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:Transcriptomic study of the impact of osmopriming on rape seeds (Brassica napus L.; cv 'Libomir') during priming process and after germination. The assays were replicated twice on two independent priming and germination experiments. Seeds were osmoprimed in PEG solution (-1.2 MPa osmotic potential) during 7 days, dried to initial moisture content and then germinated for 7 hours on water. The analysis during different phases of priming procedure (soaking and drying), after whole osmopriming process and germination were done. 10 samples, four condition experiment; non dried primed seeds (Pnd) vs. dry unprimed seeds (UPd) (PEG soaking), non dried primed seeds (Pnd) vs dry primed seeds (Pd) (drying after soaking), dry primed seeds (Pd) vs. dry unprimed seeds (UPd) (full osmopriming process), primed seeds imbibed on water (P7h) vs unprimed seeds imbibed on water (UP7h) (germination after osmopriming). Biological replicates: 2 replicates for comparison PEG soaking, drying after soaking, full osmopriming process and germination after osmopriming.
Project description:The WRKY gene family has a very ancient origin but has faced extensive duplication only in the plant kingdom so much that Arabidopsis (Arabidopsis thaliana) has 74 copies of WRKY genes encoding transcription factors while 109 can be found in Rice (Oryza sativa L.). Several studies in the last decade has pointed their involvement in an heterogeneous number of biological processes, from development to hormone signalling, dormancy and senescence, but a wide number of WRKY genes are transcriptionally regulated during biotic or abiotic stresses. To investigate involvement of WRKY genes upon host and non-host infection (different strain of Magnaporthe grisea) and osmotic stress in Rice, we performed a gene family transcription analysis using custom microarray. Results indicate that a relevant part of WRKY genes are involved during at least one of these stresses, that there is little difference in transcriptional regulation between host and non-host infection or between different tissues upon the same osmotic stress. Moreover, are evident groups of genes that, often with opposite behaviour, are co-regulated in all or most of the studied conditions. We thus formulated the hypothesis that WRKY genes might be part of co-regulatory networks with other WRKY genes. Keywords: stress response We analyzed 40 arrays and tested 6 conditions: BR29 (Non-host Pathogen), BR32 (Non-host Pathogen), FR13 (Host pathogen), Osmotic leaves 5 hours, Osmotic roots 1 hour and Osmotic roots 5 hours. 2 biological replicated were analyzed and between 2 to 4 technical replicates applied for each biological sample.