Auxin response factors () act as key elements of the auxin-signaling pathway and play important roles in the process of a plant's growth, development, and response to environmental conditions. We studied the implication of the gene in the tomato response to salt (150 mM of NaCl) and drought (15% PEG 20000) stresses. The functional characterization of knockdown tomato mutants revealed that the downregulation of this gene enhanced primary root length and root branching and reduced plant wilting.
View Article and Find Full Text PDFRoot-knot nematodes (RKN) from the genus Meloidogyne induce the dedifferentiation of root vascular cells into giant multinucleate feeding cells. These feeding cells result from an extensive reprogramming of gene expression, and auxin is known to be a key player in their development. However, little is known about how the auxin signal is transmitted during giant cell development.
View Article and Find Full Text PDFThe complex and dynamic three-dimensional organization of chromatin within the nucleus makes understanding the control of gene expression challenging, but also opens up possible ways to epigenetically modulate gene expression. Because plants are sessile, they evolved sophisticated ways to rapidly modulate gene expression in response to environmental stress, that are thought to be coordinated by changes in chromatin conformation to mediate specific cellular and physiological responses. However, to what extent and how stress induces dynamic changes in chromatin reorganization remains poorly understood.
View Article and Find Full Text PDFLead (Pb) contamination is a widespread environmental problem due to its toxicity to living organisms. L., a member of the Brassicaceae family, commonly found in the Mediterranean regions, is characterized by its ability to tolerate and accumulate Pb in soils and hydroponic cultures.
View Article and Find Full Text PDFUnderstanding the mechanisms underlying differentiation of inflorescence and flower meristems is essential towards enlarging our knowledge of reproductive organ formation and to open new prospects for improving yield traits. Here, we show that SlDOF9 is a new modulator of floral differentiation in tomato. CRISPR/Cas9 knockout strategy uncovered the role of SlDOF9 in controlling inflorescence meristem and floral meristem differentiation via the regulation of cell division genes and inflorescence architecture regulator LIN.
View Article and Find Full Text PDFdisplays a large diversity of horticultural groups with cantaloupe melon the most cultivated type. Using a combination of single-molecule sequencing, 10X Genomics link-reads, high-density optical and genetic maps, and chromosome conformation capture (Hi-C), we assembled a chromosome scale var. Charentais mono genome.
View Article and Find Full Text PDFTomato is a widely cultivated crop, which can grow in many environments. However, temperature above 30°C impairs its reproduction, subsequently impacting fruit yield. We assessed the impact of high-temperature stress (HS) in two tomato experimental populations, a multi-parental advanced generation intercross (MAGIC) population and a core-collection (CC) of small-fruited tomato accessions.
View Article and Find Full Text PDFFruit formation comprises a series of developmental transitions among which the fruit set process is essential in determining crop yield. Yet, our understanding of the epigenetic landscape remodelling associated with the flower-to-fruit transition remains poor. We investigated the epigenetic and transcriptomic reprogramming underlying pollination-dependent and auxin-induced flower-to-fruit transitions in the tomato (Solanum lycopersicum) using combined genomewide transcriptomic profiling, global ChIP-sequencing and whole genomic DNA bisulfite sequencing (WGBS).
View Article and Find Full Text PDFAlthough the reference genome of Solanum tuberosum Group Phureja double-monoploid (DM) clone is available, knowledge on the genetic diversity of the highly heterozygous tetraploid Group Tuberosum, representing most cultivated varieties, remains largely unexplored. This lack of knowledge hinders further progress in potato research. In conducted investigation, we first merged and manually curated the two existing partially-overlapping DM genome-based gene models, creating a union of genes in Phureja scaffold.
View Article and Find Full Text PDFAuxin controls multiple aspects of plant growth and development. However, its role in stress responses remains poorly understood. Auxin acts on the transcriptional regulation of target genes, mainly through Auxin Response Factors ().
View Article and Find Full Text PDFWith the forecasted fast increase in world population and global climate change, providing sufficient amounts of quality food becomes a major challenge for human society. Seed and fruit crop yield is determined by developmental processes including flower initiation, pollen fertility and fruit set. Fruit set is defined as the transition from flower to young fruit, a key step in the development of sexually reproducing higher plants.
View Article and Find Full Text PDFBackground: "Omics" approaches may provide useful information for a deeper understanding of speciation events, diversification and function innovation. This can be achieved by investigating the molecular similarities at sequence level between species, allowing the definition of ortholog and paralog genes. However, the spreading of sequenced genome, often endowed with still preliminary annotations, requires suitable bioinformatics to be appropriately exploited in this framework.
View Article and Find Full Text PDFAdvances in deciphering the functional architecture of eukaryotic genomes have been facilitated by recent breakthroughs in sequencing technologies, enabling a more comprehensive representation of genes and repeat elements in genome sequence assemblies, as well as more sensitive and tissue-specific analyses of gene expression. Here we show that PacBio sequencing has led to a substantially improved genome assembly of Medicago truncatula A17, a legume model species notable for endosymbiosis studies, and has enabled the identification of genome rearrangements between genotypes at a near-base-pair resolution. Annotation of the new M.
View Article and Find Full Text PDFPlant growth and development is coordinated by complex networks of interacting hormones, and cross-talk between ethylene and auxin signaling is essential for a wide range of plant developmental processes. Nevertheless, the molecular links underlying the interaction between the two hormones remain poorly understood. In order to decipher the cross-talk between the Ethylene Response Factor Sl-ERF.
View Article and Find Full Text PDFRNA-Seq is a widely used technology that allows an efficient genome-wide quantification of gene expressions for, for example, differential expression (DE) analysis. After a brief review of the main issues, methods and tools related to the DE analysis of RNA-Seq data, this article focuses on the impact of both the replicate number and library size in such analyses. While the main drawback of previous relevant studies is the lack of generality, we conducted both an analysis of a two-condition experiment (with eight biological replicates per condition) to compare the results with previous benchmark studies, and a meta-analysis of 17 experiments with up to 18 biological conditions, eight biological replicates and 100 million (M) reads per sample.
View Article and Find Full Text PDFSurvival biomass production and crop yield are heavily constrained by a wide range of environmental stresses. Several phytohormones among which abscisic acid (ABA), ethylene and salicylic acid (SA) are known to mediate plant responses to these stresses. By contrast, the role of the plant hormone auxin in stress responses remains so far poorly studied.
View Article and Find Full Text PDFAs part of normal development most eukaryotic organisms, ranging from insects and mammals to plants, display variations in nuclear ploidy levels resulting from somatic endopolyploidy. Endoreduplication is the major source of endopolyploidy in higher plants. Endoreduplication is a remarkable characteristic of the fleshy pericarp tissue of developing tomato fruits, where it establishes a highly integrated cellular system that acts as a morphogenetic factor supporting cell growth.
View Article and Find Full Text PDFMADS-box transcription factors are key elements of the genetic networks controlling flower and fruit development. Among these, the class D clade gathers AGAMOUS-like genes which are involved in seed, ovule, and funiculus development. The tomato genome comprises two class D genes, Sl-AGL11 and Sl-MBP3, both displaying high expression levels in seeds and in central tissues of young fruits.
View Article and Find Full Text PDFThe TomExpress platform was developed to provide the tomato research community with a browser and integrated web tools for public RNA-Seq data visualization and data mining. To avoid major biases that can result from the use of different mapping and statistical processing methods, RNA-Seq raw sequence data available in public databases were mapped de novo on a unique tomato reference genome sequence and post-processed using the same pipeline with accurate parameters. Following the calculation of the number of counts per gene in each RNA-Seq sample, a communal global normalization method was applied to all expression values.
View Article and Find Full Text PDFThe involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants.
View Article and Find Full Text PDFIn modern viticulture, grafting commercial grapevine varieties on interspecific rootstocks is a common practice required for conferring resistance to many biotic and abiotic stresses. Nevertheless, the use of rootstocks to gain these essential traits is also known to impact grape berry development and quality, although the underlying mechanisms are still poorly understood. In grape berries, the onset of ripening (véraison) is regulated by a complex network of mobile signals including hormones such as auxins, ethylene, abscisic acid, and brassinosteroids.
View Article and Find Full Text PDFOur knowledge of the factors mediating ethylene-dependent ripening of climacteric fruit remains limited. The transcription of ethylene-regulated genes is mediated by ethylene response factors (ERFs), but mutants providing information on the specific role of the ERFs in fruit ripening are still lacking, likely due to functional redundancy among this large multigene family of transcription factors. We present here a comprehensive expression profiling of tomato (Solanum lycopersicum) ERFs in wild-type and tomato ripening-impaired tomato mutants (Never-ripe [Nr], ripening-inhibitor [rin], and non-ripening [nor]), indicating that out of the 77 ERFs present in the tomato genome, 27 show enhanced expression at the onset of ripening while 28 display a ripening-associated decrease in expression, suggesting that different ERFs may have contrasting roles in fruit ripening.
View Article and Find Full Text PDFEthylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2) which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin.
View Article and Find Full Text PDFBackground: Tomato fruit ripening is controlled by ethylene and is characterized by a shift in color from green to red, a strong accumulation of lycopene, and a decrease in β-xanthophylls and chlorophylls. The role of other hormones, such as auxin, has been less studied. Auxin is retarding the fruit ripening.
View Article and Find Full Text PDFMost land plant species live in symbiosis with arbuscular mycorrhizal fungi. These fungi differentiate essential functional structures called arbuscules in root cortical cells from which mineral nutrients are released to the plant. We investigated the role of microRNA393 (miR393), an miRNA that targets several auxin receptors, in arbuscular mycorrhizal root colonization.
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