Protein composition and functioning of yellow lupine (Lupinus luteus L.) embryo axis mitochondria under salinity

Wydział Biologii: Instytut Biologii EksperymentalnejCelem pracy było wykazanie, czy zasolenie prowadzi do zmian w składzie białkowym mitochondriów oraz sprawdzenie, czy warunki zasolenia mogą prowadzić do programowanej śmierci komórki (PCD). Analizy przeprowadzone na izolowanych osiach zarodkowych łubinu żółtego Lupinus luteus hodowanych in vitro na pożywkach z różnymi stężeniami NaCl wykazały zmiany w metabolizmie mitochondriów jak również całego organu. W warunkach zasolenia zmianie uległ poziom białek mitochondrialnych analizowany metodą elektroforezy dwukierunkowej. Spośród białek, których poziom zmienił się (wzrósł lub obniżył się) pod wpływem zasolenia, 48 wytypowano do identyfikacji z zastosowaniem spektrometrii mas. Wśród zidentyfikowanych białek znalazły się enzymy cyklu Krebsa, mitochondrialnego łańcucha transportu elektronów oraz uczestniczące w biogenezie mitochondriów i białka stresowe. Zasolenie prowadziło do warunków stresu oksydacyjnego (wzrost poziomu H2O2 i peroksydacji lipidów), jednak aktywność mitochondrialnych enzymów antyoksydacyjnych uległa obniżeniu. Analiza ultrastruktury wykazała szereg zmian w strukturze komórki obejmujących deformacje retikulum endoplazmatycznego, zwiększenie stopnia wakuolizacji komórki oraz degradację chromatyny w jądrze komórkowym. Pod wpływem zasolenia pojawiały się symptomy PCD w postaci uszkodzeń DNA (elektroforeza kometkowa) oraz fragmentacji DNA.The aim of this study was to demonstrate whether salinity leads to changes in mitochondria protein composition and to verify whether the conditions of salinity can lead to programmed cell death (PCD). The analysis conducted on isolated embryonic axes of yellow lupine, Lupinus luteus grown in vitro on media with different concentrations of NaCl showed changes in the metabolism of mitochondria as well as the entire organ. Changes in the level of mitochondrial proteins under salinity condition were analyzed using two-dimension electrophoresis. Among the proteins which levels changed (increased or decreased) due to salinity, 48 were selected for identification using mass spectrometry. Among the identified proteins were enzymes of the Krebs cycle, mitochondrial electron transport chain and participating in the biogenesis of mitochondria and stress response. Salinity led to conditions of oxidative stress (increasing levels of H2O2 and lipid peroxidation), but the activity of mitochondrial antioxidant enzymes decreased. Analysis of ultrastructure revealed a number of changes in the structure of cell including deformation the endoplasmic reticulum, increased cytoplasmic vacuolisation and degradation of chromatin in the nucleus. Salinity-induced changes led to the emergence of symptoms of PCD in the form of DNA damage (comet assay) and DNA fragmentation

Protein composition and functioning of yellow lupine (Lupinus luteus L.) embryo axis mitochondria under salinity

Wydział Biologii: Instytut Biologii EksperymentalnejCelem pracy było wykazanie, czy zasolenie prowadzi do zmian w składzie białkowym mitochondriów oraz sprawdzenie, czy warunki zasolenia mogą prowadzić do programowanej śmierci komórki (PCD). Analizy przeprowadzone na izolowanych osiach zarodkowych łubinu żółtego Lupinus luteus hodowanych in vitro na pożywkach z różnymi stężeniami NaCl wykazały zmiany w metabolizmie mitochondriów jak również całego organu. W warunkach zasolenia zmianie uległ poziom białek mitochondrialnych analizowany metodą elektroforezy dwukierunkowej. Spośród białek, których poziom zmienił się (wzrósł lub obniżył się) pod wpływem zasolenia, 48 wytypowano do identyfikacji z zastosowaniem spektrometrii mas. Wśród zidentyfikowanych białek znalazły się enzymy cyklu Krebsa, mitochondrialnego łańcucha transportu elektronów oraz uczestniczące w biogenezie mitochondriów i białka stresowe. Zasolenie prowadziło do warunków stresu oksydacyjnego (wzrost poziomu H2O2 i peroksydacji lipidów), jednak aktywność mitochondrialnych enzymów antyoksydacyjnych uległa obniżeniu. Analiza ultrastruktury wykazała szereg zmian w strukturze komórki obejmujących deformacje retikulum endoplazmatycznego, zwiększenie stopnia wakuolizacji komórki oraz degradację chromatyny w jądrze komórkowym. Pod wpływem zasolenia pojawiały się symptomy PCD w postaci uszkodzeń DNA (elektroforeza kometkowa) oraz fragmentacji DNA.The aim of this study was to demonstrate whether salinity leads to changes in mitochondria protein composition and to verify whether the conditions of salinity can lead to programmed cell death (PCD). The analysis conducted on isolated embryonic axes of yellow lupine, Lupinus luteus grown in vitro on media with different concentrations of NaCl showed changes in the metabolism of mitochondria as well as the entire organ. Changes in the level of mitochondrial proteins under salinity condition were analyzed using two-dimension electrophoresis. Among the proteins which levels changed (increased or decreased) due to salinity, 48 were selected for identification using mass spectrometry. Among the identified proteins were enzymes of the Krebs cycle, mitochondrial electron transport chain and participating in the biogenesis of mitochondria and stress response. Salinity led to conditions of oxidative stress (increasing levels of H2O2 and lipid peroxidation), but the activity of mitochondrial antioxidant enzymes decreased. Analysis of ultrastructure revealed a number of changes in the structure of cell including deformation the endoplasmic reticulum, increased cytoplasmic vacuolisation and degradation of chromatin in the nucleus. Salinity-induced changes led to the emergence of symptoms of PCD in the form of DNA damage (comet assay) and DNA fragmentation

Evolution of antioxidative systems

Życie na Ziemi rozwijało się w drodze ewolucji przez około 3,5 miliarda lat. Procesowi temu towarzyszyły zmiany składu atmosfery, w tym zmiany zawartości tlenu. Pierwotne organizmy rozwinęły się w warunkach, kiedy zawartość tlenu w atmosferze oscylowała wokół poziomu 0,02%. Nabycie przez organizmy zdolności do pozyskiwania energii na drodze reakcji fotosyntezy i katalizowania rozszczepienia cząsteczki wody z wykorzystaniem energii słonecznej zapoczątkowało stopniowe zwiększenie się zawartości tlenu w atmosferze i umożliwiło wykształcenie metabolizmu tlenowego. Wzrastająca zawartość tlenu, ze względu na jego właściwości utleniające, była toksyczna dla ówcześnie żyjących organizmów. Stało się to przyczyną promowania w toku ewolucji rozwoju wczesnych mechanizmów antyoksydacyjnych oraz wykształcenia nowych sprawniejszych układów mających na celu usuwanie nadmiaru niebezpiecznych reaktywnych form tlenu. Przez lata organizmy nabyły zdolność do regulowania ilości powstających reaktywnych form tlenu oraz wykorzystywania ich obecności w procesach sygnalizacji i przekazywania informacji.Life on Earth had evolved about 3.5 billion years ago. Evolutionary processes were accompanied by changes in the composition of the atmosphere, including changes in oxygen level. Primitive organisms have evolved in an environment in which the atmospheric oxygen content was fluctuating around 0.02%. These organisms, after having acquired the ability to generate energy through the process of photosynthesis and to catalyze splitting of water using solar energy, gave rise to gradual increase of the oxygen level in the atmosphere and provided a basis for the evolution of aerobic metabolism. The increased oxygen level, due to its oxidizing properties, appeared toxic to living organisms. This led to the development of early antioxidant mechanisms and their further evolution to more efficient systems for removal of dangerous reactive oxygen species. In the course of the evolution, organisms have acquired ability to control the amount of generated reactive oxygen species and to use them in signaling processes and transduction of information

Endogenous Polyamines and Ethylene Biosynthesis in Relation to Germination of Osmoprimed Brassica napus Seeds under Salt Stress

Currently, seed priming is reported as an efficient and low-cost approach to increase crop yield, which could not only promote seed germination and improve plant growth state but also increase abiotic stress tolerance. Salinity represents one of the most significant abiotic stresses that alters multiple processes in plants. The accumulation of polyamines (PAs) in response to salt stress is one of the most remarkable plant metabolic responses. This paper examined the effect of osmopriming on endogenous polyamine metabolism at the germination and early seedling development of Brassica napus in relation to salinity tolerance. Free, conjugated and bound polyamines were analyzed, and changes in their accumulation were discussed with literature data. The most remarkable differences between the corresponding osmoprimed and unprimed seeds were visible in the free (spermine) and conjugated (putrescine, spermidine) fractions. The arginine decarboxylase pathway seems to be responsible for the accumulation of PAs in primed seeds. The obvious impact of seed priming on tyramine accumulation was also demonstrated. Moreover, the level of ethylene increased considerably in seedlings issued from primed seeds exposed to salt stress. It can be concluded that the polyamines are involved in creating the beneficial effect of osmopriming on germination and early growth of Brassica napus seedlings under saline conditions through moderate changes in their biosynthesis and accumulation

Contribution of Exogenous Proline to Abiotic Stresses Tolerance in Plants: A Review

Abiotic stresses are the major environmental factors that play a significant role in decreasing plant yield and production potential by influencing physiological, biochemical, and molecular processes. Abiotic stresses and global population growth have prompted scientists to use beneficial strategies to ensure food security. The use of organic compounds to improve tolerance to abiotic stresses has been considered for many years. For example, the application of potential external osmotic protective compounds such as proline is one of the approaches to counteract the adverse effects of abiotic stresses on plants. Proline level increases in plants in response to environmental stress. Proline accumulation is not just a signal of tension. Rather, according to research discussed in this article, this biomolecule improves plant resistance to abiotic stress by rising photosynthesis, enzymatic and non-enzymatic antioxidant activity, regulating osmolyte concentration, and sodium and potassium homeostasis. In this review, we discuss the biosynthesis, sensing, signaling, and transport of proline and its role in the development of various plant tissues, including seeds, floral components, and vegetative tissues. Further, the impacts of exogenous proline utilization under various non-living stresses such as drought, salinity, high and low temperatures, and heavy metals have been extensively studied. Numerous various studies have shown that exogenous proline can improve plant growth, yield, and stress tolerance under adverse environmental factors

New Insight on Water Status in Germinating <i>Brassica napus</i> Seeds in Relation to Priming-Improved Germination

Seed priming is a pre-sowing method successfully used to improve seed germination. Since water plays a crucial role in germination, the aim of this study was to investigate the relationship between better germination performances of osmoprimed Brassica napus seeds and seed water status during germination. To achieve this goal, a combination of different kinds of approaches was used, including nuclear magnetic resonance (NMR) spectroscopy, TEM, and SEM as well as semi-quantitative PCR (semi-qPCR). The results of this study showed that osmopriming enhanced the kinetics of water uptake and the total amount of absorbed water during both the early imbibition stage and in the later phases of seed germination. The spin&#8315;spin relaxation time (T2) measurement suggests that osmopriming causes faster water penetration into the seed and more efficient tissue hydration. Moreover, factors potentially affecting water relations in germinating primed seeds were also identified. It was shown that osmopriming (i) changes the microstructural features of the seed coat, e.g., leads to the formation of microcracks, (ii) alters the internal structure of the seed by the induction of additional void spaces in the seed, (iii) increases cotyledons cells vacuolization, and (iv) modifies the expression pattern of aquaporin genes

Sugar Starvation Disrupts Lipid Breakdown by Inducing Autophagy in Embryonic Axes of Lupin (Lupinus spp.) Germinating Seeds

Under nutrient deficiency or starvation conditions, the mobilization of storage compounds during seed germination is enhanced to primarily supply respiratory substrates and hence increase the potential of cell survival. Nevertheless, we found that, under sugar starvation conditions in isolated embryonic axes of white lupin (Lupinus albus L.) and Andean lupin (Lupinus mutabilis Sweet) cultured in vitro for 96 h, the disruption of lipid breakdown occurs, as was reflected in the higher lipid content in the sugar-starved (-S) than in the sucrose-fed (+S) axes. We postulate that pexophagy (autophagic degradation of the peroxisome—a key organelle in lipid catabolism) is one of the reasons for the disruption in lipid breakdown under starvation conditions. Evidence of pexophagy can be: (i) the higher transcript level of genes encoding proteins of pexophagy machinery, and (ii) the lower content of the peroxisome marker Pex14p and its increase caused by an autophagy inhibitor (concanamycin A) in -S axes in comparison to the +S axes. Additionally, based on ultrastructure observation, we documented that, under sugar starvation conditions lipophagy (autophagic degradation of whole lipid droplets) may also occur but this type of selective autophagy seems to be restricted under starvation conditions. Our results also show that autophagy occurs at the very early stages of plant growth and development, including the cells of embryonic seed organs, and allows cell survival under starvation conditions