Alleviation of salinity and dark-enforced dormancy in Allenrolfea occidentalis seeds under various thermoperiods

2000 ◽  
Vol 48 (6) ◽  
pp. 745 ◽  
Author(s):  
Bilquees Gul ◽  
M. Ajmal Khan ◽  
Darrell J. Weber
Keyword(s):  
Growth Regulators ◽  
Temperature Regime ◽  
Critical Factor ◽  
Moderate Temperature ◽  
Germination Inhibition ◽  
Complete Darkness ◽  
Reversal Effect ◽  
Higher Temperature ◽  
Growth Promoting ◽  
Allenrolfea Occidentalis

The effect of germination-regulating chemicals on the alleviation of salinity-enforced germination inhibition of Allenrolfea occidentalis (S.Wats.) Kuntze at various thermoperiods in complete darkness was investigated. There was poor germination at cool temperatures and germination-regulating chemicals were ineffective in alleviating this effect. Germination in the dark increased progressively with increase in temperature and maximum germination was obtained at 25–35˚C thermoperiod. Ethephon and fusicoccin (FC) substantially reverted dark-induced inhibition at moderate thermoperiods. All other germination-regulating chemicals were more effective at moderate temperature, while germination was not specifically different from control at higher temperature. Salinity-enforced germination inhibition was partially alleviated by all growth regulators at the higher temperature regime (25–35˚C). Best reversal was obtained with the application of ethephon and FC. Our results suggest that temperature is the most critical factor influencing the germination of Allenrolfea seeds. Allenrolfea occidentalis seeds germinated better at higher than at lower temperatures in the dark and all of the growth-promoting compounds showed their maximum reversal effect at higher temperatures.

scholarly journals The Arabidopsis Root Tip (Phospho)Proteomes at Growth-Promoting versus Growth-Repressing Conditions Reveal Novel Root Growth Regulators

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1665
Author(s):  
Natalia Nikonorova ◽  
Evan Murphy ◽  
Cassio Flavio Fonseca de Lima ◽  
Shanshuo Zhu ◽  
Brigitte van de Cotte ◽  
...  
Keyword(s):  
Cell Wall ◽  
Root Growth ◽  
Growth Regulators ◽  
Growth Regulation ◽  
Phosphorylation Site ◽  
Primary Root ◽  
Root Tip ◽  
Arabidopsis Root ◽  
Growth Promoting ◽  
The Impact

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.

RBS/Channeling Diffusion Studies of High Energy Au Implanted Mg Single Crystals

1991 ◽  
Vol 235 ◽  
Author(s):  
R. C. Da Selva ◽  
M. F. Da Silva ◽  
L. Thomé ◽  
A. A. Melo ◽  
J. C. Soares
Keyword(s):  
Single Crystals ◽  
Temperature Regime ◽  
High Energy ◽  
Back Diffusion ◽  
Thermally Activated ◽  
Diffusion Studies ◽  
Higher Temperature ◽  
Diffusion Behaviour ◽  
Thermally Activated Process

ABSTRACTRBS/channeling analyses of high energy Au implantation into Mg are presented. The diffusion behaviour of Au was studied and the occurrence of essentially two distinct regimes were observed: the segregation regime at lower temperatures correlated with the damage introduced by the high energy implantation and the higher temperature regime as a normal thermally activated process of back-diffusion.

scholarly journals Effect of Moderate Temperature Thermal Modification Combined with Wax Impregnation on Wood Properties

2020 ◽  
Vol 10 (22) ◽  
pp. 8231
Author(s):  
Jing-Wen Zhang ◽  
Hong-Hai Liu ◽  
Lin Yang ◽  
Tian-Qi Han ◽  
Qin Yin
Keyword(s):  
Mechanical Strength ◽  
Dimensional Stability ◽  
Color Change ◽  
Strength Loss ◽  
Wood Properties ◽  
Thermal Modification ◽  
Moderate Temperature ◽  
Modulus Of Rupture ◽  
Internal Surfaces ◽  
Higher Temperature

Thermal modification (TM) improves the hydrophobicity, dimensional stability, and durability of wood, but TM commonly results in severe color change and mechanical strength loss as wood is treated at higher temperature. In this study, Pterocarpus macrocarpus Kurz wood was thermally modified at moderate temperature (150 °C) and higher temperature (200 °C), and subsequently TM wood at 150 °C was subjected to wax impregnation (WI), the effect of a combination of TM and WI on the hygroscopicity, dimensional stability, and mechanical properties, as well as the micro-structure of wood, were investigated and compared. The results showed that the mass loss of wood was slight at 150 °C TM, while it became severe at 200 °C TM conditions. TM conditions affected the amount of the subsequent wax impregnation; the equilibrium moisture content (EMC), water absorption ratio, and adsorption and absorption swelling of the 150 °C TM + WI group were lower than that of 200 °C TM, and presented the lowest value. Moderate temperature TM could improve the hydrophobicity and dimensional stability of wood, but WI played a key role in the improvement. TM decreased the modulus of rupture (MOR) of wood, while WI improved the MOR. TM increased the modulus of elasticity (MOE) of wood, but WI had little effect on MOE; Scanning electron microscope (SEM) observation showed that the wax was successfully impregnated into the wood interior, and presented an even distribution on the internal surfaces of wood cells; Fourier-transform infrared spectroscopy (FTIR) spectra verified the changes of –OH and C=O after TM and TM + WI, which contributed to decreasing hygroscopicity and improving the dimensional stability of the wood. Impregnated wax improved wood mechanical strength, but decreased the lightness, and deepened the color of wood. The combination of thermal modification at moderate temperature with subsequent wax impregnation is a practical approach for improving wood properties.

Interfacial Gas Desorption and Diffusion during the Low Thermal Stress Fusion of III/V Materials to Si

2002 ◽  
Vol 722 ◽  
Author(s):  
Phil Mages ◽  
Paul K. L. Yu
Keyword(s):  
Thermal Stress ◽  
Temperature Regime ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Gas Generation ◽  
Gas Desorption ◽  
Bubble Density ◽  
Higher Temperature ◽  
Trapped Gas ◽  
And Behavior

AbstractA Low Thermal Stress (LTS) process, involving the removal of most of the InGaAs(P) material, was used to allow for wafer-fusion of InGaAs(P) samples to Si. The formation and behavior of bubbles of trapped gas between the thinned layer of InGaAs(P) material and the thick Si substrate were studied due to the yield problems such bubbles represent. Observations revealed a low temperature regime <300°C, during which significant gas generation occurred but only weak, reversible bonds were formed. The higher temperature regime, 300°-650°C, was characterized by no significant increase in bubble density, but resulted in a reduction or complete blockage of gas escape during storage. Further investigation of the higher temperature regime indicated continued production of gas, but with a tendency of the gases produced above 300°C to escape from the interface without the formation of bubbles under normal conditions. This information led to the development of a scalable LTS process requiring no modification of the wafers prior to bonding and utilizing sample pre-heating to 300°C before InGaAs(P) removal and subsequent high temperature treatment to 650°C for permanent bond formation.

scholarly journals Evidence for Increased Aggressiveness in a Recent Widespread Strain of Puccinia striiformis f. sp. tritici Causing Stripe Rust of Wheat

2009 ◽  
Vol 99 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Eugene A. Milus ◽  
Kristian Kristensen ◽  
Mogens S. Hovmøller
Keyword(s):  
Stripe Rust ◽  
Temperature Regime ◽  
Puccinia Striiformis ◽  
Yellow Rust ◽  
Severe Disease ◽  
Lesion Length ◽  
Eastern United States ◽  
Inoculation Site ◽  
Temperature Regimes ◽  
Higher Temperature

Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based on virulence phenotype and amplified fragment length polymorphism. The objective of this research was to quantify differences in aggressiveness among isolates representative of the pre-2000 and post-2000 populations. Representative isolates were evaluated at low (10 to 18°C) and high (12 to 28°C) temperature regimes for latent period, lesion length, lesion width, lesion area, and spore production on adult plants of a susceptible wheat cultivar with no known genes for resistance to stripe rust. “New” isolates (since 2000) were significantly more aggressive than “old” isolates (before 2000) for all variables. At the low temperature regime, new isolates sporulated 2.1 days (16%) sooner, grew 0.3 mm per day (18%) faster, produced 999 (140%) more spores per inoculation site per day, and produced 6.5 (71%) more spores per mm2 of lesion per day compared with old isolates. At the high temperature regime, new isolates sporulated 3 days (26%) sooner, grew 0.2 mm per day (18%) and 2.2 mm2 per day (88%) faster, grew 1.2 mm (50%) wider, produced 774 (370%) more spores per inoculation site per day, and produced 6.2 (159%) more spores per mm2 of lesion per day than old isolates. New isolates showed significant adaptation to the warm temperature regime for all variables. Based on these results and previously published models for stripe rust epidemics, recent severe stripe rust epidemics were most likely enhanced by the pathogen's increased aggressiveness, especially at higher temperature. Furthermore, these results demonstrate that wheat rust fungi can adapt to warmer temperatures and cause severe disease in previously unfavorable environments.

Effect of light, salinity, and temperature on seed germination of Limonium stocksii

2004 ◽  
Vol 82 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Sabahat Zia ◽  
M Ajmal Khan
Keyword(s):  
Seed Germination ◽  
Temperature Regime ◽  
Germination Rate ◽  
Gradual Decrease ◽  
Salinity Treatment ◽  
Optimal Temperature ◽  
Complete Darkness ◽  
Temperature Regimes ◽  
Effect Of Light ◽  
Recovery Temperature

Limonium stocksii (Boiss.) Kuntze (Plumbaginaceae) is a perennial, woody shrub distributed at Hawks Bay, Karachi, Pakistan. Experiments were carried out to investigate seed germination responses of L. stocksii at different salinities (0, 100, 200, 300, 400, and 500 mmol/L NaCl) and under different temperature regimes (10:20, 15:25, 20:30, and 25:35 °C), both in a 12 h dark : 12 h light photoperiod and in complete darkness. The highest percentage of germination (about 100%) was obtained at 0, 100, and 200 mmol/L NaCl at 20:30 °C, and a further increase in salinity resulted in a gradual decrease in germination. Less than 5% of seeds germinated at 500 mmol/L NaCl. Germination under salinity treatment at 15:25 °C was slightly more inhibitory than the optimal temperature regime, whereas under both 10:20 and 25:35 °C temperature regimes, seed germination was substantially reduced and few seeds germinated at concentrations higher than 200 mmol/L NaCl. Germination rate was fastest at 20:30 °C and slowest at 10:20 °C. Relatively low seed germination was obtained in the dark in comparison to seeds germinated in a 12-h photoperiod under saline conditions. Recovery experiments showed that exposure of seeds to various salinity and temperature regimes had little effect on viability of seeds.Key words: germination, light, Limonium stocksii, NaCl, recovery, temperature.

Synthetic Plant Growth Regulators. III. The Preparation of Further Tricyclic Helminthosporic Acid Analogues with Gibberellin-like Properties

1979 ◽  
Vol 32 (4) ◽  
pp. 817 ◽  
Author(s):  
AL Cossey ◽  
LN Mander ◽  
SG Pyne
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Cis And Trans

7-Methyl-7,8-dihydro-4a,7-methano-4aH-benzocycloheptene-2,6(9H,5H-dione (6) was prepared and reduced to a 3 : 7 mixture of the trans- and cis-decalin derived ketones (8) and (15). Each compound was further elaborated to the plant-growth-promoting acids (13), (14), (16) and (17). Dienone (5) was also reduced (NaBH4, hydrogenation) to a 7 : 3 mixture of the cis- and trans-decalin derivatives (11) and (9). The stereochemistry of (11), and by inference (12), was determined by correlation with the known ketone (7).

scholarly journals Phenotypic and genotypic characterization of inhabitant PGPR strains of Pseudomonas from apple orchards

2015 ◽  
Vol 7 (2) ◽  
pp. 893-902
Author(s):  
Kumari Manorma ◽  
Shweta Sharma ◽  
Mohinder Kaur
Keyword(s):  
Antifungal Activity ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Siderophore Production ◽  
Pseudomonas Sp ◽  
Genotypic Analysis ◽  
Plant Growth Promoting ◽  
Growth Promoting

Aim of present research was to isolate and characterize the Pseudomonas strains phenotypically and genotypically from the rhizospheric soil of apple orchard at Maggota (Shimla district) Himachal Pradesh. Phenotypic identification of the test isolates was based on morphological, physiological and biochemical characterization of the bacteria followed by genotypic analysis using rRNA gene sequencing and RAPD-PCR analysis. The fourteen Pseudomonas sp. isolates were screened out for various plant growth promoting activities such as siderophore production, antifungal activity, phosphate solubilisation, HCN and ammonia production, production of plant growth regulators and lytic enzymes. Isolates showed production of plant growth regulators (auxins, gibberellins and cytokinins) in the range of 19.67-83.33μg/ml, 21.00-58.67 μg/ml and 12.33-43.33 μg/ml respectively. Pseudomonas strains showed phosphate solubilising activity in the range of 12.33-63.33 Pi μg/ml, 53.66-93.44 % SU siderophore production and 11.33-96.33mm (diameter) protease activity in plate assay. Five Pseudomonas isolates i.e. An-16-kul, An-1-mag, An-2-mag, An-3-mag and An-6-mag showed maximum antifungal activity against plant pathogenic fungi. Therefore, the aim of present investigation was to study multifarious plant growth promoting qualities of Pseudomonas sp. and to select more efficient PGPR strain of fluorescent Pseudomonas sp. which can be further used as biofertilizer.

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