| 1. |
- Alallaq, Sanaria, et al.
(författare)
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Red Light Controls Adventitious Root Regeneration by Modulating Hormone Homeostasis in Picea abies Seedlings
- 2020
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Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Vegetative propagation relies on the capacity of plants to regeneratede novoadventitious roots (ARs), a quantitative trait controlled by the interaction of endogenous factors, such as hormones and environmental cues among which light plays a central role. However, the physiological and molecular components mediating light cues during AR initiation (ARI) remain largely elusive. Here, we explored the role of red light (RL) on ARI in de-rooted Norway spruce seedlings. We combined investigation of hormone metabolism and gene expression analysis to identify potential signaling pathways. We also performed extensive anatomical characterization to investigate ARI at the cellular level. We showed that in contrast to white light, red light promoted ARI likely by reducing jasmonate (JA) and JA-isoleucine biosynthesis and repressing the accumulation of isopentyl-adenine-type cytokinins. We demonstrated that exogenously applied JA and/or CK inhibit ARI in a dose-dependent manner and found that they possibly act in the same pathway. The negative effect of JA on ARI was confirmed at the histological level. We showed that JA represses the early events of ARI. In conclusion, RL promotes ARI by repressing the accumulation of the wound-induced phytohormones JA and CK.
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| 2. |
- Lakehal, Abdellah, et al.
(författare)
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A Molecular Framework for the Control of Adventitious Rooting by TIR1/AFB2-Aux/IAA-Dependent Auxin Signaling in Arabidopsis
- 2019
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Ingår i: Molecular Plant. - : Elsevier. - 1674-2052 .- 1752-9867. ; 12:11, s. 1499-1514
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Tidskriftsartikel (refereegranskat)abstract
- In Arabidopsis thaliana, canonical auxin-dependent gene regulation is mediated by 23 transcription factors from the AUXIN RESPONSE FACTOR (ARF) family that interact with auxin/indole acetic acid repressors (Aux/IAAs), which themselves form co-receptor complexes with one of six TRANSPORT INHIBITOR1/AUXIN-SIGNALLING F-BOX (TIR1/AFB) proteins. Different combinations of co-receptors drive specific sensing outputs, allowing auxin to control a myriad of processes. ARF6 and ARF8 are positive regulators of adventitious root initiation upstream of jasmonate, but the exact auxin co-receptor complexes controlling the transcriptional activity of these proteins has remained unknown. Here, using loss-of-function mutants we show that three Aux/IAA genes, IAA6, IAA9, and IAA17, act additively in the control of adventitious root (AR) initiation. These three IAA proteins interact with ARF6 and/or ARF8 and likely repress their activity in AR development. We show that TIR1 and AFB2 are positive regulators of AR formation and TIR1 plays a dual role in the control of jasmonic acid (JA) biosynthesis and conjugation, as several JA biosynthesis genes are up-regulated in the tir1-1 mutant. These results lead us to propose that in the presence of auxin, TIR1 and AFB2 form specific sensing complexes with IAA6, IAA9, and/or IAA17 to modulate JA homeostasis and control AR initiation.
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| 3. |
- Lakehal, Abdellah, et al.
(författare)
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Multiple Roles of Jasmonates in Shaping Rhizotaxis : Emerging Integrators
- 2020
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Ingår i: Jasmonate in Plant Biology. - New York, NY : Humana Press. - 9781071601419 - 9781071601440 - 9781071601426 ; , s. 3-22
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Bokkapitel (refereegranskat)abstract
- The root system and its architecture enormously contribute to plant survival and adaptation to the environment. Depending on the intrinsic genetic information and the surrounding rhizosphere, plants develop a highly plastic root system, which is a critical determinant for survival. Plant root system, which includes primary root (PR), lateral roots (LR) and adventitious roots (AR), is shaped by tightly controlled developmental programs. Phytohormones are the main signaling components that orchestrate and coordinate the genetic information and the external stimuli to shape the root system patterning or rhizotaxis. Besides their role in plant stress responses and defense against herbivory and pathogen attacks, jasmonic acid and its derivatives, including the receptor-active conjugate jasmonoyl-L-isoleucine (JA-Ile), emerge as potential regulators of rhizotaxis. In this chapter, we summarize and discuss the recent progress achieved during the recent years to understand the JA-mediated genetic and molecular networks guiding PR, LR, and AR initiation. We highlight the role of JAs as critical integrators in shaping rhizotaxis.
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| 4. |
- Mahapatra, Sarbanee, et al.
(författare)
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Microplastics and nanoplastics in environment: Sampling, characterization and analytical methods
- 2024
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Ingår i: Groundwater for Sustainable Development. - : Elsevier BV. - 2352-801X. ; 26
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Forskningsöversikt (refereegranskat)abstract
- Microplastics (MPs) and nanoplastics (NPs) have gained increasing attention in environmental research due to their ubiquitousness and potential impacts on natural environments and human health as per the UN Sustainable Development Goals (SDGs), particularly SDG-14 to address global threats where at least 12 SDGs, directly/indirectly impacts. Present review is undertaken to highlight the process of breakdown of diverse groups of plastic products in soil, surface water, and groundwater under the influence of different factors (UV, light, heat, microbe, etc.), which are mobilized as MPs/NPs to the surface water, groundwater, air, soil, and living organisms by different natural and anthropogenic processes. Review also highlights a comprehensive overview of the methodology for sampling, characterization, and analysis for these minuscule plastic particles (PPs) in various environmental samples, encompassing surface/subsurface water, sediments, soils, and biological organisms. The collection, extraction, and characterization of MPs/NPs, typically employ filtration processes, wherein a known volume of water is passed through a fine mesh to capture MPs/NPs from water samples. Sediment/soil samples require sieving and density separation techniques to isolate PPs from the surrounding matrix. Biological samples require digestion steps to remove organic matter, leaving behind plastics for analysis. Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and scanning electron microscopy (SEM) are commonly utilized to determine the polymer composition, size, shape, and surface characteristics of PPs. Quantification involves several approaches, visual counting, image analysis, and spectroscopic techniques. Abundance of MPs/NPs in the respective environmental samples (water, air, soil, etc.) can be determined by comparing the richness (i.e., number/mass) of plastics to the volume or weight of the original sample. Such comprehensive analytical methodologies contribute to understand the scope and magnitude of plastic pollution and its potential repercussions for ecosystems and human well-being, which are essential for developing the effective strategies to mitigate these pressing global environmental challenges for sustainable development.
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| 5. |
- Maity, Jyoti Prakash, et al.
(författare)
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Furfural removal from water by bioremediation process by indigenous Pseudomonas putida (OSBH3) and Pseudomonas aeruginosa (OSBH4) using novel suphala media : An optimization for field application
- 2023
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Ingår i: GROUNDWATER FOR SUSTAINABLE DEVELOPMENT. - : Elsevier BV. - 2352-801X. ; 20, s. 100895-
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Tidskriftsartikel (refereegranskat)abstract
- The release of furfural as effluent from industries has been considered a major pollution source since it adversely affects health and the environment. In a proper nutrient condition, the indigenous microbial removal process is always considered efficient, economical, and eco-friendly. Thus, the main objective is to employ the effective indigenous bacteria to remove the furfural from wastewater. In the present study, the indigenous isolates OSBH3 (strain number) and OSBH4 (strain number) were isolated from furfural-containing-oily-sludge and were iden-tified by 16S-rRNA technique with >99% nucleotide similarity as Pseudomonas putida (P. putida) (Acc. No. GU329915) and Pseudomonas aeruginosa (P. aeruginosa) (Acc. No. GU329916) respectively. In a batch experi-ment, the furfural degradation was observed higher in the presence of the most efficient isolate P. putida (compare to P. aeruginosa) at different nutrient conditions including Suphala (Nitrogen-Phosphorous-fertilizer), glucose, and carbohydrate-free synthetic media (CFM). Generally, the furfural degradation rate was lower in CFM than the other substrates (Nitrogen-Phosphorous-fertilizer/glucose), in the presence of P. putida or P. aeruginosa. The furfural degradation efficiency was observed higher in presence of P. putida, compare to P. aeruginosa. Experimentally, the total (100%) degradation of furfural (500 mg/L) was noticed by P. Putida within 12h incubation time in presence of 1 mg/L Suphala. Even among different factors (based on 'Taguchi L9 orthogonal array study'), the suphala (Nitrogen-Phosphorous-fertilizer) was influential in degrading the furfural at level 2, where the effects of pH and glucose were noticed at level 2 and level 2, respectively. The experimental findings supported the orthogonal array study positively. The bacterial (P. putida) growth rate and furfural degradation were promoted at the condition of 1 mg/L suphala, 2 mg/L glucose (pH 7.2), where the furfural was used by P. putida as the sole-carbon-source for growth. Thus, the indigenous P. putida (OSBH3; Acc. No. GU329915) (in presence of modified nitrogen-phosphorous-fertilizer media), can be applicable for furfural (Toxic) remediation from industrial effluent water by the eco-friendly process.
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| 6. |
- Pacurar, Daniel Ioan, et al.
(författare)
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The Arabidopsis Cop9 signalosome subunit 4 (CNS4) is involved in adventitious root formation
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The COP9 signalosome (CSN) is an evolutionary conserved multiprotein complex that regulates many aspects of plant development by controlling the activity of CULLIN-RING E3 ubiquitin ligases (CRLs). CRLs ubiquitinate and target for proteasomal degradation a vast number of specific substrate proteins involved in many developmental and physiological processes, including light and hormone signaling and cell division. As a consequence of CSN pleiotropic function, complete loss of CSN activity results in seedling lethality. Therefore, a detailed analysis of CSN physiological functions in adult Arabidopsis plants has been hampered by the early seedling lethality of csn null mutants. Here we report the identification and characterization of a viable allele of the Arabidopsis COP9 signalosome subunit 4 (CSN4). The allele, designated csn4-2035, suppresses the adventitious root (AR) phenotype of the Arabidopsis superroot2-1 mutant, potentially by altering its auxin signaling. Furthermore, we show that although the csn4-2035 mutation affects primary and lateral root (LR) formation in the 2035 suppressor mutant, CSN4 and other subunits of the COP9 complex seem to differentially control AR and LR development.
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| 7. |
- Ranjan, Alok, 1992, et al.
(författare)
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Adhesion Microscopy as a Nanoscale Probe for Oxidation and Charge Generation at Metal-Oxide Interfaces
- 2023
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Ingår i: ACS Applied Electronic Materials. - 2637-6113. ; 5:9, s. 5176-5186
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Tidskriftsartikel (refereegranskat)abstract
- We introduce a method combining adhesion and conductivity measurements using conduction atomic force microscopy (AFM) to infer the localized surface redox reactions and charge generation resulting from defects created during the electrical stressing of a thin oxide film. The method is demonstrated on a 3.3 nm thick SiO2, which is stressed by applying voltage to the AFM tip until soft dielectric breakdown (SBD) occurs, with the localized current-voltage characteristics and the tip-surface adhesion forces measured before and after the SBD event. The results show that under SBD, the field-driven diffusion of oxygen ions to the AFM tip leads to greatly enhanced adhesion because the oxygen reaching the surface forms strong chemical bonds with the tip material via oxidation. The electrical stressing also generates charged oxygen vacancy defects, and these are observed as an enhanced adhesion arising from image charge forces. The data presented can be corroborated to the physics of dielectric breakdown in transistor gate materials and conductive filament formation in memristor devices and could be extended to other technologies involving diffusion and surface reactivity of oxygen, e.g., solid oxide fuel cells and catalytic supports.
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| 8. |
- Ranjan, Alok, 1992, et al.
(författare)
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Estimating the Number of Defects in a Single Breakdown Spot of a Gate Dielectric
- 2024
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 45:5, s. 809-812
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Tidskriftsartikel (refereegranskat)abstract
- Conduction Atomic Force Microscopy (CAFM) is used to locally stress a 3.5 nm thick SiO2 film to induce soft dielectric breakdown (SBD). The tip-to-surface adhesion and current-voltage (I-V) characteristic at the breakdown location are measured by the CAFM before and after the SBD event. The adhesion force is enhanced after SBD because oxygen ion and charged defects are created at the SBD location during stressing which increases the adhesion via image charge forces. We show that the change in adhesion force, supported by charge transport modeling of the I-V data, can be effectively used to estimate the density and number of defects (~20-30) generated during SBD at a single breakdown spot. The information could be useful to assess the post-breakdown reliability and performance variability of the device.
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| 9. |
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| 10. |
- Ranjan, Alok, et al.
(författare)
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Molecular basis of differential adventitious rooting competence in poplar genotypes
- 2022
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Ingår i: Journal of Experimental Botany. - : Oxford University Press. - 0022-0957 .- 1460-2431. ; 73:12, s. 4046-4064
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Tidskriftsartikel (refereegranskat)abstract
- Recalcitrant adventitious root (AR) development is a major hurdle in propagating commercially important woody plants. Although significant progress has been made to identify genes involved in subsequent steps of AR development, the molecular basis of differences in apparent recalcitrance to form AR between easy-to-root and difficult-to-root genotypes remains unknown. To address this, we generated cambium tissue-specific transcriptomic data from stem cuttings of hybrid aspen, T89 (difficult-to-root) and hybrid poplar OP42 (easy-to-root), and used transgenic approaches to verify the role of several transcription factors in the control of adventitious rooting. Increased peroxidase activity was positively correlated with better rooting. We found differentially expressed genes encoding reactive oxygen species scavenging proteins to be enriched in OP42 compared with T89. A greater number of differentially expressed transcription factors in cambium cells of OP42 compared with T89 was revealed by a more intense transcriptional reprograming in the former. PtMYC2, a potential negative regulator, was less expressed in OP42 compared with T89. Using transgenic approaches, we demonstrated that PttARF17.1 and PttMYC2.1 negatively regulate adventitious rooting. Our results provide insights into the molecular basis of genotypic differences in AR and implicate differential expression of the master regulator MYC2 as a critical player in this process.
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