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Effect of osmotic stress on in vitro translational capacity of polysomes and on the composition of polysome-associated proteins in germinating seeds of pea (Pisum sativum L.)

100%

Brosowska-Arendt W., Weidner S.

Acta Societatis Botanicorum Poloniae

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2012

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tom 81

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nr 3

Plant growth throughout the world is often limited by unfavourable environmental conditions. This paper reports results of a study on long- and short-term osmotic stress (−0.5 MPa) followed by a recovery on in vitro translational capacity of polysomes and on the composition of polysome-associated proteins in germinating pea (Pisum sativum L.) seeds. Here we show that, under osmotic stress, cytoskeleton-bound polysomes were charaterized by the highest translation activity, which may be indicative of an important role that this population of polysomes plays in the synthesis of the so-called “stress proteins”. We also find out that in response to osmotic stress, new proteins (22.01, 96.47 and 105.3 kDa), absent in the unstressed sample, associated with the total pool of polysomes, whereas the protein of 22.95 kDa, which was present in the embryonic tissue of seeds germinating under unstressed conditions, disappeared. These changes may have affected both the stability and the translational capacity of polysomes.

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Effect of osmotic stress on the formation of a population of polysomes and their stability in pea (Pisum sativum L.) seeds

100%

Brosowska-Arendt W., Weidner S.

Acta Physiologiae Plantarum

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2011

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tom 33

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nr 4

Plants growing under natural conditions are constantly exposed to various stress factors, which can restrain their productivity and limit yields. This paper deals with the effect of long- and short-term osmotic stress followed by recovery on the formation of polysomes and their stability during germination of pea (Pisum sativum L.) seeds. By isolating polysomes, it is possible to obtain an index which evidences the ability of tissues to synthesize proteins. Changes in the distribution of polysomes often precede measurable changes in amounts of proteins. Under osmotic stress, the dominant population of polysomes was the population of free polysomes (FP). The share of membrane-bound polysomes (MBP) and cytoskeletonbound polysomes (CBP) and cytoskeleton-membranebound polysomes (CMBP) in the total fraction of ribosomes increased under intensive (-1.0 and -1.5 MPa) osmotic stress. These results can suggest that the bound forms of polysomes play an important role in the synthesis of stress proteins. In addition, the stability of polysomes isolated from pea early seedlings growing under unstressed control and osmotic stress conditions was tested. It turned out that polysomes formed under osmotic stress conditions (especially the CMBP) were more resistant to the activity of exogenous ribonucleases than the polysomes in the control samples. Under stress conditions it is highly likely that ribosomes become more densely packed on mRNA thus making it more resistant to ribonuclease. This is just one of the many mechanisms regulating stability of mRNA.

3

Changes in the proteome of pea (Pisum sativum L.) seeds germinating under optimal and osmotic stress conditions and subjected to post-stress recovery

81%

Brosowska-Arendt W., Gallardo K., Sommerer N., Weidner S.

Acta Physiologiae Plantarum

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2014

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tom 36

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nr 03

Plants growing under natural conditions are exposed to a variety of stresses, which can lead to undesirable changes in the physiological processes and yielding. These changes can be regulated at different levels, resulting in the synthesis of specific proteins which participate in the plant’s response to stress. The purpose of this study was to determine changes in the accumulation of proteins in germinating pea (Pisum sativum L.) seeds under optimal and osmotic (short- and long-term) stress conditions as well as recovery following a short-term stress. For identification of the proteins, two-dimensional electrophoresis and mass spectrometry (MALDI-TOF) were employed. Germination in optimal conditions increased the accumulation of several proteins involved in glycolysis, Krebs cycle, synthesis of fatty acids, cell growth, cellular transport and detoxification. Osmotic stress, in turn, depressed the accumulation of proteins involved in glycolysis, synthesis of fatty acids, detoxication, methionine conversions, cellular transport, translation, growth control and of cytoskeletal proteins, but raised the accumulation of enzymes of the tricarboxylic acid cycle as well as proteins participating in signal transduction and protection (chaperones). One protein, 6a-hydroxymaackian-3-O-methyltransferase, which is involved in the synthesis of pisatin, was present only under osmotic stress conditions and recovery. Pisatin is synthesized mainly in response to microbiological infections and under stress conditions, indicating its key role in the acquisition of stress tolerance by plants.

4

Effect of osmotic stress and post-stress recovery on the content of phenolics and properties of antioxidants in germinating seeds of grapevine Vitis californica

61%

Weidner S., Brosowska-Arendt W., Szczechura W., Karamac M., Kosinska A., Amarowicz R.

Acta Societatis Botanicorum Poloniae

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2011

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tom 80

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nr 1

The tested material consisted of grapevine Vitis californica stratified seeds germinated under optimum conditions (+25°C in water), under osmotic stress (-0.2 MPa in PEG solution) and submitted to recovery after stress (+25°C in water). The germinating seeds were determined to contain tannins, catechins and the following phenolic acids: gallic, caffeic, p-coumaric and ferulic. The acids occurred in free, ester- and glycoside-bound forms. The dominant form of phenolic acids was the ester-bound fraction. Gallic acid was the most abundant phenolic acid in germinating seeds, while ferulic acid appeared in the smallest amounts. Our analysis of tannins demonstrated that osmotic stress depressed their concentration. Presence of catechin group compounds such as catechin and epicatechin was also determined. In each sample epicatechin was dominant. The total concentration of catechin increased under stress conditions and declined during post-stress recovery. Catechins are a constituent of tannins and their increase under osmotic stress is most probably caused by the breakdown of some tannins in seeds germinating under stress conditions. Samples submitted to osmotic stress were also found to contain less of total phenolic compounds, whereas in samples which underwent post-stress recovery the total level of phenolic compounds increased. Compared to extracts from seeds germinating under optimum conditions, osmotic stress depressed the capacity of extract to scavenge DPPH● (2,2-diphenyl-1-picrylhydrazyl) and ABTS●+ – 2,2-Azino-bis (3-etylbenzothiazoline-6- -sulfonic acid) free radicals, but the antioxidant activity rose in seeds submitted to recovery after stress. Positive correlation was therefore demonstrated between the total content of phenolic acids in germinating grapevine seeds and the reducing power of extracts obtained from these seeds and their free radical scavenging activity. The results suggest that osmotic stress inhibits the activity of antioxidizing enzymes in germinating grapevine seeds. Thus, the antioxidative defence system is largely blocked under osmotic stress. It seems that a very high oxidoreductive potential in grapevine tissues prior to occurrence of osmotic stress is essential for maintaining proper homeostasis of oxidation and reduction reactions.

5

Phenolic compounds and properties of antioxidants in grapevine roots [Vitis vinifera L.] under low-temperature stress followed by recovery

61%

Weidner S., Kordala E., Brosowska-Arendt W., Karamac M., Kosinska A., Amarowicz R.

Acta Societatis Botanicorum Poloniae

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2009

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tom 78

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nr 4

279-286

The research has been performed on roots of Vitis vinifera, cv. Himrod, obtained from seedlings grown under chill stress conditions (+10oC in the day and +7oC at night), under optimum conditions (+25oC in the day and +18oC at night) and from seedling which underwent a recover period after the chill stress treatment. The purpose of the study has been to determine quantitative and qualitative changes in phenolic compounds as well as to demonstrate changes in antiradical properties of extracts from grapevine roots, which appeared as a result of chill stress and during recovery under the optimum conditions following the stress. Phenolic compounds from grapevine roots were extracted using 80% acetone. The total content of phenolics was determined by colorimetry. The content of tannins was tested by precipitation with bovine serum albumin. The reducing power as well as DPPH• free radical and ABTS+• cation radical scavenging activity of the extracts were also tested. In order to identify phenolic compounds present in the extracts the RP-HPLC technique was employed. The tested material was found to contain tannins and three identified phenolic acids: ferulic, caffeic and p-coumaric ones. The latter occurred in the highest concentrations (from 4.46 to 6.28 µg/g fresh matter). Ferulic acid appeared in smaller amounts (from 1.68 to 2.65 µg/g fresh matter), followed by caffeic acid (from 0.87 to 1.55 µg/g fresh matter). Significantly less total phenolic compounds occurred in roots of seedlings subjected to chill stress. However, the total content of these compounds increased significantly in roots of plants which underwent recovery after chill stress. Concentration of tannins was determined by two methods. The content of condensed tannins was depressed in roots as a result of low temperature stress, whereas the content of condensed and hydrolysing tannins (determined via the BSA method) rose under chill stress conditions. A significant increase in tannins in root extracts (determined with both methods) was found during the recovery process after the stress. The three identified phenolic acids appeared in grapevine roots as ester-bound compounds. It has been demonstrated that the content of phenolic acids significantly fell as a result of low temperatures, but increased during recovery after chill stress. The weakest ability to scavenge DPPH• and ABTS+• free radicals as well as the reducing power were shown by the extract obtained from grapevine roots from the seedlings subjected to chill stress. Both free radical scavenging activity and reducing power were observed to increase considerably during recovery after stress. This seems to prove that during the recovery process following chill stress the synthesis of antioxidative compounds in grapevine roots is much more intensive.

Ograniczanie wyników

3 Acta Societatis Botanicorum Poloniae

2 Acta Physiologiae Plantarum

5 Brosowska-Arendt W.

5 Weidner S.

2 Amarowicz R.

2 Karamac M.

2 Kosinska A.

1 Gallardo K.

1 Kordala E.

1 Sommerer N.

1 Szczechura W.

1 2014

1 2012

2 2011

1 2009

Effect of osmotic stress on in vitro translational capacity of polysomes and on the composition of polysome-associated proteins in germinating seeds of pea (Pisum sativum L.)

Effect of osmotic stress on the formation of a population of polysomes and their stability in pea (Pisum sativum L.) seeds

Changes in the proteome of pea (Pisum sativum L.) seeds germinating under optimal and osmotic stress conditions and subjected to post-stress recovery

Effect of osmotic stress and post-stress recovery on the content of phenolics and properties of antioxidants in germinating seeds of grapevine Vitis californica

Phenolic compounds and properties of antioxidants in grapevine roots [Vitis vinifera L.] under low-temperature stress followed by recovery