21 results on '"Trifa Y"'
Search Results
2. Effects of nitrogen rates on grain yield and nitrogen agronomic efficiency of durum wheat genotypes under different environments
- Author
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Ayadi, S., Karmous, C., Chamekh, Z., Hammami, Z., Baraket, M., Esposito, S., Rezgui, S., and Trifa, Y.
- Published
- 2016
- Full Text
- View/download PDF
3. Extra-ribosomal function(s) of the plastid ribosomal protein L4 in the expression of ribosomal components in spinach
- Author
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Trifa, Y. and Lerbs-Mache, S.
- Published
- 2000
- Full Text
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4. Predicting yield reduction in improved barley ( Hordeum vulgare L.) varieties and landraces under salinity using selected tolerance traits
- Author
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Hammami, Z., primary, Gauffreteau, A., additional, BelhajFraj, M., additional, Sahli, A., additional, Jeuffroy, M.-H., additional, Rezgui, S., additional, Bergaoui, K., additional, McDonnell, R., additional, and Trifa, Y., additional
- Published
- 2017
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5. Genetic variability of Nitrogen Use Efficiency components in Tunisian improved genotypes and landraces of durum wheat
- Author
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Ayadi S, Karmous C, Hammami Z, Tamani Z, Tamani N, Trifa Y, Rezgui S., ESPOSITO, SERGIO, Ayadi, S, Karmous, C, Hammami, Z, Tamani, Z, Tamani, N, Trifa, Y, Esposito, Sergio, and Rezgui, S.
- Published
- 2012
6. Effects of nitrogen rates on grain yield and nitrogen agronomic efficiency of durum wheat genotypes under different environments
- Author
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Ayadi, S., primary, Karmous, C., additional, Chamekh, Z., additional, Hammami, Z., additional, Baraket, M., additional, Esposito, S., additional, Rezgui, S., additional, and Trifa, Y., additional
- Published
- 2015
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7. Comparative performance of δ13C, ion accumulation and agronomic parameters for phenotyping durum wheat genotypes under various irrigation water salinities.
- Author
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Chamekh, Z., Karmous, C., Ayadi, S., Sahli, A., Belhaj Fraj, M., Yousfi, S., Rezgui, S., Ben Aissa, N., Serret, M.D., McCann, I., Trifa, Y., Amara, H., and Araus, J.L.
- Subjects
WHEAT genetics ,BIOACCUMULATION in plants ,WHEAT breeding ,IRRIGATION water ,CARBON isotopes ,EFFECT of saline waters on plants ,WHEAT yields - Abstract
The use of efficient selection traits for screening under contrasting irrigation water salinity is a challenge for breeders. To identify patterns, grain yield ( GY) and yield components (kernels m
−2 , thousand kernels weight), growth traits (plant height, biomass), flag leaf ion accumulation (Na+ and K+ ), carbon isotope composition ( δ13 Cgrain ) and nitrogen concentration (Ngrain ) of grains were assessed on 25 durum wheat genotypes (G) in two consecutive growing seasons (2010 and 2011), in three semi-arid locations in Tunisia. Each location differed in their irrigation water salinity as measured by electrical conductivity: Echbika ( S1, 6 dS m−1 ), Barrouta ( S2, 12 dS m−1 ) and Sidi Bouzid ( S3, 18 dS m−1 ). GY was shown to be negatively correlated to Ngrain as well as to δ13 Cgrain . This is confirmed by a multiple linear regression analysis that showed that both δ13 Cgrain and Ngrain were the major determinant components for GY variability under S3. A high genotypic variability was observed and the improved genotype Maali exhibited the most stable GY under the three irrigation water salinities and the two cropping seasons. Maali showed the lowest δ13 Cgrain . This indicates that tolerance in durum wheat is likely to be correlated to the ability of maintaining a high stomatal conductance. According to our data suggests δ13 Cgrain can be used for an efficient screening of salt tolerant durum wheat. Under our experimental conditions, Ngrain was shown to be highly correlated to δ13 Cgrain and can therefore be easier-to-use trait to assess the tolerance to salinity. [ABSTRACT FROM AUTHOR]- Published
- 2017
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8. IN VITRO CULTURE USED FOR SCREENING SALT STRESS TOLERANT LETTUCE CULTIVARS
- Author
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Maamouri, A., primary, Trifa, Y., additional, Kouki, K., additional, Aounallah, K., additional, and Karmous, C., additional
- Published
- 2012
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9. Use of single serum progesterone level measurement as a predictor of the fetal viability during the first trimester
- Author
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Trifa Yousif Muttalib
- Subjects
Progesterone ,Fetal viability ,First trimester ,Medicine - Abstract
Background and objective: Approximately one in third of pregnant women experience discomfort, pain and or vaginal bleeding during the first trimester of pregnancy. Ultrasound is known to be a useful tool in detecting and diagnosing the viability of the fetus but it is sometimes inconclusive. In cases in which pregnant women experience symptoms of discomfort, serum progesterone may be admitted to the patient for counseling and prediction of the continuity of pregnancy. This study aimed to estimate the relation between single serum progesterone level and the viability of the fetus during the first trimester. Method: A prospective study was carried out in Maternity teaching hospital-Erbil city to estimate the accuracy of single serum progesterone measurement for the prediction of fetal viability at the end of the first trimester. All the cases have been detected by ultrasound device that has been for women who attended the hospital and reported the feeling of discomfort, pain and bleeding early in the first trimester of pregnancy, serum progesterone level of the patients were compared between viable and nonviable fetuses. Results: A total of 97 participants were involved in this study; 57 participants had a viable pregnancy at the end of the first trimester, and 40 participants had un-viable pregnancy that has been terminated either by spontaneous abortion or termination performed for missed abortion. The mean of serum progesterone level in viable pregnancies was (19.358 ng\ml) when compared with the non-viable pregnancies which were (11.082 ng\ml). The differences were statistically significant (P
- Published
- 2018
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10. The nuclear RPL4 gene encodes a chloroplast protein that co-purifies with the T7-like transcription complex as well as plastid ribosomes.
- Author
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Trifa, Y, Privat, I, Gagnon, J, Baeza, L, and Lerbs-Mache, S
- Abstract
We have cloned and sequenced the cDNA and the gene coding for plastid ribosomal protein L4 (RPL4) from two higher plant species, spinach and Arabidopsis thaliana. Ribosomal protein L4 is one of the ribosomal proteins for which extraribosomal functions in transcriptional regulation has been demonstrated in prokaryotes. Sequence comparison of the two plant cDNAs and genes shows that the RPL4 gene has acquired a remarkable 3' extension during evolutionary transfer to the nuclear genome. This extension harbors an intron and codes for a glutamic and aspartic acid-rich amino acid sequence that resembles highly acidic C-terminal tails of some transcription factors. Co-purification of ribosomal protein L4 with plastid RNA polymerase and transcription factor CDF2 using different purification protocols as well as the surprising amino acid sequence of the L4 protein make it a likely candidate to play a role in plastid transcriptional regulation.
- Published
- 1998
11. Variation of Grain Yield, Grain Protein Content and Nitrogen Use Efficiency Components under Different Nitrogen Rates in Mediterranean Durum Wheat Genotypes
- Author
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Sawsen Ayadi, Salma Jallouli, Zoubeir Chamekh, Inès Zouari, Simone Landi, Zied Hammami, Fatma Ben Azaiez, Mokhtar Baraket, Sergio Esposito, Youssef Trifa, Ayadi, S., Jallouli, S., Chamekh, Z., Zouari, I., Landi, S., Hammami, Z., Azaiez, F. E. B., Baraket, M., Esposito, S., and Trifa, Y.
- Subjects
Triticum durum ,improved ,food and beverages ,Plant Science ,stepwise analysi ,landraces ,nitrogen ,utilization efficiency ,stepwise analysis ,landrace ,Agronomy and Crop Science ,Food Science - Abstract
Nitrogen (N) is a crucial nutrient for plant growth and development. To optimize agricultural environments, N fertilizers represent a critical tool to regulate crop productivity. The improvement of nitrogen use efficiency (NUE) represents a promising tool that may enable cereal production to meet future food demand. Wheat reported contrasting behaviors in N utilization showing specific abilities depending on genotype. This study selected two landraces and two improved genotypes from Northern Africa to investigate grain yield (GY), grain protein content (GPC) and NUE. Plants were grown under three levels of N supply: 0, 75, 150 kg N ha−1 and for two consecutive years. Results reported a better NUE (0.40 kg kg N−1) obtained under 150 kg N ha−1, while N utilization efficiency (NUtE) showed a 13% increase using 75 kg N ha−1 compared with 150 kg N ha−1. Under low nitrogen rate (0 N), crop N supply (CNS) and N uptake efficiency (NUpE) were shown as determinant factors for improved genotypes GY (R2 = 0.72), while NUtE represented the most determinant component for GPC in landraces (R2 = 0.92). Multivariate regression models explained the dependence in GPC on NUE, NUpE, and NUtE. In conclusion, our results recognize GPC and NUtE as suitable selection traits to identify durum wheat with higher NUE.
- Published
- 2022
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12. Nitrogen assimilation under different nitrate nutrition in Tunisian durum wheat landraces and improved genotypes
- Author
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Youssef Trifa, Giorgia Capasso, Marco Lentini, Salma Jallouli, Chahine Karmous, Zoubeir Chamekh, Simone Landi, Sergio Esposito, Sawsen Ayadi, Manuela Cardi, Valeria Paradisone, Ayadi, S., Jallouli, S., Landi, S., Capasso, G., Chamekh, Z., Cardi, M., Paradisone, V., Lentini, M., Karmous, C., Trifa, Y., and Esposito, Sergio
- Subjects
0106 biological sciences ,0301 basic medicine ,Nitrogen assimilation ,glutamate synthase ,chemistry.chemical_element ,Plant Science ,01 natural sciences ,nitrogen use efficiency ,03 medical and health sciences ,chemistry.chemical_compound ,Nitrate ,Glutamate synthase ,Genotype ,Nitrogen metabolism ,Nitrogen cycle ,Ecology, Evolution, Behavior and Systematics ,Hydroponic culture ,biology ,glucose-6-phosphade dehydrogenase ,Nitrogen ,Horticulture ,030104 developmental biology ,chemistry ,biology.protein ,Triticum varieties ,010606 plant biology & botany - Abstract
The effects of nitrate were studied in wheat varieties grown in hydroponic culture: two landraces (Azizi and Bidi), and two improved genotypes (Om Rabiaa and Khiar) from Tunisia. Nitrogen (N) supply generally induced an increase in plant height in all varieties, albeit to a different extent; interestingly, landraces exhibited the same N Uptake Efficiency (NUpE) as other varieties, and a lower Nitrogen Utilization Efficiency (NUtE); in contrast, improved genotypes exhibit a better NUtE at high N. Nitrate reductase activity (NRA) was sensibly and constitutively higher in the improved genotypes in the roots, while NRA was strongly influenced by nitrate supply in the leaves of Bidi landrace. Glutamine synthetase (GS) activity was similar in all varieties studied, in contrast, ferredoxin-glutamate synthase (Fd- GOGAT) activity and occurrence were increased by nitrate. Intriguingly, glutamate dehydrogenase (GDH) activity followed an opposite behaviour with respect to GOGAT. Glucose-6P-dehydrogenase (G6PDH), which provides reductants for N assimilation, increased in roots upon nitrate supply, but the different plastidial and cytosolic isoforms differently changed in the different varieties studied. The data suggest that landraces present higher metabolic flexibility as compared with improved cultivars; therefore, the metabolic changes observed could be suitable for the identification of factors limiting the NUtE.
- Published
- 2020
13. Scalable Spin Squeezing in Two-Dimensional Arrays of Dipolar Large-S Spins.
- Author
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Trifa Y and Roscilde T
- Abstract
We theoretically show that the spin-spin interactions realized in two-dimensional Mott insulators of large-spin magnetic atoms (such as Cr, Er, or Dy) lead to scalable spin squeezing along the nonequilibrium unitary evolution initialized in a coherent spin state. An experimentally relevant perturbation to the collective squeezing dynamics is offered by a quadratic Zeeman shift, which leads instead to squeezing of individual spins. Making use of a truncated cumulant expansion for the quantum fluctuations of the spin array, we show that, for sufficiently small quadratic shifts, the spin squeezing dynamics is akin to that produced by the paradigmatic one-axis-twisting model-as expected from an effective separation between collective-spin and spin-wave variables. Scalable spin squeezing is shown to be protected by the robustness of long-range ferromagnetic order to quadratic shifts in the equilibrium phase diagram of the system that we reconstruct via quantum Monte Carlo and mean-field theory.
- Published
- 2024
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14. The efficiency of chlorophyll fluorescence as a selection criterion for salinity and climate aridity tolerance in barley genotypes.
- Author
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Hammami Z, Tounsi-Hammami S, Nhamo N, Rezgui S, and Trifa Y
- Abstract
Introduction: In the Near East and North Africa (NENA) region, crop production is being affected by various abiotic factors, including freshwater scarcity, climate, and soil salinity. As a result, farmers in this region are in search of salt-tolerant crops that can thrive in these harsh environments, using poor-quality groundwater. The main staple food crop for most of the countries in this region, Tunisia included, is barley., Methods: The present study was designed to investigate the sensitivity and tolerance of six distinct barley genotypes to aridity and salinity stresses in five different natural field environments by measuring their photosynthetic activity., Results and Discussion: The results revealed that tolerant genotypes were significantly less affected by these stress factors than sensitive genotypes. The genotypes that were more susceptible to salinity and aridity stress exhibited a significant decline in their photosynthetic activity. Additionally, the fluorescence yields in growth phases J, I, and P declined significantly in the order of humid environment (BEJ), semi-arid site (KAI), and arid environment (MED) and became more significant when salt stress was added through the use of saline water for irrigation. The stress adversely affected the quantum yield of primary photochemistry (φP0), the quantum yield of electron transport (φE0), and the efficiency by trapped excitation (ψ0) in the vulnerable barley genotypes. Moreover, the performance index (PI) of the photosystem II (PSII) was found to be the most distinguishing parameter among the genotypes tested. The PI of sensitive genotypes was adversely affected by aridity and salinity. The PI of ICARDA20 and Konouz decreased by approximately 18% and 33%, respectively, when irrigated with non-saline water. The reduction was even greater, reaching 39%, for both genotypes when irrigated with saline water. However, tolerant genotypes Souihli and Batini 100/1B were less impacted by these stress factors.The fluorescence study provided insights into the photosynthetic apparatus of barley genotypes under stress. It enabled reliable salinity tolerance screening. Furthermore, the study confirmed that the chlorophyll a fluorescence induction curve had an inflection point (step K) even before the onset of visible signs of stress, indicating physiological disturbances, making chlorophyll fluorescence an effective tool for identifying salinity tolerance in barley., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hammami, Tounsi-Hammami, Nhamo, Rezgui and Trifa.)
- Published
- 2024
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15. Different Roles of Heat Shock Proteins (70 kDa) During Abiotic Stresses in Barley ( Hordeum vulgare ) Genotypes.
- Author
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Landi S, Capasso G, Ben Azaiez FE, Jallouli S, Ayadi S, Trifa Y, and Esposito S
- Abstract
In this work, the involvement of heat shock proteins (HSP70) in barley ( Hordeum vulgare ) has been studied in response to drought and salinity. Thus, 3 barley genotypes usually cultivated and/or selected in Italy, 3 Middle East/North Africa landraces and genotypes and 1 improved genotype from ICARDA have been studied to identify those varieties showing the best stress response. Preliminarily, a bioinformatic characterization of the HSP70s protein family in barley has been made by using annotated Arabidopsis protein sequences. This study identified 20 putative HSP70s orthologs in the barley genome. The construction of un-rooted phylogenetic trees showed the partition into four main branches, and multiple subcellular localizations. The enhanced HSP70s presence upon salt and drought stress was investigated by both immunoblotting and expression analyses. It is worth noting the Northern Africa landraces showed peculiar tolerance behavior versus drought and salt stresses. The drought and salinity conditions indicated the involvement of specific HSP70s to counteract abiotic stress. Particularly, the expression of cytosolic MLOC_67581, mitochondrial MLOC_50972, and encoding for HSP70 isoforms showed different expressions and occurrence upon stress. Therefore, genotypes originated in the semi-arid area of the Mediterranean area can represent an important genetic source for the improvement of commonly cultivated high-yielding varieties.
- Published
- 2019
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16. Genetic variation of salt-stressed durum wheat ( Triticum turgidum subsp. durum Desf.) genotypes under field conditions and gynogenetic capacity.
- Author
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Ayed-Slama O, Bouhaouel I, Chamekh Z, Trifa Y, Sahli A, Ben Aissa N, and Slim-Amara H
- Abstract
Agriculture has new challenges against the climate change: the preservation of genetic resources and the rapid creation of new varieties better adapted to abiotic stress, specially salinity. In this context, the agronomic performance of 25 durum wheat ( Triticum turgidum subsp. durum Desf.) genotypes (nineteen landraces and six improved varieties), cultivated in two semi-arid regions in the center area of Tunisia, were assessed. These sites (Echbika, 2.2 g l
-1 ; Barrouta, 4.2 g l-1 ) differ by their degree of salinity of the water irrigation. The results showed that most of the agronomic traits (e.g. spike per meter square, thousand kernels weight and grain yield) were reduced by salinity. Durum wheat landraces, Mahmoudi and Hmira, and improved varieties, Maali and Om Rabia showed the widest adaptability to different quality of irrigation water. Genotypes including Jneh Kotifa and Arbi were estimated as stable genotypes under adverse conditions. Thereafter, salt-tolerant (Hmira and Jneh Khotifa) and the most cultivated high-yielding (Karim, Razzak and Khiar) genotypes were tested for their gynogenetic ability to obtain haploids and doubled haploid lines. Genotypes with good induction capacity had not necessarily a good capacity of regeneration of haploid plantlets. In our conditions, Hmira and Khiar exhibited the best gynogenetic ability (3.1% and 2.9% of haploid plantlets, respectively).- Published
- 2018
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17. Comparative effect of salinity on growth, grain yield, water use efficiency, δ(13)C and δ(15)N of landraces and improved durum wheat varieties.
- Author
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Chamekh Z, Ayadi S, Karmous C, Trifa Y, Amara H, Boudabbous K, Yousfi S, Serret MD, and Araus JL
- Subjects
- Carbon metabolism, Conservation of Natural Resources, Genotype, Mediterranean Region, Nitrogen metabolism, Triticum genetics, Triticum growth & development, Triticum metabolism, Water Quality, Sodium Chloride metabolism, Stress, Physiological, Triticum physiology
- Abstract
Supplemental irrigation with low-quality water will be paramount in Mediterranean agriculture in the future, where durum wheat is a major crop. Breeding for salinity tolerance may contribute towards improving resilience to irrigation with brackish water. However, identification of appropriate phenotyping traits remains a bottleneck in breeding. A set of 25 genotypes, including 19 landraces and 6 improved varieties most cultivated in Tunisia, were grown in the field and irrigated with brackish water (6, 13 and 18dSm(-1)). Improved genotypes exhibited higher grain yield (GY) and water use efficiency at the crop level (WUEyield or 'water productivity'), shorter days to flowering (DTF), lower N concentration (N) and carbon isotope composition (δ(13)C) in mature kernels and lower nitrogen isotope composition (δ(15)N) in the flag leaf compared with landraces. GY was negatively correlated with DTF and the δ(13)C and N of mature kernels and was positively correlated with the δ(15)N of the flag leaf. Moreover, δ(13)C of mature kernels was negatively correlated with WUEyield. The results highlight the importance of shorter phenology together with photosynthetic resilience to salt-induced water stress (lower δ(13)C) and nitrogen metabolism (higher N and δ(15)N) for assessing genotypic performance to salinity., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2016
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18. DNA content in embryo and endosperm of maize kernel (Zea mays L.): impact on GMO quantification.
- Author
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Trifa Y and Zhang D
- Subjects
- Zea mays embryology, DNA, Plant analysis, Plants, Genetically Modified genetics, Seeds chemistry, Zea mays genetics
- Abstract
PCR-based techniques are the most widely used methods for the quantification of genetically modified organisms (GMOs) through the determination of the ratio of transgenic DNA to total DNA. It is shown that the DNA content per mass unit is significantly different among 10 maize cultivars. The DNA contents of endosperms, embryos, and teguments of individual kernels from 10 maize cultivars were determined. According to our results, the tegument's DNA ratio reaches at maximum 3.5% of the total kernel's DNA, whereas the endosperm's and the embryo's DNA ratios are nearly equal to 50%. The embryo cells are diploid and made of one paternal and one maternal haploid genome, whereas the endosperm is constituted of triploid cells made of two maternal haploid genomes and one paternal haploid genome. Therefore, it is shown, in this study, that the accuracy of the GMO quantification depends on the reference material used as well as on the category of the transgenic kernels present in the mixture.
- Published
- 2004
- Full Text
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19. Differential regulation of TGA transcription factors by post-transcriptional control.
- Author
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Pontier D, Privat I, Trifa Y, Zhou JM, Klessig DF, and Lam E
- Subjects
- Arabidopsis genetics, Arabidopsis growth & development, Arabidopsis metabolism, Arabidopsis Proteins genetics, Arabidopsis Proteins metabolism, Basic-Leucine Zipper Transcription Factors, DNA-Binding Proteins genetics, Gene Expression Regulation, Plant, Genes, Plant genetics, Peptide Hydrolases metabolism, Plant Proteins genetics, Plants, Genetically Modified, Nicotiana cytology, Nicotiana genetics, Nicotiana metabolism, Transcription Factors genetics, DNA-Binding Proteins metabolism, Plant Proteins metabolism, Protein Processing, Post-Translational, Transcription Factors metabolism
- Abstract
Transcription factors often belong to multigene families and their individual contribution in a particular regulatory network remains difficult to assess. We show here that specific members from a family of conserved Arabidopsis bZIP transcription factors, the TGA proteins, are regulated in their protein stability by developmental stage-specific proteolysis. Using GFP fusions of three different Arabidopsis TGA factors that represent members of distinct subclasses of the TGA factor family, we demonstrate that two of these TGA proteins are specifically targeted for proteolysis in mature leaf cells. Using a supershift gel mobility assay, we found evidence for similar regulation of the cognate proteins as compared to the GFP fusion proteins expressed under the cauliflower mosaic virus (CaMV) 35S promoter. Using various inhibitors, we showed that the expression of at least one of these three TGA factors could be stabilized by inhibition of proteasome-mediated proteolysis. This study indicates that TGA transcription factors may be regulated by distinct pathways of targeted proteolysis that can serve to modulate the contribution of specific members of a multigene family in complex regulatory pathways.
- Published
- 2002
- Full Text
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20. Nitric oxide and salicylic acid signaling in plant defense.
- Author
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Klessig DF, Durner J, Noad R, Navarre DA, Wendehenne D, Kumar D, Zhou JM, Shah J, Zhang S, Kachroo P, Trifa Y, Pontier D, Lam E, and Silva H
- Subjects
- Adenosine Diphosphate Ribose metabolism, Second Messenger Systems, Nicotiana genetics, Nicotiana immunology, Nitric Oxide metabolism, Plants, Toxic, Salicylic Acid metabolism, Signal Transduction, Nicotiana metabolism
- Abstract
Salicylic acid (SA) plays a critical signaling role in the activation of plant defense responses after pathogen attack. We have identified several potential components of the SA signaling pathway, including (i) the H(2)O(2)-scavenging enzymes catalase and ascorbate peroxidase, (ii) a high affinity SA-binding protein (SABP2), (iii) a SA-inducible protein kinase (SIPK), (iv) NPR1, an ankyrin repeat-containing protein that exhibits limited homology to IkappaBalpha and is required for SA signaling, and (v) members of the TGA/OBF family of bZIP transcription factors. These bZIP factors physically interact with NPR1 and bind the SA-responsive element in promoters of several defense genes, such as the pathogenesis-related 1 gene (PR-1). Recent studies have demonstrated that nitric oxide (NO) is another signal that activates defense responses after pathogen attack. NO has been shown to play a critical role in the activation of innate immune and inflammatory responses in animals. Increases in NO synthase (NOS)-like activity occurred in resistant but not susceptible tobacco after infection with tobacco mosaic virus. Here we demonstrate that this increase in activity participates in PR-1 gene induction. Two signaling molecules, cGMP and cyclic ADP ribose (cADPR), which function downstream of NO in animals, also appear to mediate plant defense gene activation (e.g., PR-1). Additionally, NO may activate PR-1 expression via an NO-dependent, cADPR-independent pathway. Several targets of NO in animals, including guanylate cyclase, aconitase, and mitogen-activated protein kinases (e.g., SIPK), are also modulated by NO in plants. Thus, at least portions of NO signaling pathways appear to be shared between plants and animals.
- Published
- 2000
- Full Text
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21. NPR1 differentially interacts with members of the TGA/OBF family of transcription factors that bind an element of the PR-1 gene required for induction by salicylic acid.
- Author
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Zhou JM, Trifa Y, Silva H, Pontier D, Lam E, Shah J, and Klessig DF
- Subjects
- Amino Acid Sequence, Arabidopsis drug effects, Arabidopsis genetics, Arabidopsis metabolism, Base Sequence, Basic-Leucine Zipper Transcription Factors genetics, Binding Sites genetics, DNA Probes genetics, Molecular Sequence Data, Plant Proteins genetics, Point Mutation, Salicylic Acid pharmacology, Signal Transduction, Transcription Factors genetics, Arabidopsis Proteins, Basic-Leucine Zipper Transcription Factors metabolism, Genes, Plant drug effects, Plant Proteins metabolism, Transcription Factors metabolism
- Abstract
NPR1 is a critical component of the salicylic acid (SA)-mediated signal transduction pathway leading to the induction of defense genes, such as the pathogenesis-related (PR)-1 gene, and enhanced disease resistance. Using a yeast two-hybrid screen, we identified several NPR1-interacting proteins (NIPs). Two of these NIPs are members of the TGA/OBF family of basic leucine zipper (bZIP) transcription factors; this family has been implicated in the activation of SA-responsive genes, including PR-1. Six TGA family members were tested and shown to differentially interact with NPR1: TGA2 and TGA3 showed strong affinity for NPR1; TGA5 and TGA6 exhibited weaker affinity; and TGA1 and TGA4 displayed little or no detectable interaction with NPR1, respectively. Interestingly, the amino-termini of these factors were found to decrease their stability in yeast and differentially affect their apparent affinity toward NPR1. The interacting regions on NPR1 and the TGA factors were also defined. Each of four point mutations in NPR1 that disrupt SA signaling in Arabidopsis completely blocked interaction of NPR1 with TGA2 and TGA3. TGA2 and TGA3 were also found to bind the SA-responsive element of the Arabidopsis PR-1 promoter. These results directly link NPR1 to SA-induced PR-1 expression through members of the TGA family of transcription factors.
- Published
- 2000
- Full Text
- View/download PDF
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