DLACZEGO TAUNTAUNY MAJĄ DWIE PARY NOZDRZY? ADAPTACJE ORGANIZMÓW DO ŻYCIA W EKSTREMALNYCH ŚRODOWISKACH W UNIWERSUM SAGI GWIEZDNE WOJNY

Jedną z ważniejszych cech organizmów jest zdolność adaptacji do otaczającego środowiska. Celem artykułu jest porównanie adaptacji do zróżnicowanych warunków występujących na pustyni, w ekstremalnie zimnych regionach i w środowisku wodnym u organizmów zamieszkujących Ziemię oraz stworzeń wymyślonych na potrzeby sagi Gwiezdne wojny. Omówione zostaną niektóre charakterystyczne dla sagi gatunki: sarlacc, banty, eopi, tauntauny, wampy, morski zabójca opee (ang. opee sea killer), ryba colo claw (ang. colo claw fish), morski potwór sando (ang. sando aqua monster) i aiwha. Występujące u fikcyjnych stworzeń przystosowania do środowiska zostaną porównane z adaptacjami wykształconymi przez wykazujące podobieństwo gatunki zamieszkujące Ziemię. Mechanizm tych przystosowań zostanie wyjaśniony na podstawie aktualnej wiedzy biologicznej.Jedną z ważniejszych cech organizmów jest zdolność adaptacji do otaczającego środowiska. Celem artykułu jest porównanie adaptacji do zróżnicowanych warunków występujących na pustyni, w ekstremalnie zimnych regionach i w środowisku wodnym u organizmów zamieszkujących Ziemię oraz stworzeń wymyślonych na potrzeby sagi Gwiezdne wojny. Omówione zostaną niektóre charakterystyczne dla sagi gatunki: sarlacc, banty, eopi, tauntauny, wampy, morski zabójca opee (ang. opee sea killer), ryba colo claw (ang. colo claw fish), morski potwór sando (ang. sando aqua monster) i aiwha. Występujące u fikcyjnych stworzeń przystosowania do środowiska zostaną porównane z adaptacjami wykształconymi przez wykazujące podobieństwo gatunki zamieszkujące Ziemię. Mechanizm tych przystosowań zostanie wyjaśniony na podstawie aktualnej wiedzy biologicznej

Tough Sprouting – Impact of Cadmium on Physiological State and Germination Rate of Soybean Seeds

Seed germination is the earliest process in plant development and is crucial for further plant growth and fitness. The process is regulated by various internal and external factors, including soil pollutants such as nonessential metals. In the present study, we examined in detail the impact of short-term imbibition in Cd solutions at several concentrations (5, 10, and 25 mg/L) on germination rate and physiological state of soybean seeds. The results showed that although Cd was readily absorbed by the seeds, the metal had no effect on seeds cell viability, oxidative stress intensity, or germination percentage. In contrast, imbibition in Cd solution led to slight reduction in antioxidant capacity of seeds. Seedlings grown from seeds pretreated with metal showed no differences in growth in relation to the control. Taken together, the results indicate that soybean seeds are relatively tolerant even to high Cd concentration (up to 25 mg/L)

Soybean Seedlings Enriched with Iron and Magnesium - Impact on Germination, Growth and Antioxidant Properties

Abstract Iron (Fe) and magnesium (Mg) deficiency in human diets is a widespread problem observed in various regions of the world. Insufficient Fe uptake results in the development of iron dependent anaemia and depressed physical and intellectual performance. In turn Mg deficiency is associated with alterations in neuromuscular and cardiovascular systems. An emerging alternative to traditional supplementation of these elements in the form of pills, liquids or effervescent tablets, is introduction of fortified food products. In present study we show that preincubation of soybean seeds in Fe and Mg solutions leads to elevated content of these elements in the seedlings. Importantly the pretreatment did not affect germination rate, seedlings growth or, with an exception of Fe supplementation at highest concentration, antioxidant capacity. The obtained results indicate that preincubation of seeds in Fe and Mg solutions may be a promising method of obtaining enriched soybean sprouts

The role of epigenetic and epitranscriptomic modifications in plants exposed to non-essential metals

Contamination of the soil with non-essential metals and metalloids is a serious problem in many regions of the world. These non-essential metals and metalloids are toxic to all organisms impacting crop yields and human health. Crop plants exposed to high concentrations of these metals leads to perturbed mineral homeostasis, decreased photosynthesis efficiency, inhibited cell division, oxidative stress, genotoxic effects and subsequently hampered growth. Plants can activate epigenetic and epitranscriptomic mechanisms to maintain cellular and organism homeostasis. Epigenetic modifications include changes in the patterns of cytosine and adenine DNA base modifications, changes in cellular non-coding RNAs, and remodeling histone variants and covalent histone tail modifications. Some of these epigenetic changes have been shown to be long-lasting and may therefore contribute to stress memory and modulated stress tolerance in the progeny. In the emerging field of epitranscriptomics, defined as chemical, covalent modifications of ribonucleotides in cellular transcripts, epitranscriptomic modifications are postulated as more rapid modulators of gene expression. Although significant progress has been made in understanding the plant’s epigenetic changes in response to biotic and abiotic stresses, a comprehensive review of the plant’s epigenetic responses to metals is lacking. While the role of epitranscriptomics during plant developmental processes and stress responses are emerging, epitranscriptomic modifications in response to metals has not been reviewed. This article describes the impact of non-essential metals and metalloids (Cd, Pb, Hg, Al and As) on global and site-specific DNA methylation, histone tail modifications and epitranscriptomic modifications in plants

NADPH oxidase is involved in regulation of gene expression and ROS overproduction in soybean (Glycine max L.) seedlings exposed to cadmium

Cadmium-induced oxidative burst is partially mediated by NADPH oxidase. The aim of the present research was to evaluate the role of NADPH oxidase in soybeans’ response to short-term cadmium stress. The application of an NADPH oxidase inhibitor, diphenyleneiodonium chloride (DPI), affected expression of two Cd-inducible genes, encoding DOF1 and MYBZ2 transcription factors. This effect was observed after 3 h of treatment. Interestingly, Cd-dependent increases in NADPH oxidase activity occurred only after a period of time ranging from 6 and 24 h of stress. Stimulation of the enzyme correlated in time with a significant accumulation of reactive oxygen species (ROS). Further analysis revealed that pharmacological inhibition of NADPH oxidase activity during 24 h of Cd stress does not affect Cd uptake, seedling growth, or the level of lipid peroxidation. The role of NADPH oxidase in the response of soybean seedlings to short-term Cd exposure is discussed

Regulation of the expression of genes encoding proteins engaged in signal transduction pathways in soybean seedlings (Glycine max L.) treated with cadmium

Wydział Biologii: Instytut Biologii EksperymentalnejCelem rozprawy doktorskiej jest kompleksowe zbadanie szlaków sygnalnych aktywowanych w siewkach soi poddanych działaniu kadmu. . Badania obejmowały pomiary ekspresji 15 genów powiązanych z różnymi szlakami przekazywania sygnałów w korzeniach soi traktowanych roztworami kadmu w dwóch stężeniach (10 mg L-1 i 25 mg L-1) przez krótkie okresy czasu (3, 6 i 24 h). Uzyskane wyniki wykazały, że kadm indukuje ekspresję genów kodujących białka zaangażowane w metabolizm etylenu (syntazę kwasu 1-aminocyklopropano-1-karboksylowego - ACS), generowanie tlenku azotu (reduktazę azotanową – NR), kaskady kinaz aktywowanych mitogenami (MAPKK2) i regulację ekspresji innych genów (czynniki transkrypcyjne DOF1, MYBZ2 i bZIP62). Wzrost ekspresji genu ACS był skorelowany z indukcją biosyntezy etylenu, a indukcja genu NR ze wzrostem aktywności reduktazy azotanowej. Dane literaturowe pokazują, że krótkotrwały stres kadmowy prowadzi do akumulacji etylenu, tlenku azotu oraz generowanych przez oksydazę NADPH reaktywnych form tlenu. Doświadczenia z zastosowaniem zmiatacza tlenku azotu (PTIO) i inhibitora oksydazy NADPH (DPI), wykazały, że PTIO, niweluje zależny od kadmu wzrost ekspresji wszystkich genów indukowanych przez Cd po 3 godzinach, zaś w tym samym wariancie czasowym, DPI, zwiększa zależną od Cd indukcję genów DOF1 i MYBZ2. Również inhibitor syntezy etylenu, CoCl2, moduluje ekspresję szeregu genów (MAPKK2, NR, DOF1 i bZIP62), jednakże, w zastosowanych warunkach nie hamuje biosyntezy etylenu. Podsumowując, uzyskane wyniki wskazują, że etylen, NO, kaskady MAPK oraz czynniki transkrypcyjne DOF1, MYBZ2 i bZIP62 uczestniczą w przekazywaniu sygnału w siewkach soi narażonych na krótkotrwały stres kadmowy.The aim of present study is a comprehensive examination of signaling pathways engaged in the transduction of cadmium signal in soybean seedlings. The research includes analysis of expression of 15 genes involved in various signal transduction pathways in soybean seedlings exposed to cadmium at two concentrations (10 mg L-1 and 25 mg L-1) for short time periods (3, 6 and 24 h). The obtained results show that cadmium causes induction of genes encoding proteins involved in ethylene metabolism (1-aminocyclopropane-1-carboxylic acid synthase - ACS), nitric oxide generation (nitrate reductase - NR), MAPK cascades (MAPKK2) and regulates the expression of other genes (DOF1, MYBZ2 and bZIP62 transcriptions factors). Increase in ACS expression was correlated with induction of ethylene biosynthesis, while induction of NR gene with increase in nitrate reductase activity. Literature data show that short term cadmium stress leads to the accumulation of ethylene, nitric oxide and reactive oxygen species generated mainly by NADPH oxiadase. Experiments performed with the use of nitric oxide scavenger (PTIO) and NADPH oxidase inhibitor (DPI) showed that PTIO reversed the observed Cd-dependent induction of expression of all investigated genes after 3 h, while in the same time variant, DPI, caused augmentation of Cd-dependent induction of DOF1 and MYBZ2 genes. Also inhibitor of ethylene synthesis, CoCl2, caused modulation of expression of several genes (MAPKK2, NR, DOF1 and bZIP62), however, it did not inhibit ethylene production. Taken together obtained results imply that ethylene, NO, MAPK cascades and DOF1, MYBZ2 and bZIP62 transcription factors are engaged in the transduction of cadmium signal in soybean seedlings exposed to short term cadmium stress

Plant Recovery after Metal Stress—A Review

Contamination of the environment with metals, their adverse impact on plant performance and transmission to the human food chain through crops and vegetables are important concerns worldwide. Although the literature on metal contamination, toxicity and plant response to this stress factor is quite abundant, there are very limited reports on the phenomenon of plant recovery after metal stress. The present article reviews available literature on the recovery process examined in various plant species, in response to several metals (Al, Cd, Cu, Ni, Pb, Zn), applied at different concentrations and treatment duration. The reviewed studies have been carried out in laboratory conditions. However, it should be highlighted that although metal stress is not as transient as most of other stress factors (e.g., drought, heat, chilling), metal concentration in the soil may still decrease due to, e.g., leaching to lower soil layers or uptake by organisms. Thus, in natural conditions, plants may be subjected to post-metal-stress conditions. The review also discusses the mechanism behind efficient recovery and the impact of post metal stress on future plant performance—possible acquisition of stress memory, adaptation to unfavorable conditions and cross-tolerance towards other stress factors

The toxic Doppelganger: on the ionic and molecular mimicry of

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The toxic Doppelganger: on the ionic and molecular mimicry of cadmium

Cadmium is a toxic heavy metal which can cause numerous alterations in cell functioning. Exposure to cadmium leads to generation of reactive oxygen species, disorders in membrane structure and functioning, inhibition of respiration, disturbances in ion homeostasis, perturbations in cell division, and initiation of apoptosis and necrosis. This heavy metal is considered a carcinogen by the Agency for Toxic Substances and Disease Registry. At least some of the described toxic effects could result from the ability of cadmium to mimic other divalent ions and alert signal transduction networks. This review describes the role of cadmium mimicry in its uptake, reactive oxygen species generation, alterations in calmodulin, Wnt/β-catenin and estrogen signaling pathways, and modulation of neurotransmission. The last section is dedicated to the single known case of a favorable function performed by cadmium mimicry: marine diatoms, which live in zinc deficient conditions, utilize cadmium as a cofactor in carbonic anhydrase - so far the only described cadmium enzyme