Cytosolic CTP Production Limits the Establishment of Photosynthesis in Arabidopsis

CTP synthases (CTPS) comprise a protein family of the five members CTPS1-CTPS5 in Arabidopsis, all located in the cytosol. Specifically, downregulation of CTPS2 by amiRNA technology results in plants with defects in chlorophyll accumulation and photosynthetic performance early in development. CTP and its deoxy form dCTP are present at low levels in developing seedlings. Thus, under conditions of fast proliferation, the synthesis of CTP (dCTP) can become a limiting factor for RNA and DNA synthesis. The higher sensitivity of ami-CTPS2 lines toward the DNA-Gyrase inhibitor ciprofloxacin, together with reduced plastid DNA copy number and 16S and 23S chloroplast ribosomal RNA support this view. High expression and proposed beneficial biochemical features render CTPS2 the most important isoform for early seedling development. In addition, CTPS2 was identified as an essential enzyme in embryo development before, as knock-out mutants were embryo lethal. In line with this, ami-CTPS2 lines also exhibited reduced seed numbers per plant.

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Ectopic Expression of Glycine max GmNAC109 Enhances Drought Tolerance and ABA Sensitivity in Arabidopsis

Biomolecules ◽

10.3390/biom9110714 ◽

2019 ◽

Vol 9 (11) ◽

pp. 714 ◽

Cited By ~ 4

Author(s):

Nguyen ◽

Hoang ◽

Nguyen ◽

Binh ◽

Watanabe ◽

...

Keyword(s):

Glycine Max ◽

Drought Tolerance ◽

Water Deficit ◽

Ectopic Expression ◽

Wild Type ◽

Aba Sensitivity ◽

Leaf Tissues ◽

Early Seedling ◽

Early Seedling Development ◽

Higher Sensitivity

The NAC (NAM, ATAF1/2, CUC2) transcription factors are widely known for their various functions in plant development and stress tolerance. Previous studies have demonstrated that genetic engineering can be applied to enhance drought tolerance via overexpression/ectopic expression of NAC genes. In the present study, the dehydration- and drought-inducible GmNAC109 from Glycine max was ectopically expressed in Arabidopsis (GmNAC109-EX) plants to study its biological functions in mediating plant adaptation to water deficit conditions. Results revealed an improved drought tolerance in the transgenic plants, which displayed greater recovery rates by 20% to 54% than did the wild-type plants. In support of this finding, GmNAC109-EX plants exhibited lower water loss rates and decreased endogenous hydrogen peroxide production in leaf tissues under drought, as well as higher sensitivity to exogenous abscisic acid (ABA) treatment at germination and early seedling development stages. In addition, analyses of antioxidant enzymes indicated that GmNAC109-EX plants possessed stronger activities of superoxide dismutase and catalase under drought stress. These results together demonstrated that GmNAC109 acts as a positive transcriptional regulator in the ABA-signaling pathway, enabling plants to cope with adverse water deficit conditions.

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Species Specific Immunoassays to Measure Blood Platelet and Coagulation Activation in the Rat

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650711 ◽

1996 ◽

Vol 76 (06) ◽

pp. 1090-1095 ◽

Cited By ~ 9

Author(s):

C Ravanat ◽

M Freund ◽

S Schuhler ◽

P Grunert ◽

L Meyer ◽

...

Keyword(s):

Antithrombin Iii ◽

Plasma Concentrations ◽

Simultaneous Detection ◽

Blood Platelet ◽

Coagulation Activation ◽

Platelet Factor ◽

Prethrombotic State ◽

Low Levels ◽

Species Specific ◽

Higher Sensitivity

SummaryThe purpose of this study was to develop specific and sensitive immunoassays to detect early indices of hypercoagulability in the rat. Rat platelet factor 4 (rPF4) and rat fibrinopeptide A (rFPA) assays, tools for the detection of activation of platelets and coagulation respectively, were designed using antibodies raised against purified rPF4 and against synthetic rFPA. The relevance of these new assays and of the commercially available ELISA kit for thrombin-antithrombin III (TAT) complexes was demonstrated in a rat model of a prethrombotic state induced by intravenous infusion of varying doses of thromboplastin (90 to 2400 μl/kg/h). In this model, the immunoassays allowed simultaneous detection of low levels of rFPA and rPF4 which were correlated with fibrinogen and platelet consumption and TAT generation and further proved to be of higher sensitivity than the classical methods of platelet count or measurement of fibrinogen levels. Plasma concentrations of rFPA, rPF4 and TAT were dependent on infusion time and thromboplastin dose, while hirudin (1 mg/kg) prevented their appearance. Thus the new specific immunoassays for rPF4 and rFPA and the commercial human TAT assay represent useful tools for pathophysiological studies or the screening of antithrombotic drugs in rats.

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Faculty Opinions recommendation of Role of root UV-B sensing in Arabidopsis early seedling development.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1144900.618295 ◽

2009 ◽

Author(s):

Hanjo Hellmann

Keyword(s):

Seedling Development ◽

Early Seedling ◽

Early Seedling Development

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Zinc Seed Priming Improves Spinach Germination at Low Temperature

Agriculture ◽

10.3390/agriculture11030271 ◽

2021 ◽

Vol 11 (3) ◽

pp. 271

Author(s):

Muhammad Imran ◽

Asim Mahmood ◽

Günter Neumann ◽

Birte Boelt

Keyword(s):

Low Temperature ◽

Temperature Stress ◽

Multispectral Imaging ◽

Germination Rate ◽

Cost Effective ◽

Seed Priming ◽

Seedling Development ◽

Low Temperature Stress ◽

Early Seedling ◽

Early Seedling Development

Low temperature during germination hinders germination speed and early seedling development. Zn seed priming is a useful and cost-effective tool to improve germination rate and resistance to low temperature stress during germination and early seedling development. Spinach was tested to improve germination and seedling development with Zn seed priming under low temperature stress conditions. Zn priming increased seed Zn concentration up to 48 times. The multispectral imaging technique with VideometerLab was used as a non-destructive method to differentiate unprimed, water- and Zn-primed spinach seeds successfully. Localization of Zn in the seeds was studied using the 1,5-diphenyl thiocarbazone (DTZ) dying technique. Active translocation of primed Zn in the roots of young seedlings was detected with laser confocal microscopy. Zn priming of spinach seeds at 6 mM Zn showed a significant increase in germination rate and total germination under low temperature at 8 °C.

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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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Polyamine oxidase 2 is involved in regulating excess spermidine contents during seed germination and early seedling development in Arabidopsis thaliana

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2019.07.022 ◽

2019 ◽

Vol 516 (4) ◽

pp. 1248-1251

Author(s):

Yoshihiro Takahashi ◽

Tatsuaki Uemura ◽

Yuuta Teshima

Keyword(s):

Arabidopsis Thaliana ◽

Seed Germination ◽

Polyamine Oxidase ◽

Seedling Development ◽

Early Seedling ◽

Early Seedling Development

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Early seedling development in relation to seed mass and morph in Cakile edentula

Canadian Journal of Botany ◽

10.1139/b94-053 ◽

1994 ◽

Vol 72 (3) ◽

pp. 402-406 ◽

Cited By ~ 9

Author(s):

Jianhua Zhang

Keyword(s):

Surface Area ◽

Seed Mass ◽

Long Distance ◽

Seed Surface ◽

Large Seed ◽

Cakile Edentula ◽

Early Seedling ◽

Seed Reserves ◽

Early Seedling Development ◽

Growth Of Seedlings

Cakile edentula produces dimorphic seeds from the upper and lower fruit segments. The upper seeds are well adapted to long-distance dispersal and have greater mean seed mass and surface area than those from the lower seeds. Great mean mass of the upper seeds is probably adaptive because it ensured early independent growth of seedlings and thus enhanced their chances of surviving environmental stresses. Large seed reserves also resulted in high chlorophyll content of the cotyledons. Large seed surface area resulted in large cotyledon area and cotyledon area to biomass ratio of the subsequent seedlings, but the adaptive advantage is not clear. Since increased seed surface area necessitates great protective tissues (fruit coat) that may improve the buoyant ability of seeds, large seed surface area of the upper seeds may be a result of selection for dispersal. Key words: seed mass, seed dimorphism, establishment, sand dune, selection, Cakile edentula.

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