Topic
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: Barley aleurone layers provide a convenient tissue for the study of both substrate- and hormone-induced enzyme formation, and the time course of this inhibition suggests that the inhibition may be a secondary one.
Abstract: Nitrate induces the formation of nitrate reductase activity in barley (Hordeum vulgare L cv Himalaya) aleurone layers Previous work has demonstrated de novo synthesis of alpha-amylase by gibberellic acid in the same tissue The increase in nitrate reductase activity is inhibited by cycloheximide and 6-methylpurine, but not by actinomycin D Nitrate does not induce alpha-amylase synthesis, and it has no effect on the gibberellic acid-induced synthesis of alpha-amylase Also, there is little or no direct effect of gibberellic acid (during the first 6 hr of induction) or of abscisic acid on the nitrate-induced formation of nitrate reductase Gibberellic acid does interfere with nitrate reductase activity during long-term experiments (greater than 6 hr) However, the time course of this inhibition suggests that the inhibition may be a secondary one Barley aleurone layers therefore provide a convenient tissue for the study of both substrate- and hormone-induced enzyme formation
45 citations
TL;DR: Chlorophyll (Chl) degradation was found to be related to the endogenous gibberellin (GA) content in shoots during senescence in the perennial plant Paris polyphylla var.
Abstract: Chlorophyll (Chl) degradation was found to be related to the endogenous gibberellin (GA) content in shoots during senescence in the perennial plant Paris polyphylla var. yunnanensis (Franch.). Treatment with gibberellic acid (GA3) significantly increased the content of endogenous GAs (GA4 + GA7), retarded the senescence of shoots, and the degradation of proteins and Chl. Chlorophyllase, Mg-dechelation and peroxidase activities increased more in control plants than in those treated with GA3. GA3 treatment also protected lipoxygenase activity, which decreased significantly in control plants.
45 citations
Journal Article•
45 citations
TL;DR: It is proposed that the interconversion of cytokinins initiated by red light, or gibberellic acid in the dark, is one of the primary events leading to radicle elongation in light-sensitive lettuce seed.
Abstract: Using the soybean callus bioassay it has been shown that dormant lettuce seeds (Lactuca sativa L. cv. Grand Rapids) contain large amounts of water soluble cytokinins and small amounts of butanol soluble ones. When the seeds are irradiated with red light, or imbibed with 5 mg/1 gibberellic acid in the dark, the total cytokinin content of the seeds decreases, the level of water soluble cytokinins decreases, and the level of the butanol soluble cytokinins increases. Far-red light does not reverse this effect completely although cytokinin activity in the butanol extracts decreases following such irradiation.
It is proposed that the interconversion of cytokinins initiated by red light, or gibberellic acid in the dark, is one of the primary events leading to radicle elongation in light-sensitive lettuce seed.
45 citations
TL;DR: It is shown that the calcium sensor, CML39, is important in various developmental processes from seeds to mature plants, as well as during germination and seedling establishment, and RNA sequencing analysis of cml39 seedlings suggests that changes in chromatin modification may underlie some of the phenotypes associated with cML39 mutants, consistent with previous reports that orthologs of Cml39 participate in gene silencing.
Abstract: We show that the calcium sensor, CML39, is important in various developmental processes from seeds to mature plants. This study bridges previous work on CML39 as a stress-induced gene and highlights the importance of calcium signalling in plant development. In addition to the evolutionarily-conserved Ca2+ sensor, calmodulin (CaM), plants possess a large family of CaM-related proteins (CMLs). Using a cml39 loss-of-function mutant, we investigated the roles of CML39 in Arabidopsis and discovered a range of phenotypes across developmental stages and in different tissues. In mature plants, loss of CML39 results in shorter siliques, reduced seed number per silique, and reduced number of ovules per pistil. We also observed changes in seed development, germination, and seed coat properties in cml39 mutants in comparison to wild-type plants. Using radicle emergence as a measure of germination, cml39 mutants showed more rapid germination than wild-type plants. In marked contrast to wild-type seeds, the germination of developing, immature cml39 seeds was not sensitive to cold-stratification. In addition, germination of cml39 seeds was less sensitive than wild-type to inhibition by ABA or by treatments that impaired gibberellic acid biosynthesis. Tetrazolium red staining indicated that the seed-coat permeability of cml39 seeds is greater than that of wild-type seeds. RNA sequencing analysis of cml39 seedlings suggests that changes in chromatin modification may underlie some of the phenotypes associated with cml39 mutants, consistent with previous reports that orthologs of CML39 participate in gene silencing. Aberrant ectopic expression of transcripts for seed storage proteins in 7-day old cml39 seedlings was observed, suggesting mis-regulation of early developmental programs. Collectively, our data support a model where CML39 serves as an important Ca2+ sensor during ovule and seed development, as well as during germination and seedling establishment.
45 citations