cd) and lead (Pb) induced marked inhibition in the contents of soluble carbohydrate, proteins and ribonucleic acid. Heavy metals also induced marked increases of the total percentage of abnormalities. Moreover, different types of chromosomal aberrations were observed in response to heavy metals. On the contrary, gibberellic acid (GA3) stimulated mitotic activity and biochemical constituents of the yielded seeds of Vicia faba. Gibberellic acid could be also counteracted the adverse effects of heavy metals on mitotic index and some metabolic mechanisms of broad bean plants. In addition, electrophoretic profiles of broad bean seeds proteins showed quantitative differences between major bands obtained in control and treated plants.
TL;DR: Kaurenoic and grandiflorenic acid, isolated from Wedelia paludosa (Asteraceae), some derivatives from these acids and other naturally occurring kaurane diterpenes showed a remarkable activity either in the inhibition or in stimulation of L. sativa growth.
Abstract: Kaurenoic and grandiflorenic acid, isolated from Wedelia paludosa (Asteraceae), some derivatives from these acids (alcohols, esters, amides, lactones, oximes) and other naturally occurring kaurane diterpenes were tested for their action on the growth of radical and shoot of Lactuca sativa. Gibberellic acid, GA3, a commercially available phytohormone, belonging to the same class of diterpenes, was also tested. Some of the tested substances showed a remarkable activity either in the inhibition or in stimulation of L. sativa growth. The activity, in some cases, was even higher than that of GA3.
Journal Article•
TL;DR: There may be a close relationship between hormone contents in berries and the degree of seed development, and the highest contents of hormones were found in Italia and the lowest in Perlette.
Abstract: Concentrations of indole-3-acetic acid (IAA), gibberellic acid (GA3) and abscisic acid (ABA) were measured by gas chromatography (GC) in the berries of 3 grape cultivars having different berry set mechanisms to elucidate the possible relationship between endogenous hormones and berry set mechanisms. The results obtained showed that the levels of IAA, GA3 and ABA in seeded Italia, empty seeded Cavus and stenospermocarpic seedless Perlette changed during ripening. While Italia exhibited a hormonal pattern similar to that of Cavus, Perlette showed a different IAA and ABA pattern compared to the other cultivars. Generally, IAA and GA3 were high in the early stages of berry growth. The concentrations of IAA and GA3 in the berries declined to very low levels at the time of ripening. On the other hand, changes in ABA levels were closely associated with ripening. The highest contents of hormones were found in Italia and the lowest in Perlette. Cavus was placed between them with intermediate concentrations. From the results, it was concluded that there may be a close relationship between hormone contents in berries and the degree of seed development.
TL;DR: It was observed that cashew embryos were found to be autonomy of growth regulator as the age increases and medium composition is only critical at very young age of the embryo.
Abstract: Embryos from immature nuts of cashew ( Anacardium occidentale L.) were cultured in vitro to regenerate improved hybrid plantlets. Explants (embryo) were excised from developing F1 hybrid immature nuts derived from diallel cross and harvested at 2-, 4-, 6- and 8-weeks after pollination (WAPo) for in vitro culture. The explants were surface sterilized, aseptically dissected and cultured into pure basal Murashige and Skoog (MS) agar medium and MS medium supplemented with 1 mM each of naphthaleneacetic acid (NAA), benzyladenine (BA) and gibberellic acid (GA3) and subsequently observed for germination and survival rates until successful ones were transferred to the field. Age of explants was found to significantly influence both the germination and survival rates. Explants of 6 weeks old and above were found to give better germination rate and highest survival percentage in this study. Only MS medium supplemented with 1 mM of gibberellic acid (MS+GA 3 ) supported germination and growth at 2-WAPo, suggesting the essentiality of GA3 as a growth regulator to a very young cashew embryo. Analysis also showed that factors such as medium composition, age of embryo and genotype (accession) significantly influence the germination rate of cashew embryo. It was observed that cashew embryos were found to be autonomy of growth regulator as the age increases and medium composition is only critical at very young age of the embryo. Successful germinated explants simultaneously produced shoot and root and were ready for transfer to field and acclimatization, between 90 and 112 days after inoculation. African Journal of Biotechnology Vol. 4 (6), pp. 548-553, 2005
Journal Article•
TL;DR: In this article, the authors examined the single and combinational effect of gibberellins (GA3, GA4+7) and jasmonic acid (JA) on enlargement of Chinese yam tubers in field.
Abstract: We have examined the single and combinational effect of gibberellins (GA3, GA4+7) and jasmonic acid (JA) on enlargement of Chinese yam tubers in field. In a single treatment, gibberellin promoted the tuber enlargement by one time application, whereas the lowest concentration (100ppm) led to the highest tuber yield rather than accumulative application. The effect of GA4+7 enhancing tuber yield was only recognised at the highest concentration by a single treatment. Tuber weight was decreased at the highest JA concentration, otherwise the lowest concentration of JA (5 ppm) significantly promoted the tuber weight by a single treatment (FS1). The combination of GA 50 ppm plus JA 5ppm enhanced remarkably the tuber weight by a single treatment (FS1). It is suggested that the combined treatment of yam plants with both gibberellic acid and jasmonic acid has promoted tuber yield.
TL;DR: Using DRCs, particularly gibberellic acid and thiourea, as a preseeding treatment can overcome the problem of reduced germination in invasive Prosopis juliflora, results suggest.
Abstract: The effect of different types and concentrations of dormancy regulating chemicals (DRCs) on innate and induced dormancy was evaluated under optimal germination conditions in the invasive Prosopis juliflora shrub. Lower concentrations of gibberellic acid (0.3 mM) and kinetin (0.05 mM) were more effective in enhancing germination % and rate at higher concentrations of NaCl, but the reverse was true for thiourea. None of the DRCs alleviated innate dormancy of P. juliflora. Germination % and rate decreased as salinity increased. Percent final germination of non-treated seeds was significantly reduced at 500 mM NaCl and virtually inhibited in 600 mM NaCl. Germination reduction in 500 mM NaCl was not alleviated by any of the DRCs, but inhibition induced at 600 mM NaCl was partially alleviated by all the DRCs. Gibberellic acid had a significantly greater effect than kinetin in alleviating germination inhibition. For restoration of saline soil through the use of P. juliflora, results suggest using DRCs, particularly gibberellic acid and thiourea, as a preseeding treatment can overcome the problem of reduced germination.
TL;DR: The results suggest that OsSIN is a new member in the GA pathway regulating rice stem development, and was more insensitive to endogenous gibberellic acid levels than the wild type.
01 Jun 2005
TL;DR: Suspension culture of cucumber has been an inefficient method for production of somatic embryos owing to problems with embryo maturation and conversion, but MS medium supplemented with 87.6 mM sucrose was more effective in somatic embryo production than other sugars.
Abstract: Suspension culture of cucumber (Cucumis sativus L.) has been an inefficient method for production of somatic embryos owing to problems with embryo maturation and conversion. Embryogenic callus of cv. Green Long was induced on semisolid Murashige and Skoog (MS) medium containing 6.8 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.2 μM 6-benzylaminopurine (BA). A large number of globular somatic embryos were obtained on transfer of the callus to MS liquid medium supplemented with 87.6 mM sucrose, 1.1 μM 2,4-D, and improved by the addition of 342.4 μMl-glutamine. MS medium supplemented with 87.6 mM sucrose was more effective in somatic embryo production than other sugars. Subsequent development led to the formation of heart-and torpedo-shaped embryos. Maturation of somatic embryos occurred on plant growth regulator-free MS semi-solid medium containing 175.2 mM sucrose and 0.5 gl−1 activated charcoal. Conversion of embryos into plants was achieved on half-strength MS semi-solid medium containing 87.6 mM sucrose and 1.4 μM gibberellic acid (GA3) in a 16h photoperiod. Twenty-seven percent of embryos were converted into normal plants.
TL;DR: Analysis of mutant plants has implicated heterotrimeric guanine nucleotide-binding protein (G protein) components in regulation of seed germination by all three of these hormones.
Abstract: Seed germination and early seedling growth are regulated by an intricate network of hormonal signaling pathways. The plant hormones gibberellic acid (GA) and brassinosteroids (BRs) are important positive regulators of these processes, whereas the hormone abscisic acid (ABA) is a potent negative regulator. In Arabidopsis, analysis of mutant plants has implicated heterotrimeric guanine nucleotide-binding protein (G protein) components in regulation of seed germination by all three of these hormones.
TL;DR: In this article, mutant analysis has implicated heterotrimeric guanine nucleotide binding protein (G protein) signaling in GA-stimulated expression of several genes, including expression of the gene encoding the hydrolytic enzyme α-amylase, which breaks down carbohydrate reserves and thus mobilizes nutrients that nourish the young seedling.
Abstract: Seed germination and early seedling growth are regulated by an intricate network of hormonal signaling pathways. The plant hormones gibberellic acid (GA) and abscisic acid (ABA) are particularly important positive and negative regulators of these processes, respectively. In the cereal rice, mutant analysis has implicated heterotrimeric guanine nucleotide–binding protein (G protein) signaling in GA-stimulated expression of several genes, including expression of the gene encoding the hydrolytic enzyme α-amylase, which breaks down carbohydrate reserves and thus mobilizes nutrients that nourish the young seedling.