Project description:The translocase of the inner membrane 17-1 (Tim17-1) plays a defined role in germination in Arabidopsis thaliana A transcriptomic analysis of Attim17-1 during seed germination
Project description:RNAseq profiling of 10 time points during germination in Arabidopsis, from freshly harvested seed, through mature seed, stratification, germination and to post-germination.
Project description:sRNA-seq profiling of 10 time points during germination in Arabidopsis, from freshly harvested seed, through mature seed, stratification, germination and to post-germination.
Project description:methylC-seq profiling of 4 time points during germination in Arabidopsis, from mature seed, through stratification, germination and to post-germination.
Project description:Elucidating direct roles of natural variation in biological processes has been challenging due to the difficulty in dissecting the causal role of a gene in traits displaying continuous variation. The decision of a seed to germinate is an easily quantifiable binary choice, which makes it an ideal phenotype to assess the contribution of natural variation in adaptation of plants to begin their lifecycle under optimal conditions. seeds must integrate a complex array of environmental signals to begin their lifecycle under optimal conditions. Light availability is a crucial environmental stimulus that promotes germination in many small seed plant species including Arabidopsis thaliana. Upon perception of light by photoreceptors, phytohormones act as internal signals to coordinate germination but the karrikin (KAR) signalling pathway through the HTL/KAI2 receptor is thought to play a rudimentary role in Arabidopsis germination (REF). Here we show that the AtHTL/KAI2 pathway is required and sufficient to promote germination under low light conditions. Activation of the AtHTL/KAI2 receptor by nanomolar Karrikin2 (KAR2) concentrations or inactivation of SMAX1 bypass the light requirement for germination. By performing a screen of A. thaliana accessions that can germinate under low light conditions, we identified an accession from Afghanistan (Ara-1) which misexpressed AtKAI2/HTL and had a nearly identical transcriptional signature to the activation of AtKAI2 upon addition of KAR2 in the reference accession. Our data suggest that AtKAI2 is a central regulator of germination in natural Arabidopsis populations in response to light availability, to optimize germination timing in their ecological niche.
Project description:In response to environmental light signals, transcriptomic adjustment plays an important role in Arabidopsis seed germination and seedling development. G-box cis-element is commonly present in promoters of genes positively or negatively responding to the light signal. For the pursuit of additional transcriptional regulator modulating light-mediated transcriptome changes, we have identified AtbZIP16, a basic region/leucine zipper motif transcription factor, via G-box DNA affinity chromatography. We have confirmed that AtbZIP16 possesses G-box-specific binding activity. Analyses of atbzip16 mutants indicate that AtbZIP16 is a negative regulator in phyB-mediated inhibition of cell elongation, but a positive regulator in phytochrome-mediated seed germination process. Transcriptomic analysis supports that AtbZIP16 is primarily a transcriptional repressor regulating light-, GA- and ABA-responsive genes. Chromatin immunoprecipitation study revealed that AtbZIP16 could directly target RGL2, a DELLA gene, and indirectly repress the expression of PIL5 gene, which encodes a bHLH protein inhibiting seed germination in Arabidopsis. Our study indicated that, through repressing the expression of RGL2 and the antagonizing the expression of PIL5, AtbZIP16 functions to promote seed germination and hypocotyl elongation during early stages of Arabidopsis seedling development. In response to environmental light signals, transcriptomic adjustment plays an important role in Arabidopsis seed germination and seedling development. G-box cis-element is commonly present in promoters of genes positively or negatively responding to the light signal. For the pursuit of additional transcriptional regulator modulating light-mediated transcriptome changes, we have identified AtbZIP16, a basic region/leucine zipper motif transcription factor, via G-box DNA affinity chromatography. We have confirmed that AtbZIP16 possesses G-box-specific binding activity. Analyses of atbzip16 mutants indicate that AtbZIP16 is a negative regulator in phyB-mediated inhibition of cell elongation, but a positive regulator in phytochrome-mediated seed germination process. Transcriptomic analysis supports that AtbZIP16 is primarily a transcriptional repressor regulating light-, GA- and ABA-responsive genes. Chromatin immunoprecipitation study revealed that AtbZIP16 could directly target RGL2, a DELLA gene, and indirectly repress the expression of PIL5 gene, which encodes a bHLH protein inhibiting seed germination in Arabidopsis. Our study indicated that, through repressing the expression of RGL2 and the antagonizing the expression of PIL5, AtbZIP16 functions to promote seed germination and hypocotyl elongation during early stages of Arabidopsis seedling development.
Project description:There are four major seed developmental phases in Arabidopsis seed development: morphogenesis, maturation, dormancy and germination. What methylation changes occurring in the different phases, if any, remains unknown. To uncover the possible role of DNA methylation in different parts of the seed, we characterized the methylome of four major seed developmental phases of Arabidopsis using Illumina sequencing: global stage (glob) and linear cotyledon stage (lcot) for morphogenesis phase; mature green stage (mg) and post mature green stage (pmg) for maturation phase; dry seed (dry) for dormancy phase; leaves (leaf) from 4 week plant for vegetative tissues. Illumina sequencing of bisulfite-converted genomic DNA from six seed developmental stages in Arabidopsis: global stage (glob), linear cotyledon stage (lcot), mature green stage (mg), post mature green stage (pmg), dry seed (dry) and leaves (leaf) from 4 week plant.
Project description:Seed maturation, dormancy and germination are distinct physiological processes. Transition from maturation to dormancy, and from dormancy into germination are not only critical developmental phases in the plant life cycle but are also important agricultural traits. These developmental processes and their phase transitions are fine determined and coordinately regulated by genetic makeup and environmental cues. SCARECROW-LIKE15 (SCL15) has been demonstrated to be essential for repressing the seed maturation programme in vegetative tissues (Gao et al., Nat Commun, 2015, 6:7243). Here we report that SCL15 is also important for seed dormancy maintenance, germination timing and seed vigor performance based on the effects of SCL15 mutation on plant germination, growth and reproduction when compared with wild type Arabidopsis and over-expression lines 35S:SCL15 and Napin:SCL15. Seed dormancy is enhanced by the mutation of SCL15 in a GA signaling dependent way, indicating that SCL15 plays a negative role for primary dormancy release. Seed germination is positively regulated by SCL15 through interaction with ABA, GA and auxin signaling. SCL15 acts as positive regulator of seed vigor and effect of SCL15 mRNA abundance on seed reserve accumulation and seed development during late embryogenesis may contribute to the seed vigor performance.
Project description:In response to environmental light signals, transcriptomic adjustment plays an important role in Arabidopsis seed germination and seedling development. G-box cis-element is commonly present in promoters of genes positively or negatively responding to the light signal. For the pursuit of additional transcriptional regulator modulating light-mediated transcriptome changes, we have identified AtbZIP16, a basic region/leucine zipper motif transcription factor, via G-box DNA affinity chromatography. We have confirmed that AtbZIP16 possesses G-box-specific binding activity. Analyses of atbzip16 mutants indicate that AtbZIP16 is a negative regulator in phyB-mediated inhibition of cell elongation, but a positive regulator in phytochrome-mediated seed germination process. Transcriptomic analysis supports that AtbZIP16 is primarily a transcriptional repressor regulating light-, GA- and ABA-responsive genes. Chromatin immunoprecipitation study revealed that AtbZIP16 could directly target RGL2, a DELLA gene, and indirectly repress the expression of PIL5 gene, which encodes a bHLH protein inhibiting seed germination in Arabidopsis. Our study indicated that, through repressing the expression of RGL2 and the antagonizing the expression of PIL5, AtbZIP16 functions to promote seed germination and hypocotyl elongation during early stages of Arabidopsis seedling development. In response to environmental light signals, transcriptomic adjustment plays an important role in Arabidopsis seed germination and seedling development. G-box cis-element is commonly present in promoters of genes positively or negatively responding to the light signal. For the pursuit of additional transcriptional regulator modulating light-mediated transcriptome changes, we have identified AtbZIP16, a basic region/leucine zipper motif transcription factor, via G-box DNA affinity chromatography. We have confirmed that AtbZIP16 possesses G-box-specific binding activity. Analyses of atbzip16 mutants indicate that AtbZIP16 is a negative regulator in phyB-mediated inhibition of cell elongation, but a positive regulator in phytochrome-mediated seed germination process. Transcriptomic analysis supports that AtbZIP16 is primarily a transcriptional repressor regulating light-, GA- and ABA-responsive genes. Chromatin immunoprecipitation study revealed that AtbZIP16 could directly target RGL2, a DELLA gene, and indirectly repress the expression of PIL5 gene, which encodes a bHLH protein inhibiting seed germination in Arabidopsis. Our study indicated that, through repressing the expression of RGL2 and the antagonizing the expression of PIL5, AtbZIP16 functions to promote seed germination and hypocotyl elongation during early stages of Arabidopsis seedling development. Three biological replicates for 4-d-old seedlings grown under dark or red-light and long-day (0.5 ?mole m-2 sec-1) contitions.