The impact of aluminium on the distribution of cell wall glycoproteins of pea root tip and their Al-binding capacity

2001 ◽  
Vol 47 (3) ◽  
pp. 629-636 ◽  
Author(s):  
Saule Kenjebaeva ◽  
Yoko Yamamoto ◽  
Hideaki Matsumoto
Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1665
Author(s):  
Natalia Nikonorova ◽  
Evan Murphy ◽  
Cassio Flavio Fonseca de Lima ◽  
Shanshuo Zhu ◽  
Brigitte van de Cotte ◽  
...  

Auxin plays a dual role in growth regulation and, depending on the tissue and concentration of the hormone, it can either promote or inhibit division and expansion processes in plants. Recent studies have revealed that, beyond transcriptional reprogramming, alternative auxin-controlled mechanisms regulate root growth. Here, we explored the impact of different concentrations of the synthetic auxin NAA that establish growth-promoting and -repressing conditions on the root tip proteome and phosphoproteome, generating a unique resource. From the phosphoproteome data, we pinpointed (novel) growth regulators, such as the RALF34-THE1 module. Our results, together with previously published studies, suggest that auxin, H+-ATPases, cell wall modifications and cell wall sensing receptor-like kinases are tightly embedded in a pathway regulating cell elongation. Furthermore, our study assigned a novel role to MKK2 as a regulator of primary root growth and a (potential) regulator of auxin biosynthesis and signalling, and suggests the importance of the MKK2 Thr31 phosphorylation site for growth regulation in the Arabidopsis root tip.


2001 ◽  
Vol 47 (10) ◽  
pp. 935-942 ◽  
Author(s):  
Rajam Rajendran ◽  
Yoshiyuki Ohta

The fermented food, whole meal Natto, viscous polymeric material from Natto, Natto bean, cooked soya bean, and 28 bacterial isolates from Natto were studied for their binding capacity to foodborne mutagenic-carcinogenic heterocyclic amines. The mutagenic heterocyclic amines used were Trp-P-1 (3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole); Trp-P-2 (3-amino-1-methyl-5H-pyrido(4,3-b)indole); Glu-P-1 (2-amino-6-methyldipyrido(1,2-a:3'2'-d)imidazole); PhIP (2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine); IQ (2-amino-3-methylimidazo(4,5-f)quinoline); MeIQ (2-amino-3,4-dimethylimidazo(4,5-f)quinoxaline); MeIQx (2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline); and MeAαC (2-amino-3-methyl-9H-pyrido(2,3)indole). The lyophilized Natto and other fractions of Natto exhibited high binding activity towards Trp-P-1, Trp-P-2, PhIP, and MeAαC, while Glu-P-1, IQ, and MeIQ were not effectively bound. The binding capacity of bacterial isolates (Bacillus natto) were isolate-mutagen dependent. Heat treated lyophilized cells, cell wall, and cytoplasmic contents of the bacterial isolate with the highest binding capacity were analyzed for their ability to bind different heterocyclic amines. The results indicate the importance of the cell wall in binding to heterocyclic amines, whereas the cytoplasmic contents were less effective. Heat-treated cells were not much different from that of viable cells in their binding. The impact of different factors, such as pH, incubation time, metal ions, different concentrations of sodium chloride and alcohol, various enzymes, and acetylation of mutagens on binding of Trp-P-1 and IQ, were discussed. The significance of the present results is also discussed from the viewpoint that Natto, a fermented food, is able to scavenge dietary mutagenic heterocyclic amines through binding.Key words: fermented food, mutagens, heterocyclic amines, Natto, binding.


2021 ◽  
Author(s):  
Natalia Nikonorova ◽  
Evan Murphy ◽  
Cassio Flavio Fonseca de Lima ◽  
Shanshuo Zhu ◽  
Brigitte van de Cotte ◽  
...  

ABSTRACTAuxin plays a dual role in growth regulation and, depending on the tissue and concentration of the hormone, it can either promote or inhibit division and expansion processes in plants. Recent studies revealed that, beyond transcriptional reprogramming, alternative auxin-controlled mechanisms regulate root growth. Here, we explored the impact of different auxin concentrations on the root tip proteome and phosphoproteome, generating a unique resource. From the phosphoproteome data we pinpointed (novel) growth regulators, such as the RALF34-THE1 module. Our results together with previously published studies suggest that auxin, H+-ATPases, cell wall modifications and cell wall sensing receptor-like kinases are tightly embedded in a pathway regulating cell elongation. Furthermore, our study assigned a novel role to MKK2 as a regulator of primary root growth and a (potential) regulator of auxin biosynthesis and signalling, and suggests the importance of the MKK2 Thr31phosphorylation site for growth regulation in theArabidopsisroot tip.ONE SENTENCE SUMMARYAn auxin-triggered Arabidopsis root tip (phospho)proteome reveals novel root growth regulators


2019 ◽  
pp. 392-400 ◽  
Author(s):  
Gunnar Kleuker ◽  
Christa M. Hoffmann

The harvest of sugar beet leads to root tip breakage and surface damage through mechanical impacts, which increase storage losses. For the determination of textural properties of sugar beet roots with a texture analyzer a reliable method description is missing. This study aimed to evaluate the impact of washing, soil tare, storage period from washing until measurement, sample distribution and number of roots on puncture and compression measurements. For this purpose, in 2017 comprehensive tests were conducted with sugar beet roots grown in a greenhouse. In a second step these tests were carried out with different Beta varieties from a field trial, and in addition, a flexural test was included. Results show that the storage period after washing and the sample distribution had an influence on the puncture and compression strength. It is suggested to wash the roots by hand before the measurement and to determine the strength no later than 48 h after washing. For reliable and comparable results a radial distribution of measurement points around the widest circumference of the root is recommended for the puncture test. The sample position of the compression test had an influence on the compressive strength and therefore, needs to be clearly defined. For the puncture and the compression test it was possible to achieve stable results with a small sample size, but with increasing heterogeneity of the plant stand a higher number of roots is required. The flexural test showed a high variability and is, therefore, not recommended for the analysis of sugar beet textural properties.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Amandine Leroy ◽  
Xavier Falourd ◽  
Loïc Foucat ◽  
Valérie Méchin ◽  
Fabienne Guillon ◽  
...  

Abstract Background Biomass recalcitrance is governed by various molecular and structural factors but the interplay between these multiscale factors remains unclear. In this study, hot water pretreatment (HWP) was applied to maize stem internodes to highlight the impact of the ultrastructure of the polymers and their interactions on the accessibility and recalcitrance of the lignocellulosic biomass. The impact of HWP was analysed at different scales, from the polymer ultrastructure or water mobility to the cell wall organisation by combining complementary compositional, spectral and NMR analyses. Results HWP increased the kinetics and yield of saccharification. Chemical characterisation showed that HWP altered cell wall composition with a loss of hemicelluloses (up to 45% in the 40-min HWP) and of ferulic acid cross-linking associated with lignin enrichment. The lignin structure was also altered (up to 35% reduction in β–O–4 bonds), associated with slight depolymerisation/repolymerisation depending on the length of treatment. The increase in $${T}_{1\rho }^{H}$$ T 1 ρ H , $${T}_{HH}$$ T HH and specific surface area (SSA) showed that the cellulose environment was looser after pretreatment. These changes were linked to the increased accessibility of more constrained water to the cellulose in the 5–15 nm pore size range. Conclusion The loss of hemicelluloses and changes in polymer structural features caused by HWP led to reorganisation of the lignocellulose matrix. These modifications increased the SSA and redistributed the water thereby increasing the accessibility of cellulases and enhancing hydrolysis. Interestingly, lignin content did not have a negative impact on enzymatic hydrolysis but a higher lignin condensed state appeared to promote saccharification. The environment and organisation of lignin is thus more important than its concentration in explaining cellulose accessibility. Elucidating the interactions between polymers is the key to understanding LB recalcitrance and to identifying the best severity conditions to optimise HWP in sustainable biorefineries.


Biologia ◽  
2008 ◽  
Vol 63 (2) ◽  
Author(s):  
Lucia Mikolajová ◽  
Halina Vargová ◽  
Zora Hanáčková ◽  
Milada Čiamporová

AbstractUltrastructure was investigated along the files of developing epidermal cells in the root tip of a model plant Medicago sativa, in which all rhizodermal cells are potential hair-forming trichoblasts. Differentiation at subcellular level was observed up to the stage of bulge initiation in the trichoblasts. Root hair initiation indicated by the emergence of bulges from trichoblasts was detected at various distances from the root tip and, it was independent of the trichoblast size.During rhizodermal cell differentiation, starch grains accumulated in the plastids. Nuclei located in the central part of the young, meristematic cells moved towards the inner periclinal wall as the central vacuole enlarged. The bulging region of the trichoblasts located opposite the nucleus and was rich in mitochondria, ER, ribosomes, and Golgi bodies, and contained also vesicles enclosing fibrillar material. This material responded positively to phosphotungstic acid, which was used for detection of cell wall polysaccharides. The cell wall thickness within the bulging domain was significantly lower than in other parts of trichoblasts. We suggest that internalization of cell wall polysaccharides occurs within the bulging area, contributing to local thinning of the cell wall and providing a source of osmotically active compounds for maintaining turgor in the trichoblast. Thus, the internalization process might be necessary for root hair outgrowth.


2005 ◽  
Vol 1048 (1) ◽  
pp. 500-504 ◽  
Author(s):  
SONJA VELJOVIĆ-JOVANOVIĆ ◽  
BILJANA KUKAVICA ◽  
TIJANA CVETIĆ ◽  
MILOŠ MOJOVIĆ ◽  
ŽELJKO VUČINIĆ

2008 ◽  
Vol 74 (22) ◽  
pp. 6848-6858 ◽  
Author(s):  
F. Abram ◽  
E. Starr ◽  
K. A. G. Karatzas ◽  
K. Matlawska-Wasowska ◽  
A. Boyd ◽  
...  

ABSTRACT Sigma B (σB) is an alternative sigma factor that controls the transcriptional response to stress in Listeria monocytogenes and is also known to play a role in the virulence of this human pathogen. In the present study we investigated the impact of a sigB deletion on the proteome of L. monocytogenes grown in a chemically defined medium both in the presence and in the absence of osmotic stress (0.5 M NaCl). Two new phenotypes associated with the sigB deletion were identified using this medium. (i) Unexpectedly, the strain with the ΔsigB deletion was found to grow faster than the parent strain in the growth medium, but only when 0.5 M NaCl was present. This phenomenon was independent of the carbon source provided in the medium. (ii) The ΔsigB mutant was found to have unusual Gram staining properties compared to the parent, suggesting that σB contributes to the maintenance of an intact cell wall. A proteomic analysis was performed by two-dimensional gel electrophoresis, using cells growing in the exponential and stationary phases. Overall, 11 proteins were found to be differentially expressed in the wild type and the ΔsigB mutant; 10 of these proteins were expressed at lower levels in the mutant, and 1 was overexpressed in the mutant. All 11 proteins were identified by tandem mass spectrometry, and putative functions were assigned based on homology to proteins from other bacteria. Five proteins had putative functions related to carbon utilization (Lmo0539, Lmo0783, Lmo0913, Lmo1830, and Lmo2696), while three proteins were similar to proteins whose functions are unknown but that are known to be stress inducible (Lmo0796, Lmo2391, and Lmo2748). To gain further insight into the role of σB in L. monocytogenes, we deleted the genes encoding four of the proteins, lmo0796, lmo0913, lmo2391, and lmo2748. Phenotypic characterization of the mutants revealed that Lmo2748 plays a role in osmotolerance, while Lmo0796, Lmo0913, and Lmo2391 were all implicated in acid stress tolerance to various degrees. Invasion assays performed with Caco-2 cells indicated that none of the four genes was required for mammalian cell invasion. Microscopic analysis suggested that loss of Lmo2748 might contribute to the cell wall defect observed in the ΔsigB mutant. Overall, this study highlighted two new phenotypes associated with the loss of σB. It also demonstrated clear roles for σB in both osmotic and low-pH stress tolerance and identified specific components of the σB regulon that contribute to the responses observed.


2006 ◽  
Vol 143 (2) ◽  
pp. 773-783 ◽  
Author(s):  
Fushi Wen ◽  
Hans D. VanEtten ◽  
George Tsaprailis ◽  
Martha C. Hawes

2020 ◽  
Author(s):  
Colin Peter Singer Kruse ◽  
Alexander D Meyers ◽  
Proma Basu ◽  
Sarahann Hutchinson ◽  
Darron R Luesse ◽  
...  

Abstract Background: Understanding of gravity sensing and response is critical to long-term human habitation in space and can provide new advantages for terrestrial agriculture. To this end, the altered gene expression profile induced by microgravity has been repeatedly queried by microarray and RNA-seq experiments to understand gravitropism. However, the quantification of altered protein abundance in space has been minimally investigated. Results: Proteomic (iTRAQ-labelled LC-MS/MS) and transcriptomic (RNA-seq) analyses simultaneously quantified protein and transcript differential expression of three-day old, etiolated Arabidopsis thaliana seedlings grown aboard the International Space Station along with their ground control counterparts. Protein extracts were fractionated to isolate soluble and membrane proteins and analyzed to detect differentially phosphorylated peptides. In total, 968 RNAs, 107 soluble proteins, and 103 membrane proteins were identified as differentially expressed. In addition, the proteomic analyses identified 16 differential phosphorylation events. Proteomic data delivered novel insights and simultaneously provided new context to previously made observations of gene expression in microgravity. There is a sweeping shift in post-transcriptional mechanisms of gene regulation including RNA-decapping protein DCP5, the splicing factors GRP7 and GRP8, and AGO4,. These data also indicate AHA2 and FERONIA as well as CESA1 and SHOU4 as central to the cell wall adaptations seen in spaceflight. Patterns of tubulin-a 1, 3,4 and 6 phosphorylation further reveal an interaction of microtubule and redox homeostasis that mirrors osmotic response signaling elements. The absence of gravity also results in a seemingly wasteful dysregulation of plastid gene transcription. Conclusions: The datasets gathered from Arabidopsis seedlings exposed to microgravity revealed marked impacts on post-transcriptional regulation, cell wall synthesis, redox/microtubule dynamics, and plastid gene transcription. The impact of post-transcriptional regulatory alterations represents an unstudied element of the plant microgravity response with the potential to significantly impact plant growth efficiency and beyond. What’s more, addressing the effects of microgravity on AHA2, CESA1, and alpha tubulins has the potential to enhance cytoskeletal organization and cell wall composition, thereby enhancing biomass production and growth in microgravity. Finally, understanding and manipulating the dysregulation of plastid gene transcription has further potential to address the goal of enhancing plant growth in the stressful conditions of microgravity.


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