scholarly journals Annexin 1 Is a Component of eATP-Induced Cytosolic Calcium Elevation in Arabidopsis thaliana Roots

2021 ◽  
Vol 22 (2) ◽  
pp. 494
Author(s):  
Amirah Mohammad-Sidik ◽  
Jian Sun ◽  
Ryoung Shin ◽  
Zhizhong Song ◽  
Youzheng Ning ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cytosolic Calcium ◽  
Loss Of Function ◽  
Transport Pathway ◽  
Annexin 1 ◽  
Signalling Molecule ◽  
Ros Accumulation ◽  
Intracellular Ros ◽  
Genetic Level ◽  
Calcium Elevation

Extracellular ATP (eATP) has long been established in animals as an important signalling molecule but this is less understood in plants. The identification of Arabidopsis thaliana DORN1 (Does Not Respond to Nucleotides) as the first plant eATP receptor has shown that it is fundamental to the elevation of cytosolic free Ca2+ ([Ca2+]cyt) as a possible second messenger. eATP causes other downstream responses such as increase in reactive oxygen species (ROS) and nitric oxide, plus changes in gene expression. The plasma membrane Ca2+ influx channels involved in eATP-induced [Ca2+]cyt increase remain unknown at the genetic level. Arabidopsis thaliana Annexin 1 has been found to mediate ROS-activated Ca2+ influx in root epidermis, consistent with its operating as a transport pathway. In this study, the loss of function Annexin 1 mutant was found to have impaired [Ca2+]cyt elevation in roots in response to eATP or eADP. Additionally, this annexin was implicated in modulating eATP-induced intracellular ROS accumulation in roots as well as expression of eATP-responsive genes.

scholarly journals Impaired Cuticle Functionality and Robust Resistance to Botrytis cinerea in Arabidopsis thaliana Plants With Altered Homogalacturonan Integrity Are Dependent on the Class III Peroxidase AtPRX71

2021 ◽  
Vol 12 ◽  
Author(s):  
Riccardo Lorrai ◽  
Fedra Francocci ◽  
Kay Gully ◽  
Helle J. Martens ◽  
Giulia De Lorenzo ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Botrytis Cinerea ◽  
Primary Cell Wall ◽  
Loss Of Function ◽  
Class Iii ◽  
Ros Accumulation ◽  
Receptor Like Kinase ◽  
Cuticle Ultrastructure ◽  
Class Iii Peroxidase

Pectin is a major cell wall component that plays important roles in plant development and response to environmental stresses. Arabidopsis thaliana plants expressing a fungal polygalacturonase (PG plants) that degrades homogalacturonan (HG), a major pectin component, as well as loss-of-function mutants for QUASIMODO2 (QUA2), encoding a putative pectin methyltransferase important for HG biosynthesis, show accumulation of reactive oxygen species (ROS), reduced growth and almost complete resistance to the fungal pathogen Botrytis cinerea. Both PG and qua2 plants show increased expression of the class III peroxidase AtPRX71 that contributes to their elevated ROS levels and reduced growth. In this work, we show that leaves of PG and qua2 plants display greatly increased cuticle permeability. Both increased cuticle permeability and resistance to B. cinerea in qua2 are suppressed by loss of AtPRX71. Increased cuticle permeability in qua2, rather than on defects in cuticle ultrastructure or cutin composition, appears to be dependent on reduced epidermal cell adhesion, which is exacerbated by AtPRX71, and is suppressed by the esmeralda1 mutation, which also reverts the adhesion defect and the resistant phenotype. Increased cuticle permeability, accumulation of ROS, and resistance to B. cinerea are also observed in mutants lacking a functional FERONIA, a receptor-like kinase thought to monitor pectin integrity. In contrast, mutants with defects in other structural components of primary cell wall do not have a defective cuticle and are normally susceptible to the fungus. Our results suggest that disrupted cuticle integrity, mediated by peroxidase-dependent ROS accumulation, plays a major role in the robust resistance to B. cinerea of plants with altered HG integrity.

Quantitative analysis of herbivore-induced cytosolic calcium by using a Cameleon (YC 3.6) calcium sensor in Arabidopsis thaliana

2014 ◽  
Vol 171 (2) ◽  
pp. 136-139 ◽  
Author(s):  
Francesca Verrillo ◽  
Andrea Occhipinti ◽  
Chidananda Nagamangala Kanchiswamy ◽  
Massimo E. Maffei
Keyword(s):  
Arabidopsis Thaliana ◽  
Quantitative Analysis ◽  
Cytosolic Calcium ◽  
Calcium Sensor

scholarly journals Protection against hydrogen peroxide cytotoxicity in Rat-1 fibroblasts provided by the oncoprotein Bcl-2: maintenance of calcium homoeostasis is secondary to the effect of Bcl-2 on cellular glutathione

1999 ◽  
Vol 340 (1) ◽  
pp. 291-297 ◽  
Author(s):  
Matthäus M. RIMPLER ◽  
Ursula RAUEN ◽  
Thorsten SCHMIDT ◽  
Tarik MÖRÖY ◽  
Herbert DE GROOT
Keyword(s):  
Cell Death ◽  
Calcium Concentration ◽  
Cell Injury ◽  
Cytosolic Calcium ◽  
Glutathione Metabolism ◽  
Transfected Cells ◽  
Cytosolic Calcium Concentration ◽  
Glutathione Status ◽  
Calcium Elevation ◽  
Reduced State

The oncoprotein Bcl-2 protects cells against apoptosis, but the exact molecular mechanism that underlies this function has not yet been identified. Studying H2O2-induced cell injury in Rat-1 fibroblast cells, we observed that Bcl-2 had a protective effect against the increase in cytosolic calcium concentration and subsequent cell death. Furthermore, overexpression of Bcl-2 resulted in an alteration of cellular glutathione status: the total amount of cellular glutathione was increased by about 60% and the redox potential of the cellular glutathione pool was maintained in a more reduced state during H2O2 exposure compared with non-Bcl-2-expressing controls. In our cytotoxicity model, disruption of cellular glutathione homoeostasis closely correlated with the pathological elevation of cytosolic calcium concentration. Stabilization of the glutathione pool by Bcl-2, N-acetylcysteine or glucose delayed the cytosolic calcium increase and subsequent cell death, whereas depletion of glutathione by DL-buthionine-(S,R)-sulphoximine, sensitized Bcl-2-transfected cells towards cytosolic calcium increase and cell death. We therefore suggest that the protection exerted by Bcl-2 against H2O2-induced cytosolic calcium elevation and subsequent cell death is secondary to its effect on the cellular glutathione metabolism.

scholarly journals The efficacy of CRISPR-mediated cytosine base editing with the RPS5a promoter in Arabidopsis thaliana

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Minkyung Choi ◽  
Jae-Young Yun ◽  
Jun-Hyuk Kim ◽  
Jin-Soo Kim ◽  
Sang-Tae Kim
Keyword(s):  
Arabidopsis Thaliana ◽  
Cytidine Deaminase ◽  
Biological Research ◽  
Loss Of Function ◽  
Nucleotide Substitutions ◽  
Viral Origin ◽  
Nonsense Mutations ◽  
Base Editing ◽  
Low Efficiency ◽  
Viable System

AbstractCRISPR/Cas9-mediated genome editing is an important and versatile technology in modern biological research. Recent advancements include base-editing CRISPR tools that enable targeted nucleotide substitutions using a fusion protein comprising a nickase variant of Cas9 and a base deaminase. Improvements in base editing efficiencies and inheritable of edited loci need to be made to make CRISPR a viable system in plants. Here, we report efficiency of cytosine base editors (CBEs) in Arabidopsis thaliana by applying the strong endogenous RPS5a promoter to drive the expression of nickase Cas9 and either rAPOBEC1 from rat (BE3) or the PmCDA1 activation-induced cytidine deaminase from sea lamprey (AIDv2). Compared with the strong heterologous CaMV35S promoter of viral origin, the RPS5a promoter improved CBE efficiency by 32% points with the number of T1 plants showing over 50% conversion ratio when the LFY gene was targeted. CBE induced nonsense mutations in LFY via C-to-T conversion, which resulted in loss-of-function lfy phenotypes; defects in LFY function were associated with the targeted base substitutions. Our data suggest that optimal promoter choice for CBE expression may affect base-editing efficiencies in plants. The results provide a strategy to optimize low-efficiency base editors and demonstrate their applicability for functional assays and trait development in crop research.

scholarly journals Bi-phasic effect of gelatin in myogenesis and skeletal muscle regeneration

2021 ◽  
Author(s):  
Xiaoling Liu ◽  
Er Zu ◽  
Xinyu Chang ◽  
Xiaowei Ma ◽  
Ziqi Wang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Antioxidant System ◽  
Muscle Regeneration ◽  
Chain Complex ◽  
Skeletal Muscle Regeneration ◽  
High Dose ◽  
Mild Stress ◽  
Ecm Remodeling ◽  
Ros Accumulation ◽  
Intracellular Ros

Skeletal muscle regeneration requires extracellular matrix (ECM) remodeling, including an acute and transient breakdown of collagen that produces gelatin. Although the physiological function of this process is unclear, it has inspired us to apply gelatin to injured skeletal muscle for a potential pro-regenerative effect. Here we elaborate on a bi-phasic effect of gelatin in skeletal muscle regeneration, mediated by hormetic effects of reactive oxygen species (ROS). Low-dose gelatin stimulates ROS production from NADPH oxidase 2 (NOX2) and simultaneously upregulates antioxidant system for cellular defense, reminiscent of the adaptive compensatory process during mild stress. This response triggers the release of myokine IL-6 that stimulates myogenesis and facilitates muscle regeneration. By contrast, high-dose gelatin stimulates ROS overproduction from NOX2 and mitochondrial chain complex, and ROS accumulation by suppressing antioxidant system, triggering release of TNFα, which inhibits myogenesis and regeneration. Our results have revealed a bi-phasic role of gelatin in regulating skeletal muscle repair mediated by intracellular ROS, antioxidant system, and cytokines (IL-6 and TNFα) signaling.

scholarly journals Control of auxin-regulated root development by the Arabidopsis thaliana SHY2/IAA3 gene

Development ◽  
1999 ◽  
Vol 126 (4) ◽  
pp. 711-721 ◽  
Author(s):  
Q. Tian ◽  
J.W. Reed
Keyword(s):  
Arabidopsis Thaliana ◽  
Lateral Root ◽  
Tissue Specificity ◽  
Plant Hormone ◽  
Root Formation ◽  
Auxin Transport ◽  
Feedback Regulation ◽  
Loss Of Function ◽  
Leaf Formation ◽  
Induced Genes

The plant hormone auxin controls many aspects of development and acts in part by inducing expression of various genes. Arabidopsis thaliana semidominant shy2 (short hypocotyl) mutations cause leaf formation in dark-grown plants, suggesting that SHY2 has an important role in regulating development. Here we show that the SHY2 gene encodes IAA3, a previously known member of the Aux/IAA family of auxin-induced genes. Dominant shy2 mutations cause amino acid changes in domain II, conserved among all members of this family. We isolated loss-of-function shy2 alleles including a putative null mutation. Gain-of-function and loss-of-function shy2 mutations affect auxin-dependent root growth, lateral root formation, and timing of gravitropism, indicating that SHY2/IAA3 regulates multiple auxin responses in roots. The phenotypes suggest that SHY2/IAA3 may activate some auxin responses and repress others. Models invoking tissue-specificity, feedback regulation, or control of auxin transport may explain these results.

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