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:Large gene families and the frequent overlapping functions of homologous genes remain a major challenge for functional genetics in plants. In recent years, the development of homology-based gene silencing using computationally generated artificial microRNAs (amiRNAs) has been demonstrated to be a promising tool for functional genomics in plants. In this study, through a forward genetics screen, we isolated an abscisic acid-insensitive amiRNA line targeting five previously uncharacterized F-box Insensitive to ABA (FIA) genes. Notably, a triple mutant in the identified FIA genes FIA1, FIA3 and FIA4 (f1/f3/f4), that are expressed in germinating seeds, exhibited ABA insensitivity in the inhibition of seed germination. In contrast, this ABA insensitivity was not observed in a double mutant of two FIA genes FIA1 and FIA4 (f1/f4). Further investigation of the FIA1 interactome using F box decoy lines revealed the gibberellin (GA)-responsive GASA1 protein that has been reported to encode a small stress signaling peptide as an interacting partner. We found that abscisic acid promoted the ubiquitination of GASA1 in Arabidopsis, leading to its degradation via the 26S proteasome pathway. Together, our study reveals that abscisic acid represses seed germination through FIA proteins and regulates the FIA interactor, GA-responsive GASA1.
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:The phytohormone abscisic acid (ABA) promotes seed dormancy and inhibits seed germination and seedling development. It remains unclear how chromatin remodeling influences ABA responses. In the present study, an artificial microRNA targeting two Sucrose Non-Fermenting 2 (SNF2)-family chromatin remodeling ATPases, SPLAYED (SYD) and PHOTOPERIOD-INDEPENDENT EARLY FLOWERING1 (PIE1), was identified through unbiased forward genetic screenings of artificial microRNA (amiRNA)-expressing pooled seed libraries exhibiting ABA-insensitive seed germination. T-DNA insertional mutants of syd and pie1, along with amiRNA-expressing knockdown lines amiR-SYD and amiR-PIE1, confirmed that SYD, but not PIE1, is essential for promoting ABA-inhibition of seed germination. Transcriptome analyses revealed that the ABA catabolism gene CYP707A3 and the gibberellin (GA) biosynthesis genes GA20OX2, GA20OX3, GA3OX2, GA3OX3, and GA3OX4 were upregulated in amiR-SYD mutant seeds compared to control seeds under ABA treatment during germination. The ABA hyposensitivity observed in amiR-SYD mutants was reversed by treatment with uniconazole, an inhibitor of ABA catabolism and GA biosynthesis, suggesting that the reduced ABA sensitivity in amiR-SYD mutants results from increased ABA degradation and GA production. These findings demonstrate that the SYD-associated chromatin remodeling complex positively regulates ABA responses during seed germination, unlike its close homolog BRAHMA (BRM), which acts as a negative regulator of the ABA response.
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:Many plant lncRNAs regulate gene expression by binding to chromatin, but how they are retained at the target loci is unclear. We identify a new, chromatin-localized lncRNA - MUSHER, which activates two parallel regulatory pathways to increase Arabidopsis seed dormancy. MUSHER is upregulated in response to high temperatures, contributing to the induction of secondary dormancy. It promotes DOG1 expression by recruitment of the CPSF complex to enhance the proximal cleavage and polyadenylation at the DOG1 transcript. It also increases ABA sensitivity in seeds by activating PIR1 gene transcription. These genes, located on different chromosomes, are both bound by MUSHER, despite lacking sequence homology. The chromatin association of MUSHER enables the integration of the DOG1- and ABA pathways to adjust seed germination timing. Additionally, MUSHER and other lncRNAs interact with U1 snRNP, which is required for their chromatin localisation, revealing a novel function of U1 snRNP in plants. Founded by National Science Centre Grant, Poland (UMO‐2021/41/B/NZ3/0260, UMO‐2024/53/B/NZ3/02252, UMO‐2024/53/B/NZ1/03741).
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.