CDNA cloning and differential expression patterns of ascorbate peroxidase during post-harvest in Brassica rapa L.
Department of Life Science, II University of Naples, via Vivaldi 43, 81100 Caserta, Italy.Molecular Biology Reports (Impact Factor: 2.02). 04/2012; 39(8):7843-53. DOI: 10.1007/s11033-012-1627-7
Ascorbate is an antioxidant and a cofactor of many dioxygenases in plant and animal cell metabolism. A well-recognized enzyme consuming ascorbate is ascorbate peroxidase (APX), which catalyses the reduction of hydrogen peroxide to water with the simultaneous oxidation of ascorbate with a high specificity. The isolation and characterisation of new Apx cDNAs, could provide new insights about the physiological roles and regulation of these enzymes. In this work chloroplastic (Br-chlApx) and cytosolic (Br-cApx) isoform transcripts were isolated by RT-PCR in Brassica rapa and expression changes were analysed by semi-quantitative RT-PCR performed in different tissues (layer, stalk and florets) at different days (0, 4 and 14 day). The result showed that BrApx isoforms were differentially expressed and the Br-chlApx, in particular in the layer, had the highest expression level and remained unchanged also after 14 day after harvest. In addition, expression changes were compared with total BrAPX activity and the results showed that the activity decreased in all tissues at 14 day after harvest, independently of transcripts. Finally, additional solutes as the substrate of APX ascorbate and its oxidized form, dehydroascorbate, as well as α-tocopherol, the major vitamin E compound that prevents the propagation of lipid peroxidation in thylakoid membranes, were followed. The changes in the BrApx expression, BrAPX activity and metabolites can provide further evidence of the close relationships that exist between antioxidants which compensate for each other and suggest that there are multiple sites of reciprocal control.
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- "During this stress, ZAT12 induces the expression of other TFs and the up-regulation of the H 2 O 2 -scavenging enzyme, the cytosolic ascorbate peroxidase (Woodrow et al., 2012a). ROS accumulation is a common consequence of both biotic and abiotic stresses, including hypoxia and anoxia. "
ABSTRACT: The plants are exposed to environmental changes which are perceived as stresses when they are quick and extreme. Drought, salt and extreme temperatures, in particular, limit agricultural crops productivity, affecting all stages of plant growth and reproduction and therefore strongly decreasing crop yield. Worldwide estimates show that most yield loss (70%) can be directly due to abiotic stresses. Moreover the increasing phenomena of anthropization and the incorrect use of agricultural land have strongly contributed to land degradation. A large number of abiotic stress responsive genes have been reported in a variety of plants including Arabidopsis and the major crops such as barley, maize, rice and wheat. Transcriptional control of the expression of these genes is a crucial part of the plant response to abiotic stresses. Therefore in the last years the transcriptional mechanisms involved in the response to several abiotic stresses have been the subject of intense research, that have been productive in identifying transcription factors (TFs) as important 'key or master regulators' of gene expression under stress. An increasing number of TFs have been recently described and essential transcription factor binding regions have been identified for many genes. In fact, these systems of regulation work thanks to specific cis-elements located in the promoter regions of target genes, which are called regulons. The main regulons which respond to abiotic stresses are DREB1-CBF (dehydration-responsive element binding protein 1/C-repeat binding factor) which is involved in the cold stress response, DREB2 that acts in ABA-independent gene expression for response to heat and osmotic stress, whereas the ABA-responsive element (ABRE) binding protein (AREB)/ABRE binding factor (ABF) regulon operates in gene expression depending on ABA under osmotic stress. Other regulons, such as MYB/MYC and NAC regulons, induce or repress the expression of genes involved in abiotic stress-responsive. In the last few years, several studies have evidenced that TFs are powerful tools to engineer enhanced stress tolerance in plants. Therefore, in this chapter, we will summarize the major TFs involved in crop plants abiotic stress signalling and responses and the relative plants adaptive mechanisms at the molecular level. A major knowledge on molecular mechanisms that occur in stress condition are the one way pass for the improvement of stress tolerance in crop plants.Emerging Technologies and Management of Crop Stress Tolerance, 1st Edition. Volume 1-Biological Techniques, I edited by Paraviz Ahmad, Saiema Rasool, 06/2014: chapter Transcription Factors and Environmental Stresses in Plants: pages 57-72; Elsevier., ISBN: 9780128008768
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ABSTRACT: Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a key adaptor molecule for the tumor necrosis factor superfamily and Toll-like/interleukin-1 receptor superfamily. It plays an important role in innate and adaptive immunity. The TRAF6 of Japanese scallop Mizuhopecten yessoensis (designated as MyTRAF6) was identified and characterized in this study. The full-length cDNA of MyTRAF6 was 2,407 bp, which consisted of 239-bp 5'-terminal untranslated region, 1,974-bp open reading frame encoding a polypeptide of 657 amino acids, 194-bp of 3'-terminal untranslated region followed by a canonical polyadenylation signal sequence AATAAA and a poly (A) tail. The predicted amino acid sequence of MyTRAF6 contained the characteristic motifs of TRAF proteins, including a Zinc finger of RING-type, two Zinc fingers of TRAF-type, and a MATH (meprin and TRAF homology) domain. It had an overall identity of 43-96 % with those of other TRAF6s, the highest identity (96 %) with Chlamys farreri TRAF6, and the least identity (43 %) with Meleagris gallopavo TRAF6. Phylogenetic analysis classified MyTRAF6 as a true TRAF6 ortholog. In addition, the promoter of MyTRAF6 was also identified by genome walking. It contained several potential transcription factor-binding sites and three single nucleotide polymorphisms. qRT-PCR analysis revealed that MyTRAF6 was highly expressed in hemocytes of adult M. yessoensis. MyTRAF6 transcript level in the hemocytes reached a maximum 6 h after Vibrio anguilarum challenge. The results indicated that MyTRAF6 may fulfill an important function during M. yessoensis bacterial infection. It could be a key effector molecule involved in the innate defense of molluscs.Molecular Biology Reports 05/2013; 40(8). DOI:10.1007/s11033-013-2573-8 · 2.02 Impact Factor
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