Gibberellin biosynthesis and its regulation

2012 ◽  
Vol 444 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Peter Hedden ◽  
Stephen G. Thomas

The GAs (gibberellins) comprise a large group of diterpenoid carboxylic acids that are ubiquitous in higher plants, in which certain members function as endogenous growth regulators, promoting organ expansion and developmental changes. These compounds are also produced by some species of lower plants, fungi and bacteria, although, in contrast to higher plants, the function of GAs in these organisms has only recently been investigated and is still unclear. In higher plants, GAs are synthesized by the action of terpene cyclases, cytochrome P450 mono-oxygenases and 2-oxoglutarate-dependent dioxygenases localized, respectively, in plastids, the endomembrane system and the cytosol. The concentration of biologically active GAs at their sites of action is tightly regulated and is moderated by numerous developmental and environmental cues. Recent research has focused on regulatory mechanisms, acting primarily on expression of the genes that encode the dioxygenases involved in biosynthesis and deactivation. The present review discusses the current state of knowledge on GA metabolism with particular emphasis on regulation, including the complex mechanisms for the maintenance of GA homoeostasis.

2019 ◽  
Vol 19 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Manoj Kumar Dhar ◽  
Sonal Mishra ◽  
Archana Bhat ◽  
Sudha Chib ◽  
Sanjana Kaul

Abstract A plant communicates within itself and with the outside world by deploying an array of agents that include several attractants by virtue of their color and smell. In this category, the contribution of ‘carotenoids and apocarotenoids’ is very significant. Apocarotenoids, the carotenoid-derived compounds, show wide representation among organisms. Their biosynthesis occurs by oxidative cleavage of carotenoids, a high-value reaction, mediated by carotenoid cleavage oxygenases or carotenoid cleavage dioxygenases (CCDs)—a family of non-heme iron enzymes. Structurally, this protein family displays wide diversity but is limited in its distribution among plants. Functionally, this protein family has been recognized to offer a role in phytohormones, volatiles and signal production. Further, their wide presence and clade-specific functional disparity demands a comprehensive account. This review focuses on the critical assessment of CCDs of higher plants, describing recent progress in their functional aspects and regulatory mechanisms, domain architecture, classification and localization. The work also highlights the relevant discussion for further exploration of this multi-prospective protein family for the betterment of its functional understanding and improvement of crops.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaoming Song ◽  
Qihang Yang ◽  
Yun Bai ◽  
Ke Gong ◽  
Tong Wu ◽  
...  

AbstractSimple sequence repeats (SSRs) are one of the most important genetic markers and widely exist in most species. Here, we identified 249,822 SSRs from 3,951,919 genes in 112 plants. Then, we conducted a comprehensive analysis of these SSRs and constructed a plant SSR database (PSSRD). Interestingly, more SSRs were found in lower plants than in higher plants, showing that lower plants needed to adapt to early extreme environments. Four specific enriched functional terms in the lower plant Chlamydomonas reinhardtii were detected when it was compared with seven other higher plants. In addition, Guanylate_cyc existed in more genes of lower plants than of higher plants. In our PSSRD, we constructed an interactive plotting function in the chart interface, and users can easily view the detailed information of SSRs. All SSR information, including sequences, primers, and annotations, can be downloaded from our database. Moreover, we developed Web SSR Finder and Batch SSR Finder tools, which can be easily used for identifying SSRs. Our database was developed using PHP, HTML, JavaScript, and MySQL, which are freely available at http://www.pssrd.info/. We conducted an analysis of the Myb gene families and flowering genes as two applications of the PSSRD. Further analysis indicated that whole-genome duplication and whole-genome triplication played a major role in the expansion of the Myb gene families. These SSR markers in our database will greatly facilitate comparative genomics and functional genomics studies in the future.


2021 ◽  
Author(s):  
Yuriy Lykholat

The book contains the study results of the environmental and soil conditions of the transformed territories, the ecological patterns of woody plants natural communities’ formation as well as the features of the herbaceous communities’ succession in flooded areas. The current state of forest areas is highlighted, the problems of forest management and their exploitation in Ukraine are outlined. Aspects of anthropogenic impact on natural aquatic ecosystems are shown and various biotesting methods of negative effects are characterized. The relationship between the presence of exogenous biologically active chemical compounds in the environment and damage to the endocrine system of animals has been revealed. The scientific manuscript is intended for ecologists, specialists interested in environmental management and environmental protection. The book may be useful for graduate students and scientific researchers.


2018 ◽  
Vol 7 (2) ◽  
pp. 20-26
Author(s):  
Lyubov Georgievna Demenina ◽  
Anna Borisovna Petrova ◽  
Kristina Andreevna Savitskaya ◽  
Lyudmila Mikhailovna Kavelenova

The paper deals with the peculiarities of the biological characteristics of the most important fruit crops of temperate climates - apple and pear (Rosaceae family, subfamily Maloideae), taking into account the world, national and regional cultivation. Both cultures are characterized by significant food and commodity value, have some differences in the chemical composition of the fruit, including the leading components of the mass and biologically active substances, which determine the peculiarities of their use in the human diet. In both global and national fruit-growing, pears play a secondary role compared to apple, giving way to the number of varieties, the volume of production and the areas occupied. Based on the analysis of available statistical data of the FAO database, the dynamics of changes from 1990 to 2016 of the world production of apple and pear fruits with visualization on the continents, identifying world leaders and major trends are considered. For the USSR (from 1962 to 1990) and in Russian Federation (from 1992 to 2016) the paper presents a picture of changes in the volume of fruit production, discusses the status of fruit production in the country. The features of the historical development and current state of fruit growing in the Samara Region and prospects are discussed.


2014 ◽  
Vol 1065-1069 ◽  
pp. 114-118
Author(s):  
Shuo Fu Tian ◽  
Chao Jin Lu ◽  
Yuan Wang

It is the components, living things evolution processes, development environments, distribution layers and the earliest time for coal series formation that are investigated and studied in detail based on the author’s graduation thesis, the “Geobiology” , the “China coal petrology” and the other’s some references in this paper. And it is considered that mainly two types of the Coal Series might be distinguish in the geologic history in China, respectively consisted of the lower organisms (especially the lower plants, blue-green algae) and higher organisms (especially the higher plants, pteridophyta, gymnosperms, Anthophyta). Meanwhile, the conclusions can be drawn that the development of the organisms is not only controlled by the environments, on the other hand, the environments and their sediments are also affected by the ecologies of the organisms. So the coal bed or coal series can be used as the marks of the environment explanation, perhaps having some Significances of Geobiology. In additional, the relationship with an unconformity or disconformity is discussed here, too.


2008 ◽  
Vol 3 (7) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Xiaoning Wang ◽  
David E. Wedge ◽  
Nurhayat Tabanca ◽  
Robert D. Johnson ◽  
Stephen J. Cutler ◽  
...  

There is great incentive to discover biologically active natural products from higher plants that are more effective than synthetic agrochemicals and are environmentally safe. Research emphasis at the US Department of Agriculture has therefore been on the development of alternative approaches to utilizing natural plant products in pest management. Discovery and evaluation of natural product fungicides is largely dependent upon the availability of miniaturized antifungal bioassays. We report on the development of a miniaturized 24-well leaf disk assay for evaluating plant extracts and pure compounds. Compounds applied directly to the leaf surface can be evaluated in a dose-response for fungicidal activity and phytotoxicity. The assay is sensitive to microgram quantities, can determine chemical sensitivity between fungal isolates, and adaptable to complex mixtures, lipophilic extracts, and non-polar compounds. The use of digital imaging and analytical software provided quantitative data and the ability to fine tune the data analysis. Identification of new potential lead compounds can be repeated quickly in time and real on-the-leaf-surface activity can be evaluated in high throughput formats and published in a reasonable time.


2020 ◽  
Vol 61 (11) ◽  
pp. 1832-1849 ◽  
Author(s):  
Peter Hedden

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.


Author(s):  
Bauyrzhan Smailov ◽  
Sanzhar Alybayev ◽  
Izat Smekenov ◽  
Aibek Mursalimov ◽  
Murat Saparbaev ◽  
...  

Germination is a process of seed sprouting that facilitates embryo growth. The breakdown of reserved starch in the endosperm into simple sugars is essential for seed germination and subsequent seedling growth. At the early stage of germination, gibberellic acid (GA) activates transcription factor GAMYB to promote de novo synthesis of isoforms of α-amylase in the aleurone layer and scutellar epithelium of the embryo. Here, we demonstrate that wheat germination is regulated by plant target of rapamycin (TOR) signaling. TOR is a central component of the essential-nutrient–dependent pathway controlling cell growth in all eukaryotes. It is known that rapamycin, a highly specific allosteric inhibitor of TOR, is effective in yeast and animal cells but ineffective in most of higher plants likely owing to structural differences in ubiquitous rapamycin receptor FKBP12. The action of rapamycin on wheat growth has not been studied. Our data show that rapamycin inhibits germination of wheat seeds and of their isolated embryos in a dose-dependent manner. The involvement of Triticum aestivum TOR (TaTOR) in wheat germination was consistent with the suppression of wheat embryo growth by specific inhibitors of the TOR kinase: pp242 or torin1. Rapamycin or torin1 interfered with GA function in germination because of a potent inhibitory effect on α-amylase and GAMYB gene expression. The TOR inhibitors selectively targeted the GA-dependent gene expression, whereas expression of the abscisic acid-dependent ABI5 gene was not affected by either rapamycin or torin1. To determine whether the TaTOR kinase activation takes place during wheat germination, we examined phosphorylation of a ribosomal protein, T. aestivum S6 kinase 1 (TaS6K1; a substrate of TOR). The phosphorylation of serine 467 (S467) in a hydrophobic motif on TaS6K1 was induced in a process of germination triggered by GA. Moreover, the germination-induced phosphorylation of TaS6K1 on S467 was dependent on TaTOR and was inhibited by rapamycin or torin1. Besides, a gibberellin biosynthesis inhibitor (paclobutrazol; PBZ) blocked not only α-amylase gene expression but also TaS6K1 phosphorylation in wheat embryos. Thus, a hormonal action of GA turns on the synthesis of α-amylase in wheat germination via activation of the TaTOR–S6K1 signaling pathway.


2020 ◽  
Vol 9 (8) ◽  
pp. 2380 ◽  
Author(s):  
Houssam Aheget ◽  
María Tristán-Manzano ◽  
Loubna Mazini ◽  
Marina Cortijo-Gutierrez ◽  
Pablo Galindo-Moreno ◽  
...  

Summary: Exosomes are extracellular vesicles released by the vast majority of cell types both in vivo and ex vivo, upon the fusion of multivesicular bodies (MVBs) with the cellular plasma membrane. Two main functions have been attributed to exosomes: their capacity to transport proteins, lipids and nucleic acids between cells and organs, as well as their potential to act as natural intercellular communicators in normal biological processes and in pathologies. From a clinical perspective, the majority of applications use exosomes as biomarkers of disease. A new approach uses exosomes as biologically active carriers to provide a platform for the enhanced delivery of cargo in vivo. One of the major limitations in developing exosome-based therapies is the difficulty of producing sufficient amounts of safe and efficient exosomes. The identification of potential proteins involved in exosome biogenesis is expected to directly cause a deliberate increase in exosome production. In this review, we summarize the current state of knowledge regarding exosomes, with particular emphasis on their structural features, biosynthesis pathways, production techniques and potential clinical applications.


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