scholarly journals Herbicides as Probes in Plant Biology

Weed Science ◽  
2010 ◽  
Vol 58 (3) ◽  
pp. 340-350 ◽  
Author(s):  
Franck E. Dayan ◽  
Stephen O. Duke ◽  
Klaus Grossmann
Keyword(s):  
Protein Targeting ◽  
Critical Role ◽  
Photosynthetic Electron Transport ◽  
Molecular Probes ◽  
Ps Ii ◽  
Physiological Processes ◽  
Nonmevalonate Pathway ◽  
Transport Chain ◽  
Target Sites ◽  
Acetyl Coenzyme A Carboxylase

Herbicides are small molecules that inhibit specific molecular target sites within plant biochemical pathways and/or physiological processes. Inhibition of these sites often has catastrophic consequences that are lethal to plants. The affinity of these compounds for their respective target sites makes them useful tools to study and dissect the intricacies of plant biochemical and physiological processes. For instance, elucidation of the photosynthetic electron transport chain was achieved in part by the use of herbicides, such as terbutryn and paraquat, which act on photosystem II and I, respectively, as physiological probes. Work stemming from the discovery of the binding site of PS II–inhibiting herbicides was ultimately awarded the Nobel Prize in 1988. Although not as prestigious as the seminal work on photosynthesis, our knowledge of many other plant processes expanded significantly through the ingenious use of inhibitors as molecular probes. Examples highlight the critical role played by herbicides in expanding our understanding of the fundamental aspects of the synthesis of porphyrins and the nonmevalonate pathway, the evolution of acetyl-coenzyme A carboxylase, cell wall physiology, the functions of microtubules and the cell cycle, the role of auxin and cyanide, the importance of subcellular protein targeting, and the development of selectable markers.

Plant Response to Combinations of Mesotrione and Photosystem II Inhibitors

2006 ◽  
Vol 20 (1) ◽  
pp. 267-274 ◽  
Author(s):  
Julie A. Abendroth ◽  
Alex R. Martin ◽  
Fred W. Roeth
Keyword(s):  
Photosystem Ii ◽  
Joint Action ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Carotenoid Biosynthesis ◽  
Ps Ii ◽  
Whole Plant ◽  
Transport Chain ◽  
Leaf Necrosis ◽  
Plant Level

Photosystem II (PS II) inhibitors halt electron flow within the photosynthetic electron transport chain, thereby leading to increased oxidative stress. As a result, their addition to mesotrione, which inhibits carotenoid biosynthesis by inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD), is complementary. Field and greenhouse experiments were conducted in 2002 and 2003 to investigate the joint action of POST mesotrione plus PS II inhibitor herbicide combinations. The joint action of mesotrione plus PS II inhibitors was investigated across five plant species, three PS II inhibitors, and two moisture environments to determine their influence on the joint action response. Rates of mesotrione evaluated ranged from 4.4 to 87.6 g ai/ha alone and in combination with reduced rates of atrazine, bromoxynil, and metribuzin. In the field, all combinations of mesotrione at 8.8, 17.5, and 35.0 g/ha plus atrazine, bromoxynil, or metribuzin were synergistic for necrosis 6 d after treatment (DAT) on sunflower. Addition of atrazine at 280 g/ha to mesotrione at 8.8 g/ha increased velvetleaf leaf necrosis by 18 to 47%. In the greenhouse, the addition of bromoxynil at 70 g/ha to mesotrione at 17.5 g/ha increased leaf necrosis by 23 to 34% and biomass reduction by 38 to 47%. Synergism on Palmer amaranth occurred similarly under both normal and dry moisture environments at application. Plant height at application was found to influence detection of synergism on the whole-plant level.

scholarly journals PPARs as Metabolic Sensors and Therapeutic Targets in Liver Diseases

2021 ◽  
Vol 22 (15) ◽  
pp. 8298
Author(s):  
Hugo Christian Monroy-Ramirez ◽  
Marina Galicia-Moreno ◽  
Ana Sandoval-Rodriguez ◽  
Alejandra Meza-Rios ◽  
Arturo Santos ◽  
...  
Keyword(s):  
Liver Diseases ◽  
Metabolic Regulation ◽  
Structural Changes ◽  
Critical Role ◽  
The Body ◽  
Molecular Characteristics ◽  
Signal Pathways ◽  
Virus Infections ◽  
Physiological Processes ◽  
Hepatic Level

Carbohydrates and lipids are two components of the diet that provide the necessary energy to carry out various physiological processes to help maintain homeostasis in the body. However, when the metabolism of both biomolecules is altered, development of various liver diseases takes place; such as metabolic-associated fatty liver diseases (MAFLD), hepatitis B and C virus infections, alcoholic liver disease (ALD), and in more severe cases, hepatocelular carcinoma (HCC). On the other hand, PPARs are a family of ligand-dependent transcription factors with an important role in the regulation of metabolic processes to hepatic level as well as in other organs. After interaction with specific ligands, PPARs are translocated to the nucleus, undergoing structural changes to regulate gene transcription involved in lipid metabolism, adipogenesis, inflammation and metabolic homeostasis. This review aims to provide updated data about PPARs’ critical role in liver metabolic regulation, and their involvement triggering the genesis of several liver diseases. Information is provided about their molecular characteristics, cell signal pathways, and the main pharmacological therapies that modulate their function, currently engaged in the clinic scenario, or in pharmacological development.

scholarly journals Differences in Ionic, Enzymatic, and Photosynthetic Features Characterize Distinct Salt Tolerance in Eucalyptus Species

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1401
Author(s):  
Hazar Balti ◽  
Mejda Abassi ◽  
Karl-Josef Dietz ◽  
Vijay Kumar
Keyword(s):  
Dynamic Range ◽  
Hydrolytic Enzymes ◽  
Woody Species ◽  
Photosynthetic Electron Transport ◽  
Fold Increase ◽  
Dose Dependence ◽  
Eucalyptus Species ◽  
Transport Chain ◽  
The Face ◽  
Young Leaves

In the face of rising salinity along coastal regions and in irrigated areas, molecular breeding of tolerant crops and reforestation of exposed areas using tolerant woody species is a two-way strategy. Thus, identification of tolerant plants and of existing tolerance mechanisms are of immense value. In the present study, three Eucalyptus ecotypes with potentially differential salt sensitivity were compared. Soil-grown Eucalyptus plants were exposed to 80 and 170 mM NaCl for 30 days. Besides analysing salt effects on ionic/osmotic balance, and hydrolytic enzymes, plants were compared for dynamics of light-induced redox changes in photosynthetic electron transport chain (pETC) components, namely plastocyanin (PC), photosystem I (PSI) and ferredoxin (Fd), parallel to traditional chlorophyll a fluorescence-based PSII-related parameters. Deconvoluted signals for PC and Fd from PSI allowed identification of PC and PSI as the prime salinity-sensitive components of pETC in tested Eucalyptus species. Eucalyptus loxophleba portrayed efficient K+-Na+ balance (60–90% increased K+) along with a more dynamic range of redox changes for pETC components in old leaves. Young leaves in Eucalyptus loxophleba showed robust endomembrane homeostasis, as underlined by an increased response of hydrolytic enzymes at lower salt concentration (~1.7–2.6-fold increase). Findings are discussed in context of salinity dose dependence among different Eucalyptus species.

scholarly journals The Role of Selected Wavelengths of Light in the Activity of Photosystem II in Gloeobacter violaceus

2021 ◽  
Vol 22 (8) ◽  
pp. 4021
Author(s):  
Monika Kula-Maximenko ◽  
Kamil Jan Zieliński ◽  
Ireneusz Ślesak
Keyword(s):  
Photosystem Ii ◽  
Spectral Composition ◽  
Photosynthetic Electron Transport ◽  
Metabolic Energy ◽  
Light Conditions ◽  
Gloeobacter Violaceus ◽  
Transport Chain ◽  
Cyanobacterial Culture ◽  
Photosynthetic Antennas

Gloeobacter violaceus is a cyanobacteria species with a lack of thylakoids, while photosynthetic antennas, i.e., phycobilisomes (PBSs), photosystem II (PSII), and I (PSI), are located in the cytoplasmic membrane. We verified the hypothesis that blue–red (BR) light supplemented with a far-red (FR), ultraviolet A (UVA), and green (G) light can affect the photosynthetic electron transport chain in PSII and explain the differences in the growth of the G. violaceus culture. The cyanobacteria were cultured under different light conditions. The largest increase in G. violaceus biomass was observed only under BR + FR and BR + G light. Moreover, the shape of the G. violaceus cells was modified by the spectrum with the addition of G light. Furthermore, it was found that both the spectral composition of light and age of the cyanobacterial culture affect the different content of phycobiliproteins in the photosynthetic antennas (PBS). Most likely, in cells grown under light conditions with the addition of FR and G light, the average antenna size increased due to the inactivation of some reaction centers in PSII. Moreover, the role of PSI and gloeorhodopsin as supplementary sources of metabolic energy in the G. violaceus growth is discussed.

scholarly journals Dual Roles of the Activin Signaling Pathway in Pancreatic Cancer

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 821
Author(s):  
Wanglong Qiu ◽  
Chia-Yu Kuo ◽  
Yu Tian ◽  
Gloria H. Su
Keyword(s):  
Pancreatic Cancer ◽  
Signaling Pathway ◽  
Critical Role ◽  
Genetic Mutations ◽  
Cancer Genetic ◽  
Dual Roles ◽  
Activin Signaling ◽  
Physiological Processes ◽  
Cancer Types ◽  
Related Proteins

Activin, a member of the TGF-β superfamily, is involved in many physiological processes, such as embryonic development and follicle development, as well as in multiple human diseases including cancer. Genetic mutations in the activin signaling pathway have been reported in many cancer types, indicating that activin signaling plays a critical role in tumorigenesis. Recent evidence reveals that activin signaling may function as a tumor-suppressor in tumor initiation, and a promoter in the later progression and metastasis of tumors. This article reviews many aspects of activin, including the signaling cascade of activin, activin-related proteins, and its role in tumorigenesis, particularly in pancreatic cancer development. The mechanisms regulating its dual roles in tumorigenesis remain to be elucidated. Further understanding of the activin signaling pathway may identify potential therapeutic targets for human cancers and other diseases.

scholarly journals Effects of Different Planting Densities on Photosynthesis in Maize Determined via Prompt Fluorescence, Delayed Fluorescence and P700 Signals

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 276
Author(s):  
Wanying Chen ◽  
Bo Jia ◽  
Junyu Chen ◽  
Yujiao Feng ◽  
Yue Li ◽  
...  
Keyword(s):  
Electron Transport ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Electron Transport Chain ◽  
Plant Density ◽  
Photosynthetic Electron Transport ◽  
Planting Density ◽  
Strong Impact ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain

The mutual shading among individual field-grown maize plants resulting from high planting density inevitably reduces leaf photosynthesis, while regulating the photosynthetic transport chain has a strong impact on photosynthesis. However, the effect of high planting density on the photosynthetic electron transport chain in maize currently remains unclear. In this study, we simultaneously measured prompt chlorophyll a fluorescence (PF), modulated 820 nm reflection (MR) and delayed chlorophyll a fluorescence (DF) in order to investigate the effect of high planting density on the photosynthetic electron transport chain in two maize hybrids widely grown in China. PF transients demonstrated a gradual reduction in their signal amplitude with increasing planting density. In addition, high planting density induced positive J-step and G-bands of the PF transients, reduced the values of PF parameters PIABS, RC/CSO, TRO/ABS, ETO/TRO and REO/ETO, and enhanced ABS/RC and N. MR kinetics showed an increase of their lowest point with increasing high planting density, and thus the values of MR parameters VPSI and VPSII-PSI were reduced. The shapes of DF induction and decay curves were changed by high planting density. In addition, high planting density reduced the values of DF parameters I1, I2, L1 and L2, and enhanced I2/I1. These results suggested that high planting density caused harm on multiple components of maize photosynthetic electron transport chain, including an inactivation of PSII RCs, a blocked electron transfer between QA and QB, a reduction in PSI oxidation and re-reduction activities, and an impaired PSI acceptor side. Moreover, a comparison between PSII and PSI activities demonstrated the greater effect of plant density on the former.

scholarly journals In Vitro and in Vivo Imaging of Nitroxyl with Copper Fluorescent Probe in Living Cells and Zebrafish

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2551 ◽  
Author(s):  
Sathyadevi Palanisamy ◽  
Yu-Liang Wang ◽  
Yu-Jen Chen ◽  
Chiao-Yun Chen ◽  
Fu-Te Tsai ◽  
...  
Keyword(s):  
Critical Role ◽  
Model Organism ◽  
Living Cells ◽  
Biological Species ◽  
Zebrafish Model ◽  
Physiological Processes ◽  
Collective Data ◽  
Angeli's Salt

Nitroxyl (HNO) plays a critical role in many physiological processes which includes vasorelaxation in heart failure, neuroregulation, and myocardial contractility. Powerful imaging tools are required to obtain information for understanding the mechanisms involved in these in vivo processes. In order to develop a rapid and high sensitive probe for HNO detection in living cells and the zebrafish model organism, 2-((2-(benzothiazole-2yl)benzylidene) amino)benzoic acid (AbTCA) as a ligand, and its corresponding copper(II) complex Cu(II)-AbTCA were synthesized. The reaction results of Cu(II)-AbTCA with Angeli’s salt showed that Cu(II)-AbTCA could detect HNO quantitatively in a range of 40–360 µM with a detection limit of 9.05 µM. Furthermore, Cu(II)-AbTCA is more selective towards HNO over other biological species including thiols, reactive nitrogen, and reactive oxygen species. Importantly, Cu(II)-AbTCA was successfully applied to detect HNO in living cells and zebrafish. The collective data reveals that Cu(II)-AbTCA could be used as a potential probe for HNO detection in living systems.

Localization and quantification of endoplasmic reticulum Ca(2+)-ATPase isoform transcripts

1995 ◽  
Vol 269 (3) ◽  
pp. C775-C784 ◽  
Author(s):  
K. D. Wu ◽  
W. S. Lee ◽  
J. Wey ◽  
D. Bungard ◽  
J. Lytton
Keyword(s):  
Endoplasmic Reticulum ◽  
Critical Role ◽  
Qualitative Assessment ◽  
Cell Physiology ◽  
Striated Muscles ◽  
Physiological Processes ◽  
Alternatively Spliced ◽  
Spleen Lymphocytes ◽  
Fast Twitch ◽  
In Cells

The Ca(2+)-adenosinetriphosphatase pump of the sarcoplasmic or endoplasmic reticulum (SERCA) plays a critical role in Ca2+ signaling and homeostasis in all cells and is encoded by a family of homologous and alternatively spliced genes. To understand more clearly the role the different isoforms play in cell physiology, we have undertaken a quantitative and qualitative assessment of the tissue distribution of transcripts encoding each SERCA isoform. SERCA1 expression is restricted to fast-twitch striated muscles, SERCA2a to cardiac and slow-twitch striated muscles, whereas SERCA2b is ubiquitously expressed. SERCA3 is expressed most abundantly in large and small intestine, thymus, and cerebellum and at lower levels in spleen, lymph node, and lung. In situ hybridization analyses revealed SERCA3 transcripts in cells of the intestinal crypt, the thymic cortex, and Purkinje cells in cerebellum. In addition, SERCA3 was expressed abundantly in isolated rat spleen lymphocytes, in various murine lymphoid cell lines, and in primary cultured microvascular endothelial cells. This analysis demonstrates that SERCA3 is expressed selectively in cells in which Ca2+ signaling plays a critical and sensitive role in regulating physiological processes.

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