scholarly journals Kinetin affects the level of chloroplast polyamines and transglutaminase activity during senescence of barley leaves.

2009 ◽  
Vol 56 (2) ◽  
Author(s):  
Ewa Sobieszczuk-Nowicka ◽  
Przemysław Wieczorek ◽  
Jolanta Legocka
Keyword(s):  
Leaf Senescence ◽  
Covalent Bonds ◽  
Transglutaminase Activity ◽  
Barley Leaves ◽  
Tgase Activity ◽  
Barley Leaf ◽  
Chloroplast Senescence

We analysed the level of polyamines (PAs) bound to thylakoids and the level and activity of thylakoid transglutaminases throughout barley leaf senescence, retarded by kinetin. The level of PAs bound to thylakoids changed in senescing barley leaves: bound putrescine (PU) and spermidine (SD) increased throughout senescence, whereas bound spermine (SM) decreased. Kinetin diminished the increase in thylakoid-bound PU and SD and almost completely abolished the decrease of the bound SM. These data suggest different roles of PU/SD and SM in thylakoid degradation. Immunodetection of transglutaminases (TGase) in thylakoid fraction revealed three bands of 33, 58 and 78 kDa. During senescence the intensity of all bands increased and it was correlated with an increase in TGase activity. Kinetin down-regulated the accumulation of the 58- and 78-kDa TGases and the TGase activity. We postulate that formation of covalent bonds between PAs and proteins by TGase is involved in chloroplast senescence. The kinetin-mediated preservation of low TGase levels and activity throughout leaf senescence may represent an important component of the mechanism of kinetin action in the retardation of leaf senescence.

scholarly journals The role of cytokinins in the development and metabolism of barley leaves. I. The effect of cytokinins on leaf senescence

2015 ◽  
Vol 46 (2) ◽  
pp. 357-368 ◽  
Author(s):  
A. Woźny ◽  
A. Szweykowska ◽  
J. Legocka
Keyword(s):  
Nucleic Acids ◽  
Leaf Senescence ◽  
Rna Synthesis ◽  
Similar Extent ◽  
Mesophyll Cells ◽  
Barley Leaves ◽  
Barley Leaf ◽  
Cytokinin Action ◽  
Natural Cytokinin

The loss of chlorophyll during dark-induced ageing of barley leaves was prevented to a similar extent by kinetin and the natural cytokinin, 6-Δ<sup>2</sup>-iso-pentenylarninopurine (2iP). A concentration of 400 μM appeared to be optimal in both cases. In the presence of 2iP the structure of mesophyll cells in dark-incubated leaves was maintained unchanged. A distinct correlation has been found between the retardation by 2iP of the chlorophyll loss, the rate of S2P-incorporation into nucleic acids and the maintaining of the RNase activity at a low level. The importance of the RNA synthesis and the rate of its de-gradation in the cytokinin action in barley leaf senescence will be subjected to future experiments.

scholarly journals RIMAPS and Varlogram Analysis of Barley Leaf Surfaces

2004 ◽  
Vol 12 (5) ◽  
pp. 24-27 ◽  
Author(s):  
Eduardo A. Favret ◽  
Néstor O. Fuentes
Keyword(s):  
Quantitative Method ◽  
Average Power ◽  
Plant Tissues ◽  
Wild Type ◽  
Abaxial Side ◽  
Leaf Surfaces ◽  
Barley Leaves ◽  
Leaf Mutant ◽  
Barley Leaf ◽  
Average Power Spectrum

It is a common practice to use microscopic images to describe the differences observed between plant tissues. The images illustrate the taxonomic characteristics of the studied species. In this work we introduce a quantitative method for conducting these analyses utilizing digitized images obtained via scanning electron microscopy (SEM) of barley leaf surfaces. The topography of the leaf surfaces of a narrow-leaf mutant and its wild type mother line was characterized, see figure 1, using the Rotated Image with Maximum Average Power Spectrum (RIMAPS) technique and the Variogram method. Spectra resulting from RIMAPS analysis allow us to identify the specimens and to distinguish between the adaxial or the abaxial side of the leaf. These results are complemented by obtaining the typical scale lengths that characterize the abaxial surfaces of both the mutant and the mother line barley leaves.

scholarly journals Dark-Induced Barley Leaf Senescence – A Crop System for Studying Senescence and Autophagy Mechanisms

2021 ◽  
Vol 12 ◽  
Author(s):  
Ewelina Paluch-Lubawa ◽  
Ewelina Stolarska ◽  
Ewa Sobieszczuk-Nowicka
Keyword(s):  
Leaf Senescence ◽  
Control Mechanism ◽  
Morphological Changes ◽  
Plant Cells ◽  
Cell Components ◽  
Barley Leaf ◽  
Quality Control Mechanism ◽  
Crop System ◽  
Made In

This review synthesizes knowledge on dark-induced barley, attached, leaf senescence (DILS) as a model and discusses the possibility of using this crop system for studying senescence and autophagy mechanisms. It addresses the recent progress made in our understanding of DILS. The following aspects are discussed: the importance of chloroplasts as early targets of DILS, the role of Rubisco as the largest repository of recoverable nitrogen in leaves senescing in darkness, morphological changes of these leaves other than those described for chloroplasts and metabolic modifications associated with them, DILS versus developmental leaf senescence transcriptomic differences, and finally the observation that in DILS autophagy participates in the circulation of cell components and acts as a quality control mechanism during senescence. Despite the progression of macroautophagy, the symptoms of degradation can be reversed. In the review, the question also arises how plant cells regulate stress-induced senescence via autophagy and how the function of autophagy switches between cell survival and cell death.

EPR spin labeling measurements of thylakoid membrane fluidity during barley leaf senescence

2014 ◽  
Vol 171 (12) ◽  
pp. 1046-1053 ◽  
Author(s):  
Ivan Jajić ◽  
Anna Wiśniewska-Becker ◽  
Tadeusz Sarna ◽  
Małgorzata Jemioła-Rzemińska ◽  
Kazimierz Strzałka
Keyword(s):  
Membrane Fluidity ◽  
Leaf Senescence ◽  
Thylakoid Membrane ◽  
Spin Labeling ◽  
Barley Leaf

scholarly journals Decreased R:FR Ratio in Incident White Light Affects the Composition of Barley Leaf Lipidome and Freezing Tolerance in a Temperature-Dependent Manner

2020 ◽  
Vol 21 (20) ◽  
pp. 7557
Author(s):  
Terézia Kovács ◽  
Mohamed Ahres ◽  
Tamás Pálmai ◽  
László Kovács ◽  
Matsuo Uemura ◽  
...  
Keyword(s):  
Double Bond ◽  
White Light ◽  
Red Light ◽  
Frost Tolerance ◽  
Light Illumination ◽  
Dependent Manner ◽  
Bond Index ◽  
Double Bond Index ◽  
Barley Leaves ◽  
Barley Leaf

In cereals, C-repeat binding factor genes have been defined as key components of the light quality-dependent regulation of frost tolerance by integrating phytochrome-mediated light and temperature signals. This study elucidates the differences in the lipid composition of barley leaves illuminated with white light or white light supplemented with far-red light at 5 or 15 °C. According to LC-MS analysis, far-red light supplementation increased the amount of monogalactosyldiacylglycerol species 36:6, 36:5, and 36:4 after 1 day at 5 °C, and 10 days at 15 °C resulted in a perturbed content of 38:6 species. Changes were observed in the levels of phosphatidylethanolamine, and phosphatidylserine under white light supplemented with far-red light illumination at 15 °C, whereas robust changes were observed in the amount of several phosphatidylserine species at 5 °C. At 15 °C, the amount of some phosphatidylglycerol species increased as a result of white light supplemented with far-red light illumination after 1 day. The ceramide (42:2)-3 content increased regardless of the temperature. The double-bond index of phosphatidylglycerol, phosphatidylserine, phosphatidylcholine ceramide together with total double-bond index changed when the plant was grown at 15 °C as a function of white light supplemented with far-red light. white light supplemented with far-red light increased the monogalactosyldiacylglycerol/diacylglycerol ratio as well. The gene expression changes are well correlated with the alterations in the lipidome.

Respiration of barley plants IV. Protein catabolism and the formation of amides in starving leaves

1950 ◽  
Vol 136 (885) ◽  
pp. 632-649 ◽  
Keyword(s):  
Glutamic Acid ◽  
Aspartic Acid ◽  
Total Carbon ◽  
Protein Catabolism ◽  
Indirect Methods ◽  
Previous Discussion ◽  
Barley Leaves ◽  
Barley Leaf ◽  
Direct And Indirect Methods ◽  
Made In

In a continuation of earlier studies the nitrogenous constituents of barley leaves have been investigated with the object of gaining more direct evidence on the nature of protein catabolism in starving leaves. Particular attention was given to the origin and identification of the amides. Tissue proteins were separated and partially analyzed by direct and indirect methods. The amino-acids of the barley-leaf protein were very similar to those of the proteins prepared from grasses. From these and other data estimates of the amide-N, glutamic acid and aspartic acid were obtained. The amide-N content of the whole protein of the leaves agreed closely with that of the separated protein. There was evidence that the release of amide-N proceeded uniformly as the proteins were broken down during starvation. Asparagine was identified as a product of catabolism by direct isolation from starved leaves; recovery of the crystalline product amounted to 60% of the total stable amide-N of the crude extract. Glutamine was not isolated, but additional evidence of its presence in the leaves was obtained. An analysis of the relation between proteolysis and formation of amides confirmed several of the suggestions made in a previous discussion. Most of the amide-N of the starved leaves was of secondary origin, and there were clear indications of a secondary synthesis of the aspartic acid combined in asparagine. Glutamine amide-N was formed secondarily during the early stages of starvation, but evidence of the origin of glutamic acid was inconclusive. The data of different experiments indicated that the breakdown of tissue proteins contributed between 20 and 40% of the total carbon lost from the leaves as respiratory carbon dioxide.

Morphological, histochemical and ultrastructural indicators of maize and barley leaf senescence

2006 ◽  
Vol 50 (4) ◽  
pp. 565-573 ◽  
Author(s):  
I. Kolodziejek ◽  
M. Waleza ◽  
A. Mostowska
Keyword(s):  
Leaf Senescence ◽  
Barley Leaf

scholarly journals Optimization of microwave-assisted extraction of flavonoids from young barley leaves

2017 ◽  
Vol 31 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Tian Gao ◽  
Min Zhang ◽  
Zhongxiang Fang ◽  
Qifeng Zhong
Keyword(s):  
Leaf Extract ◽  
Radical Scavenging ◽  
Extraction Yield ◽  
Microwave Assisted Extraction ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Water As Solvent ◽  
Barley Leaves ◽  
Barley Leaf ◽  
Conventional Extraction

AbstractA central composite design combined with response surface methodology was utilized to optimise microwave-assisted extraction of flavonoids from young barley leaves. The results showed that using water as solvent, the optimum conditions of microwave-assisted extraction were extracted twice at 1.27 W g−1microwave power and liquid-solid ratio 34.02 ml g−1for 11.12 min. The maximum extraction yield of flavonoids (rutin equivalents) was 80.78±0.52%. Compared with conventional extraction method, the microwave-assisted extraction was more efficient as the extraction time was only 6.18% of conventional extraction, but the extraction yield of flavonoids was increased by 5.47%. The main flavonoid components from the young barley leaf extract were probably 33.36% of isoorientin-7-O-glueoside and 54.17% of isovitexin-7-O-glucoside, based on the HPLC-MS analysis. The barley leaf extract exhibited strong reducing power as well as the DPPH radical scavenging capacity.

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