Plant Responses to Light Stress: Oxidative Damages, Photoprotection, and Role of Phytohormones

2016 ◽  
pp. 181-213 ◽  
Author(s):  
Aditya Banerjee ◽  
Aryadeep Roychoudhury
Keyword(s):  
Light Stress ◽  
Plant Responses ◽  
Oxidative Damages ◽  
Stress Oxidative

scholarly journals The Role of Chloroplast Gene Expression in Plant Responses to Environmental Stress

2020 ◽  
Vol 21 (17) ◽  
pp. 6082 ◽  
Author(s):  
Yi Zhang ◽  
Aihong Zhang ◽  
Xiuming Li ◽  
Congming Lu
Keyword(s):  
Gene Expression ◽  
Environmental Stress ◽  
Stress Responses ◽  
Light Stress ◽  
High Light ◽  
Plant Responses ◽  
Chloroplast Gene ◽  
Chloroplast Gene Expression ◽  
Endosymbiotic Origin

Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment.

Role of potassium transporter KUP8 in plant responses to heavy metals

2021 ◽  
Author(s):  
María Sanz‐Fernández ◽  
Alejandro Rodríguez‐González ◽  
Luisa M. Sandalio ◽  
María C. Romero‐Puertas
Keyword(s):  
Heavy Metals ◽  
Plant Responses ◽  
Potassium Transporter

scholarly journals Multifunctional Role of Chitosan Edible Coatings on Antioxidant Systems in Fruit Crops: A Review

2021 ◽  
Vol 22 (5) ◽  
pp. 2633
Author(s):  
Giuseppina Adiletta ◽  
Marisa Di Matteo ◽  
Milena Petriccione
Keyword(s):  
State Of The Art ◽  
Antioxidant Systems ◽  
Edible Coatings ◽  
Ros Production ◽  
Oxygen Species ◽  
Fruit Crops ◽  
Oxidative Damages ◽  
Film Forming ◽  
Anti Oxidant

Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years.

scholarly journals Transcriptomic and genetic approaches reveal an essential role of the NAC transcription factor SlNAP1 in the growth and defense response of tomato

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiao Wang ◽  
Chenfei Zheng ◽  
Xiangqi Shao ◽  
Zhangjian Hu ◽  
Jianxin Li ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Defense Response ◽  
Global Climate ◽  
Plant Responses ◽  
Multiple Stresses ◽  
Bacterial Diseases ◽  
Bacterial Wilt Disease ◽  
Transgenic Lines ◽  
Breeding Target

AbstractWith global climate change, plants are frequently being exposed to various stresses, such as pathogen attack, drought, and extreme temperatures. Transcription factors (TFs) play crucial roles in numerous plant biological processes; however, the functions of many tomato (Solanum lycopersicum L.) TFs that regulate plant responses to multiple stresses are largely unknown. Here, using an RNA-seq approach, we identified SlNAP1, a NAC TF-encoding gene, which was strongly induced by various stresses. By generating SlNAP1 transgenic lines and evaluating their responses to biotic and abiotic stresses in tomato, we found that SlNAP1-overexpressing plants showed significantly enhanced defense against two widespread bacterial diseases, leaf speck disease, caused by Pseudomonas syringae pv. tomato (Pst) DC3000, and root-borne bacterial wilt disease, caused by Ralstonia solanacearum. In addition, SlNAP1 overexpression dramatically improved drought tolerance in tomato. Although the SlNAP1-overexpressing plants were shorter than the wild-type plants during the early vegetative stage, eventually, their fruit yield increased by 10.7%. Analysis of different hormone contents revealed a reduced level of physiologically active gibberellins (GAs) and an increased level of salicylic acid (SA) and abscisic acid (ABA) in the SlNAP1-overexpressing plants. Moreover, EMSAs and ChIP-qPCR assays showed that SlNAP1 directly activated the transcription of multiple genes involved in GA deactivation and both SA and ABA biosynthesis. Our findings reveal that SlNAP1 is a positive regulator of the tomato defense response against multiple stresses and thus may be a potential breeding target for improving crop yield and stress resistance.

scholarly journals The differential role of reactive oxygen species in early and late stages of cancer

2017 ◽  
Vol 313 (6) ◽  
pp. R646-R653 ◽  
Author(s):  
Mohamad Assi
Keyword(s):  
Reactive Oxygen Species ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Reactive Oxygen ◽  
Pentose Phosphate ◽  
Oxygen Species ◽  
Redox Biology ◽  
Oxidative Damages ◽  
Late Stages

The large doses of vitamins C and E and β-carotene used to reduce reactive oxygen species (ROS) production and oxidative damages in cancerous tissue have produced disappointing and contradictory results. This therapeutic conundrum was attributed to the double-faced role of ROS, notably, their ability to induce either proliferation or apoptosis of cancer cells. However, for a ROS-inhibitory approach to be effective, it must target ROS when they induce proliferation rather than apoptosis. On the basis of recent advances in redox biology, this review underlined a differential regulation of prooxidant and antioxidant system, respective to the stage of cancer. At early precancerous and neoplastic stages, antioxidant activity decreases and ROS appear to promote cancer initiation via inducing oxidative damage and base pair substitution mutations in prooncogenes and tumor suppressor genes, such as RAS and TP53, respectively. Whereas in late stages of cancer progression, tumor cells escape apoptosis by producing high levels of intracellular antioxidants, like NADPH and GSH, via the pentose phosphate pathway to buffer the excessive production of ROS and related intratumor oxidative injuries. Therefore, antioxidants should be prohibited in patients with advanced stages of cancer and/or undergoing anticancer therapies. Interestingly, the biochemical and biophysical properties of some polyphenols allow them to selectively recognize tumor cells. This characteristic was exploited to design and deliver nanoparticles coated with low doses of polyphenols and containing chemotherapeutic drugs into tumor-bearing animals. First results are encouraging, which may revolutionize the conventional use of antioxidants in cancer.

scholarly journals Role of Ca2+ in Mediating Plant Responses to Extracellular ATP and ADP

2018 ◽  
Vol 19 (11) ◽  
pp. 3590 ◽  
Author(s):  
Greg Clark ◽  
Stanley Roux
Keyword(s):  
Cytosolic Calcium ◽  
Defense Responses ◽  
Receptor Activation ◽  
Extracellular Atp ◽  
Extracellular Nucleotides ◽  
Nucleoside Triphosphate ◽  
Plant Responses ◽  
Downstream Signaling ◽  
Nucleoside Triphosphate Diphosphohydrolase

Among the most recently discovered chemical regulators of plant growth and development are extracellular nucleotides, especially extracellular ATP (eATP) and extracellular ADP (eADP). Plant cells release ATP into their extracellular matrix under a variety of different circumstances, and this eATP can then function as an agonist that binds to a specific receptor and induces signaling changes, the earliest of which is an increase in the concentration of cytosolic calcium ([Ca2+]cyt). This initial change is then amplified into downstream-signaling changes that include increased levels of reactive oxygen species and nitric oxide, which ultimately lead to major changes in the growth rate, defense responses, and leaf stomatal apertures of plants. This review presents and discusses the evidence that links receptor activation to increased [Ca2+]cyt and, ultimately, to growth and diverse adaptive changes in plant development. It also discusses the evidence that increased [Ca2+]cyt also enhances the activity of apyrase (nucleoside triphosphate diphosphohydrolase) enzymes that function in multiple subcellular locales to hydrolyze ATP and ADP, and thus limit or terminate the effects of these potent regulators.

scholarly journals Cadmium toxicity in plants

2005 ◽  
Vol 17 (1) ◽  
pp. 21-34 ◽  
Author(s):  
María P. Benavides ◽  
Susana M. Gallego ◽  
María L. Tomaro
Keyword(s):  
Metal Ions ◽  
Cadmium Toxicity ◽  
Environmental Pollutants ◽  
Environmental Pollutant ◽  
Present Knowledge ◽  
Plant Responses ◽  
Cellular Mechanisms ◽  
Higher Plant ◽  
Potential Damage

Heavy metals are important environmental pollutants and their toxicity is a problem of increasing significance for ecological, evolutionary, nutritional, and environmental reasons. Plants posses homeostatic cellular mechanisms to regulate the concentration of metal ions inside the cell to minimize the potential damage that could result from the exposure to nonessential metal ions. This paper summarizes present knowledge in the field of higher plant responses to cadmium, an important environmental pollutant. Knowledge concerning metal toxicity, including mechanisms of cadmium homeostasis, uptake, transport and accumulation are evaluated. The role of the cell wall, the plasma membrane and the mycorrhizas, as the main barriers against cadmium entrance to the cell, as well as some aspects related to phytochelatin-based sequestration and compartmentalization processes are also reviewed. Cadmium-induced oxidative stress was also considered as one of the most studied topics of cadmium toxicity.

On the Role of Salicylic Acid in Plant Responses to Environmental Stresses

2017 ◽  
pp. 17-34 ◽  
Author(s):  
José A. Hernández ◽  
Pedro Diaz-Vivancos ◽  
Gregorio Barba-Espín ◽  
María José Clemente-Moreno
Keyword(s):  
Salicylic Acid ◽  
Environmental Stresses ◽  
Plant Responses

scholarly journals Arabidopsis Mediator subunit 17 connects transcription with DNA repair after UV-B exposure

2021 ◽  
Author(s):  
Marisol Giustozzi ◽  
Santiago Freytes ◽  
Aime Jaskolowski ◽  
Micaela Lichy ◽  
Julieta L. Mateos ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Transcription Initiation ◽  
Plant Responses ◽  
Repair System ◽  
Root Tips ◽  
Direct Role ◽  
Altered Expression ◽  
Eukaryotic Organisms

Mediator 17 (MED17) is a subunit of the Mediator complex that regulates transcription initiation in eukaryotic organisms. In yeast and humans, MED17 also participates in DNA repair, physically interacting with proteins of the Nucleotide Excision DNA Repair system. We here analyzed the role of MED17 in Arabidopsis plants exposed to UV-B radiation, which role has not been previously described. Comparison of med17 mutant transcriptome to that of WT plants showed that almost one third of transcripts with altered expression in med17 plants are also changed by UV-B exposure in WT plants. To validate the role of MED17 in UV-B irradiated plants, plant responses to UV-B were analyzed, including flowering time, DNA damage accumulation and programmed cell death in the meristematic cells of the root tips. Our results show that med17 and OE MED17 plants have altered responses to UV-B; and that MED17 participates in various aspects of the DNA damage response (DDR). Increased sensitivity to DDR after UV-B in med17 plants can be due to altered regulation of UV-B responsive transcripts; but additionally MED17 physically interacts with DNA repair proteins, suggesting a direct role of this Mediator subunit during repair. Finally, we here also show that MED17 is necessary to regulate the DDR activated by ATR, and that PDCD5 overexpression reverts the deficiencies in DDR shown in med17 mutants. Together, the data presented demonstrates that MED17 is an important regulator of the DDR after UV-B radiation in Arabidopsis plants.

scholarly journals Genes Encoding Cucumber Full-Size ABCG Proteins Show Different Responses to Plant Growth Regulators and Sclareolide

2015 ◽  
Vol 34 (4) ◽  
pp. 720-736 ◽  
Author(s):  
Adam Rajsz ◽  
Anna Warzybok ◽  
Magdalena Migocka
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Expression Profiles ◽  
Plant Responses ◽  
Full Size ◽  
Genes Encoding ◽  
Plant Genes ◽  
Cucumber Roots

AbstractFull-size members of the ABCG (ATP-binding cassette, subfamily G) subfamily of ABC transporters have been found only in plants and fungi. The plant genes encoding full-size ABCGs identified so far appeared to be differentially regulated under various environmental constraints, plant growth regulators, and microbial elicitors, indicating a broad functional role of these proteins in plant responses to abiotic and biotic stress. Nevertheless, the structure and physiological function of full-size ABCGs in many plant species are still unknown. We have recently identified 16 genes encoding full-size ABCG proteins in cucumber and found that the transcripts of two of them, CsABCG36 (CsPDR8) and CsABCG40 (CsPDR12), are most abundant in roots and are significantly affected by phytohormones and auxin herbicide. In this study, we analyzed the structure and phylogeny of all the full-size cucumber ABCG transporters and studied the organ expression profiles of the remaining 14 CsABCG genes. In addition, we investigated the effect of different plant growth regulators and the diterpene sclareolide on CsABCG expression in cucumber roots. Until now, the full-size plant ABCG transporters have been grouped into five different clusters. The new phylogenetic analysis of full-size ABCGs from model plants and cucumber clustered these proteins into six different subgroups. Interestingly, the expression profiles of cucumber ABCG genes assigned to the same clusters were not correlated, suggesting functional diversification or different regulatory mechanisms of the full-size cucumber ABCG proteins.

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