SUMMARY
Cytosolic glyceraldehyde‐3‐phosphate dehydrogenase (GAPC) is a glycolytic enzyme, but undergoes stress‐induced nuclear translocation for moonlighting. We previously reported that in response ...to heat stress, GAPC accumulated in the nucleus to modulate transcription and thermotolerance. Here we show a cellular and molecular mechanism that mediates heat‐induced nuclear translocation of cytosolic GAPC in Arabidopsis thaliana. Heat‐induced GAPC nuclear accumulation and plant heat tolerance were reduced in Arabidopsis phospholipase D (PLD) knockout mutants of pldδ and pldα1pldδ, but not of pldα1. These changes were restored to wild type by genetic complementation with active PLDδ, but not with catalytically inactive PLDδ. GAPC overexpression enhanced the seedling thermotolerance and the expression of heat‐inducible genes, but this effect was abolished in the pldδ background. Heat stress elevated the levels of the PLD product phosphatidic acid (PA) in the nucleus in wild type, but not in pldδ plants. Lipid labeling demonstrated the heat‐induced nuclear co‐localization of PA and GAPC, which was impaired by zinc, which inhibited the PA–GAPC interaction, and by the membrane trafficking inhibitor brefeldin A (BFA). The GAPC nuclear accumulation and seedling thermotolerance were also decreased by treatment with zinc or BFA. Our data suggest that PLDδ and PA are critical for the heat‐induced nuclear translocation of GAPC. We propose that PLDδ‐produced PA mediates the process via lipid–protein interaction and that the lipid mediation acts as a cellular conduit linking stress perturbations at cell membranes to nuclear functions in plants coping with heat stress.
Significance Statement
We found that the plasma membrane‐associated PLDδ and its product phosphatidic acid (PA) mediate heat‐induced nuclear translocation of cytosolic GAPC, and the lipid mediator PA may act as a cellular conduit linking stress perturbations at cell membranes to nuclear functions in plants coping with changing environments.
Abstract
Various stress conditions induce the nuclear translocation of cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC), but its nuclear function in plant stress responses remains elusive. ...Here we show that GAPC interacts with a transcription factor to promote the expression of heat-inducible genes and heat tolerance in Arabidopsis. GAPC accumulates in the nucleus under heat stress. Overexpression of
GAPC
enhances heat tolerance of seedlings and the expression of heat-inducible genes whereas knockout of
GAPCs
has opposite effects. Screening of Arabidopsis transcription factors identifies nuclear factor Y subunit C10 (NF-YC10) as a GAPC-binding protein. The effects of
GAPC
overexpression are abolished when
NF-YC10
is deficient, the heat-induced nuclear accumulation of GAPC is suppressed, or the GAPC-NF-YC10 interaction is disrupted.
GAPC
overexpression also enhances the binding ability of NF-YC10 to its target promoter. The results reveal a cellular and molecular mechanism for the nuclear moonlighting of a glycolytic enzyme in plant response to environmental changes.
Diacylglycerol kinase (DGK) phosphorylates diacylglycerol (DAG) to generate phosphatidic acid (PA), and both DAG and PA are lipid mediators in the cell. Here we show that DGK1 in rice (Oryza sativa) ...plays important roles in root growth and development.
Two independent OsDGK1-knockout (dgk1) lines exhibited a higher density of lateral roots (LRs) and thinner seminal roots (SRs), whereas OsDGK1-overexpressing plants displayed a lower LR density and thicker SRs than wild-type (WT) plants.
Overexpression of OsDGK1 led to a decline in the DGK substrate DAG whereas specific PA species decreased in dgk1 roots. Supplementation of DAG to OsDGK1-overexpressing seedlings restored the LR density and SR thickness whereas application of PA to dgk1 seedlings restored the LR density and SR thickness to those of the WT. In addition, treatment of rice seedlings with the DGK inhibitor R59022 increased the level of DAG and decreased PA, which also restored the root phenotype of OsDGK1-overexpressing seedlings close to that of the WT.
Together, these results indicate that DGK1 and associated lipid mediators modulate rice root architecture; DAG promotes LR formation and suppresses SR growth whereas PA suppresses LR number and promotes SR thickness.
Lipids function not only as the major structural components of cell membranes, but also as molecular messengers that transduce signals to trigger downstream signaling events in the cell. Phosphatidic ...acid (PA), the simplest and a minor class of glycerophospholipids, is a key intermediate for the synthesis of membrane and storage lipids, and also plays important roles in mediating diverse cellular and physiological processes in eukaryotes ranging from microbes to mammals and higher plants. PA comprises different molecular species that can act differently, and is found in virtually all organisms, tissues, and organellar membranes, with variations in total content and molecular species composition. The cellular levels of PA are highly dynamic in response to stimuli and multiple enzymatic reactions can mediate its production and degradation. Moreover, its unique physicochemical properties compared with other glycerophospholipids allow PA to influence membrane structure and dynamics, and interact with various proteins. PA has emerged as a class of new lipid mediators modulating various signaling and cellular processes via its versatile effects, such as membrane tethering, conformational changes, and enzymatic activities of target proteins, and vesicular trafficking.
Monomeric perylene diimide (PDI) small molecules display a high absorption coefficient and crystallinity in solid‐state thin films due to strong π–π interactions between the molecules. To take ...advantage of these exciting properties of PDIs, N,N'‐bis(1‐ethylpropyl)perylene‐3,4,9,10‐tetracarboxylic diimide (EP‐PDI) was mixed with a binary blend of PTB7 and PC71BM to fabricate an efficient ternary blend, which were in turn used to produce organic photovoltaic (OPV) devices well suited to indoor applications (PTB7=poly({4,8‐bis(2‐ethylhexyl)oxybenzo1,2‐b:4,5‐b′dithiophene‐2,6‐diyl}{3‐fluoro‐2‐(2‐ethylhexyl)carbonylthieno3,4‐bthiophenediyl}), PC71BM=6,6‐phenyl‐C71‐butyric acid methyl ester). We varied the PC71BM/EP‐PDI weight ratio to investigate the influence of EP‐PDI on the optical, electrical, and morphological properties of the PTB7:PC71BM:EP‐PDI ternary blend. Compared with the reference PTB7:PC71BM binary blend, the ternary blends showed strong optical absorption in the wavelength range in which the spectra of indoor LED lamps show their strongest peaks. The addition of EP‐PDI to the binary blend was found to play an important role in altering the morphology of the blend in such a way as to facilitate charge transport in the resulting ternary blend. Apparently, as a result, the optimal PTB7:PC71BM:EP‐PDI‐based inverted OPV device exhibited a power conversion efficiency (PCE) of 15.68 %, a fill factor (FF) of 68.5 %, and short‐circuit current density (JSC) of 56.7 μA cm−2 under 500 lx (ca. 0.17 mW cm−2) indoor LED light conditions.
An efficient ternary blend system for application in indoor organic photovoltaic (OPV) devices has been developed. The ternary blend system PTB7:PC71BM:EP‐PDI was designed to produce optimal OPV devices under indoor light‐emitting‐diode (LED) light conditions. The campion OPV device exhibited a high power conversion efficiency (PCE) of 15.68 % under 500 lx (ca. 0.17 mW cm−2) indoor LED light conditions.
The unique properties of organic photovoltaics (OPVs) offer great promise in emerging applications such as wearable electronics or the Internet of Things. For their successful utilization, OPV ...operation should be designed for versatile irradiation circumstances in addition to solar light since they should be capable of providing electric power when there is no sunlight or when they operate indoors. Here, a quaternary OPV (Q‐OPV) as a semitransparent, colorful energy platform that operates efficiently under both solar and artificial light irradiation is demonstrated. The experimentally optimized Q‐OPV shows a broadened spectral response and improved charge transport process with suppressed recombination, thereby providing high output powers that are sufficient to autonomously operate low‐power electronic devices. In addition, the Q‐OPV benefits from improved morphological stability with a reduced driving force for grain growth by the increased entropy in the quaternary blend system. The important features of the Q‐OPV platform such as semitransparency, high tolerance to film thickness, and color codability, while pursuing the improved performance and thermal durability, further open new opportunities as an all‐day (24/7/365) power generator in broad practical applications.
Quaternary blend organic photovoltaics (Q‐OPVs) exhibit efficient operation under diverse irradiation conditions and improved thermal durability with suppressed morphological evolution during operation. The unique properties of the Q‐OPVs such as semitransparency, high film thickness tolerance, and color codability expand their applicability to emerging energy systems, which operate autonomously by any incident light all day, even when there is no sunlight.
ABSTRACT Narrow-line Seyfert 1 galaxies (NLS1s) are arguably one of the key active galactic nucleus (AGN) subclasses in investigating the origin of the black hole mass-stellar velocity dispersion ( ) ...relation because of their high accretion rate and significantly low . Currently, it is under discussion whether present-day NLS1s offset from the relation. Using the directly measured stellar velocity dispersion of 93 NLS1s at z < 0.1, and estimates based on the updated mass estimators, we investigate the relation of NLS1s in comparison with broad-line AGNs. We find no strong evidence that the NLS1s deviates from the relation, which is defined by reverberation-mapped type 1 AGNs and quiescent galaxies. However, there is a clear trend of the offset with the host galaxy morphology, i.e., galaxies that are more inclined toward the LOS have higher stellar velocity dispersions, suggesting that the rotational broadening plays a role in measuring stellar velocity dispersion based on the single-aperture spectra from the Sloan Digital Sky Survey. In addition, we provide the virial factor (f = 1.12), for estimators based on the FWHM of Hβ, by jointly fitting the relation using quiescent galaxies and reverberation-mapped AGNs.
Phospholipases D (PLD) and C (PLC) hydrolyze the phosphodiesteric linkages of the head group of membrane phospholipids. PLDs and PLCs in plants occur in different forms: the calcium-dependent ...phospholipid binding domain-containing PLDs (C2-PLDs), the plekstrin homology and phox homology domain-containing PLDs (PX/PH-PLDs), phosphoinositide-specific PLC (PI-PLC), and non-specific PLC (NPC). They differ in structures, substrate selectivities, cofactor requirements, and/or reaction conditions. These enzymes and their reaction products, such as phosphatidic acid (PA), diacylglycerol (DAG), and inositol polyphosphates, play important, multifaceted roles in plant response to abiotic and biotic stresses. Here, we review biochemical properties, cellular effects, and physiological functions of PLDs and PLCs, particularly in the context of their roles in stress response along with advances made on the role of PA and DAG in cell signaling in plants. The mechanism of actions, including those common and distinguishable among different PLDs and PLCs, will also be discussed.
In this study, wasted mask is chosen as a pyrolysis feedstock whose generation has incredibly increased these days due to COVID-19. We suggest a way to produce value-added chemicals (e.g., aromatic ...compounds) from the mask with high amounts through catalytic fast pyrolysis (CFP). To this end, the effects of zeolite catalyst properties on the upgradation efficiency of pyrolytic products produced from pyrolysis of wasted mask were investigated. The compositions and yields of pyrolytic gases and oils were characterized as functions of pyrolysis temperature and the type of zeolite catalyst (HBeta, HY, and HZSM-5), including the mesoporous catalyst of Al-MCM-41. The mask was pyrolyzed in a fixed bed reactor, and the pyrolysis gases evolved in the reactor was routed to a secondary reactor inside which the zeolite catalyst was loaded. It was chosen 550 °C as the CFP temperature to compare the catalyst performance for the production of benzene, toluene, ethylbenzene, and xylene (BTEX) because this temperature gave the highest oil yield (80.7 wt%) during the non-catalytic pyrolysis process. The large pore zeolite group of HBeta and HY led to 134% and 67% higher BTEX concentrations than HZSM-5, respectively, likely because they had larger pores, higher surface areas, and higher acid site density than the HZSM-5. This is the first report of the effect of zeolite characteristics on BTEX production via CFP.
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•Catalytic pyrolysis for transforming COVID-19 mask to BTEX was investigated.•HZSM-5 was not effective at making BTEX from the mask due to small pores.•Big enough pores allowing branched hydrocarbons enter and acidity are required to transform the mask to BTEX.
Effective valorization of COVID-19 mask to value-added chemicals like BTEX via catalytic pyrolysis is highly associated with large pores and high acid site density of zeolite.
•Catalytic copyrolysis of yellow poplar and high density polyethylene was performed.•Torrefaction of yellow poplar produced large amounts of aromatics.•HZSM-5 produced larger amounts of aromatics ...than Al-MCM-41.•In-situ catalytic co-pyrolysis was more efficient than ex-situ reaction.
The catalytic pyrolysis of lignocellulosic biomass with aluminosilicate catalysts is a promising method for the direct production of liquid hydrocarbon fuels consisting mainly of aromatic compounds (e.g., benzene, toluene, and xylenes). On the other hand, the economic and commercial viability of this process is limited by the low yields of aromatic hydrocarbons. In this study, the effects of biomass torrefaction, co-feeding of plastic wastes, their combination, and the catalytic upgrading mode (in-situ vs ex-situ) on the aromatic formation efficiency during the catalytic pyrolysis of yellow poplar were evaluated systematically to maximize the production of aromatic hydrocarbons. Two representative catalysts for catalytic pyrolysis (i.e., microporous HZSM-5 and mesoporous Al-MCM-41) were used in this case study. The torrefaction of yellow poplar led to the enhanced production of aromatic hydrocarbons in the catalytic co-pyrolysis of yellow poplar and high-density polyethylene over both catalysts. The experimental yields of aromatic hydrocarbons from the catalytic co-pyrolysis of torrefied yellow poplar and high-density polyethylene were also higher than their theoretical yields, highlighting the synergistic aromatic formation by the interaction of torrefied yellow poplar and high-density polyethylene. Between the two catalysts, microporous HZSM-5 exhibited much higher activity for aromatic production from catalytic co-pyrolysis owing to its strong acidity and appropriate pore structure. Compared to ex-situ catalytic co-pyrolysis, the in-situ catalytic co-pyrolysis of torrefied yellow poplar and high-density polyethylene produced larger amounts of aromatic hydrocarbons due to the more effective contact between the pyrolysis vapors and HZSM-5.
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