scholarly journals Peptide-Bound Methionine Sulfoxide (MetO) Levels and MsrB2 Abundance Are Differentially Regulated during the Desiccation Phase in Contrasted Acer Seeds

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 391 ◽  
Author(s):  
Natalia Wojciechowska ◽  
Shirin Alipour ◽  
Ewelina Stolarska ◽  
Karolina Bilska ◽  
Pascal Rey ◽  
...  

Norway maple and sycamore produce desiccation-tolerant (orthodox) and desiccation-sensitive (recalcitrant) seeds, respectively. Drying affects reduction and oxidation (redox) status in seeds. Oxidation of methionine to methionine sulfoxide (MetO) and reduction via methionine sulfoxide reductases (Msrs) have never been investigated in relation to seed desiccation tolerance. MetO levels and the abundance of Msrs were investigated in relation to levels of reactive oxygen species (ROS) such as hydrogen peroxide, superoxide anion radical and hydroxyl radical (•OH), and the levels of ascorbate and glutathione redox couples in gradually dried seeds. Peptide-bound MetO levels were positively correlated with ROS concentrations in the orthodox seeds. In particular, •OH affected MetO levels as well as the abundance of MsrB2 solely in the embryonic axes of Norway maple seeds. In this species, MsrB2 was present in oxidized and reduced forms, and the latter was favored by reduced glutathione and ascorbic acid. In contrast, sycamore seeds accumulated higher ROS levels. Additionally, MsrB2 was oxidized in sycamore throughout dehydration. In this context, the three elements •OH level, MetO content and MsrB2 abundance, linked together uniquely to Norway maple seeds, might be considered important players of the redox network associated with desiccation tolerance.

2020 ◽  
Vol 21 (23) ◽  
pp. 9197
Author(s):  
Natalia Wojciechowska ◽  
Shirin Alipour ◽  
Ewelina Stolarska ◽  
Karolina Bilska ◽  
Pascal Rey ◽  
...  

The levels of methionine sulfoxide (MetO) and the abundances of methionine sulfoxide reductases (Msrs) were reported as important for the desiccation tolerance of Acer seeds. To determine whether the MetO/Msrs system is related to reactive oxygen species (ROS) and involved in the regulation of germination in orthodox and recalcitrant seeds, Norway maple and sycamore were investigated. Changes in water content, MetO content, the abundance of MsrB1 and MsrB2 in relation to ROS content and the activity of reductases depending on nicotinamide adenine dinucleotides were monitored. Acer seeds differed in germination speed—substantially higher in sycamore—hydration dynamics, levels of hydrogen peroxide, superoxide anion radicals (O2•−) and hydroxyl radicals (•OH), which exhibited peaks at different stages of germination. The MetO level dynamically changed, particularly in sycamore embryonic axes, where it was positively correlated with the levels of O2•− and the abundance of MsrB1 and negatively with the levels of •OH and the abundance of MsrB2. The MsrB2 abundance increased upon sycamore germination; in contrast, it markedly decreased in Norway maple. We propose that the ROS–MetO–Msr redox system, allowing balanced Met redox homeostasis, participates in the germination process in sycamore, which is characterized by a much higher speed compared to Norway maple.


2020 ◽  
Vol 61 (6) ◽  
pp. 1158-1167 ◽  
Author(s):  
Shirin Alipour ◽  
Natalia Wojciechowska ◽  
Ewelina Stolarska ◽  
Karolina Bilska ◽  
Ewa Marzena Kalemba

Abstract Desiccation tolerance is a developmental program enabling seed survival in a dry state and is common in seeds categorized as orthodox. We focused on NAD and its phosphorylated form (NADP) because their continual switching between reduced (NAD(P)H) and oxidized (NAD(P)+) forms is involved in the modulation of redox signaling and the determination of the reducing power and further antioxidant responses. Norway maple and sycamore seeds representing the orthodox and recalcitrant categories, respectively, were used as models in a comparison of responses to water loss. The process of desiccation up to 10% water content (WC) was monitored in Norway maple seeds, while dehydration up to 30% WC was monitored in desiccation-sensitive sycamore seeds. Norway maple and sycamore seeds, particularly their embryonic axes, exhibited a distinct redox status during dehydration and desiccation. High NADPH levels, NAD+ accumulation, low and stable NAD(P)H/NAD(P)+ ratios expressed as reducing power and high NADPH-dependent enzyme activity were reported in Norway maple seeds and were considered attributes of orthodox-type seeds. The contrasting results of sycamore seeds contributed to their low antioxidant capacity and high sensitivity to desiccation. NADPH deficiency, low NADPH-dependent enzyme activity and lack of NAD+ accumulation were primary features of sycamore seeds, with implications for their NAD(P)H/NAD(P)+ ratios and reducing power and with effects on many seed traits. Thus, we propose that the distinct levels of pyridine nucleotides and their redox status contribute to orthodox and recalcitrant phenotype differentiation in seeds by affecting cellular redox signaling, metabolism and the antioxidant system.


Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1250
Author(s):  
Ewelina Stolarska ◽  
Karolina Bilska ◽  
Natalia Wojciechowska ◽  
Agnieszka Bagniewska-Zadworna ◽  
Pascal Rey ◽  
...  

Two related tree species, Norway maple (Acer platanoides L.) and sycamore (Acer pseudoplatanus L.), produce desiccation-tolerant (orthodox) and desiccation-sensitive (recalcitrant) seeds, respectively. We compared the seeds of these two species to characterize the developmentally driven changes in the levels of peptide-bound methionine sulfoxide (MetO) and the abundance of methionine sulfoxide reductases (Msrs) B1 and B2, with respect to the cellular redox environment. Protein oxidation at the Met level was dynamic only in Norway maple seeds, and the reduced MsrB2 form was detected only in this species. Cell redox status, characterized by the levels of reduced and oxidized ascorbate, glutathione, and nicotinamide adenine dinucleotide (NAD)/phosphate (NADP), was clearly more reduced in the Norway maple seeds than in the sycamore seeds. Clear correlations between MetO levels, changes in water content and redox status were reported in orthodox Acer seeds. The abundance of Msrs was correlated in both species with redox determinants, mainly ascorbate and glutathione. Our data suggest that MsrB2 is associated with the acquisition of desiccation tolerance and that ascorbate might be involved in the redox pathway enabling the regeneration of Msr via intermediates that are not known yet.


1999 ◽  
Vol 9 (1) ◽  
pp. 13-37 ◽  
Author(s):  
N. W. Pammenter ◽  
Patricia Berjak

AbstractA suite of mechanisms or processes that together have been implicated in the acquisition and maintenance of desiccation tolerance in orthodox seeds is discussed in the context of the behaviour of desiccation-sensitive seeds, and where appropriate, parallels are drawn with the situation in vegetative plant tissues that tolerate dehydration. Factors included are: physical characteristics of cells and intracellular constituents; insoluble reserve accumulation; intracellular de-differentiation; metabolic ‘switching off’; presence, and efficient operation, of antioxidant systems; accumulation of putatively protective substances including LEAs, sucrose and other oligosaccharides, as well as amphipathic molecules; the presence and role of oleosins; and the presence and operation of repair systems during rehydration. The variable response to dehydration shown by desiccation-sensitive seeds is considered in terms of the absence or incomplete expression of this suite of mechanisms or processes.Three categories of damage are envisaged: (i) reduction in cell volume which can lead to mechanical damage; (ii) aqueous-based degradative processes, probably consequent upon deranged metabolism at intermediate water contents. This is termed ‘metabolism-induced damage’ and its extent will depend upon the metabolic rate and the rate of dehydration; and (iii) the removal of water intimately associated with macromolecular surfaces leading to denaturation: this is referred to as desiccation damagesensu stricto. The effects of drying rate and the maturity status of seeds are considered in relation to the responses to dehydration, leading to the conclusion that the concept of critical water contents on a species basis is inappropriate. Viewing seed postharvest physiology in terms of a continuum of behaviour is considered to be more realistic than attempting precise categorization.Rapid dehydration of excised embryonic axes (or other explants) from desiccation-sensitive seeds permits retention of viability (in the short term) to water contents approaching the level of non-freezable water. This opens up the possibility of long-term conservation, by cryopreservation techniques, of the genetic resources of species producing non-orthodox seeds.


2020 ◽  
Vol 21 (10) ◽  
pp. 3612
Author(s):  
Hanna Kijak ◽  
Ewelina Ratajczak

Long-term seed storage is important for protecting both economic interests and biodiversity. The extraordinary properties of seeds allow us to store them in the right conditions for years. However, not all types of seeds are resilient, and some do not tolerate extreme desiccation or low temperature. Seeds can be divided into three categories: (1) orthodox seeds, which tolerate water losses of up to 7% of their water content and can be stored at low temperature; (2) recalcitrant seeds, which require a humidity of 27%; and (3) intermediate seeds, which lose their viability relatively quickly compared to orthodox seeds. In this article, we discuss the genetic bases for desiccation tolerance and longevity in seeds and the differences in gene expression profiles between the mentioned types of seeds.


2007 ◽  
Vol 34 (7) ◽  
pp. 601 ◽  
Author(s):  
Stanislawa Pukacka ◽  
Ewelina Ratajczak

The ascorbate–glutathione system was studied during development and desiccation of seeds of two Acer species differing in desiccation tolerance: Norway maple (Acer platanoides L., orthodox) and sycamore (Acer pseudoplatanus L., recalcitrant). The results showed remarkable differences in the concentration and redox balance of ascorbate and glutathione between these two kinds of seeds during development, and a significant dependence between glutathione content and acquisition of desiccation tolerance in Norway maple seeds. There were relatively small differences between the species in the activities of enzymes of the ascorbate–glutathione cycle: ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (GR, EC 1.6.4.2). At the end of seed maturation, ascorbic acid content and the activities of the above enzymes was about the same in both species The electrophoretic pattern of APX isoenzymes was also similar for both species, and the intensity of the bands decreased at the end of seed maturation in both species. When sycamore seeds were desiccated to a moisture content of less than 26%, there was a marked decrease in seed viability and an increase in the production of reactive oxygen species. During desiccation, Norway maple seeds had a more active defence system, which was reflected in a higher glutathione content, a higher glutathione redox status, a higher ascorbate redox status, and higher activities of APX, MR, DHAR, GR and GPX (glutathione peroxidase). During desiccation, sulfhydryl-to-disulfide transition into proteins was more intense in Norway maple seeds than sycamore seeds. All of these results suggest that, in orthodox seeds, the ascorbate–glutathione cycle plays an important role in the acquisition of tolerance to desiccation, in protein maturation, and in protection from reactive oxygen species.


Antioxidants ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 155 ◽  
Author(s):  
Lindsay Bruce ◽  
Diana Singkornrat ◽  
Kelsey Wilson ◽  
William Hausman ◽  
Kelli Robbins ◽  
...  

The deleterious alteration of protein structure and function due to the oxidation of methionine residues has been studied extensively in age-associated neurodegenerative disorders such as Alzheimer’s and Parkinson’s Disease. Methionine sulfoxide reductases (MSR) have three well-characterized biological functions. The most commonly studied function is the reduction of oxidized methionine residues back into functional methionine thus, often restoring biological function to proteins. Previous studies have successfully overexpressed and silenced MSR activity in numerous model organisms correlating its activity to longevity and oxidative stress. In the present study, we have characterized in vivo effects of MSR deficiency in Drosophila. Interestingly, we found no significant phenotype in animals lacking either methionine sulfoxide reductase A (MSRA) or methionine sulfoxide reductase B (MSRB). However, Drosophila lacking any known MSR activity exhibited a prolonged larval third instar development and a shortened lifespan. These data suggest an essential role of MSR in key biological processes.


1994 ◽  
Vol 4 (2) ◽  
pp. 127-133 ◽  
Author(s):  
W. E. Finch-Savage ◽  
P. S. Blake

AbstractFruit and seed development in Quercus robur L. were studied on a single tree over five consecutive seasons. Patterns of growth in the cotyledons and embryonic axes differed between years and resulted in seeds of very different sizes. Moisture content at shedding also differed between years, and late-shed seeds had lower moisture contents than early-shed seeds. Moisture content at shedding was negatively correlated with desiccation tolerance. Seed development in Q. robur therefore appeared indeterminate and did not end in a period of rapid desiccation.Sensitivity to desiccation in Q. robur was not due to an inability to accumulate dehydrin proteins, ABA or soluble sugars, substances that have been linked with the acquisition of desiccation tolerance in orthodox seeds. There were great similarities between several aspects of Q. robur seed development and that of orthodox seeds before the latter entered the terminal phase of rapid desiccation. This pattern of seed development contrasted with that reported for the highly desiccation-sensitive seeds of Avicennia marina.


2021 ◽  
Vol 22 (1) ◽  
pp. 402
Author(s):  
Natalia Wojciechowska ◽  
Agnieszka Bagniewska-Zadworna ◽  
Julia Minicka ◽  
Kornel M. Michalak ◽  
Ewa M. Kalemba

Beech seeds are produced irregularly, and there is a need for long-term storage of these seeds for forest management practices. Accumulated reactive oxygen species broadly oxidize molecules, including amino acids, such as methionine, thereby contributing to decreased seed viability. Methionine oxidation can be reversed by the activity of methionine sulfoxide reductases (Msrs), which are enzymes involved in the regulation of many developmental processes and stress responses. Two types of Msrs, MsrB1 and MsrB2, were investigated in beech seeds to determine their abundance and localization. MsrB1 and MsrB2 were detected in the cortical cells and the outer area of the vascular cylinder of the embryonic axes as well as in the epidermis and parenchyma cells of cotyledons. The abundances of MsrB1 and MsrB2 decreased during long-term storage. Ultrastructural analyses have demonstrated the accumulation of these proteins in protein storage vacuoles and in the cytoplasm, especially in close proximity to the cell membrane. In silico predictions of possible Msr interactions supported our findings. In this study, we investigate the contribution of MsrB1 and MsrB2 locations in the regulation of seed viability and suggest that MsrB2 is linked with the longevity of beech seeds via association with proper utilization of storage material.


Antioxidants ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 114 ◽  
Author(s):  
Pascal Rey ◽  
Lionel Tarrago

Oxidation of methionine (Met) leads to the formation of two S- and R-diastereoisomers of Met sulfoxide (MetO) that are reduced back to Met by methionine sulfoxide reductases (MSRs), A and B, respectively. Here, we review the current knowledge about the physiological functions of plant MSRs in relation with subcellular and tissue distribution, expression patterns, mutant phenotypes, and possible targets. The data gained from modified lines of plant models and crop species indicate that MSRs play protective roles upon abiotic and biotic environmental constraints. They also participate in the control of the ageing process, as shown in seeds subjected to adverse conditions. Significant advances were achieved towards understanding how MSRs could fulfil these functions via the identification of partners among Met-rich or MetO-containing proteins, notably by using redox proteomic approaches. In addition to a global protective role against oxidative damage in proteins, plant MSRs could specifically preserve the activity of stress responsive effectors such as glutathione-S-transferases and chaperones. Moreover, several lines of evidence indicate that MSRs fulfil key signaling roles via interplays with Ca2+- and phosphorylation-dependent cascades, thus transmitting ROS-related information in transduction pathways.


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