Freezing tolerance of plants: current understanding and selected emerging concepts

2003 ◽  
Vol 81 (12) ◽  
pp. 1216-1223 ◽  
Author(s):  
Charles L Guy
Keyword(s):  
Gene Expression ◽  
Phase Transition ◽  
Freezing Tolerance ◽  
Higher Plants ◽  
Freezing Stress ◽  
Plant Tissues ◽  
Tolerance Mechanisms ◽  
Master Regulator ◽  
Spatial Redistribution ◽  
Physical Changes

The formation of ice on and inside plant tissues represents a major challenge to survival. The resulting phase transition and spatial redistribution of liquid water from inside the cell to extracellular ice results in physical changes to cells and enormous physical stresses and strains. The ability of higher plants to acclimate and tolerate freezing stress is a complex quantitative trait and the product of the activities of not one, but a sizable suite of genes. Many of the known cold-regulated genes are under the control of a primary master regulator, CBF/DREB1, but it is not likely to be the sole master regulator. In considering the origin of freezing tolerance in higher plants, it has been suggested that freezing tolerance likely arose by adopting drought tolerance mechanisms. This may explain why many genes responsive to cold stress are also responsive to drought and (or) other osmotic stresses.Key words: abiotic, dehydration, gene expression, physiology, signal transduction, transcriptome.

scholarly journals Melatonin as Master Regulator in Plant Growth, Development and Stress Alleviator for Sustainable Agricultural Production: Current Status and Future Perspectives

2020 ◽  
Vol 13 (1) ◽  
pp. 294
Author(s):  
Khadija Nawaz ◽  
Rimsha Chaudhary ◽  
Ayesha Sarwar ◽  
Bushra Ahmad ◽  
Asma Gul ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plant Growth ◽  
Crop Production ◽  
Higher Plants ◽  
Regulation Of Gene Expression ◽  
Current Status ◽  
Master Regulator ◽  
Abiotic Stressors ◽  
Pathogenesis Related Protein ◽  
Growth Development

Melatonin, a multifunctional signaling molecule, is ubiquitously distributed in different parts of a plant and responsible for stimulating several physiochemical responses against adverse environmental conditions in various plant systems. Melatonin acts as an indoleamine neurotransmitter and is primarily considered as an antioxidant agent that can control reactive oxygen and nitrogen species in plants. Melatonin, being a signaling agent, induces several specific physiological responses in plants that might serve to enhance photosynthesis, growth, carbon fixation, rooting, seed germination and defense against several biotic and abiotic stressors. It also works as an important modulator of gene expression related to plant hormones such as in the metabolism of indole-3-acetic acid, cytokinin, ethylene, gibberellin and auxin carrier proteins. Additionally, the regulation of stress-specific genes and the activation of pathogenesis-related protein and antioxidant enzyme genes under stress conditions make it a more versatile molecule. Because of the diversity of action of melatonin, its role in plant growth, development, behavior and regulation of gene expression it is a plant’s master regulator. This review outlines the main functions of melatonin in the physiology, growth, development and regulation of higher plants. Its role as anti-stressor agent against various abiotic stressors, such as drought, salinity, temperatures, UV radiation and toxic chemicals, is also analyzed critically. Additionally, we have also identified many new aspects where melatonin may have possible roles in plants, for example, its function in improving the storage life and quality of fruits and vegetables, which can be useful in enhancing the environmentally friendly crop production and ensuring food safety.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

scholarly journals DIPG-40. TARGETING MASTER REGULATOR DEPENDENCIES IN DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii294-iii295
Author(s):  
Jovana Pavisic ◽  
Chankrit Sethi ◽  
Chris Jones ◽  
Stergios Zacharoulis ◽  
Andrea Califano
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Treatment Options ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Low Grade ◽  
Precision Oncology ◽  
Pontine Glioma ◽  
Convection Enhanced Delivery ◽  
Master Regulator

Abstract Diffuse intrinsic pontine glioma (DIPG) remains a fatal disease with no effective drugs to date. Mutation-based precision oncology approaches are limited by lack of targetable mutations and genetic heterogeneity. We leveraged systems biology methodologies to discover common targetable disease drivers—master regulator proteins (MRs)—in DIPG to expand treatment options. Using the metaVIPER algorithm, we interrogated an integrated low grade glioma and GBM gene regulatory network with 31 DIPG-gene expression signatures to identify tumor-specific MRs by differential expression of their transcriptional targets. Unsupervised clustering identified MR signatures of upregulated activity in RRM2/TOP2A in 13 patients, CD3D in 5 patients, and MMP7, TACSTD2, RAC2 and SLC15A1/SLC34A2 in individual patients, all of which can be targeted. Notably, intratumoral administration of etoposide by convection enhanced delivery was effective in murine proneural gliomas in which TOP2 was identified as a MR while RRM2—targetable by drugs such as cladribine—has been shown to be a positive regulator of glioma progression whose knock-down inhibits tumor growth. We also prioritized drugs by their ability to reverse MR-activity signatures using a large drug-perturbation database. Patients clustered by predicted drug sensitivities with distinct groups of tumors predicted to respond to proteasome inhibitors, Thiotepa or Volasertib all of which have early evidence in treating gliomas. We will refine this analysis in a multi-institutional study of >100 patient gene expression profiles to define MR signatures driving known biological/molecular disease subtypes, use DIPG cell lines recapitulating common MR architectures to optimize therapy prioritization, and validate our findings in vivo.

Cold Response of Dedifferentiated Barley Cells at the Gene Expression, Hormone Composition, and Freezing Tolerance Levels: Studies on Callus Cultures

2012 ◽  
Vol 54 (2) ◽  
pp. 337-349 ◽  
Author(s):  
Ildikó Vashegyi ◽  
Zsuzsa Marozsán-Tóth ◽  
Gábor Galiba ◽  
Petre I. Dobrev ◽  
Radomira Vankova ◽  
...  
Keyword(s):  
Gene Expression ◽  
Freezing Tolerance ◽  
Callus Cultures ◽  
Cold Response

scholarly journals The Halophyte Halostachys caspica AP2/ERF Transcription Factor HcTOE3 Positively Regulates Freezing Tolerance in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangliu Yin ◽  
Youling Zeng ◽  
Jieyun Ji ◽  
Pengju Wang ◽  
Yufang Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Abscisic Acid ◽  
Freezing Tolerance ◽  
Critical Role ◽  
Extreme Temperature ◽  
Freezing Stress ◽  
Antioxidant Enzyme Activities ◽  
Transcription Factor Gene ◽  
Factor Gene ◽  
Halostachys Caspica

The APETALA2 (AP2) and ethylene-responsive element-binding factor (ERF) gene family is one of the largest plant-specific transcription factor gene families, which plays a critical role in plant development and evolution, as well as response to various stresses. The TARGET OF EAT3 (TOE3) gene is derived from Halostachys caspica and belongs to the AP2 subfamily with two AP2 DNA-binding domains. Currently, AP2 family mainly plays crucial roles in plant growth and evolution, yet there are few reports about the role of AP2 in abiotic stress tolerance. Here, we report HcTOE3, a new cold-regulated transcription factor gene, which has an important contribution to freezing tolerance. The main results showed that the expression of HcTOE3 in the H. caspica assimilating branches was strongly induced by different abiotic stresses, including high salinity, drought, and extreme temperature (heat, chilling, and freezing), as well as abscisic acid and methyl viologen treatments. Overexpressing HcTOE3 gene (OE) induced transgenic Arabidopsis plant tolerance to freezing stress. Under freezing treatment, the OE lines showed lower content of malondialdehyde and electrolyte leakage and less accumulation of reactive oxygen species compared with the wild type. However, the survival rates, antioxidant enzyme activities, and contents of osmotic adjustment substance proline were enhanced in transgenic plants. Additionally, the OE lines increased freezing tolerance by up-regulating the transcription level of cold responsive genes (CBF1, CBF2, COR15, COR47, KIN1, and RD29A) and abscisic acid signal transduction pathway genes (ABI1, ABI2, ABI5, and RAB18). Our results suggested that HcTOE3 positively regulated freezing stress and has a great potential as a candidate gene to improve plant freezing tolerance.

scholarly journals Phenylalanine and Tyrosine as Exogenous Precursors of Wheat (Triticum aestivum L.) Secondary Metabolism through PAL-Associated Pathways

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 476 ◽  
Author(s):  
Pavel Feduraev ◽  
Liubov Skrypnik ◽  
Anastasiia Riabova ◽  
Artem Pungin ◽  
Elina Tokupova ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Metabolic Pathways ◽  
Phenylalanine Ammonia Lyase ◽  
Higher Plants ◽  
Aromatic Amino Acids ◽  
Triticum Aestivum L ◽  
Plant Tissues ◽  
Plant Metabolism ◽  
Wide Range ◽  
Number Of Genes

Reacting to environmental exposure, most higher plants activate secondary metabolic pathways, such as the metabolism of phenylpropanoids. This pathway results in the formation of lignin, one of the most important polymers of the plant cell, as well as a wide range of phenolic secondary metabolites. Aromatic amino acids, such as phenylalanine and tyrosine, largely stimulate this process, determining two ways of lignification in plant tissues, varying in their efficiency. The current study analyzed the effect of phenylalanine and tyrosine, involved in plant metabolism through the phenylalanine ammonia-lyase (PAL) pathway, on the synthesis and accumulation of phenolic compounds, as well as lignin by means of the expression of a number of genes responsible for its biosynthesis, based on the example of common wheat (Triticum aestivum L.).

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