The Current Status of Research on Gibberellin Biosynthesis

Peter Hedden

doi:10.1093/pcp/pcaa092

The Current Status of Research on Gibberellin Biosynthesis

Plant and Cell Physiology ◽

10.1093/pcp/pcaa092 ◽

2020 ◽

Vol 61 (11) ◽

pp. 1832-1849 ◽

Cited By ~ 1

Author(s):

Peter Hedden

Keyword(s):

Gibberellic Acid ◽

Vascular Plants ◽

Molecular Mechanisms ◽

Bacterial Species ◽

Current Status ◽

Fusarium Fujikuroi ◽

Environmental Cues ◽

Gibberellin Biosynthesis ◽

Gibberellin Metabolism ◽

Recent Advances

Abstract Gibberellins are produced by all vascular plants and several fungal and bacterial species that associate with plants as pathogens or symbionts. In the 60 years since the first experiments on the biosynthesis of gibberellic acid in the fungus Fusarium fujikuroi, research on gibberellin biosynthesis has advanced to provide detailed information on the pathways, biosynthetic enzymes and their genes in all three kingdoms, in which the production of the hormones evolved independently. Gibberellins function as hormones in plants, affecting growth and differentiation in organs in which their concentration is very tightly regulated. Current research in plants is focused particularly on the regulation of gibberellin biosynthesis and inactivation by developmental and environmental cues, and there is now considerable information on the molecular mechanisms involved in these processes. There have also been recent advances in understanding gibberellin transport and distribution and their relevance to plant development. This review describes our current understanding of gibberellin metabolism and its regulation, highlighting the more recent advances in this field.

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Recent advances in understanding amyotrophic lateral sclerosis and emerging therapies

Faculty Reviews ◽

10.12703/b/9-12 ◽

2020 ◽

Vol 9 ◽

Author(s):

Lauren M Gittings ◽

Rita Sattler

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Molecular Mechanisms ◽

Clinical Stage ◽

Treatment Options ◽

Therapeutic Interventions ◽

Current Status ◽

Stage Of Development ◽

Recent Advances ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that is characterized by degeneration of both upper and lower motor neurons and subsequent progressive loss of muscle function. Within the last decade, significant progress has been made in the understanding of the etiology and pathobiology of the disease; however, treatment options remain limited and only two drugs, which exert a modest effect on survival, are approved for ALS treatment in the US. Therefore, the search for effective ALS therapies continues, and over 60 clinical trials are in progress for patients with ALS and other therapeutics are at the pre-clinical stage of development. Recent advances in understanding the genetics, pathology, and molecular mechanisms of ALS have led to the identification of novel targets and strategies that are being used in emerging ALS therapeutic interventions. Here, we review the current status and mechanisms of action of a selection of emerging ALS therapies in pre-clinical or early clinical development, including gene therapy, immunotherapy, and strategies that target neuroinflammation, phase separation, and protein clearance.

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The Effects of Gibberellic Acid on Sex Expression and Secondary Sexual Characteristics in Papaya

HortScience ◽

10.21273/hortsci.49.3.378 ◽

2014 ◽

Vol 49 (3) ◽

pp. 378-383 ◽

Cited By ~ 2

Author(s):

Jennifer Han ◽

Jan E. Murray ◽

Qingyi Yu ◽

Paul H. Moore ◽

Ray Ming

Keyword(s):

Gibberellic Acid ◽

Regulatory Element ◽

Sex Expression ◽

Gibberellin Biosynthesis ◽

Branch Number ◽

Secondary Sexual Characteristics ◽

Gibberellin Metabolism ◽

Inflorescence Morphology ◽

Sex Type ◽

Sexual Characteristics

The vegetative forms of male (XY), female (XX), and hermaphrodite (XYh) papaya (Carica papaya L.) plants are phenotypically identical. However, the flower and inflorescence morphology of each sex type is unique. Gynodioecious varieties SunUp, SunUp Diminutive mutant, and dioecious AU9 were used to test the response of papaya to gibberellic acid (GA3). Exogenous applications of GA3 on female and hermaphrodite flowers of papaya did not yield any sex reversal phenotype but caused a significant increase in peduncle elongation and inflorescence branch number in all treated plants. An increase in flower number was seen in females but not hermaphrodites or males. There was an increase in plant height for all treated plants except SunUp Diminutive mutant, suggesting that the mechanism causing the dwarf phenotype is independent of gibberellins. Gibberellin metabolism genes were identified in the papaya genome, none of which mapped to the sex-determining region of either the male- or hermaphrodite-specific region of papaya Y or Yh chromosome. We hypothesize that a transacting regulatory element that enhances gibberellin biosynthesis plays a role in the extreme length of the male papaya peduncle.

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Clinical Candidates Targeting the ATR–CHK1–WEE1 Axis in Cancer

Cancers ◽

10.3390/cancers13040795 ◽

2021 ◽

Vol 13 (4) ◽

pp. 795

Author(s):

Lukas Gorecki ◽

Martin Andrs ◽

Jan Korabecny

Keyword(s):

Cell Cycle ◽

Cancer Cells ◽

Molecular Mechanisms ◽

Patient Survival ◽

Current Status ◽

Future Perspectives ◽

Phase Ii Trials ◽

Anticancer Treatment ◽

Positive Outlook ◽

Insight Into

Selective killing of cancer cells while sparing healthy ones is the principle of the perfect cancer treatment and the primary aim of many oncologists, molecular biologists, and medicinal chemists. To achieve this goal, it is crucial to understand the molecular mechanisms that distinguish cancer cells from healthy ones. Accordingly, several clinical candidates that use particular mutations in cell-cycle progressions have been developed to kill cancer cells. As the majority of cancer cells have defects in G1 control, targeting the subsequent intra‑S or G2/M checkpoints has also been extensively pursued. This review focuses on clinical candidates that target the kinases involved in intra‑S and G2/M checkpoints, namely, ATR, CHK1, and WEE1 inhibitors. It provides insight into their current status and future perspectives for anticancer treatment. Overall, even though CHK1 inhibitors are still far from clinical establishment, promising accomplishments with ATR and WEE1 inhibitors in phase II trials present a positive outlook for patient survival.

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Desiccation Tolerance as the Basis of Long-Term Seed Viability

International Journal of Molecular Sciences ◽

10.3390/ijms22010101 ◽

2020 ◽

Vol 22 (1) ◽

pp. 101

Author(s):

Galina Smolikova ◽

Tatiana Leonova ◽

Natalia Vashurina ◽

Andrej Frolov ◽

Sergei Medvedev

Keyword(s):

Desiccation Tolerance ◽

Vascular Plants ◽

Molecular Mechanisms ◽

Regulation Of Gene Expression ◽

Seed Viability ◽

Late Embryogenesis Abundant ◽

Maturation Stage ◽

Terrestrial Plants ◽

Complex Anatomy ◽

Orthodox Seeds

Desiccation tolerance appeared as the key adaptation feature of photoautotrophic organisms for survival in terrestrial habitats. During the further evolution, vascular plants developed complex anatomy structures and molecular mechanisms to maintain the hydrated state of cell environment and sustain dehydration. However, the role of the genes encoding the mechanisms behind this adaptive feature of terrestrial plants changed with their evolution. Thus, in higher vascular plants it is restricted to protection of spores, seeds and pollen from dehydration, whereas the mature vegetative stages became sensitive to desiccation. During maturation, orthodox seeds lose up to 95% of water and successfully enter dormancy. This feature allows seeds maintaining their viability even under strongly fluctuating environmental conditions. The mechanisms behind the desiccation tolerance are activated at the late seed maturation stage and are associated with the accumulation of late embryogenesis abundant (LEA) proteins, small heat shock proteins (sHSP), non-reducing oligosaccharides, and antioxidants of different chemical nature. The main regulators of maturation and desiccation tolerance are abscisic acid and protein DOG1, which control the network of transcription factors, represented by LEC1, LEC2, FUS3, ABI3, ABI5, AGL67, PLATZ1, PLATZ2. This network is complemented by epigenetic regulation of gene expression via methylation of DNA, post-translational modifications of histones and chromatin remodeling. These fine regulatory mechanisms allow orthodox seeds maintaining desiccation tolerance during the whole period of germination up to the stage of radicle protrusion. This time point, in which seeds lose desiccation tolerance, is critical for the whole process of seed development.

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Strategies for strain improvement in Fusarium fujikuroi: overexpression and localization of key enzymes of the isoprenoid pathway and their impact on gibberellin biosynthesis

Applied Microbiology and Biotechnology ◽

10.1007/s00253-012-4377-5 ◽

2012 ◽

Vol 97 (7) ◽

pp. 2979-2995 ◽

Cited By ~ 24

Author(s):

Sabine Albermann ◽

Pia Linnemannstöns ◽

Bettina Tudzynski

Keyword(s):

Strain Improvement ◽

Fusarium Fujikuroi ◽

Gibberellin Biosynthesis ◽

Key Enzymes ◽

Isoprenoid Pathway

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Cellular modulation by the elasticity of biomaterials

Journal of Materials Chemistry B ◽

10.1039/c5tb02077h ◽

2016 ◽

Vol 4 (1) ◽

pp. 9-26 ◽

Cited By ~ 51

Author(s):

Fengxuan Han ◽

Caihong Zhu ◽

Qianping Guo ◽

Huilin Yang ◽

Bin Li

Keyword(s):

Extracellular Matrix ◽

Cell Fate ◽

Molecular Mechanisms ◽

Matrix Elasticity ◽

Recent Advances

The elasticity of the extracellular matrix has been increasingly recognized as a dominating factor of cell fate and activities. This review provides an overview of the general principles and recent advances in the field of matrix elasticity-dependent regulation of a variety of cellular activities and functions, the underlying biomechanical and molecular mechanisms, as well as the pathophysiological implications.

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Immune thrombocytopenic purpura: Historical perspective, current status, recent advances and future directions

Indian Pediatrics ◽

10.1007/s13312-012-0195-1 ◽

2012 ◽

Vol 49 (10) ◽

pp. 811-818 ◽

Cited By ~ 8

Author(s):

P. Anoop

Keyword(s):

Immune Thrombocytopenic Purpura ◽

Historical Perspective ◽

Current Status ◽

Future Directions ◽

Thrombocytopenic Purpura ◽

Recent Advances

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Insulin receptors: binding kinetics and structure-function relationship of insulin

Physiological Reviews ◽

10.1152/physrev.1984.64.4.1321 ◽

1984 ◽

Vol 64 (4) ◽

pp. 1321-1378 ◽

Cited By ~ 146

Author(s):

S. Gammeltoft

Keyword(s):

Plasma Membrane ◽

Binding Affinity ◽

Insulin Action ◽

Molecular Mechanisms ◽

Physiological Role ◽

Insulin Receptors ◽

Binding Kinetics ◽

Antigenic Determinants ◽

Insulin Degradation ◽

Recent Advances

During the last decade, earlier suggestions that insulin acts at the plasma membrane level via combination with receptors have been amply confirmed in studies of 125I-labeled insulin binding kinetics. Efforts have been devoted to the development of homogeneous, stable, and bioactive tracers, and a preparation of monoiodo[TyrA14]insulin showed 100-125% biological activity. The initially simple model of reversible, bimolecular, and noncooperative interaction between receptor and insulin has been revised to include the existence of at least three affinity states that may be linked to modulation of the biological response induced by the insulin-receptor complex. Thus negative cooperativity seems important in reducing oscillations of insulin action with variations in plasma insulin concentration, and formation of a high-affinity state or positive cooperativity may lead to desensitization of receptors. The kinetic phenomena suggest that receptor-binding affinity and function are actively regulated by insulin itself. At present the receptor model is purely functional and does not imply molecular mechanisms. However, recent advances in the analysis of receptor structure and biochemistry promise that the molecular equivalents of the kinetic phenomena may be elucidated in the near future. Furthermore the reaction between receptor and insulin is irreversible because of degradation of receptor-bound insulin, which may result in termination of the metabolic activation. Morphological and biochemical work suggests that internalization of the receptor-insulin complex from the plasma membrane transfers insulin to intracellular organelles like the lysosomes, the Golgi apparatus, or nucleus, where degradation by insulin protease takes place, whereas the receptor is recycled back to the membrane. Recent advances in the studies of biosynthesis and cellular dynamics of receptors indicate that intracellular processing and redistribution of binding sites may play a role in the mechanism of insulin action. Insulin receptors are widely distributed in all cell types, but evidence has accumulated that receptors show tissue and species variations in their functional properties regarding binding affinity, insulin specificity, cooperativity, and insulin degradation and in structural properties such as antigenic determinants and glycosidic composition. Perhaps these differences reflect cellular adaptations and variations in the physiological role of insulin.(ABSTRACT TRUNCATED AT 400 WORDS)

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