Project description:ra12-02_aba-seed - ra12-02_aba-seed - Identification of ABA signaling factors and targets in Arabidopsis developing seeds by comparing ABA deficient and wild type genotypes - Transcriptome comparison of developing seeds harvested at 10 DAP from two ABA-deficient mutants (nced2 nced5 nced9 and nced2 nced5 nced6 nced9) and wild type (Columbia-0)
Project description:ra14-04_nced - abaseed - Identification of abscisic acid (ABA) signaling factors and targets in Arabidopsis developing seeds by comparing ABA deficient and wild type genotypes. Transcriptome comparison of developing seeds harvested at 14 DAP from two ABA-deficient mutants (nced2 nced5 nced9 and nced2 nced5 nced6 nced9) and wild type (Columbia-0).
Project description:ra14-04_nced - abaseed - Identification of abscisic acid (ABA) signaling factors and targets in Arabidopsis developing seeds by comparing ABA deficient and wild type genotypes. Transcriptome comparison of developing seeds harvested at 14 DAP from two ABA-deficient mutants (nced2 nced5 nced9 and nced2 nced5 nced6 nced9) and wild type (Columbia-0). 6 dye-swaps - gene knockout, genomic comparison.
Project description:The mads-box mutant line showed an abscisic acid (ABA)-insensitive phenotype. The AGAMOUS-LIKE 67 (AT1G77950) gene encodes a transcription factor that is nuclear-localized, as observed by transiently transformed epidermal onion cells, specifically expressed in seeds and involved in an ABA signaling pathway during seed germination (Fernández-Arbaizar et al. 2012). SALK_050367 seeds were obtained from the Arabidopsis Biological Resource Center, ABRC.
Project description:Wheat seed dormancy is released by after-ripening, and germination and seminal root growth of after-ripened/non-dormant seeds can be inhibited by treatment with exogenous ABA. We used Affymetrix GeneChip Wheat Genome Array to detail transcriptional programs affected by after-ripening of dormant seeds and imbibition of after-ripened seeds in ABA.
Project description:Production of morphologically and physiologically variable seeds is an important strategy that helps plants to survive in unpredictable natural conditions. However, the model plant Arabidopsis thaliana and most agronomically essential crops yield visually homogenous seeds. Using automated phenotype analysis, we observed that in Arabidopsis small seeds tend to have higher primary and secondary dormancy levels when compared to large ones. Transcriptomic analysis revealed distinct gene expression profiles between large and small seeds. Large seeds had higher expression of translation-related genes implicated in germination competence. In contrast, small seeds showed elevated expression of many positive regulators of dormancy, including a key regulator of this process – the DOG1 gene. Differences in DOG1 expression were associated with differential production of its alternative cleavage and polyadenylation isoforms where in small seeds proximal poly(A) site is selected resulting in a short mRNA isoform. Furthermore, single-seed RNA-seq analysis demonstrated that large seeds resemble DOG1 knockout mutant seeds. Finally, on the single seed level, the expression of genes affected by seed size was correlated with the expression of genes positioning seeds on the path towards germination. Our results demonstrate an unexpected link between seed size and dormancy phenotypes in a species producing highly homogenous seed pools, suggesting that the correlation between seed morphology and physiology is more widespread than initially assumed.
Project description:Wheat seed germination and seminal root growth can be inhibited by treatment with exogenous ABA We used Affymetrix GeneChip Wheat Genome Array to detail transcriptional programs affected by ABA during imbibition After-ripened seeds imbibed in ABA for 24 h were used for RNA extraction and hybridization on Affymetrix GeneChip. After-ripened seeds were generated by storing dormant seeds at room temperature for 10 months.
Project description:Aim To identify genes specifically involved in the storage reserve mobilisation programme in Arabidopsis. Background: During germination and early post-germinative growth in Arabidopsis seed storage reserves are broken down to provide energy and nutrients for the developing seedling. Genes encoding enzymes involved in the mobilisation of both storage lipid and protein are expressed strongly 1-2 days following imbibition and then fall to very low levels. The regulatory mechanisms controlling expression of these genes are poorly understood. Although germination and reserve mobilisation occur at the same time we have obtained evidence using Abscisic Acid (ABA) treated seeds that the events are regulated by two separate programmes. Arabidopsis seeds treated with 10mM ABA still express genes involved in the mobilisation of storage reserves and break down storage lipid even though germination is blocked. ABA treated seeds therefore provide a powerful system for the identification of genes involved specifically in the reserve mobilisation programme. Microarray analysis will allow us to gain a global undertanding of the processes involved in storage reserve mobilisation and should also result in the identification of regulatory genes involved in this process. Experimental Set-up All seeds are Col-4 imbibed on plates containing 1/2 MS media for 4 days in the dark. All plant material will be grown in controlled environment growth rooms under defined light and temperature regimes. There are two parts to the experimental design. 1. Time course to identify genes involved in both seed storage reserve and germination programmes Comparison of mRNAs from seeds immediately after imbibition (storage reserve and germination programme genes being induced) with 2 day (storage reserve genes maximally expressed) and 7 day old seedlings (storage reserve and germination programme genes off, photoautotrophic genes on) will allow the identification of genes exclusively presentor present at enhanced levels at the peak of reserve mobilisation (day 2). 2. ABA treatment experiment to identify genes involved in the storage reserve programme ABA treatment blocks germination but does not block reserve mobilisation. Microarray analysis will be performed on RNA isolated from 2 day old seed imbibed in the presence of ABA. Comparison of the results of this experiment with those of the time course experiment should allow us to distinguish between genes involved in the two major programmes that we have uncovered.
Project description:ZFP3, a nuclear C2H2 zinc finger protein acts as a negative regulator of ABA- suppressed germination. Regulated over-expression of ZFP3 and closely related ZFP1, ZFP4, ZFP6 and ZFP7 confers ABA insensitivity to seed germination while the zfp3,zfp4 double mutant displays enhanced ABA susceptibility. Reduced expression of a large set of ABA-induced genes such as RAB18 and transcription factors ABI3, ABI4, ABI5 and RGL2 in ZFP3ox seedling suggests that ZFP3 indeed negatively regulates ABA signaling. Analysis of ZFP3ox plants revealed multiple phenotypic alterations such as semidwarf growth habit, defects in fertility and enhanced sensitivity of hypocotyl elongation to red but not to far-red or blue light. Analysis of genetic interactions with phytochrome and abi mutants suggested that ZFP3 amplifies red light signals perceived by photoreceptors other than phyB, and controlled by ABI5 downstream of ZFP3. Comparison of ZFP3 overexpressing and wild type Arabidopsis seedlings
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.