1
|
Soltabayeva A, Kurmanbayeva A, Bekturova A, Oshanova D, Nurbekova Z, Srivastava S, Standing D, Zdunek-Zastocka E, Sagi M. Corrigendum to "Endogenous ureides are employed as a carbon source in Arabidopsis plants exposed to carbon starvation conditions" Plant Sci. 344 (2024) 1-9/112108. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 349:112257. [PMID: 39271440 DOI: 10.1016/j.plantsci.2024.112257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/15/2024]
|
2
|
Nurbekova Z, Srivastava S, Nja ZD, Khatri K, Patel J, Choudhary B, Turečková V, Strand M, Zdunek-Zastocka E, Omarov R, Standing D, Sagi M. AAO2 impairment enhances aldehyde detoxification by AAO3 in Arabidopsis leaves exposed to UV-C or Rose-Bengal. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 120:272-288. [PMID: 39190782 DOI: 10.1111/tpj.16985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 07/20/2024] [Accepted: 07/31/2024] [Indexed: 08/29/2024]
Abstract
Among the three active aldehyde oxidases in Arabidopsis thaliana leaves (AAO1-3), AAO3, which catalyzes the oxidation of abscisic-aldehyde to abscisic-acid, was shown recently to function as a reactive aldehyde detoxifier. Notably, aao2KO mutants exhibited less senescence symptoms and lower aldehyde accumulation, such as acrolein, benzaldehyde, and 4-hydroxyl-2-nonenal (HNE) than in wild-type leaves exposed to UV-C or Rose-Bengal. The effect of AAO2 expression absence on aldehyde detoxification by AAO3 and/or AAO1 was studied by comparing the response of wild-type plants to the response of single-functioning aao1 mutant (aao1S), aao2KO mutants, and single-functioning aao3 mutants (aao3Ss). Notably, aao3Ss exhibited similar aldehyde accumulation and chlorophyll content to aao2KO treated with UV-C or Rose-Bengal. In contrast, wild-type and aao1S exhibited higher aldehyde accumulation that resulted in lower remaining chlorophyll than in aao2KO leaves, indicating that the absence of active AAO2 enhanced AAO3 detoxification activity in aao2KO mutants. In support of this notion, employing abscisic-aldehyde as a specific substrate marker for AAO3 activity revealed enhanced AAO3 activity in aao2KO and aao3Ss leaves compared to wild-type treated with UV-C or Rose-Bengal. The similar abscisic-acid level accumulated in leaves of unstressed or stressed genotypes indicates that aldehyde detoxification by AAO3 is the cause for better stress resistance in aao2KO mutants. Employing the sulfuration process (known to activate aldehyde oxidases) in wild-type, aao2KO, and molybdenum-cofactor sulfurase (aba3-1) mutant plants revealed that the active AAO2 in WT employs sulfuration processes essential for AAO3 activity level, resulting in the lower AAO3 activity in WT than AAO3 activity in aao2KO.
Collapse
|
3
|
Soltabayeva A, Kurmanbayeva A, Bekturova A, Oshanova D, Nurbekova Z, Srivastava S, Standing D, Zdunek-Zastocka E, Sagi M. Endogenous ureides are employed as a carbon source in Arabidopsis plants exposed to carbon starvation conditions. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 344:112108. [PMID: 38705480 DOI: 10.1016/j.plantsci.2024.112108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 04/01/2024] [Accepted: 04/23/2024] [Indexed: 05/07/2024]
Abstract
Ureides, the degraded products of purine catabolism in Arabidopsis, have been shown to act as antioxidant and nitrogen sources. Herein we elucidate purine degraded metabolites as a carbon source using the Arabidopsis Atxdh1, Ataln, and Ataah knockout (KO) mutants vis-à-vis wild-type (WT) plants. Plants were grown under short-day conditions on agar plates containing half-strength MS medium with or without 1% sucrose. Notably, the absence of sucrose led to diminished biomass accumulation in both shoot and root tissues of the Atxdh1, Ataln, and Ataah mutants, while no such effect was observed in WT plants. Moreover, the application of sucrose resulted in a reduction of purine degradation metabolite levels, specifically xanthine and allantoin, predominantly within the roots of WT plants. Remarkably, an increase in proteins associated with the purine degradation pathway was observed in WT plants in the presence of sucrose. Lower glyoxylate levels in the roots but not in the shoot of the Atxdh1 mutant in comparison to WT, were observed under sucrose limitation, and improved by sucrose application in root, indicating that purine degradation provided glyoxylate in the root. Furthermore, the deficit of purine-degraded metabolites in the roots of mutants subjected to carbon starvation was partially mitigated through allantoin application. Collectively, these findings signify that under conditions of sucrose limitation and short-day growth, purines are primarily remobilized within the root system to augment the availability of ureides, serving as an additional carbon (as well as nitrogen) source to support plant growth.
Collapse
|
4
|
Zdunek-Zastocka E, Michniewska B, Pawlicka A, Grabowska A. Cadmium Alters the Metabolism and Perception of Abscisic Acid in Pisum sativum Leaves in a Developmentally Specific Manner. Int J Mol Sci 2024; 25:6582. [PMID: 38928288 PMCID: PMC11203977 DOI: 10.3390/ijms25126582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
Abscisic acid (ABA) plays a crucial role in plant defense mechanisms under adverse environmental conditions, but its metabolism and perception in response to heavy metals are largely unknown. In Pisum sativum exposed to CdCl2, an accumulation of free ABA was detected in leaves at different developmental stages (A, youngest, unexpanded; B1, youngest, fully expanded; B2, mature; C, old), with the highest content found in A and B1 leaves. In turn, the content of ABA conjugates, which was highest in B2 and C leaves under control conditions, increased only in A leaves and decreased in leaves of later developmental stages after Cd treatment. Based on the expression of PsNCED2, PsNCED3 (9-cis-epoxycarotenoid dioxygenase), PsAO3 (aldehyde oxidase) and PsABAUGT1 (ABA-UDP-glucosyltransferase), and the activity of PsAOγ, B2 and C leaves were found to be the main sites of Cd-induced de novo synthesis of ABA from carotenoids and ABA conjugation with glucose. In turn, β-glucosidase activity and the expression of genes encoding ABA receptors (PsPYL2, PsPYL4, PsPYL8, PsPYL9) suggest that in A and B1 leaves, Cd-induced release of ABA from inactive ABA-glucosyl esters and enhanced ABA perception comes to the forefront when dealing with Cd toxicity. The distinct role of leaves at different developmental stages in defense against the harmful effects of Cd is discussed.
Collapse
|
5
|
Orzechowski S, Compart J, Zdunek-Zastocka E, Fettke J. Starch parameters and short-term temperature fluctuations - Important but not yet in focus? JOURNAL OF PLANT PHYSIOLOGY 2023; 280:153902. [PMID: 36565529 DOI: 10.1016/j.jplph.2022.153902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/15/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Plants are regularly challenged by unfavorable environmental conditions. As climate change continues, adverse situations such as drought, heat, and cold are expected to increase and become more severe. Most starchy crops are affected by such stresses. In recent years, researchers have made many new discoveries about starch metabolism in general and also on granule structure, including effects on starch following longer-term temperature stresses. However, in this study, we focus on short-term temperature stress on storage starch granule properties. Here our knowledge is less and it is likely that also short-term temperature stresses can affect various starch parameters. Therefore, we see a need for this type of analysis and discuss the matter in more detail and we conclude that a deeper knowledge particularly of starch granule parameters could allow targeted breeding of cultivars that exhibit different starch characteristics as a result of short-term stress. For these reasons, we are convinced that more comprehensive research on the effects of short-term temperature stress on starch granule characteristics is important, necessary, and timely.
Collapse
|
6
|
Orzechowski S, Sitnicka D, Grabowska A, Compart J, Fettke J, Zdunek-Zastocka E. Effect of Short-Term Cold Treatment on Carbohydrate Metabolism in Potato Leaves. Int J Mol Sci 2021; 22:ijms22137203. [PMID: 34281256 PMCID: PMC8268532 DOI: 10.3390/ijms22137203] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 11/19/2022] Open
Abstract
Plants are often challenged by an array of unfavorable environmental conditions. During cold exposure, many changes occur that include, for example, the stabilization of cell membranes, alterations in gene expression and enzyme activities, as well as the accumulation of metabolites. In the presented study, the carbohydrate metabolism was analyzed in the very early response of plants to a low temperature (2 °C) in the leaves of 5-week-old potato plants of the Russet Burbank cultivar during the first 12 h of cold treatment (2 h dark and 10 h light). First, some plant stress indicators were examined and it was shown that short-term cold exposure did not significantly affect the relative water content and chlorophyll content (only after 12 h), but caused an increase in malondialdehyde concentration and a decrease in the expression of NDA1, a homolog of the NADH dehydrogenase gene. In addition, it was shown that the content of transitory starch increased transiently in the very early phase of the plant response (3–6 h) to cold treatment, and then its decrease was observed after 12 h. In contrast, soluble sugars such as glucose and fructose were significantly increased only at the end of the light period, where a decrease in sucrose content was observed. The availability of the monosaccharides at constitutively high levels, regardless of the temperature, may delay the response to cold, involving amylolytic starch degradation in chloroplasts. The decrease in starch content, observed in leaves after 12 h of cold exposure, was preceded by a dramatic increase in the transcript levels of the key enzymes of starch degradation initiation, the α-glucan, water dikinase (GWD-EC 2.7.9.4) and the phosphoglucan, water dikinase (PWD-EC 2.7.9.5). The gene expression of both dikinases peaked at 9 h of cold exposure, as analyzed by real-time PCR. Moreover, enhanced activities of the acid invertase as well as of both glucan phosphorylases during exposure to a chilling temperature were observed. However, it was also noticed that during the light phase, there was a general increase in glucan phosphorylase activities for both control and cold-stressed plants irrespective of the temperature. In conclusion, a short-term cold treatment alters the carbohydrate metabolism in the leaves of potato, which leads to an increase in the content of soluble sugars.
Collapse
|
7
|
Zdunek-Zastocka E, Grabowska A, Michniewska B, Orzechowski S. Proline Concentration and Its Metabolism Are Regulated in a Leaf Age Dependent Manner But Not by Abscisic Acid in Pea Plants Exposed to Cadmium Stress. Cells 2021; 10:946. [PMID: 33923901 PMCID: PMC8073832 DOI: 10.3390/cells10040946] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 12/11/2022] Open
Abstract
The accumulation of proline is one of the defense mechanisms of plants against the harmful effects of adverse environmental conditions; however, when pea plants were treated for 12 h with CdCl2, the proline concentration decreased in the youngest A (not expanded) and B1 (expanded) leaves, and did not change significantly in the B2 (mature, expanded) or C (the oldest) leaves. After 24 h of cadmium (Cd) stress, the proline concentration remained low in A and B1 leaves, while in B2 and C leaves, it increased, and after 48 h, an increase in the proline concentration in the leaves at each stage of development was observed. The role of proline in the different phases of plant response to the Cd treatment is discussed. Changes in proline accumulation corresponded closely with changes in the transcript levels of PsP5CS2, a gene encoding D1-pyrroline-5-carboxylate synthetase involved in proline synthesis, and PsPDH1, a gene encoding proline dehydrogenase engaged in proline degradation. CdCl2 application induced the expression of PsProT1 and PsProT2, genes encoding proline transporters, especially during the first 12 h of treatment in A and B1 leaves. When the time courses of abscisic acid (ABA) and proline accumulation were compared, it was concluded that an increase in the proline concentration in the leaves of Cd-treated pea plants was more related to a decrease in chlorophyll concentration (leaves B2 and C) and an increase in the malondialdehyde level (A and B1 leaves) than with an increase in ABA concentration alone. Exogenous application of ABA (0.5, 5, 50 µM) significantly increased the proline concentration in the A leaves of pea plants only, and was accompanied by an elevated and repressed expression of PsP5CS2 and PsPDH1 in these leaves, respectively. The presented results suggest that under Cd stress, the accumulation of proline in leaves of pea plants may take place independently of the ABA signaling.
Collapse
|
8
|
Zdunek-Zastocka E, Grabowska A. The interplay of PsABAUGT1 with other abscisic acid metabolic genes in the regulation of ABA homeostasis during the development of pea seeds and germination in the presence of H 2O 2. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 285:79-90. [PMID: 31203896 DOI: 10.1016/j.plantsci.2019.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/08/2019] [Accepted: 05/03/2019] [Indexed: 06/09/2023]
Abstract
Inactivation of abscisic acid (ABA) in vitro may be catalyzed either by ABA 8'-hydroxylase (ABA8'OH) or by ABA uridine diphosphate glucosyltransferase (ABAUGT), which conjugates ABA with glucose. However, the involvement of these enzymes in the control of ABA content in vivo, especially ABAUGT, has not been fully elucidated. In pea seeds, both PsABAUGT1 and PsABA8'OH1 contribute to the reduction of ABA content during seed maturation and imbibition; however, during the first hours of imbibition, a high expression of only PsABAUGT1 was observed. Imbibition of seeds with H2O2 increased the ABA content despite the oxygen availability and altered the expression of metabolic genes. The expression of the biosynthetic gene 9-cis-epoxycarotene dioxygenase (PsNCED2) was increased, while that of PsABAUGT1 was decreased in each H2O2 experiment despite O2 availability. Under hypoxia, only seeds imbibed with H2O2 germinated, while under nonlimiting oxygen conditions, the germination rate was not altered by H2O2. Under hypoxia, the germination rate of H2O2-imbibed seeds seemed to not depend on the absolute ABA content and rather on the balance between ABA and gibberellins (GA), as H2O2 increased the expression of GA synthesis genes. Overexpression of PsABAUGT1 in Arabidopsis decreases seed ABA content, accelerates germination and reduces seed sensitivity to exogenously applied ABA, confirming the ability of PsABAUGT1 to inactivate ABA. Thus, PsABAUGT1 is a new player in the regulation of ABA content in maturating and imbibed pea seeds, both under standard conditions and in response to H2O2.
Collapse
|
9
|
Fidler J, Grabowska A, Prabucka B, Więsyk A, Góra-Sochacka A, Bielawski W, Pojmaj M, Zdunek-Zastocka E. The varied ability of grains to synthesize and catabolize ABA is one of the factors affecting dormancy and its release by after-ripening in imbibed triticale grains of cultivars with different pre-harvest sprouting susceptibilities. JOURNAL OF PLANT PHYSIOLOGY 2018; 226:48-55. [PMID: 29698912 DOI: 10.1016/j.jplph.2018.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 03/01/2018] [Accepted: 03/15/2018] [Indexed: 06/08/2023]
Abstract
Abscisic acid (ABA) is a phytohormone involved in the acquisition of primary dormancy during seeds maturation as well as dormancy maintenance in imbibed seeds. After imbibition, the ABA content decreased to a much lower level in embryos of freshly harvested triticale grains of the Leontino cultivar, which is more susceptible to pre-harvest sprouting (PHS) than embryos of the Fredro cultivar. Lower ABA content in the Leontino cultivar resulted from increased expression of TsABA8'OH1 and TsABA8'OH2, which encode ABA 8'-hydroxylase and are involved in ABA catabolism. Higher ABA content and maintenance of dormancy in Fredro grains were correlated with intensified ABA biosynthesis, which resulted from higher expression of TsNCED1, which encodes 9-cis-epoxycarotenoid dioxygenase. These results suggest that grains of triticale cultivars with different resistance to PHS vary in their ability to metabolize ABA after imbibition. After-ripening did not affect the ABA content in embryos of dry grains of either triticale cultivar. However, after-ripening caused dormancy release in Fredro grains and significantly affected the ABA content and the rate of its metabolism after imbibition. A more rapid decline in ABA content in imbibed Fredro grains was accompanied by decreased transcript levels of TsNCED1 as well as increased expression of TsABA8'OH1 and TsABA8'OH2. Thus, after-ripening may affect dormancy of grains through reduction of the ABA biosynthesis rate and intensified ABA catabolism. Overexpression of TsNCED1 in tobacco increases ABA content and delays germination, while overexpression of TsABA8'OH2 decreases ABA content, accelerates germination, and reduces the sensitivity to ABA of transgenic seeds compared to seeds of wild-type plants. Therefore, these genes might play an important role in the regulation of triticale grain dormancy, thus affecting susceptibility to PHS.
Collapse
|
10
|
Zdunek-Zastocka E, Grabowska A, Branicki T, Michniewska B. Biochemical characterization of the triticale TsPAP1, a new type of plant prolyl aminopeptidase, and its impact on proline content and flowering time in transgenic Arabidopsis plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 116:18-26. [PMID: 28482331 DOI: 10.1016/j.plaphy.2017.04.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 04/20/2017] [Accepted: 04/26/2017] [Indexed: 06/07/2023]
Abstract
Proline aminopeptidase (PAP, EC 3.4.11.5) is the only enzyme that effectively releases proline from the N-termini of peptides. The amino acid sequence of the PAP from Triticosecale, TsPAP1, comprises conserved regions, characteristic of the monomeric forms of PAP found in bacteria but not yet identified in plants. Therefore, we aimed to obtain and biochemically characterize the TsPAP1 protein. The recombinant TsPAP1 protein was received through heterologous expression of the TsPAP1 coding sequence in a bacterial expression system and purified with affinity chromatography. Gel filtration chromatography and SDS electrophoresis revealed that TsPAP1 is a monomer with a molecular mass of 37.5 kDa. TsPAP1 prefers substrates with proline at the N-terminus but is also capable of hydrolyzing β-naphthylamides of hydroxyproline and alanine. Among the peptides tested, the most preferred were di- and tripeptides, especially those with glycine in the Y position. The use of diagnostic inhibitors indicated that TsPAP1 is a serine peptidase; however, further characterization revealed that the SH residues are also important for maintaining its activity. To examine the role of TsPAP1 under physiological conditions, we developed transgenic Arabidopsis plants overexpressing TsPAP1. Compared with wild-type plants, the transgenic lines accumulated more proline, flowered an average of 3.5 days earlier, and developed more siliques than did untransformed controls. Our paper is the first to describe the biochemical properties of a novel monomeric plant PAP and contributes to the functional characterization of PAP proteins in plants.
Collapse
|
11
|
Fidler J, Zdunek-Zastocka E, Prabucka B, Bielawski W. Abscisic acid content and the expression of genes related to its metabolism during maturation of triticale grains of cultivars differing in pre-harvest sprouting susceptibility. JOURNAL OF PLANT PHYSIOLOGY 2016; 207:1-9. [PMID: 27770653 DOI: 10.1016/j.jplph.2016.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 09/07/2016] [Accepted: 09/09/2016] [Indexed: 06/06/2023]
Abstract
Abscisic acid (ABA) is a plant hormone that plays a predominant role in the onset and maintenance of primary dormancy. Peak ABA accumulation in embryos of triticale grains was observed before any significant loss of water and was higher in Fredro, a cultivar less susceptible to pre-harvest sprouting (PHS), than in Leontino, a cultivar more sensitive to PHS. At full maturity, embryonic ABA content in Fredro was twice as high as in Leontino. Two full-length cDNAs of 9-cis-epoxycarotenoid dioxygenase (TsNCED1, TsNCED2), an enzyme involved in ABA biosynthesis, and two full-length cDNAs of ABA 8'-hydroxylase (TsABA8'OH1 and TsABA8'OH2), an enzyme involved in ABA catabolism, were identified in triticale grains and characterized. The maximum transcript level of both TsNCED1 and TsNCED2 preceded the peak of ABA accumulation, suggesting that both TsNCEDs contribute to reach this peak, although the expression of TsNCED1 was significantly higher in Fredro than in Leontino. High expression of TsABA8'OH2 and TsABA8'OH1 was observed long before and at the end of the ABA accumulation peak, respectively, but no differences were observed between cultivars. The obtained results suggest that mainly TsNCED1 might be related to the higher ABA content and higher resistance of Fredro to PHS. However, Fredro embryos not only have higher ABA content, but also exhibit greater sensitivity to ABA, which may also have a significant effect on grain dormancy and lower susceptibility to PHS for grains of this cultivar.
Collapse
|
12
|
Zdunek-Zastocka E, Sobczak M. Expression of Pisum sativum PsAO3 gene, which encodes an aldehyde oxidase utilizing abscisic aldehyde, is induced under progressively but not rapidly imposed drought stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 71:57-66. [PMID: 23876699 DOI: 10.1016/j.plaphy.2013.06.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 06/29/2013] [Indexed: 06/02/2023]
Abstract
Aldehyde oxidase (AO; EC 1.2.3.1) catalyzes the final step of abscisic acid (ABA) biosynthesis, which is the oxidation of abscisic aldehyde (ABAld) to ABA. Gene expression analyses indicate that the stress-induced Pisum sativum PsAOγ isoform, which effectively uses ABAld as a substrate, is encoded by the PsAO3 gene. PsAO3 was heterologously expressed in Pichia pastoris and the recombinant PsAO3 protein revealed substrate preferences highly similar to the native PsAOγ protein present in the pea leaves and roots. Both proteins prefer indole-3-aldehyde and naphthaldehyde as substrates, although high activities against abscisic aldehyde and citral were also observed. The Km values of PsAO3 for naphthaldehyde and abscisic aldehyde (4.6 and 5.1 μM, respectively) were the lowest among the substrates tested. PsAO3 activity was almost completely inhibited by potassium cyanide, diphenyleneiodonium, and methanol. Rapidly imposed drought stress did not increase the level of PsAO3 mRNA or activity of any AO isoform, although an enhanced ABA accumulation and induction of PsNCED2 and -3 (9-cis-epoxycarotenoid dioxygenase; EC 1.13.11.51) expression, both in the pea roots and leaves, was observed. During a progressively induced drought, the level of PsAO3 transcript and PsAOγ activity increased significantly in the roots and leaves, whereas ABA accumulation occurred only in the leaves where it was accompanied by induction of the PsNCED3 expression. Therefore, we suppose that next to NCED, also AO (mainly PsAOγ) might be involved in regulation of the drought-induced ABA synthesis. However, while the "constitutive activity" of PsAOγ is sufficient for the fast generation of ABA under rapid drought stress, the enhanced PsAOγ activity is required for the progressive and long-term ABA accumulation in the leaves under progressive drought stress.
Collapse
|
13
|
Szawłowska U, Grabowska A, Zdunek-Zastocka E, Bielawski W. TsPAP1 encodes a novel plant prolyl aminopeptidase whose expression is induced in response to suboptimal growth conditions. Biochem Biophys Res Commun 2012; 419:104-9. [DOI: 10.1016/j.bbrc.2012.01.140] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 01/28/2012] [Indexed: 10/14/2022]
|
14
|
Szewińska J, Zdunek-Zastocka E, Pojmaj M, Bielawski W. Molecular Cloning and Expression Analysis of Triticale Phytocystatins During Development and Germination of Seeds. PLANT MOLECULAR BIOLOGY REPORTER 2012; 30:867-877. [PMID: 24415837 PMCID: PMC3881564 DOI: 10.1007/s11105-011-0384-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Three triticale cDNAs encoding inhibitors of cysteine endopeptidases, belonging to phytocystatins, have been identified and designated as TrcC-1, TrcC-4 and TrcC-5. Full-length cDNAs of TrcC-1 (617 bp) and TrcC-4 (940 bp), as well as a fragment of TrcC-5 cDNA (369 bp), were obtained. A high-level identity of the deduced amino acid sequence of TrcCs with other known phytocystatins, especially with wheat and barley, has been observed. Moreover, the presence of conserved domain, containing the G and W residues, the sequence of QxVxG and the sequence of LARFAV, characteristic for plant cysteine endopeptidase inhibitors, has been noted. The profiles of TrcC-1 and TrcC-5 mRNA levels in the developing seeds of two triticale cultivars that differ in their resistance to preharvest sprouting (Zorro and Disco) were similar. However, the expression of TrcC-4 was, higher in the developing seeds, and in the scutellum of germinating seeds of a cultivar more resistant to preharvest sprouting (Zorro) than in the less resistant (Disco). Additionally, the expression of TrcC-4 remained longer in developing seeds of Zorro as compared to Disco. The performed studies suggest that TrcC-4 might have an influence on the higher resistance of Zorro cultivar to preharvest sprouting.
Collapse
|
15
|
Szawłowska U, Zdunek-Zastocka E, Bielawski W. Biochemical characterisation of prolyl aminopeptidase from shoots of triticale seedlings and its activity changes in response to suboptimal growth conditions. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2011; 49:1342-1349. [PMID: 21689943 DOI: 10.1016/j.plaphy.2011.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 05/17/2011] [Indexed: 05/30/2023]
Abstract
Prolyl aminopeptidase (PAP) was isolated from the shoots of three-day-old triticale seedlings and was purified using a five-step purification procedure (acid precipitation, gel filtration, anion-exchange chromatography, hydrophobic chromatography and rechromatography). The enzyme was purified 460-fold with a recovery of 6%. Prolyl aminopeptidase appears to be a tetramer consisting of four subunits, each with a molecular weight of approximately 54kDa. Its pH and temperature optimum are pH 7.5 and 37°C, respectively. The enzyme prefers substrates with Pro and Hyp at the N-terminus, but is also capable of hydrolysing β-naphthylamides (β-NA) of Ala, Phe, and Leu. The K(m) value of PAP against Pro-β-NA was the lowest among the substrates tested and it was 1.47×10(-5)M. The activity of PAP was not inhibited by EDTA, 1,10-phenantroline, or pepstatin A. The most effective inhibitors were DFP, Pefabloc, and PMSF, which are serine protease inhibitors. However, significant inhibition was also observed in the presence of E-64, which modifies sulfhydryl groups. A significant increase of the aminopeptidase activity against Pro-β-NA was observed in shoots of triticale plants grown under salinity, drought stress, and in the presence of cadmium and aluminium ions in the nutrient solution.
Collapse
|
16
|
Zdunek-Zastocka E. The activity pattern and gene expression profile of aldehyde oxidase during the development of Pisum sativum seeds. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2010; 179:543-548. [PMID: 21802613 DOI: 10.1016/j.plantsci.2010.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Revised: 07/27/2010] [Accepted: 08/06/2010] [Indexed: 05/31/2023]
Abstract
Aldehyde oxidase (AO, EC 1.2.3.1) is a molybdenohydroxylase that is considered to catalyze the final step in the synthesis of abscisic acid (ABA) and possibly of indole-3-acetic acid (IAA). Five AO activity bands were detected after native PAGE with indole-3-aldehyde (PsAO-α, -β, -γ, -δ, -κ) and three with abscisic aldehyde (PsAO-γ, -δ, -κ) in developing seeds of Pisum sativum. At early and mid-development, PsAO-α, -β, -γ and only PsAO-γ were observed, respectively, and their localization as well as the expression of PsAOs genes was almost exclusively restricted to the maternal fruit tissues, the seed coat and pericarp. Towards the end of rapid reserve synthesis, two additional isoforms (PsAO-δ, -κ) appeared in cotyledons, coinciding with a high transcript level of PsAO2. At this developmental stage, the activity level of PsAO-γ, was still considerable in the testa, and was higher than at earlier stages in the embryonic axis, which correlated with the PsAO3 transcript level. In mature dry seeds, AO activity and the expression of PsAOs became restricted to the embryonic tissues. The possible involvement of AO isoforms in ABA or IAA synthesis during pea seed development as well as the contribution of particular PsAO genes to the formation of the dimeric pea AO isoforms is discussed.
Collapse
|
17
|
Zdunek-Zastocka E. Molecular cloning, characterization and expression analysis of three aldehyde oxidase genes from Pisum sativum L. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2008; 46:19-28. [PMID: 18006324 DOI: 10.1016/j.plaphy.2007.09.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Indexed: 05/25/2023]
Abstract
Aldehyde oxidase (AO, EC 1.2.3.1) is a molybdenohydroxylase that is considered to catalyze the last step of abscisic acid (ABA) and indole-3-acetic acid (IAA) synthesis. Three cDNAs encoding aldehyde oxidase proteins in Pisum sativum (cv. Little Marvel) were obtained based on RT-PCR (reverse transcriptase-polymerase chain reaction) strategy. The cloned genes, designated as PsAO1, PsAO2 and PsAO3, are 4630, 4347, 4600 bp in length, respectively, and show high sequence identity to each other and to aldehyde oxidases from other plant species. The deduced PsAO1, PsAO2, and PsAO3 proteins are 1373, 1367, 1367 amino acids in length, respectively, and contain consensus sequences for two iron-sulfur centers, a FAD binding domain, and a molybdenum cofactor (Moco) binding domain. PsAO1 and PsAO2 were mainly expressed in leaves of seedlings and young leaves of adult plants, while the highest PsAO3 transcript level was observed in aging leaves and matured seeds. PsAO2 mRNA was not affected by salinity or ammonium treatment, whereas the transcript level of PsAO3 increased significantly under both stress conditions, with the most pronounced changes in aging leaves, fully expanded leaves and roots. The PsAO1 transcript level was enhanced only in the presence of ammonium in the nutrient medium, but not under salinity. Based on the molecular mass of the deduced proteins and on organ-specific gene expression, studied both under control and stress conditions, the contribution of each PsAO cDNA in the formation of the previously described three dimeric pea AO isoforms and the possible involvement of the PsAO3 in abscisic acid (ABA) synthesis is discussed.
Collapse
|
18
|
Zdunek-Zastocka E, Omarov RT, Koshiba T, Lips HS. Activity and protein level of AO isoforms in pea plants (Pisum sativum L.) during vegetative development and in response to stress conditions. JOURNAL OF EXPERIMENTAL BOTANY 2004; 55:1361-9. [PMID: 15073210 DOI: 10.1093/jxb/erh134] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Among three AO isoforms detected in pea plants, the activity of PAO-1 was dominant in leaves of seedlings and young leaves of mature plants, while PAO-3 revealed the highest band intensity in old leaves and roots. PAO-1 and PAO-3 are homodimers consisting of 145 kDa and 140 kDa subunits, respectively, while PAO-2 is a heterodimer of one 145 kDa and one 140 kDa subunit. In leaves, the activity of PAO-1 disappeared gradually with leaf ageing, while in roots it was present only in seedlings but not in mature pea plants. PAO-3 could oxidize abscisic aldehyde, a precursor of abscisic acid, indicating the possible involvement of this isoform in ABA synthesis in pea. The ability of PAO-3 to oxidize abscisic aldehyde was higher in old leaves than in young ones and increased significantly both in roots and leaves of plants exposed to salinity and ammonium treatments. A marked increase of the AO protein level was observed after ammonium application but not under salinity. Interestingly, the activity of PAO isoforms may be transcriptionally and post-transcriptionally regulated during vegetative growth and in response to stress conditions, and such a regulation might be particularly important to adjust ABA levels to the recent requirements of the plant. The observations suggest that the AO isoforms have different metabolic roles and that the activity and protein level of each isoform is regulated not only by environmental conditions but also through plant developmental stages.
Collapse
|