scholarly journals NADPH Oxidase RbohD and Ethylene Signaling are Involved in Modulating Seedling Growth and Survival Under Submergence Stress

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 471 ◽  
Author(s):  
Chen-Pu Hong ◽  
Mao-Chang Wang ◽  
Chin-Ying Yang
Keyword(s):  
Seed Germination ◽  
Nadph Oxidase ◽  
Root Growth ◽  
Chlorophyll Content ◽  
Double Mutant ◽  
Hypoxic Stress ◽  
Wild Type ◽  
Hypoxic Conditions ◽  
Submergence Stress ◽  
Hypoxia Signaling

In higher plants under low oxygen or hypoxic conditions, the phytohormone ethylene and hydrogen peroxide (H2O2) are involved in complex regulatory mechanisms in hypoxia signaling pathways. The respiratory burst oxidase homolog D (RbohD), an NADPH oxidase, is involved in the primary stages of hypoxia signaling, modulating the expression of downstream hypoxia-inducible genes under hypoxic stress. In this study, our data revealed that under normoxic conditions, seed germination was delayed in the rbohD/ein2-5 double mutant, whereas postgermination stage root growth was promoted. Under submergence, the rbohD/ein2-5 double mutant line had an inhibited root growth phenotype. Furthermore, chlorophyll content and leaf survival were reduced in the rbohD/ein2-5 double mutant compared with wild-type plants under submerged conditions. In quantitative RT-PCR analysis, the induction of Ethylene-responsive factor 73/hypoxia responsive 1 (AtERF73/HRE1) and alcohol dehydrogenase 1 (AtADH1) transcripts was lower in the rbohD/ein2-5 double mutant during hypoxic stress than in wild-type plants and in rbohD and ein2-5 mutant lines. Taken together, our results indicate that an interplay of ethylene and RbohD is involved in regulating seed germination and post-germination stages under normoxic conditions. Moreover, ethylene and RbohD are involved in modulating seedling root growth, leaf chlorophyll content, and hypoxia-inducible gene expression under hypoxic conditions.

Role of gp91phox-containing NADPH oxidase in left ventricular remodeling induced by intermittent hypoxic stress

2008 ◽  
Vol 294 (5) ◽  
pp. H2197-H2203 ◽  
Author(s):  
Tetsuya Hayashi ◽  
Chika Yamashita ◽  
Chika Matsumoto ◽  
Chol-Jun Kwak ◽  
Kiwako Fujii ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Nadph Oxidase ◽  
Intermittent Hypoxia ◽  
Sleep Apnea Syndrome ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Hypoxic Stress ◽  
Wild Type ◽  
Lv Remodeling

Intermittent hypoxia due to sleep apnea syndrome is associated with cardiovascular diseases. However, the precise mechanisms by which intermittent hypoxic stress accelerates cardiovascular diseases are largely unclear. The aim of this study was to investigate the role of gp91 phox-containing NADPH oxidase in the development of left ventricular (LV) remodeling induced by intermittent hypoxic stress in mice. Male gp91 phox-deficient (gp91−/−) mice ( n = 26) and wild-type ( n = 39) mice at 7–12 wk of age were exposed to intermittent hypoxia (30 s of 4.5–5.5% O2 followed by 30 s of 21% O2 for 8 h/day during daytime) or normoxia for 10 days. Mean blood pressure and LV systolic and diastolic function were not changed by intermittent hypoxia in wild-type or gp91−/− mice, although right ventricular systolic pressure tended to be increased. In wild-type mice, intermittent hypoxic stress significantly increased the diameter of cardiomyocytes and interstitial fibrosis in LV myocardium. Furthermore, intermittent hypoxic stress increased superoxide production, 4-hydroxy-2-nonenal protein, TNF-α and transforming growth factor-β mRNA, and NF-κB binding activity in wild-type, but not gp91−/−, mice. These results suggest that gp91 phox-containing NADPH oxidase plays a crucial role in the pathophysiology of intermittent hypoxia-induced LV remodeling through an increase of oxidative stress.

scholarly journals A Transaldolase From Aquilaria Sinensis Involves in Aba-mediated Seed Germination and Root Growth

2021 ◽  
Author(s):  
Yuqing Rong ◽  
Tiezheng Li ◽  
Xiao Liu ◽  
Shepo Shi ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Seed Germination ◽  
Root Growth ◽  
Pentose Phosphate ◽  
Wild Type ◽  
Aquilaria Sinensis ◽  
Phenotypic Analysis ◽  
Aba Metabolism ◽  
Expression Of Genes ◽  
Key Factor ◽  
Key Enzyme

Abstract Transaldolase, the key enzyme of the pentose-phosphate pathway, plays an important role in plant growth and defense. Seed germination is a key factor that influences the cultivation of Aquilaria sinensis, the plant source of agarwood, which is widely used as a traditional medicine, perfume and incenses. However, little is known about the function of transaldolase in abscisic acid (ABA)-mediated seed germination. In the present study, the full-length AsTal1 gene was isolated and characterized from A. sinensis calli. Sublocalization analysis indicated that AsTal1 was localized in the cytoplasm. In addition, phenotypic analysis indicated that AsTal1-overexpressing Nicotiana benthamiana (OE) plants were less sensitive to ABA during seed germination and root growth than wild-type (WT) plants. Overexpression of AsTal1 regulated the expression of genes involved in ABA metabolism, biosynthesis and signal transduction under ABA treatment. In addition, expression of NbRbohA and NbRbohB was inhibited in the overexpression lines, whereas the abundance and activities of the antioxidative enzymes SOD, APX, and POD were higher in the transgenic plants than in the WT lines after ABA treatment. Taken together, our results indicated that AsTal1 is involved in the ABA response during seed germination and root growth by regulating the expression of genes involved in the ABA signaling pathway and the enzymes responsive to ROS.

scholarly journals MicroRNA775 and target Galactosyltransferase (GALT9) module regulates recovery from submergence induced senescence by modulating SAGs in Arabidopsis thaliana

2021 ◽  
Author(s):  
Vishnu Mishra ◽  
Archita Singh ◽  
Nidhi Gandhi ◽  
Shabari Sarkar Das ◽  
Sandeep Yadav ◽  
...  
Keyword(s):  
Enhanced Recovery ◽  
Hypoxic Condition ◽  
Developmental Changes ◽  
Wild Type ◽  
Plant Growth And Development ◽  
Protein Coding ◽  
Hypoxic Conditions ◽  
Submergence Stress ◽  
Senescence Associated Genes

SummarySubmergence induced hypoxic condition is one of the abiotic stresses which negatively affects the plant growth and development, and causes early onset of senescence. Hypoxic conditions ateres the expression of a number of non-coding microRNAs (miRNAs), besides protein-coding genes. However, the molecular function of stress-induced miRNA in submergence induced physiological or developmental changes and recovery remains to be understood. The expression of miR775 is highly induced under hypoxic stress conditions. Here, we show that miR775 is a potential post-transcriptional regulator number of targets, including Galactosyltransferase (GALT9). The expression of miR775 and target GALT9 was significantly induced and reduced respectively at 24 hours of submergence. The overexpression of miR775 (miR775-Oe) confers enhanced recovery from submergence stress and reduced accumulation of ROS, in contrast to wild type and endogenous target mimic of miR775 (MIM775) Arabidopsis plants. We observed a similar recovery phenotype in case of target galt9 mutant plants, indicating the role of miR775-GALT9 module in recovery from submergence. Further, we showed that the expression of SENESCENCE ASSOCIATED GENES (SAGs), such as SAG12, SAG29, and ORE1. was increased in MIM775 and reduced in miR775-Oe and galt9 plants. Thus, our results suggest that miR775-GALT9 module plays a crucial role in the recovery from submergence by modulating the expression of SAGs through differential accumulation of ROS.

Effects of salinity stress on seed germination and root growth of seedlings in island cotton

2019 ◽  
Vol 45 (1) ◽  
pp. 100
Author(s):  
Qing-Qing YAN ◽  
Ju-Song ZHANG ◽  
Xing-Xing LI ◽  
Yan-Ti WANG
Keyword(s):  
Seed Germination ◽  
Root Growth ◽  
Salinity Stress ◽  
Growth Of Seedlings

scholarly journals Low ABA concentration promotes root growth and hydrotropism through relief of ABA INSENSITIVE 1-mediated inhibition of plasma membrane H+-ATPase 2

2021 ◽  
Vol 7 (12) ◽  
pp. eabd4113
Author(s):  
Rui Miao ◽  
Wei Yuan ◽  
Yue Wang ◽  
Irene Garcia-Maquilon ◽  
Xiaolin Dang ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Root Growth ◽  
Experimental System ◽  
Aba Signaling ◽  
Wild Type ◽  
Normal Medium ◽  
C Terminus ◽  
Quadruple Mutant ◽  
Aba Insensitive ◽  
Aba Receptors

The hab1-1abi1-2abi2-2pp2ca-1 quadruple mutant (Qabi2-2) seedlings lacking key negative regulators of ABA signaling, namely, clade A protein phosphatases type 2C (PP2Cs), show more apoplastic H+ efflux in roots and display an enhanced root growth under normal medium or water stress medium compared to the wild type. The presence of low ABA concentration (0.1 micromolar), inhibiting PP2C activity via monomeric ABA receptors, enhances root apoplastic H+ efflux and growth of the wild type, resembling the Qabi2-2 phenotype in normal medium. Qabi2-2 seedlings also demonstrate increased hydrotropism compared to the wild type in obliquely-oriented hydrotropic experimental system, and asymmetric H+ efflux in root elongation zone is crucial for root hydrotropism. Moreover, we reveal that Arabidopsis ABA-insensitive 1, a key PP2C in ABA signaling, interacts directly with the C terminus of Arabidopsis plasma membrane H+-dependent adenosine triphosphatase 2 (AHA2) and dephosphorylates its penultimate threonine residue (Thr947), whose dephosphorylation negatively regulates AHA2.

scholarly journals Expression of NADPH Oxidase-Dependent Resistance to Listeriosis in Mice Occurs during the First 6 to 12 Hours of Liver Infection

2002 ◽  
Vol 70 (12) ◽  
pp. 7179-7181 ◽  
Author(s):  
Ronald LaCourse ◽  
Lynn Ryan ◽  
Robert J. North
Keyword(s):  
Listeria Monocytogenes ◽  
Nadph Oxidase ◽  
Bacterial Load ◽  
Wild Type ◽  
Liver Infection

ABSTRACT Wild-type mice inoculated with Listeria monocytogenes intravenously were capable of reducing the bacterial load in their livers by 90% within 6 h. In contrast, mice with deletions of the gene for NADPH oxidase were incapable of expressing this early oxygen-dependent anti-Listeria defense and consequently showed higher levels of liver infection at later times.

scholarly journals Intermittent Hypoxia Affects the Spontaneous DifferentiationIn Vitroof Human Neutrophils into Long-Lived Giant Phagocytes

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Larissa Dyugovskaya ◽  
Slava Berger ◽  
Andrey Polyakov ◽  
Peretz Lavie ◽  
Lena Lavie
Keyword(s):  
Nadph Oxidase ◽  
Intermittent Hypoxia ◽  
Oxidase Inhibitor ◽  
Human Neutrophils ◽  
Hypoxic Conditions ◽  
Oxygen Conditions ◽  
Extended Lifespan ◽  
First Time ◽  
Dose Dependent

Previously we identified, for the first time, a new small-size subset of neutrophil-derived giant phagocytes (Gϕ) which spontaneously developin vitrowithout additional growth factors or cytokines. Gϕare CD66b+/CD63+/MPO+/LC3B+and are characterized by extended lifespan, large phagolysosomes, active phagocytosis, and reactive oxygen species (ROS) production, and autophagy largely controls their formation. Hypoxia, and particularly hypoxia/reoxygenation, is a prominent feature of many pathological processes. Herein we investigated Gϕformation by applying various hypoxic conditions. Chronic intermittent hypoxia (IH) (29 cycles/day for 5 days) completely abolished Gϕformation, while acute IH had dose-dependent effects. Exposure to 24 h (56 IH cycles) decreased their size, yield, phagocytic ability, autophagy, mitophagy, and gp91-phox/p22-phoxexpression, whereas under 24 h sustained hypoxia (SH) the size and expression of LC3B and gp91-phox/p22-phoxresembled Gϕformed in normoxia. Diphenyl iodide (DPI), a NADPH oxidase inhibitor, as well as the PI3K/Akt and autophagy inhibitor LY294002 abolished Gϕformation at all oxygen conditions. However, the potent antioxidant, N-acetylcysteine (NAC) abrogated the effects of IH by inducing large CD66b+/LC3B+Gϕand increased both NADPH oxidase expression and phagocytosis. These findings suggest that NADPH oxidase, autophagy, and the PI3K/Akt pathway are involved in Gϕdevelopment.

scholarly journals IC138 Defines a Subdomain at the Base of the I1 Dynein That Regulates Microtubule Sliding and Flagellar Motility

2009 ◽  
Vol 20 (13) ◽  
pp. 3055-3063 ◽  
Author(s):  
Raqual Bower ◽  
Kristyn VanderWaal ◽  
Eileen O'Toole ◽  
Laura Fox ◽  
Catherine Perrone ◽  
...  
Keyword(s):  
Double Mutant ◽  
Essential Role ◽  
Null Allele ◽  
Flagellar Motility ◽  
Wild Type ◽  
Gene Encoding ◽  
Radial Spoke ◽  
Mutant Strains ◽  
Dynein Arms ◽  
Image Averaging

To understand the mechanisms that regulate the assembly and activity of flagellar dyneins, we focused on the I1 inner arm dynein (dynein f) and a null allele, bop5-2, defective in the gene encoding the IC138 phosphoprotein subunit. I1 dynein assembles in bop5-2 axonemes but lacks at least four subunits: IC138, IC97, LC7b, and flagellar-associated protein (FAP) 120—defining a new I1 subcomplex. Electron microscopy and image averaging revealed a defect at the base of the I1 dynein, in between radial spoke 1 and the outer dynein arms. Microtubule sliding velocities also are reduced. Transformation with wild-type IC138 restores assembly of the IC138 subcomplex and rescues microtubule sliding. These observations suggest that the IC138 subcomplex is required to coordinate I1 motor activity. To further test this hypothesis, we analyzed microtubule sliding in radial spoke and double mutant strains. The results reveal an essential role for the IC138 subcomplex in the regulation of I1 activity by the radial spoke/phosphorylation pathway.

scholarly journals Aspergillus nidulans Protein O-Mannosyltransferases Play Roles in Cell Wall Integrity and Developmental Patterning

2009 ◽  
Vol 8 (10) ◽  
pp. 1475-1485 ◽  
Author(s):  
Thanyanuch Kriangkripipat ◽  
Michelle Momany
Keyword(s):  
Cell Wall ◽  
Aspergillus Nidulans ◽  
Double Mutant ◽  
Elevated Temperatures ◽  
Cell Wall Integrity ◽  
Wild Type ◽  
Spatial Cues ◽  
Developmental Patterning ◽  
In The Wild ◽  
Increased Sensitivity

ABSTRACT Protein O-mannosyltransferases (Pmts) initiate O-mannosyl glycan biosynthesis from Ser and Thr residues of target proteins. Fungal Pmts are divided into three subfamilies, Pmt1, -2, and -4. Aspergillus nidulans possesses a single representative of each Pmt subfamily, pmtA (subfamily 2), pmtB (subfamily 1), and pmtC (subfamily 4). In this work, we show that single Δpmt mutants are viable and have unique phenotypes and that the ΔpmtA ΔpmtB double mutant is the only viable double mutant. This makes A. nidulans the first fungus in which all members of individual Pmt subfamilies can be deleted without loss of viability. At elevated temperatures, all A. nidulans Δpmt mutants show cell wall-associated defects and increased sensitivity to cell wall-perturbing agents. The Δpmt mutants also show defects in developmental patterning. Germ tube emergence is early in ΔpmtA and more frequent in ΔpmtC mutants than in the wild type. In ΔpmtB mutants, intrahyphal hyphae develop. All Δpmt mutants show distinct conidiophore defects. The ΔpmtA strain has swollen vesicles and conidiogenous cells, the ΔpmtB strain has swollen conidiophore stalks, and the ΔpmtC strain has dramatically elongated conidiophore stalks. We also show that AN5660, an ortholog of Saccharomyces cerevisiae Wsc1p, is modified by PmtA and PmtC. The Δpmt phenotypes at elevated temperatures, increased sensitivity to cell wall-perturbing agents and restoration to wild-type growth with osmoticum suggest that A. nidulans Pmts modify proteins in the cell wall integrity pathway. The altered developmental patterns in Δpmt mutants suggest that A. nidulans Pmts modify proteins that serve as spatial cues.

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