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.

Role of gibberellic acid in abolishing the detrimental effects of Cd and Pb on broad bean and lupin plants.

Abstract: This work describes the changes in photosynthetic pigments, soluble carbohydrates, proteins and activities of certain enzymes of both broad bean and lupin plants in response to heavy metals (Cd or Pb), 3 gibberellic acid (GA ) and their interactions. Significant reduction in contents of chlorophylls, soluble carbohydrates, soluble proteins were recorded in tested plants due to the treatment with either Cd or Pb. 3 Application of GA , in most cases, decreased contents of chlorophylls and soluble carbohydrates in absence and presence of either Cd or Pb, while contents of soluble proteins were markedly increased. All applied treatments greatly affected the activities of amylases, proteases, catalases and peroxidases in both 3 broad bean and lupin plants. Generally, it could be concluded that GA have (to some extent) a beneficial regulatory role in plants grown under both Cd and Pb polluted conditions.

Gibberellic acid-mediated salt signaling in seed germination.

Abstract: Seed germination initiates the postembryonic development of plants, which determines successful seedling establishment and plant propagation. It is therefore tightly regulated by diverse environmental conditions, including high salinity and drought, as well as by intrinsic developmental programs, among which gibberellic acid (GA) is best understood. Regulatory roles of GA in seed germination have been extensively studied. It is also known that high salinity inhibits germination by repressing genes encoding GA biosynthetic enzymes. However, it is still unclear how salt signals are coordinately incorporated into the GA signaling pathway at the molecular level. We recently demonstrated that a membrane-bound NAC transcription factor, NTL8, mediates salt signaling, primarily through a RGL2-independent GA pathway, in regulating seed germination. High salinity promotes NTL8 transcription and proteolytic activation of NTL8. Notably, the NTL8-mediated salt signaling is independent of abscisic acid (ABA). These observations indicate that membrane-mediated transcription control is an important component of salt signaling during seed germination.

Exogenous salicylic acid improves the germination of Limonium bicolor seeds under salt stress.

Abstract: Salicylic acid (SA) may improve plant tolerance to abiotic stresses; however, little is known about the underlying mechanisms by which this is achieved. Here, we investigated the effects of exogenous SA application on seed germination in the halophyte Limonium bicolor (Kuntze) under salt stress. Specifically, we examined the effect of salt stress on seed germination, sugar and protein contents, amylase activity, and the contents of various hormones, both in the presence and absence of exogenous SA treatments. Germination was significantly suppressed by a 200 mM NaCl treatment but was significantly improved when 0.08 mM SA was concurrently applied. During germination, the seeds treated with SA had high levels of gibberellic acid (GA) and high levels of amylase and α-amylase activity, but low abscisic acid (ABA) contents. The SA treatment upregulated the expression of key genes involved in GA biosynthesis while downregulating those involved in ABA biosynthesis, thereby triggering a favorable hormonal balance between GA and ABA that enhanced seed germination under salt stress.

Regulation of leaf form in Centaurea solstitialis L. I. Leaf development on whole plants in sterile culture

Abstract: Some factors controlling heteroblastic development in Centaurea solstitialis L. are reported and discussed. Whole plants were grown in sterile culture, and it was demonstrated that the level of available carbohydrates partly accounts for the heteroblastic series. Growing plants in sterile culture supplemented with gibberellic acid prevented the development of the adult leaf form, whereas Centaurea plants grown in media supplemented with Cycocel (CCC) formed adult leaves earlier than plants growing in media lacking CCC. When transferred to a GA-supplemented medium, plants already producing the adult leaf undergo transition to flowering, and all new leaves develop as the juvenile form. It is proposed that the heteroblastic series is in part regulated by the endogenous levels of gibberellins.