Project description:Mature seeds of Arabidopsis thaliana are desiccation tolerant, but they lose DT while progressing to germination. Yet, there is a small developmental window during which DT can be rescued by treatment with polyethylene glycol (PEG). We used microarrays to identify relevant genes in the re-establishment of desiccation tolerance by PEG.
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: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.
Project description:Mature seeds of Arabidopsis thaliana are desiccation tolerant, but they lose DT while progressing to germination. Yet, there is a small developmental window during which DT can be rescued by treatment with abscisic acid (ABA). We used a time-series of microarrays to gain temporal resolution and identify relevant genes in the re-establishment of desiccation tolerance with ABA.
Project description:Time course of the transcriptome of desiccation-sensitive 2.7-2.9 mm-long radicles of Medicago truncatula seeds at different time points during incubation in a polyethylene glycol (PEG) solution at -1.7 MPa and 10°C, resulting in a gradual re-establishment of desiccation tolerance. Gene profiling was also performed on embryos before (14 days after pollination) and after acquisition of desiccation tolerance during maturation (20 days after pollination).
Project description:Desiccation tolerance (DT) is the capacity to withstand total loss of cellular water. This property is acquired during seed filling and lost just after germination. However, in many species, a germinated seed can regain DT under adverse conditions such as osmotic stress. We discovered that the germinated seeds of the abscisic acid insensitive 5 (Mtabi5) mutant of Medicago truncatula lost their ability to re-establish DT during osmotic stress. To characterize the molecular processes that are influenced by MtABI5 during the re-establishment of DT tolerance, a transcriptome analysis was performed on the protruded radicles of germinated Mtabi5 mutants and wilt type before and after an osmotic treatment.
Project description:RNAseq from Medicago truncatula early post germination (1 and 5mm radicle seeds) from dissected radicles and cotyledons with and without PEG treatment to identify genes induced during the reinduction of the desiccation tolerance at early germination. Dessication tolerant tissues were radicles from 1mm radicle seeds treated with PEG: R1P, and cotyledons from 1- and 5-mm radicle seeds treated or not with PEG: C1, C5, C1P, C5P and desiccation sensitive tissues were radicles from 1mm radicle seeds (R1) and 5mm radicle seeds (R5).