RNA sequencing of tomato seed tissues during seed development
Ontology highlight
ABSTRACT: During maturation seeds acquire several physiological traits to enable them to survive drying and disseminate the species. Few studies have addressed the regulatory networks controlling acquisition of these traits at the tissue level particularly in endospermic seeds such as tomato, which matures in a fully hydrated environment and does not undergo maturation drying. Using temporal RNA-seq analyses of the different seed tissues during maturation, gene network and trait-based correlations were used to explore the transcriptome signatures and identify hubs associated with desiccation tolerance, longevity, germination under water stress and dormancy.
Project description:During maturation seeds acquire several physiological traits to enable them to survive drying and disseminate the species. The maternal environment during maturation can influence seed quality. RNA-seq analyses of the embryo and the endosperm of seed matured ex planta under standard or stressful condition (high temperature and/or dim light) will underly how light and temperature and a combination of both have an impact on the molecular mechanisms governing seed quality at harvest.
Project description:During their maturation, seeds acquire traits that are crucial for their survival and that are of extreme importance for seed quality. In this study, we investigate the acquisition of multiple seed quality traits, especially desiccation tolerance and longevity, by analyzing longitudinal RNA-seq data collected for various stages of seed maturation. The data was acquired for several mutants, predominantly affected in abscisic acid biosynthesis and signalling, which vary in their ability to acquire seed quality traits.
Project description:In contrast to the desiccation tolerant (DT) ‘orthodox’ seeds, the so-called ‘intermediate’ seeds cannot survive complete drying and are short-lived. All species of the genus Coffea produce intermediate seeds but show a considerable variability for the seed DT level, which may help to decipher the molecular basis of seed DT in plants. We thus led a comparative transcriptome analysis of developing seeds in three coffee species with contrasting seed DT levels. Seeds of all species shared a major transcriptional switch during late maturation that governs a general slow-down of metabolism. However, numerous key stress-related genes, including those coding for the late embryogenesis abundant protein EM6 and the osmosensitive calcium channel ERD4, were upregulated during DT acquisition in the two species with high seed DT, C. arabica and C. eugenioides. By contrast, an upregulation of numerous players of the metabolism, transport and perception of auxin was observed in C. canephora seeds with low DT. Moreover, species with high DT showed a stronger down-regulation of the mitochondrial machinery dedicated to the tricarboxylic acid cycle and oxidative phosphorylation. Accordingly, respiration measurements during seed dehydration demonstrated that intermediate seeds with the highest DT levels are better prepared to cease respiration and avoid oxidative stresses.
Project description:The intermediate seed category was defined in the early 1990s using coffee (Coffea arabica) as a model. In contrast to orthodox seeds, intermediate seeds cannot survive complete drying, which is a major constraint for seed storage, for both biodiversity conservation and agricultural purposes. However, intermediate seeds are considerably more tolerant to drying than recalcitrant seeds, which are highly sensitive to desiccation. To gain insight into the mechanisms governing such differences, changes in desiccation tolerance (DT), hormone content and the transcriptome were analysed in developing coffee seeds. Acquisition of DT coincided with a dramatic transcriptional switch characterised by the repression of primary metabolism, photosynthesis and respiration, and the upregulation of genes coding for late embryogenesis abundant (LEA) proteins, heat shock proteins (HSP) and antioxidant enzymes. Analysis of heat-stable proteome in the mature coffee seed confirmed the accumulation of LEA proteins identified at the transcript level. Transcriptome analysis also suggests a major role for ABA and for the transcription factors CaHSFA9, CaDREB2G, CaANAC029, CaPLATZ and CaDOG-like in DT acquisition. The ability of CaHSFA9 and CaDREB2G to trigger HSP gene transcription was validated by Agrobacterium-mediated transformation of coffee somatic embryos.
Project description:Measurement of changes in the mRNA transcript abundance of 1709 cDNAs in desiccated (5% RWC) and hydrated (100% RWC) Xerophyta humilis leaves and roots, and in mature seeds.
Project description:During seed maturation, the embryo accumulates nutrition storage compounds such as oil and reserve proteins, and acquires dormancy and desiccation tolerance. Arabidopsis transcription factors LEC1, LEC2, FUS3 and ABI3 are known as the master regulators of seed maturation because all these events during the seed maturation are severely affected by the respective mutants. In addition, the lec1, lec2 and fus3 mutants exhibit some heterochronic characteristics, as exemplified by the development of true leaf-like cotyledons during embryogenesis. To characterize these mutants at the whole genome expression level, microarray experiments were performed. Developing seeds were dissected from the siliques of the abi3-6 homozygous plants or the respective wild type plants (Col-0) at 12 and 16 days after flowering. Seeds samples were obtained from triplicate batches of plants and used for RNA preparation.
Project description:During seed maturation, the embryo accumulates nutrition storage compounds such as oil and reserve proteins, and acquires dormancy and desiccation tolerance. Arabidopsis transcription factors LEC1, LEC2, FUS3 and ABI3 are known as the master regulators of seed maturation because all these events during the seed maturation are severely affected by the respective mutants. In addition, the lec1, lec2 and fus3 mutants exhibit some heterochronic characteristics, as exemplified by the development of true leaf-like cotyledons during embryogenesis. To characterize these mutants at the whole genome expression level, microarray experiments were performed. Developing seeds were dissected from the siliques of the lec1-1, lec2-1, or fus3-3 homozygous plants or the respective wild type plants (Col-0 for fus3-3, WS for lec1-1 and lec2-1) at 8 and 12 days after flowering. Seeds samples were obtained from triplicate batches of plants and used for RNA preparation.
Project description:The combination of robust physiological models with “omics” studies holds promise for the discovery of genes and pathways linked to how organisms deal with drying. Here we used a transcriptomics approach in combination with an in vivo physiological model of re-establishment of desiccation tolerance (DT) in Arabidopsis thaliana seeds. We show that the incubation of desiccation-sensitive (DS) germinated Arabidopsis seeds in a polyethylene glycol (PEG) solution re-induces the mechanisms necessary for expression of DT. Based on a SNP-tile array gene expression profile, our data indicates that the re-establishment of DT, in this system, is related to a programmed reversion from a metabolic active to a quiescent state similar to prior to germination. Our findings show that transcripts of germinated seeds after the PEG treatment are dominated by those encoding LEA, seed storage and dormancy-related proteins. On the other hand, a massive repression of genes belonging to many other classes such as photosynthesis, cell wall modification and energy metabolism occurs in parallel. Furthermore, comparison with a similar system for Medicago truncatula reveals a significant overlap between the two transcriptomes. Such overlap may highlight core mechanisms and key regulators of the trait DT. Taking into account the availability of the many genetic and molecular resources for Arabidopsis, the described system may prove useful for unraveling DT in higher plants. Desiccation-sensitive seeds vs. desiccation-tolerant seeds in the same developmental stage in triplicate.
Project description:Plant seeds prepare for germination already during seed maturation. We performed a detailed transcriptome analysis of barley grain maturation, desiccation and germination in two tissue fractions (endosperm/aleurone = e/a and embryo = em) using the Affymetrix barley1 chip. Keywords: time course
Project description:Plant seeds prepare for germination already during seed maturation. We performed a detailed transcriptome analysis of barley grain maturation, desiccation and germination in two tissue fractions (endosperm/aleurone = e/a and embryo = em) using the Affymetrix barley1 chip. Experiment Overall Design: Barley developing and germinating seeds were harvested at different time points after flowering (developing) and imbibition (germinating). To further disseect the influence of different tissues, seeds were dissecte and tissues were analyzed individually.