The sulfur pathway and diagnosis of sulfate depletion in grapevine

Sulfur is an essential nutrient to all plant species. Plants assimilate sulfur in a well-described pathway, which has been taken up by roots. Regulatory mech- anism has been the subject of many research papers. However, recent studies highlighted differences between crop plants and the model plant Arabidopsis thaliana. Our work focuses on the identification of genes involved in the sulfur metabolism in the Vitis vinifera genome, and their response to sulfur deficiency and other abiotic stress endured by grapevine in the field, namely water stress. Here, we describe the identification and brief characterization of the first assimilation enzymes involved in the sulfur pathway, the enzyme responsible for sulfur activa- tion, ATP sulfurylase (ATPS), and the two enzymes that reduce sulfate to sulfide, Adenosine 50-phosphosulate reductase (APR) and Sulfite reductase (SiR). A reduc- tion was observed in the number of ATPS and APR isoforms identified in V. vinifera genome when compared to A. thaliana or Glycine max genomes. Two ATPS isoforms were present in the Vitis genome, of which only ATPS1 transcript was detected in the tested tissues, and one APR isoform, suggesting an absence of redundancy in the role of both enzymes. ATPS1, APR and SiR transcript level was up-regulated in response to 2 days exposure to sulfur deficiency in V. vinifera cell cultures, which was completely reversed by the addition of GSH to the culture medium. Apparently, oxidative stress triggered GSH has a pivotal role in the regulation of ATPS1, APR and SiR transcription level, since their up-regulation was observed in mRNA from field grapevine berries under water stress, which is known to induce oxidative stress.info:eu-repo/semantics/publishedVersio

Heat and water stress induce unique transcriptional signatures of heat-shock proteins and transcription factors in grapevine

Grapevine is an extremely important crop worldwide. In southern Europe, post-flowering phases of the growth cycle can occur under high temperatures, excessive light, and drought conditions at soil and/or atmospheric level. In this study, we subjected greenhouse grown grapevine, variety Aragonez, to two individual abiotic stresses, water deficit stress (WDS), and heat stress (HS). The adaptation of plants to stress is a complex response triggered by cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Approaches such as array-based transcript profiling allow assessing the expression of thousands of genes in control and stress tissues. Using microarrays, we analyzed the leaf transcriptomic profile of the grapevine plants. Photosynthesis measurements verified that the plants were significantly affected by the stresses applied. Leaf gene expression was obtained using a high-throughput transcriptomic grapevine array, the 23K custom-made Affymetrix Vitis GeneChip. We identified 1,594 genes as differentially expressed between control and treatments and grouped them into ten major functional categories using MapMan software. The transcriptome of Aragonez was more significantly affected by HS when compared with WDS. The number of genes coding for heat-shock proteins and transcription factors expressed solely in response to HS suggesting their expression as unique signatures of HS. However, a cross-talk between the response pathways to both stresses was observed at the level of AP2/ERF transcription factors

MicroRNA expression profiles during cotton (Gossypium hirsutum L) fiber early development

The role of microRNAs (miRNAs) during cotton fiber development remains unclear. Here, a total of 54 miRNAs belonging to 39 families were selected to characterize miRNA regulatory mechanism in eight different fiber development stages in upland cotton cv BM-1. Among 54 miRNAs, 18 miRNAs were involved in cotton fiber initiation and eight miRNAs were related to fiber elongation and secondary wall biosynthesis. Additionally, 3,576 protein-coding genes were candidate target genes of these miRNAs, which are potentially involved in cotton fiber development. We also investigated the regulatory network of miRNAs and corresponding targets in fiber initiation and elongation, and secondary wall formation. Our Gene Ontology-based term classification and KEGG-based pathway enrichment analyses showed that the miRNA targets covered 220 biological processes, 67 molecular functions, 45 cellular components, and 10 KEGG pathways. Three of ten KEGG pathways were involved in lignan synthesis, cell elongation, and fatty acid biosynthesis, all of which have important roles in fiber development. Overall, our study shows the potential regulatory roles of miRNAs in cotton fiber development and the importance of miRNAs in regulating different cell types. This is helpful to design miRNA-based biotechnology for improving fiber quality and yield

Inflammation modulates fibronectin isoform expression in colonic lamina propria fibroblasts (CLPF)

BACKGROUND: Migration of colonic lamina propria fibroblasts (CLPF) plays an important role during mucosal wound healing as well as fibrosis and fistula formation in Crohn's disease (CD). Recently, we showed that the migratory potential of CD-CLPF was significantly reduced compared to control CLPF. Fistula-derived CD-CLPF migrated less and fibrosis-CLPF more than CLPF from inflamed CD mucosa. These changes in migratory behavior were associated with changes in production of the migration-inducing fibronectin (FN) isoforms ED-A and ED-B. A permanent reduction of the migratory potential of CLPF was mediated by IFN-gamma and tumor necrosis factor (TNF) modulate FN isofom expression in CLPF and thereby might regulate CLPF migration. MATERIALS AND METHODS: Control CLPF were incubated for 72 h with IFN-gamma, TNF, IFN-gamma plus TNF, or TGF-beta1. Messenger RNA (mRNA) was isolated and expression of FN and isoforms ED-A and ED-B was quantified by real-time polymerase chain reaction. FN, ED-A, and ED-B were investigated by Western blotting. FN receptor integrin alpha5beta1 was analyzed by FACS. RESULTS: No difference was found for the surface display of integrin alpha5beta1 between stimulated and non-stimulated cells. In TGF-beta1 incubated CLPF mRNA amount of FN and isoforms ED-A and ED-B was slightly increased. IFN-gamma only decreased FN in CLPF, TNF significantly reduced FN-mRNA by 40%, FN ED-A mRNA by 25%, and ED-B mRNA by 50%. The TNF-mediated mRNA downregulation resulted in a decreased protein amount as revealed by Western blotting. CONCLUSION: Cytokines such as IFN-gamma, TNF, and TGF-beta1 modulate the production of fibronectin isoforms. Our data indicate that inflammation-induced modulation of FN-isoform production is involved in the alterations of migratory potential of CLPF isolated from CD mucosa