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

2020 ◽

Vol 12 (3) ◽

pp. 702-710

Author(s):

Ahmad ZARE ◽

Seyed A. MOOSAVI

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Water Deficit Stress ◽

Seedling Vigor ◽

Germination Characteristics ◽

Salinity Condition ◽

Normal Seed ◽

Drought And Salt Stresses ◽

Total Seed ◽

Germination Parameters

Seed germination may significantly interrupt by water stress due to drought and salinity condition. Salinity can cause osmotic pressure and induce drought stress. Water deficit stress affect normal seed germination and reduce seedling vigor. The objective of this investigation was to determine the effect of drought and salt stresses on germination characteristics of Echinops ritro and Centaurea virgata. Seeds were germinated with the concentrations of sodium chloride (0, 50, 100, 150 and 200 mmol) or in polyethylene glycol PEG6000 (0, -0.2, -0.4, -0.6, -0.8, -1 and -1.2 MPa). The highest values of germination parameters were obtained with no osmotic potential or salinity stress. At treatment by PEG, the germination was severely decreased at -0.6 MPa. While, no germination occurred at- 0.8 MPa by PEG. Results revealed that under 118 Mmol salinity, the seed germination of Centaurea virgata declined to 43% which was as close as half of its total seed germination. However, 50% reduction in seed germination of Echinops ritro was observed at 193 mmol salinity. Results indicated Echinops ritro and Centaurea virgata germination was sensitive to both the stresses. However, seedling growth was more sensitive to PEG than NaCl.

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239 Seed Germination and Seedling Characteristics of Cucurbits as Affected by Dry Heat Treatment and Subsequent Handling

HortScience ◽

10.21273/hortsci.35.3.432c ◽

2000 ◽

Vol 35 (3) ◽

pp. 432C-432

Author(s):

Hae-Jeen Bang ◽

Soo-Jung Hwang ◽

Hyun-Sook Ham ◽

Jung-Myung Lee

Keyword(s):

Heat Treatment ◽

Seed Germination ◽

Dry Heat ◽

Seed Moisture ◽

Heat Treated ◽

Emergence Rate ◽

Normal Seed ◽

Cultivar Susceptibility ◽

Dry Heat Treatment ◽

Seedling Characteristics

Dry heat treatment has been commonly used to inactivate some seed-borne pathogens in vegetable seeds. Virtually all the gourd seeds for watermelon rootstock are being treated with dry heat to inactivate cucumber green mottle mosaic virus (CGMMV, a strain of tobamovirus) and Fusarium. Seeds of five gourd and one squash cultivars were treated with dry heat (35 °C for 24 h + 50 °C for 24 h + 75 °C for 72 h) and, immediately after the dry heat treatment, the seeds (moisture content of 1% or lower) were allowed to absorb atmospheric moisture in a moisture saturated chamber until the seed moisture contents reached 2% to 8%. After the equilibrium obtained, the seeds were sealed in air-tight bags and stored for 1 day or 30 days at 20 °C. The seeds were then sown in cell trays and the emergence and seedling characteristics were evaluated. Dry heat treatment caused significant delay in emergence in all tested cultivars, but had little or no influence on the final emergence rate. Moderate to severe injury was observed in seedlings grown from dry heat-treated seeds in three out of six cultivars tested. However, little or no dry heat phytotoxicity was observed in other cultivars, thus suggesting the marked differences in cultivar susceptibility to dry heat treatment. Rapid humidification before sealing also appeared to reduce the early emergence rate in some cultivars, but had no effect on the final emergence rate in most cultivars. Storage of dry heat-treated seeds in sealed bags for 30 days before sowing was highly effective in minimizing the phytotoxicity symptoms in seedlings as compared to the seedlings grown from the seeds sown immediately after the dry heat treatment. This suggests that the reestablishment of metabolic process required for normal seed germination requires a long period after the dry heat treatment. Other characteristics associated with DH treatment will also be presented.

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

10.1101/2021.07.22.453319 ◽

2021 ◽

Author(s):

Francois Jobert ◽

Stephanie Guenin ◽

Aline Voxeur ◽

Kieran JD Lee ◽

Sophie Bouton ◽

...

Keyword(s):

Cell Wall ◽

Seed Germination ◽

Hypocotyl Elongation ◽

Mature Seed ◽

Compensatory Mechanism ◽

Physiological Disorder ◽

Knock Out ◽

Regulatory Pathways ◽

Normal Seed ◽

Long Time

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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Eggplant Germination is Promoted by Hydrogen Peroxide and Temperature in an Independent but Overlapping Manner

Molecules ◽

10.3390/molecules24234270 ◽

2019 ◽

Vol 24 (23) ◽

pp. 4270 ◽

Cited By ~ 4

Author(s):

Hana Dufková ◽

Miroslav Berka ◽

Markéta Luklová ◽

Aaron M. Rashotte ◽

Břetislav Brzobohatý ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Seed Germination ◽

Molecular Mechanisms ◽

Glyoxylate Cycle ◽

Solanum Melongena ◽

Hydrogen Peroxide Treatment ◽

Different Temperatures ◽

Altered Sensitivity ◽

Seed Proteome ◽

Differentially Abundant Proteins

Hydrogen peroxide promotes seed germination, but the molecular mechanisms underlying this process are unclear. This study presents the results of eggplant (Solanum melongena) germination analyses conducted at two different temperatures and follows the effect of hydrogen peroxide treatment on seed germination and the seed proteome. Hydrogen peroxide was found to promote eggplant germination in a way not dissimilar to that of increased temperature stimuli. LC–MS profiling detected 729 protein families, 77 of which responded to a temperature increase or hydrogen peroxide treatment. These differentially abundant proteins were found to be involved in a number of processes, including protein and amino acid metabolism, carbohydrate metabolism, and the glyoxylate cycle. There was a very low overlap between hydrogen peroxide and temperature-responsive proteins, highlighting the differences behind the seemingly similar outcomes. Furthermore, the observed changes from the seed proteome indicate that hydrogen peroxide treatment diminished the seed endogenous hydrogen peroxide pool and that a part of manifested positive hydrogen peroxide effect might be related to altered sensitivity to abscisic acid.

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The Arabidopsis SENESCENCE-ASSOCIATED GENE 13 Regulates Dark-Induced Senescence and Plays Contrasting Roles in Defense Against Bacterial and Fungal Pathogens

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-11-19-0329-r ◽

2020 ◽

Vol 33 (5) ◽

pp. 754-766 ◽

Cited By ~ 7

Author(s):

Nikhilesh Dhar ◽

Julie Caruana ◽

Irmak Erdem ◽

Krishna V. Subbarao ◽

Steven J. Klosterman ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Death ◽

Seed Germination ◽

Stress Responses ◽

Fungal Pathogens ◽

Crop Improvement ◽

Anthocyanin Accumulation ◽

Normal Seed ◽

Conserved Gene

SENESCENCE-ASSOCIATED GENE 13 (SAG13) of Arabidopsis is a widely conserved gene of unknown function that has been extensively used as a marker of plant senescence. SAG13 induction occurs during plant cell death processes, including senescence and hypersensitive response, a type of programmed cell death that occurs in response to pathogens. This implies that SAG13 expression is regulated through at least two different signaling pathways affecting these two different processes. Our work highlights a contrasting role for SAG13 in regulating resistance against disease-causing biotrophic bacterial and necrotrophic fungal pathogens with contrasting infection strategies. We provide further evidence that SAG13 is not only induced during oxidative stress but also plays a role in protecting the plant against other stresses. SAG13 is also required for normal seed germination, seedling growth, and anthocyanin accumulation. The work presented here provides evidence for the role of SAG13 in regulating multiple plant processes including senescence, defense, seed germination, and abiotic stress responses. SAG13 is a valuable molecular marker for these processes and is conserved in multiple plant species, and this knowledge has important implications for crop improvement.

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Protection of Eggplant Seed Germination from the Inhibitory Effect of o-Cresol by Bioaugmentation of Soil with Pseudomonas monteilii Strain

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2020/v32i2030400 ◽

2020 ◽

pp. 31-45

Author(s):

T. C. Shaima ◽

M. Ajisha ◽

Soumya V. Menon ◽

A. A. Mohammad Kunhi

Keyword(s):

Seed Germination ◽

Seedling Growth ◽

Contaminated Soils ◽

Hydrolytic Enzymes ◽

Inhibitory Effect ◽

Germination Percentage ◽

Respiratory Enzymes ◽

Pseudomonas Monteilii ◽

Normal Seed ◽

End Use

Bulk production and widespread end use of cresol isomers in various industrial processes result in their ubiquitous presence in the environment. Cresols are highly toxic to both fauna and flora and are included in the list of priority pollutants. This study presents the effect of o-cresol on germination of 10 different vegetable crop seeds as tested by the standard Filter Paper Method. The seeds of eggplant and long-podded cowpea were found to be highly sensitive. The most sensitive eggplant seeds were subjected to further studies in soil. Germination percentage and the seedling vigor were drastically reduced in the presence of o-cresol even at a concentration as low as 50 mg kg−1 soil. A number of abnormalities in the seedlings such as stunted root and shoot growth, non-emergence of primary leaves, and negative geotropic growth were observed. Standard 2, 3, 5-tetrazoliumtrichloride test showed marked reduction in the viability of eggplant seeds proportionate to the concentration of o-cresol (0 through 200 mg L−1) they were exposed to, which reached zero at 175 mg o-cresol L−1, indicating the inhibition of the respiratory enzymes of the seeds. Contrary to earlier reports on the effect of phenolics on the hydrolytic enzymes of germinating seeds, in the present case an enhanced activity of amylase was observed in the presence of o-cresol (50 and 150 mg kg−1 soil), whereas the protease activity was partially inhibited at higher concentration. The inhibition of seed germination by o-cresol was revoked by bioaugmentation of the soil with the cresol-degrading Pseudomonas monteilii S-CSR-0014 (2.3 x 108 CFU g−1 wet soil) enabling normal seed germination and seedling growth. The inoculated bacterium degraded 50 and 150 mg o-cresol kg−1 soil efficiently, with concomitant growth. It can be concluded that by bacterial bioaugmentation of o-cresol-contaminated soils the inhibition of germination of crop seeds could be eliminated effectively enabling healthy seedling growth.

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