Pectin remodeling belongs to a homeostatic system and triggers transcriptomic and hormonal modulations

Pectins occur in primary cell walls and consist of multiblock co‐polymers among which homogalacturonan (HG) is the simplest and most abundant form. Methylesterification patterns of HG are tuned by pectin methylesterases (PMEs), the activities of which are controlled by specific inhibitors (PMEIs). By impacting cell wall mechanical properties, PME‐mediated regulation of HG methylesterification plays a major role in several developmental processes, including seed germination and dark-grown hypocotyl elongation. Arabidopsis PME36 is preferentially expressed during the late stage of seed development and, using the knock‐out mutant pme36-1, we show here that PME36 is required to implement the characteristic pattern of de-methylesterified pectin in the mature seed. Surprisingly, while this pattern is strongly impaired in pme36-1 mature seed, no phenotypical effect is observed in the mutant during seed germination and dark-grown hypocotyl elongation, suggesting the existence of a compensatory mechanism overcoming the defect in pectin de-methylesterification. By analyzing hormone contents and gene expression, a strong, dynamic, and long-lasting physiological disorder is revealed in the mutant. These results suggest the existence of complex connections between pectin remodeling, transcriptomic regulations and hormonal homeostasis, modulating several physiological parameters to ensure the maintenance of a normal seed-to-seedling developmental program in pme36-1. Considered for a long time as an end-point passive effector mainly involved in modification of cell wall mechanics, the role of pectin methylesterification needs to be reconsidered as a modulator acting upstream of diverse regulatory pathways involved in plant development.

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The CBL-Interacting Protein Kinase NtCIPK23 Positively Regulates Seed Germination and Early Seedling Development in Tobacco (Nicotiana tabacum L.)

Plants ◽

10.3390/plants10020323 ◽

2021 ◽

Vol 10 (2) ◽

pp. 323

Author(s):

Sujuan Shi ◽

Lulu An ◽

Jingjing Mao ◽

Oluwaseun Olayemi Aluko ◽

Zia Ullah ◽

...

Keyword(s):

Protein Kinase ◽

Seed Germination ◽

Seedling Growth ◽

Hypocotyl Elongation ◽

Interacting Protein ◽

Knock Out ◽

Early Seedling Growth ◽

Tobacco Seedlings ◽

Early Seedling ◽

Cotyledon Expansion

CBL-interacting protein kinase (CIPK) family is a unique group of serine/threonine protein kinase family identified in plants. Among this family, AtCIPK23 and its homologs in some plants are taken as a notable group for their importance in ions transport and stress responses. However, there are limited reports on their roles in seedling growth and development, especially in Solanaceae plants. In this study, NtCIPK23, a homolog of AtCIPK23 was cloned from Nicotiana tabacum. Expression analysis showed that NtCIPK23 is mainly expressed in the radicle, hypocotyl, and cotyledons of young tobacco seedlings. The transcriptional level of NtCIPK23 changes rapidly and spatiotemporally during seed germination and early seedling growth. To study the biological function of NtCIPK23 at these stages, the overexpressing and CRISPR/Cas9-mediated knock-out (ntcipk23) tobacco lines were generated. Phenotype analysis indicated that knock-out of NtCIPK23 significantly delays seed germination and the appearance of green cotyledon of young tobacco seedling. Overexpression of NtCIPK23 promotes cotyledon expansion and hypocotyl elongation of young tobacco seedlings. The expression of NtCIPK23 in hypocotyl is strongly upregulated by darkness and inhibited under light, suggesting that a regulatory mechanism of light might underlie. Consistently, a more obvious difference in hypocotyl length among different tobacco materials was observed in the dark, compared to that under the light, indicating that the upregulation of NtCIPK23 contributes greatly to the hypocotyl elongation. Taken together, NtCIPK23 not only enhances tobacco seed germination, but also accelerate early seedling growth by promoting cotyledon greening rate, cotyledon expansion and hypocotyl elongation of young tobacco seedlings.

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The expansin EXP1 gene in the elongation zone is induced during soybean embryonic axis germination and differentially expressed in response to ABA and PEG treatments

Seed Science Research ◽

10.1017/s0960258520000379 ◽

2020 ◽

pp. 1-9

Author(s):

Nidia H. Montechiarini ◽

Luciana Delgado ◽

Eligio N. Morandi ◽

Néstor J. Carrillo ◽

Carlos O. Gosparini

Keyword(s):

Cell Wall ◽

Seed Germination ◽

Water Availability ◽

Expression Profiles ◽

Soybean Seed ◽

Embryonic Axis ◽

Growth Potential ◽

Elongation Zone ◽

Degenerate Primers ◽

Embryonic Axes

Abstract During soybean seed germination, the expansive growth potential of the embryonic axes is driven by water uptake while cell wall loosening occurs in cells from the elongation zone (EZ). Expansins are regarded as primary promoters of cell wall remodelling in all plant expansion processes, with the expression profiles of the soybean expansins supporting their cell or tissue specificity. Therefore, we used embryonic axes isolated from whole seed and focused on the EZ to study seed germination. Using a suite of degenerate primers, we amplified an abundantly expressed expansin gene at the EZ during soybean embryonic axis germination, which was identified as EXP1 by in silico analyses. Expression studies showed that EXP1 was induced under germination conditions in distilled water and down-regulated by abscisic acid (ABA), which inhibits soybean germination by physiologically restraining expansion. Moreover, we also identified a time window of ABA responsiveness within the first 6 h of incubation in water, after which ABA lost control of both EXP1 expression and embryonic axis germination, thus confirming the early role of EXP1 in the EZ during this process. By contrast, EXP1 levels in the EZ increased even when germination was impaired by osmotically limiting the water availability required to develop the embryonic axes’ growth potential. We propose that these higher EXP1 levels are involved in the fast germination of soybean embryonic axes as soon as water availability is re-established. Taken together, our results show strong EXP1 expression in the EZ and postulate EXP1 as a target candidate for soybean seed germination control.

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CRISPR–Cas9 gene editing as a tool for developing immunotherapy for cancer

10.31219/osf.io/dvr4t ◽

2021 ◽

Author(s):

Moataz Dowaidar

Keyword(s):

T Cells ◽

Immune Cells ◽

Peripheral Blood ◽

Gene Editing ◽

Genetically Engineered ◽

Cancer Resistance ◽

Knock Out ◽

Tumor Tissues ◽

Engineered T Cells ◽

Long Time

T cells following genome editing and transformation might be detectable in peripheral blood and tumor tissues for a long time, even more than a year. The types and diversity of T-cells in peripheral blood and tumor tissues changed following transfusion of genetically modified T-cells, and some highly suspected T-cells targeting cancer cells grew, increasing the proportion of such cells. Moreover, after getting genetically engineered T cells, anticancer cytokine secretion increased. T cells changed by gene editing have certain functions, at least from an immunological standpoint. The first clinical research using the CRISPR–Cas9 gene editing method for cancer resistance is more complicated: Using CRISPR–Cas9 gene editing technology to concurrently knock out, amplify, activate and reinfuse three genes in human immune cells. This therapeutic strategy is more demanding, because the changed immune cells have a wider target scope. The data suggest that the efficacy of gene editing in immune cells was 15–45%, and the modified cells could survive long in the peripheral blood and tumor tissues of patients. After three or four months, some T-cells became central T-cells. These encouraging findings pave the way for future experimental cancer research utilizing CRISPR technology.

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Asymbiotic Germination of Mature Seeds and the Seed Development of Vanilla Planifolia

10.21203/rs.3.rs-138206/v1 ◽

2021 ◽

Author(s):

Chih-Hsin Yeh ◽

Kai-Yi Chen ◽

Yung-I Lee

Keyword(s):

Cell Wall ◽

Seed Germination ◽

Seed Development ◽

Seed Coat ◽

Germination Percentage ◽

Vanilla Planifolia ◽

Outermost Layer ◽

Seed Pretreatment ◽

Immature Seeds ◽

Mature Seeds

Abstract Background: Vanilla planifolia is an important tropical orchid for production of natural vanilla flavor. Traditionally, V. planifolia is propagated by stem cuttings, which produces identical genotype that are sensitive to virulent pathogens. However, sexual propagation with seed germination of V. planifolia is intricate and unstable because of the extremely hard seed coat. A better understanding of seed development, especially the formation of impermeable seed coat would provide insights into seed propagation and conservation of genetic resources of Vanilla.Results: We found that soaking mature seeds in 4 % sodium hypochlorite solution from 75 to 90 min significantly increased germination and that immature seeds collected at 45 days after pollination (DAP) had the highest germination percentage. We then investigated the anatomical features during seed development that associated with the effect of seed pretreatment on raising seed germination percentage. The 45-DAP immature seeds have developed globular embryos and the thickened non-lignified cell wall at the outermost layer of the outer seed coat. After 60 DAP, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope. These features matches the significant decreases of immature seed germination percentage after 60 DAP. Conclusion: We report a reliable protocol for seed pretreatment of mature seeds and for immature seeds culture based on a defined time schedule of V. plantifolia seed development. The thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, and might play an important role in seed dormancy of V. plantifolia.

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Dimethylarsinic acid is the causal agent inducing rice straighthead disease

Journal of Experimental Botany ◽

10.1093/jxb/eraa253 ◽

2020 ◽

Vol 71 (18) ◽

pp. 5631-5644 ◽

Cited By ~ 2

Author(s):

Zhong Tang ◽

Yijie Wang ◽

Axiang Gao ◽

Yuchen Ji ◽

Baoyun Yang ◽

...

Keyword(s):

Cell Wall ◽

Stress Responses ◽

Arsenic Species ◽

Causal Agent ◽

Dimethylarsinic Acid ◽

Cell Wall Modification ◽

Physiological Disorder ◽

Field Surveys ◽

Methyltransferase Gene ◽

Oxidative Stress Responses

Abstract Straighthead disease is a physiological disorder in rice with symptoms of sterile spikelets, distorted husks, and erect panicles. Methylated arsenic species have been implicated as the causal agent of the disease, but direct evidence is lacking. Here, we investigated whether dimethylarsinic acid (DMA) causes straighthead disease and its effect on the transcriptome of young panicles. DMA addition caused typical straighthead symptoms in hydroponic culture, which were alleviated by silicon addition. DMA addition to soil at the tillering to flowering stages induced straighthead disease. Transgenic rice expressing a bacterial arsenite methyltransferase gene gained the ability to methylate arsenic to mainly DMA, with the consequence of inducing straighthead disease. Field surveys showed that seed setting rate decreased with increasing DMA concentration in the husk, with an EC50 of 0.18 mg kg−1. Transcriptomic analysis showed that 364 and 856 genes were significantly up- and down-regulated, respectively, in the young panicles of DMA-treated plants compared with control, whereas Si addition markedly reduced the number of genes affected. Among the differentially expressed genes, genes related to cell wall modification and oxidative stress responses were the most prominent, suggesting that cell wall metabolism is a sensitive target of DMA toxicity and silicon protects against this toxicity.

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Vibrio choleraeadapts to sessile and motile lifestyles by cyclic di-GMP regulation of cell shape

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2010199117 ◽

2020 ◽

Vol 117 (46) ◽

pp. 29046-29054 ◽

Cited By ~ 1

Author(s):

Nicolas L. Fernandez ◽

Brian Y. Hsueh ◽

Nguyen T. Q. Nhu ◽

Joshua L. Franklin ◽

Yann S. Dufour ◽

...

Keyword(s):

Cell Wall ◽

Cell Shape ◽

Guanosine Monophosphate ◽

Human Pathogen ◽

Flagellar Motility ◽

Wild Type ◽

Gene Encoding ◽

Regulatory Pathways ◽

Matrix Components ◽

Curved Rod

The cell morphology of rod-shaped bacteria is determined by the rigid net of peptidoglycan forming the cell wall. Alterations to the rod shape, such as the curved rod, occur through manipulating the process of cell wall synthesis. The human pathogenVibrio choleraetypically exists as a curved rod, but straight rods have been observed under certain conditions. While this appears to be a regulated process, the regulatory pathways controlling cell shape transitions inV. choleraeand the benefits of switching between rod and curved shape have not been determined. We demonstrate that cell shape inV. choleraeis regulated by the bacterial second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) by posttranscriptionally repressing expression ofcrvA, a gene encoding an intermediate filament-like protein necessary for curvature formation inV. cholerae.This regulation is mediated by the transcriptional cascade that also induces production of biofilm matrix components, indicating that cell shape is coregulated withV. cholerae’s induction of sessility. During microcolony formation, wild-typeV. choleraecells tended to exist as straight rods, while genetically engineering cells to maintain high curvature reduced microcolony formation and biofilm density. Conversely, straightV. choleraemutants have reduced swimming speed when using flagellar motility in liquid. Our results demonstrate regulation of cell shape in bacteria is a mechanism to increase fitness in planktonic and biofilm lifestyles.

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Arabidopsis MDN1 Is Involved in the Establishment of a Normal Seed Proteome and Seed Germination

Frontiers in Plant Science ◽

10.3389/fpls.2019.01118 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 1

Author(s):

Peng-Cheng Li ◽

Jun-Jie Ma ◽

Xi-Meng Zhou ◽

Guang-Hui Li ◽

Chuan-Zhi Zhao ◽

...

Keyword(s):

Seed Germination ◽

Normal Seed ◽

Seed Proteome

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The Cell Envelope Stress Response of Bacillus subtilis towards Laspartomycin C

Antibiotics ◽

10.3390/antibiotics9110729 ◽

2020 ◽

Vol 9 (11) ◽

pp. 729

Author(s):

Angelika Diehl ◽

Thomas M. Wood ◽

Susanne Gebhard ◽

Nathaniel I. Martin ◽

Georg Fritz

Keyword(s):

Cell Wall ◽

Bacillus Subtilis ◽

Stress Response ◽

Cell Envelope ◽

Resistance Mechanisms ◽

Detailed Knowledge ◽

Knock Out ◽

Lipid Ii ◽

Envelope Stress ◽

The Impact

Cell wall antibiotics are important tools in our fight against Gram-positive pathogens, but many strains become increasingly resistant against existing drugs. Laspartomycin C is a novel antibiotic that targets undecaprenyl phosphate (UP), a key intermediate in the lipid II cycle of cell wall biosynthesis. While laspartomycin C has been thoroughly examined biochemically, detailed knowledge about potential resistance mechanisms in bacteria is lacking. Here, we use reporter strains to monitor the activity of central resistance modules in the Bacillus subtilis cell envelope stress response network during laspartomycin C attack and determine the impact on the resistance of these modules using knock-out strains. In contrast to the closely related UP-binding antibiotic friulimicin B, which only activates ECF σ factor-controlled stress response modules, we find that laspartomycin C additionally triggers activation of stress response systems reacting to membrane perturbation and blockage of other lipid II cycle intermediates. Interestingly, none of the studied resistance genes conferred any kind of protection against laspartomycin C. While this appears promising for therapeutic use of laspartomycin C, it raises concerns that existing cell envelope stress response networks may already be poised for spontaneous development of resistance during prolonged or repeated exposure to this new antibiotic.

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Dependence of Plant Cell Wall Composition and Structure on Cellulose Synthase-Like Knock Out Mutant

Biophysical Journal ◽

10.1016/j.bpj.2011.11.3219 ◽

2012 ◽

Vol 102 (3) ◽

pp. 590a-591a

Author(s):

Andreia M. Smith-Moritz ◽

Jeemeng Lao ◽

Joshua L. Heazlewood ◽

Pamela C. Ronald ◽

Miguel E. Vega-Sanchez

Keyword(s):

Cell Wall ◽

Plant Cell ◽

Plant Cell Wall ◽

Cellulose Synthase ◽

Cell Wall Composition ◽

Knock Out ◽

Composition And Structure

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Cyclic Dinucleotide-Controlled Regulatory Pathways in Streptomyces Species

Journal of Bacteriology ◽

10.1128/jb.00423-15 ◽

2015 ◽

Vol 198 (1) ◽

pp. 47-54 ◽

Cited By ~ 17

Author(s):

Natalia Tschowri

Keyword(s):

Cell Wall ◽

Current Knowledge ◽

Second Messengers ◽

Streptomyces Species ◽

Content Type ◽

Regulatory Pathways ◽

Cellular Processes ◽

Signal Transduction Networks ◽

Cyclic Dinucleotides ◽

Cyclic Dinucleotide

The cyclic dinucleotides cyclic 3′,5′-diguanylate (c-di-GMP) and cyclic 3′,5′-diadenylate (c-di-AMP) have emerged as key components of bacterial signal transduction networks. These closely related second messengers follow the classical general principles of nucleotide signaling by integrating diverse signals into regulatory pathways that control cellular responses to changing environments. They impact distinct cellular processes, with c-di-GMP having an established role in promoting bacterial adhesion and inhibiting motility and c-di-AMP being involved in cell wall metabolism, potassium homeostasis, and DNA repair. The involvement of c-dinucleotides in the physiology of the filamentous, nonmotile streptomycetes remained obscure until recent discoveries showed that c-di-GMP controls the activity of the developmental master regulator BldD and that c-di-AMP determines the level of the resuscitation-promoting factor A(RpfA) cell wall-remodelling enzyme. Here, I summarize our current knowledge of c-dinucleotide signaling inStreptomycesspecies and highlight the important roles of c-di-GMP and c-di-AMP in the biology of these antibiotic-producing, multicellular bacteria.

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