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1.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206693

RESUMO

Plant overwintering may be affected in the future by climate change. Low-temperature waterlogging, associated with a predicted increase in rainfall during autumn and winter, can affect freezing tolerance, which is the main component of winter hardiness. The aim of this study was to elucidate the mechanism of change in freezing tolerance caused by low-temperature waterlogging in Lolium perenne, a cool-season grass that is well adapted to a cold climate. The work included: (i) a freezing tolerance test (plant regrowth after freezing); (ii) analysis of plant phytohormones production (abscisic acid [ABA] content and ethylene emission); (iii) measurement of leaf water content and stomatal conductance; (iv) carbohydrate analysis; and (v) analysis of Aco1, ABF2, and FT1 transcript accumulation. Freezing tolerance may be improved as a result of cold waterlogging. The mechanism of this change is reliant on multifaceted actions of phytohormones and carbohydrates, whereas ethylene may counteract ABA signaling. The regulation of senescence processes triggered by concerted action of phytohormones and glucose signaling may be an essential component of this mechanism.


Assuntos
Ácido Abscísico/metabolismo , Aclimatação , Etilenos/metabolismo , Congelamento , Estresse Fisiológico , Açúcares/metabolismo , Água , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Fenômenos Fisiológicos Vegetais , Proteínas de Plantas/genética
2.
Int J Mol Sci ; 21(14)2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32707671

RESUMO

The roles of endogenous brassinosteroids (BRs) in the modulation of reaction to drought and genetic regulation of this process are still obscure. In this study, a multidirectional analysis was performed on semi-dwarf barley (Hordeum vulgare) Near-Isogenic Lines (NILs) and the reference cultivar "Bowman" to get insights into various aspects of metabolic reaction to drought. The NILs are defective in BR biosynthesis or signaling and displayed an enhanced tolerance to drought. The BR metabolism perturbations affected the glucose and fructose accumulation under the control and stress conditions. The BR metabolism abnormalities negatively affected the sucrose accumulation as well. However, during drought, the BR-deficient NILs accumulated higher contents of sucrose than the "Bowman" cultivar. Under the control conditions, accumulation of transcripts encoding antioxidant enzymes ascorbate peroxidase (HvAPX) and superoxide dismutase (HvSOD) was BR-dependent. However, during drought, the accumulation of HvAPX transcript was BR-dependent, whereas accumulations of transcripts encoding catalase (HvCAT) and HvSOD were not affected by the BR metabolism perturbations. The obtained results reveal a significant role of BRs in regulation of the HvAPX and HvCAT enzymatic activities under control conditions and the HvAPX and HvSOD activities during physiological reactions to drought.


Assuntos
Brassinosteroides/metabolismo , Hordeum/genética , Hordeum/metabolismo , Ascorbato Peroxidases/genética , Ascorbato Peroxidases/metabolismo , Catalase/genética , Catalase/metabolismo , Secas , Frutose/metabolismo , Genes de Plantas , Glucose/metabolismo , Hordeum/crescimento & desenvolvimento , Peróxido de Hidrogênio/metabolismo , Mutação , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ribulose-Bifosfato Carboxilase/genética , Ribulose-Bifosfato Carboxilase/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo
3.
Int J Mol Sci ; 21(5)2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32164259

RESUMO

In temperature stress, the main role of heat-shock proteins (HSP) is to act as molecular chaperones for other cellular proteins. However, knowledge about the hormonal regulation of the production of the HSP is quite limited. Specifically, little is known about the role of the plant steroid hormones-brassinosteroids (BR)-in regulating the HSP expression. The aim of our study was to answer the question of how a BR deficit or disturbances in its signaling affect the accumulation of the HSP90, HSP70, HSP18, and HSP17 transcripts and protein in barley growing at 20 °C (control) and during the acclimation of plants at 5 °C and 27 °C. In barley, the temperature of plant growth modified the expression of HSPs. Furthermore, the BR-deficient mutants (mutations in the HvDWARF or HvCPD genes) and BR-signaling mutants (mutation in the HvBRI1 gene) were characterized by altered levels of the transcripts and proteins of the HSP group compared to the wild type. The BR-signaling mutant was characterized by a decreased level of the HSP transcripts and heat-shock proteins. In the BR-deficient mutants, there were temperature-dependent cases when the decreased accumulation of the HSP70 and HSP90 transcripts was connected to an increased accumulation of these HSP. The significance of changes in the accumulation of HSPs during acclimation at 27 °C and 5 °C is discussed in the context of the altered tolerance to more extreme temperatures of the studied mutants (i.e., heat stress and frost, respectively).


Assuntos
Brassinosteroides/biossíntese , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Hordeum/crescimento & desenvolvimento , Aclimatação , Vias Biossintéticas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hordeum/genética , Hordeum/metabolismo , Mutação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Temperatura
4.
J Plant Physiol ; 244: 153090, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31841952

RESUMO

The integral parts of the cell membranes are the functional proteins, which are crucial for cell life. Among them, proton-pumping ATPase and aquaporins appear to be of particular importance. There is some knowledge about the effect of the temperature during plant growth, including stress-inducing temperatures, on the accumulation of the membrane proteins: plasma membrane H+-ATPase and aquaporins, but not much is known about the effect of the phytohormones (i.e. brassinosteroids (BR)) on control of accumulation of these proteins. The aim of our study was to answer the question of how a BR deficit and disturbances in the BR perception/signalling affect the accumulation of plasma membrane H+-ATPase (PM H+-ATPase), the aquaporin HvPIP1 transcript and protein in barley growing at 20 °C and during its acclimation at 5 °C and 27 °C. For the studies, the BR-deficient mutant 522DK (derived from the wild-type Delisa), the BR-deficient mutant BW084 and the BR-signalling mutant BW312 and their wild-type Bowman were used. Generally, temperature of growth was significant factor influencing on the level of the accumulation of the H+-ATPase and HvPIP1 transcript and the PM H+-ATPase and HvPIP1 protein in barley leaves. The level of the accumulation of the HvPIP1 transcript decreased at 5 °C (compared to 20 °C), but was higher at 27 °C than at 20 °C in the analyzed cultivars. In both cultivars the protein HvPIP1 was accumulated in the highest amounts at 27 °C. On the other hand, the barley mutants with a BR deficiency or with BR signalling disturbances were characterised by an altered accumulation level of PM H+-ATPase, the aquaporin HvPIP1 transcript and protein (compared to the wild types), which may suggest the involvement of brassinosteroids in regulating PM H+-ATPase and aquaporin HvPIP1 at the transcriptional and translational levels.


Assuntos
Adenosina Trifosfatases/genética , Aquaporinas/genética , Hordeum/fisiologia , Proteínas de Plantas/genética , Aclimatação , Adenosina Trifosfatases/metabolismo , Aquaporinas/metabolismo , Brassinosteroides/metabolismo , Temperatura Baixa , Hordeum/genética , Temperatura Alta , Mutação , Proteínas de Plantas/metabolismo
5.
Plant Physiol Biochem ; 139: 215-228, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30908973

RESUMO

The purpose of experiments was to describe the alterations of content of steroid regulators (brassinosteroids, progesterone) during cold hardening of winter wheat. Further we studied physiological and biochemical changes induced by these steroids in cold hardened winter wheat together with estimation of plant frost tolerance. The endogenous brassinosteroid content was elevated in winter wheat during cold hardening while level of progesterone was lowered. A higher content of brassinosteroids (but not progesterone) was connected to better frost tolerance of winter wheat cultivars. Plant supplementation with brassinosteroid (24-epibrassinolide) and progesterone before cold hardening reduced frost damage. Tests with the inhibitors of the biosynthesis of brassinosteroids and progesterone suggested that these steroids are one of players in regulating the antioxidant system in winter wheat during cold hardening. Their role in regulating the expression of Rubisco or the Rubisco activase gene was less clear. Steroid regulators did not affect the content of the stress hormone ABA. Model studies of the membranes, made on a Langmuir bath, showed an increase in the value of the parameter describing differences in membrane compressibility (resulting from stronger interactions among the molecules in the monolayers). This suggests that 24-epibrassinolide and progesterone enter into the lipid layer and - in a similar way to sterols - stabilise the interaction among lipids. It may be significant step for better frost tolerance. The use of steroid regulators (especially brassinosteroids) as agrochemicals improving frost tolerance of winter cereals will be discussed.


Assuntos
Triticum/metabolismo , Temperatura Baixa , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Progesterona/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Triticum/genética
6.
Plant Physiol Biochem ; 137: 84-92, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30769236

RESUMO

This study focused on the idea that the toxic effect of zearalenone (ZEA) and the protective actions of the brassinosteroid - 24-epibrassinolide (EBR) as well as selenium are dependent on its accumulation in chloroplasts to a high degree. These organelles were isolated from the leaves of oxidative stress-sensitive and stress-tolerant wheat cultivars that had been grown from grains that had been incubated in a solution of ZEA (30 µM), Na2SeO4 (Se, 10 µM), EBR (0.1 µM) or in a mixture of ZEA with Se or EBR. Ultra-high performance liquid chromatography techniques indicated that ZEA was adsorbed in higher amounts in the chloroplasts in the sensitive rather than tolerant cultivar. Although the brassinosteroids and Se were also accumulated in the chloroplasts, higher levels were only found in the tolerant cultivar. The application of EBR increased the homocastasterone content, especially in the chloroplasts of the tolerant plant and after the addition of ZEA. The presence of both protectants caused a decrease in the ZEA content in studied organelles and resulted in diminishing of the oxidative stress (i.e. changes in the activity of the antioxidative enzymes). Moreover, a recovery of photosystem II and decrease in the negative impact of ZEN on Hsp90 transcript accumulation was observed in plants.


Assuntos
Brassinosteroides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Selênio/farmacologia , Esteroides Heterocíclicos/farmacologia , Triticum/efeitos dos fármacos , Zearalenona/toxicidade , Antioxidantes/metabolismo , Brassinosteroides/metabolismo , Brassinosteroides/farmacocinética , Carotenoides/metabolismo , Clorofila A/metabolismo , Cloroplastos/efeitos dos fármacos , Enzimas/metabolismo , Proteínas de Choque Térmico HSP90/genética , Proteínas de Plantas/genética , Selênio/farmacocinética , Esteroides Heterocíclicos/farmacocinética , Triticum/metabolismo , Zearalenona/farmacocinética
7.
Front Plant Sci ; 9: 769, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29946328

RESUMO

Drought is one of the most adverse abiotic factors limiting growth and productivity of crops. Among them is barley, ranked fourth cereal worldwide in terms of harvested acreage and production. Plants have evolved various mechanisms to cope with water deficit at different biological levels, but there is an enormous challenge to decipher genes responsible for particular complex phenotypic traits, in order to develop drought tolerant crops. This work presents a comprehensive approach for elucidation of molecular mechanisms of drought tolerance in barley at the seedling stage of development. The study includes mapping of QTLs for physiological and biochemical traits associated with drought tolerance on a high-density function map, projection of QTL confidence intervals on barley physical map, and the retrievement of positional candidate genes (CGs), followed by their prioritization based on Gene Ontology (GO) enrichment analysis. A total of 64 QTLs for 25 physiological and biochemical traits that describe plant water status, photosynthetic efficiency, osmoprotectant and hormone content, as well as antioxidant activity, were positioned on a consensus map, constructed using RIL populations developed from the crosses between European and Syrian genotypes. The map contained a total of 875 SNP, SSR and CGs, spanning 941.86 cM with resolution of 1.1 cM. For the first time, QTLs for ethylene, glucose, sucrose, maltose, raffinose, α-tocopherol, γ-tocotrienol content, and catalase activity, have been mapped in barley. Based on overlapping confidence intervals of QTLs, 11 hotspots were identified that enclosed more than 60% of mapped QTLs. Genetic and physical map integration allowed the identification of 1,101 positional CGs within the confidence intervals of drought response-specific QTLs. Prioritization resulted in the designation of 143 CGs, among them were genes encoding antioxidants, carboxylic acid biosynthesis enzymes, heat shock proteins, small auxin up-regulated RNAs, nitric oxide synthase, ATP sulfurylases, and proteins involved in regulation of flowering time. This global approach may be proposed for identification of new CGs that underlies QTLs responsible for complex traits.

8.
Front Plant Sci ; 9: 1963, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30687360

RESUMO

Photosynthetic acclimation to cold conditions is an important factor influencing freezing tolerance of plants. Photosynthetic enzyme activities increase as part of a photochemical mechanism underlying photosynthetic acclimation to low temperatures. Additionally, a non-photochemical mechanism may be activated to minimize photooxidative damage. The aim of this study was to test the hypothesis that differences in stomatal conductance in Hordeum vulgare plants with contrasting freezing tolerances induce various strategies for photosynthetic acclimation to cold stress. Different stomatal behaviors during the prehardening step resulted in diverse plant reactions to low-temperature stress. Plants with a relatively low freezing tolerance exhibited decreased stomatal conductance, resulting in decreased photochemical activity, faster induction of the non-photochemical mechanism, and downregulated expression of two Rubisco activase (RcaA) splicing variants. In contrast, plants with a relatively high freezing tolerance that underwent a prehardening step maintained the stomatal conductance at control level and exhibited delayed photochemical activity and RcaA expression decrease, and increased Rubisco activity, which increased net photosynthetic rate. Thus, in barley, the induction of photoinhibition avoidance (i.e., non-photochemical photoacclimation mechanism) is insufficient for an effective cold acclimation. An increase in cold-induced net photosynthetic rate due to open stomata is also necessary.

9.
Plant Sci ; 256: 5-15, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28167038

RESUMO

Climate warming can change the winter weather patterns. Warmer temperatures during winter result in a lower risk of extreme freezing events. On the other hand the predicted warm gaps during winter will decrease their freezing tolerance. Both contradict effects will affect winter survival but their resultant effect is unclear. In this paper, we demonstrate that climate warming may result in a decrease in winter survival of plants. A field study of winterhardiness of common wheat and triticale was established at 11 locations and repeated during three subsequent winters. The freezing tolerance of the plants was studied after controlled cold acclimation and de-acclimation using both plant survival analysis and chlorophyll fluorescence measurements. Cold deacclimation resistance was shown to be independent from cold acclimation ability. Further, cold deacclimation resistance appeared to be crucial for overwintering when deacclimation conditions occurred in the field. The shortening of uninterrupted cold acclimation may increase cold deacclimation efficiency, which could threaten plant survival during warmer winters. Measurements of chlorophyll fluorescence transient showed some differences triggered by freezing before and after deacclimation. We conclude that cold deacclimation resistance should be considered in the breeding of winter cereals and in future models of winter damage risk.


Assuntos
Aclimatação , Clima , Aquecimento Global , Estações do Ano , Temperatura , Triticale/fisiologia , Triticum/fisiologia , Adaptação Fisiológica , Agricultura , Clorofila/metabolismo , Grão Comestível , Congelamento , Triticale/crescimento & desenvolvimento , Triticale/metabolismo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
10.
Plant Physiol Biochem ; 109: 280-292, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27771581

RESUMO

According to predicted changes in climate, waterlogging events may occur more frequently in the future during autumn and winter at high latitudes of the Northern Hemisphere. If excess soil water coincides with the process of cold acclimation for plants, winter survival may potentially be affected. The effects of waterlogging during cold acclimation on stomatal aperture, relative water content, photochemical activity of photosystem II, freezing tolerance and plant regrowth after freezing were compared for two prehardened overwintering forage grasses, Lolium perenne and Festuca pratensis. The experiment was performed to test the hypothesis that changes in photochemical activity initiated by waterlogging-triggered modifications in the stomatal aperture contribute to changes in freezing tolerance. Principal component analysis showed that waterlogging activated different adaptive strategies in the two species studied. The increased freezing tolerance of F. pratensis was associated with increased photochemical activity connected with stomatal opening, whereas freezing tolerance of L. perenne was associated with a decrease in stomatal aperture. In conclusion, waterlogging-triggered stomatal behavior contributed to the efficiency of the cold acclimation process in L. perenne and F. pratensis.


Assuntos
Aclimatação/fisiologia , Festuca/fisiologia , Lolium/fisiologia , Estômatos de Plantas/fisiologia , Aclimatação/genética , Mudança Climática , Clima Frio , Festuca/genética , Festuca/crescimento & desenvolvimento , Inundações , Congelamento , Genótipo , Lolium/genética , Lolium/crescimento & desenvolvimento , Modelos Biológicos , Complexo de Proteína do Fotossistema II/metabolismo , Análise de Componente Principal , Estações do Ano , Especificidade da Espécie , Água/metabolismo
11.
J Plant Physiol ; 198: 49-55, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27152456

RESUMO

Alternative splicing of the Rubisco activase gene was shown to be a point for optimization of photosynthetic carbon assimilation. It can be expected to be a stress-regulated event that depends on plant freezing tolerance. The aim of the study was to examine the relationships among Rubisco activity, the expression of two Rubisco activase splicing variants and photoacclimation to low temperature. The experiment was performed on two Lolium perenne genotypes with contrasting levels of freezing tolerance. The study investigated the effect of pre-hardening (15°C) and cold acclimation (4°C) on net photosynthesis, photosystem II photochemical activity, Rubisco activity and the expression of two splicing variants of the Rubisco activase gene. The results showed an induction of Rubisco activity at both 15°C and 4°C only in a highly freezing-tolerant genotype. The enhanced Rubisco activity after pre-hardening corresponded to increased expression of the splicing variant representing the large isoform, while the increase in Rubisco activity during cold acclimation was due to the activation of both transcript variants. These boosts in Rubisco activity also corresponded to an activation of non-photochemical mechanism of photoacclimation induced at low temperature exclusively in the highly freezing-tolerant genotype. In conclusion, enhanced expression of Rubisco activase splicing variants caused an increase in Rubisco activity during pre-hardening and cold acclimation in the more freezing-tolerant Lolium perenne genotype. The induction of the transcript variant representing the large isoform may be an important element of increasing the carbon assimilation rate supporting the photochemical mechanism of photosynthetic acclimation to cold.


Assuntos
Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Lolium/enzimologia , Lolium/genética , Proteínas de Plantas/genética , Splicing de RNA/genética , Aclimatação , Clorofila/metabolismo , Clorofila A , Fluorescência , Lolium/fisiologia , Fotossíntese , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ribulose-Bifosfato Carboxilase/genética , Ribulose-Bifosfato Carboxilase/metabolismo
12.
Plant Physiol Biochem ; 99: 126-41, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26752435

RESUMO

Brassinosteroids (BR) are plant steroid hormones that were discovered more than thirty years ago, but their physiological function has yet to be fully explained. The aim of the study was to answer the question of whether/how disturbances in the production of BR in barley affects the plant's metabolism and development under conditions of optimal watering and drought. Mutants with an impaired production of BR are one of the best tools in research aimed at understanding the mechanisms of action of these hormones. The study used barley cultivars with a normal BR synthesis (wild type) and semi-dwarf allelic mutants with an impaired activity of C6-oxidase (mutation in HvDWARF), which resulted in a decreased BR synthesis. Half of the plants were subjected to drought stress in the seedling stage and the other half were watered optimally. Plants with impaired BR production were characterised by a lower height and developmental retardation. Under both optimal watering and drought, BR synthesis disorders caused the reduced production of ABA and cytokinins, but not auxins. The BR mutants also produced less osmoprotectant (proline). The optimally watered and drought-stressed mutants accumulated less sucrose, which was accompanied by changes in the production of other soluble sugars. The increased content of fructooligosaccharide (kestose) in optimally watered mutants would suggest that BR is a negative regulator of kestose production. The decreased level of nystose in the drought-stressed mutants also suggests BR involvement in the regulation of the production of this fructooligosaccharide. The accumulation of the transcripts of genes associated with stress response (hsp90) was lower in the watered and drought-stressed BR-deficient mutants. In turn, the lower efficiency of photosystem II and the net photosynthetic rate in mutants was revealed only under drought conditions. The presented research allows for the physiological and biochemical traits of two BR-barley mutants to be characterised, which helps BR function to be understood. The knowledge can also be a good starting point for some breeding companies that are interested in introducing new semi-dwarf barley cultivars.


Assuntos
Brassinosteroides/biossíntese , Secas , Hordeum/fisiologia , Água/metabolismo , Citocininas/metabolismo , Hordeum/enzimologia , Hordeum/genética , Fotossíntese
13.
Funct Plant Biol ; 43(10): 931-938, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32480516

RESUMO

Increased precipitation and snowmelt during warmer winters may lead to low-temperature waterlogging of plants. Perennial ryegrass (Lolium perenne L.) is one of the most important cool-season grasses in agriculture. It is well adapted to cold climates, and may be considered as a model system for studying the mechanisms involved in cold acclimation. The aim of this study was to evaluate the effects of waterlogging on photosynthetic acclimation to cold in perennial ryegrass. Two L. perenne genotypes that differ in their responses to waterlogging in terms of freezing tolerance were compared. We evaluated the effects of waterlogging during cold acclimation on the water-soluble carbohydrate concentration, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, photochemical efficiency of PSII, and transcript levels of the Rubisco activase (RcaA) and sucrose-sucrose fructosyltransferase (1-SST) genes. The genotype that did not accumulate water-soluble carbohydrates in the leaf under waterlogging showed a lower degree of feedback inhibition of photosynthesis under low temperature, and activated a photochemical mechanism of photosynthetic acclimation to cold. The other genotype accumulated water-soluble carbohydrates in the leaf during waterlogging, and activated a non-photochemical mechanism under cold conditions. Different photosynthetic acclimation systems to cold under waterlogging may be activated in these two contrasting L. perenne genotypes.

14.
J Plant Physiol ; 176: 61-4, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25577732

RESUMO

Rubisco activase is required to regulate the catalytic activity of Rubisco in plants, in an ATP-dependent manner. One or two Rubisco activase proteins have been identified in different plant species. In some species, the two isoforms are the products of alternative splicing of the Rubisco activase gene. The aim of this study was to confirm that Lolium perenne and Festuca pratensis plants have two isoforms of Rubisco activase and that they are the products of alternative splicing of common pre-mRNA. Protein gel blot analyses indicated that L. perenne and F. pratensis leaves contained two Rubisco activase proteins. Sequence analysis of cDNA and genomic DNA showed that differential splicing generated two mRNAs that differed in sequence only in the inclusion of 48 bp. The insertion contains a stop codon leading to the synthesis of a shorter polypeptide. Under the conditions of our experiment, the shorter splicing variant of L. perenne and F. pratensis Rubisco activase gene was preferentially produced. Any further studies concerning Rubisco activase genes in L. perenne and/or F. pratensis plants should take into consideration the mechanism of its expression.


Assuntos
Processamento Alternativo/genética , Festuca/enzimologia , Festuca/genética , Pradaria , Lolium/enzimologia , Lolium/genética , Proteínas de Plantas/genética , Sequência de Bases , Genes de Plantas , Isoenzimas/genética , Isoenzimas/metabolismo , Dados de Sequência Molecular , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase , Alinhamento de Sequência
15.
J Plant Physiol ; 171(16): 1541-4, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25128786

RESUMO

Quantitative PCR studies need proper reference genes with expression stability exclusively validated under certain experimental conditions. The expression stability of several genes commonly used as references was tested under 24-epibrassinolide (EBR) and temperature treatment. Different statistical approaches (qBase(PLUS), BestKeeper, NormFinder) were used to prepare rankings of expression stability in two species of an economic importance: common wheat (Triticum aestivum) and perennial ryegrass (Lolium perenne). Candidate reference genes were shown to be regulated differentially in these two plant species. The maximum stability values indicated that the expression stability was higher in T. aestivum. Taking into account of all ranks it seems that TBP-1 and UBI in ryegrass and ACT, ADP and EF1A in wheat should be used as reference genes in the brassinosteroids and temperature involving studies.


Assuntos
Brassinosteroides/metabolismo , Regulação da Expressão Gênica de Plantas , Lolium/genética , Esteroides Heterocíclicos/metabolismo , Triticum/genética , Perfilação da Expressão Gênica , Lolium/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Triticum/metabolismo
16.
Plant Sci ; 225: 34-44, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25017157

RESUMO

The increase in surface temperature of the Earth indicates a lower risk of exposure for temperate grassland and crop to extremely low temperatures. However, the risk of low winter survival rate, especially in higher latitudes may not be smaller, due to complex interactions among different environmental factors. For example, the frequency, degree and length of extreme winter warming events, leading to snowmelt during winter increased, affecting the risks of anoxia, ice encasement and freezing of plants not covered with snow. Future climate projections suggest that cold acclimation will occur later in autumn, under shorter photoperiod and lower light intensity, which may affect the energy partitioning between the elongation growth, accumulation of organic reserves and cold acclimation. Rising CO2 levels may also disturb the cold acclimation process. Predicting problems with winter pathogens is also very complex, because climate change may greatly influence the pathogen population and because the plant resistance to these pathogens is increased by cold acclimation. All these factors, often with contradictory effects on winter survival, make plant overwintering viability under future climates an open question. Close cooperation between climatologists, ecologists, plant physiologists, geneticists and plant breeders is strongly required to predict and prevent possible problems.


Assuntos
Adaptação Fisiológica , Mudança Climática , Clima , Fenômenos Fisiológicos Vegetais , Plantas , Estações do Ano , Temperatura , Doenças das Plantas , Neve , Estresse Fisiológico
17.
Plant Sci ; 183: 143-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22195587

RESUMO

Strictly controlled and coordinated induction of CBF regulon (a set of genes regulated by CBF proteins) promotes plant freezing tolerance. CBFs regulate the expression of COR genes that confer freezing tolerance. COR14b in barley is one of the effector genes which seems to be important in resistance to combined freezing and photoinhibition of photosynthesis. LOS2 represses the transcription of STS/ZAT10 (a negative regulator of CBF-target genes) and thus acts as a positive regulator of COR genes. In Arabidopis, low temperature induction of CBFs was reported to be gated by the circadian clock. Moreover, light-quality signals have been shown to regulate some plants' freezing tolerance genes. The aim of our study was to determine the effects of combined treatment with light and cold on the transcript levels of CBF6, FpCor14b and LOS2 genes in Festuca pratensis. We have demonstrated that the regulation of CBF6, FpCor14b and LOS2 induction kinetics in F. pratensis occurs through the interaction of temperature and light with time of day during low-temperature shift. The FpCOR14b transcript level was shown to be up-regulated by increasing light intensity. It was also proved that light quality strongly regulates CBF6, FpCor14b and LOS2 transcripts induction kinetics at low temperatures.


Assuntos
Temperatura Baixa , Resposta ao Choque Frio/genética , Festuca/genética , Regulação da Expressão Gênica de Plantas , Fotoperíodo , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Aclimatação/genética , Relógios Circadianos , Festuca/fisiologia , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase , RNA de Plantas/análise , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional
18.
J Plant Physiol ; 168(11): 1271-9, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21489653

RESUMO

Perennial ryegrass (Lolium perenne) is a high quality forage and turf grass mainly due to its excellent nutritive values and rapid establishment rate. However, this species has limited ability to perform in harsh winter climates. Though winter hardiness is a complex trait, it is commonly agreed that frost tolerance (FT) is its main component. Species growing in temperate regions can acquire FT through exposure to low, non-lethal temperatures, a phenomenon known as cold acclimation (CA). The research on molecular basis of FT has been performed on the model plants, but they are not well adapted to extreme winter climates. Thus, the mechanisms of cell response to low temperature in winter crops and agronomically important perennial grasses have yet to be revealed. Here, two L. perenne plants with contrasting levels of FT, high frost tolerant (HFT) and low frost tolerant (LFT) plants, were selected for comparative proteomic research. The work focused on analyses of leaf protein accumulation before and after 2, 8, 26 h, and 3, 5, 7, 14 and 21 days of CA, using a high-throughput two-dimensional electrophoresis, and on the identification of proteins which were accumulated differentially between the selected plants by the application of mass spectrometry (MS). Analyses of 580 protein profiles revealed a total of 42 (7.2%) spots that showed at a minimum of 1.5-fold differences in protein abundance, at a minimum of at one time point of CA between HFT and LFT genotypes. It was shown that significant differences in profiles of protein accumulation between the analyzed plants appeared most often on the 5th (18 proteins) and the 7th (19 proteins) day of CA. The proteins derived from 35 (83.3%) spots were successfully identified by the use of MS and chloroplast proteins were shown to be the major group selected as differentially accumulated during CA. The functions of the identified proteins and their probable influence on the level of FT in L. perenne are discussed.


Assuntos
Aclimatação , Temperatura Baixa , Lolium/fisiologia , Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , ATPases de Cloroplastos Translocadoras de Prótons/análise , Cloroplastos/metabolismo , Eletroforese em Gel Bidimensional , Perfilação da Expressão Gênica , Genótipo , Glutamato-Amônia Ligase/análise , Lolium/metabolismo , Espectrometria de Massas , Folhas de Planta/metabolismo , Proteínas de Plantas/análise , Proteoma/metabolismo , Proteômica , Estações do Ano
19.
J Exp Bot ; 60(12): 3595-609, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19553368

RESUMO

Festuca pratensis (meadow fescue) as the most frost-tolerant species within the Lolium-Festuca complex was used as a model for research aimed at identifying the cellular components involved in the cold acclimation (CA) of forage grasses. The work presented here also comprises the first comprehensive proteomic research on CA in a group of monocotyledonous species which are able to withstand winter conditions. Individual F. pratensis plants with contrasting levels of frost tolerance, high frost tolerant (HFT) and low frost tolerant (LFT) plants, were selected for comparative proteomic research. The work focused on the analysis of leaf protein accumulation before and after 2, 8, and 26 h, and 3, 5, 7, 14, and 21 d of CA, using high-throughput two-dimensional electrophoresis, and on the identification of proteins which were accumulated differentially between the selected plants by the application of mass spectrometry. The analyses of approximately 800 protein profiles revealed a total of 41 (5.1%) proteins that showed a minimum of a 1.5-fold difference in abundance, at a minimum of one time point of CA for HFT and LFT genotypes. It was shown that significant differences in profiles of protein accumulation between the analysed plants appeared relatively early during cold acclimation, most often after 26 h (on the 2nd day) of CA and one-half of the differentially accumulated proteins were all parts of the photosynthetic apparatus. Several proteins identified here have been reported to be differentially accumulated during cold conditions for the first time in this paper. The functions of the selected proteins in plant cells and their probable influence on the level of frost tolerance in F. pratensis, are discussed.


Assuntos
Festuca/fisiologia , Proteínas de Plantas/metabolismo , Temperatura Baixa , Eletroforese em Gel Bidimensional , Festuca/química , Festuca/genética , Regulação da Expressão Gênica de Plantas , Folhas de Planta/química , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/química , Proteínas de Plantas/genética
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