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Gibberellic acid
About: Gibberellic acid is a research topic. Over the lifetime, 6597 publications have been published within this topic receiving 109294 citations. The topic is also known as: GIBBERELLIN A3.
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TL;DR: The data suggest that the increased growth caused by inoculation with Rhizobium strain 127E14 could be the result of increased gibberellin synthesis in lima bean nodules infected with that strain.
Abstract: Dramatic differences in the height of lima beans (Phaseolus lunatus L.) treated with two different Rhizobium strains were studied. Lima beans were grown in Perlite in the greenhouse or in a minus-N culture solution in the growth chamber. The plants were inoculated with either Rhizobium sp. (lima bean) strain 127E15, which contains the constitutive nitrate reductase activity, or strain 127E14, which lacks that activity. For up to 3 weeks, no growth differences were observed in the plants inoculated with either strain. Five weeks after inoculation, however, those plants inoculated with strain 127E14 were significantly taller and had a larger number of leaves than those inoculated with strain 127E15. The difference in plant height was the result of increased internode elongation caused by inoculation with Rhizobium sp. 127E14. This response was observed with all lima bean cultivars tested, including Henderson, Fordhook, Allgreen, and Early Thorogreen. The growth difference occurred in plants cultured in the greenhouse or in the growth chamber.No differences were observed in fresh weights of nodules, roots, axes, leaves, or flowers. The number of nodules, pods, or flowers also did not differ. Acetylene reduction rates and total N content were equal in plants inoculated with strains 127E14 or 127E15.Inasmuch as only internode length and leaf number differed between Rhizobium treatments, the response appeared to be hormone-mediated. Application of gibberellic acid to the apex of plants inoculated with strain 127E15 caused an increase in plant height similar to that observed in untreated plants inoculated with strain 127E14. Conversely, the height of plants infected with strain 127E14 was decreased by application of gibberellin synthesis inhibitors to the root system. These data suggest that the increased growth caused by inoculation with strain 127E14 could be the result of increased gibberellin synthesis in lima bean nodules infected with that strain. Whether this response was related to the absence of nitrate reductase activity in strain 127E14 is unknown.
33 citations
TL;DR: In this paper, Whyte and Luckwill reported that the acid delayed the senescence of leaf disks of Rumex obtusifolium and reported that it was not widespread because it was observed in only one of seventeen species tested.
Abstract: SEVERAL chemical substances retard the decrease of chlorophyll content and the accompanying loss of protein and ribonucleic acid (RNA) which normally occurs as leaf disks senesce when they are floated on water. Among the compounds which retard senescence are the kinetins and related compounds1–5 and auxins6,7. Gibberellic acid has been reported to delay the senescence of leaf disks of Taraxacum officinale8–10, and in this work it was indicated that senescence delayed by gibberellic acid was not widespread because it was observed in only one of seventeen species tested. Whyte and Luckwill11, however, have since reported that the acid delayed the senescence of leaf disks of Rumex obtusifolium. The retardation of senescence of leaf disks of nasturtium (Trapaeolum majus) after treatment with gibberellic acid has recently been recorded in this laboratory12.
33 citations
TL;DR: The results showed a wide variation on yield, content and range of the molecule constituent of oil, with a balance of appearances and/or disappearances of a few molecules.
Abstract: Basil (O. gratissimum L) is a aromatic and medicinal plant widely used in traditional medicine in Morocco. The aim of this work was to study the effect of three plant growth regulators gibberellic acid (GA), indole 3-acetic acid (IAA) and benzylaminopurine (BAP) on the content and composition of essential oils of this plant, especially on the main compound (methyl chavicol) and its isomer (the trans-anethole). The results showed a wide variation on yield, content and range of the molecule constituent of oil, with a balance of appearances and/or disappearances of a few molecules. GA caused a slight decrease in the oil yield (0.2%), but it increased the diversity of compounds (17 molecules) with the appearance of four new compounds (naphthalene, camphor, germacrene-D, and ledene) and disappearance of (β cedrene, azulene). This variation also caused a very important decrease in the main compound (methyl chavicol) and increases its isomer (trans-anethole). IAA and BAP caused an increase in the yield of essential oil (0.30% and 0.32% respectively) without much influence on the main compounds, but with some change in the composition such as the appearance of (germacrene-D) and the disappearance of (aristolene).
33 citations
TL;DR: Priming seeds of these crops with 0.2 g/L GA3 significantly improved germination percentage, reduced mean germination time, increased shoot and root length, and total weight of the crops when the salinity level is less than 8 dS/m, however, shoots of all crops performed better than the roots.
Abstract: Low seed germination, poor seedling establishment, and less crop productivity are commonly observed problems in salt-affected soils. Genetic modification of plants for creating good varieties and selection of crop plants that have best performance on saline soils are the major accomplishments done to minimize the problem. In addition, application of Gibberellic Acid (GA3) has been reported to increase germination percentage and seedling growth performance of crop plants under salt stress. The objective of the present study was therefore to investigate the effect of GA3 on germination and early seedling growth of three important crops under saline conditions. To this effect an experiment was conducted as factorial with completely randomized design with three replicates. The factors of the experiment were salinity with four levels (0, 4, 6, 8, and 12 dS/m), hormone (GA3 at 0.2 g/L versus no GA3) and the three crops (Zea mays L., Pisums sativum Var. abyssinicum A. Braun, and Lathyrus sativus L). Consequently, priming seeds of these crops with 0.2 g/L GA3 significantly improved germination percentage, reduced mean germination time, increased shoot and root length, and total weight of the crops (P < 0.05) when the salinity level is less than 8 dS/m. However, shoots of all crops performed better than the roots.
33 citations
TL;DR: The results indicate that the embryo is responsible for the initiation of the mobilization processes which occur in the endosperm during germination and this level may be close to the amount of endogenously produced gibberellin.
Abstract: Measurements werc made of the amylolytic activity, reducing sugar, and soluble nitrogen contents of barley grain with or without normal or x-irradiated embryos. The results indicate that the embryo is responsible for the initiation of the mobilization processes which occur in the endosperm during germination. X irradiation delays this initiation and complete removal of the embryo indeftnitely postpones it. Gibberellic acid can hasten the responses of endosperm in the presence of normal or damaged embryos and can initiate them when the embryo is absent. A concentration above 2.9 x 10/sup -8/ M gibberellic acid was needed to produce an effect in the presence of the embryo, suggesting that this level may be close to the amount of endogenously produced gibberellin. (auth)
33 citations