Project description:Red rice fully dormant seeds do not germinate even under favourable germination conditions. In several species, including rice, seed dormancy can be removed by dry-afterripening (warm storage); thus, dormant and nondormant seeds can be compared for the same genotype. A weedy (red) rice genotype with strong dormancy was used for mRNA expression profiling, by RNA-Seq, of dormant and nondormant dehulled caryopses (here addressed as seeds) at two temperatures (30 °C and 10 °C) and two durations of incubation in water (8 hours and 8 days). Aim of the study was to highlight the differences in the transcriptome of dormant and nondormant imbibed seeds.
Project description:The widespread agricultural problem of pre-harvest sprouting (PHS) could potentially be overcome by improving seed dormancy. Here, we report that miR156, an important grain yield regulator, also controls seed dormancy in rice. We found that mutations in one MIR156 subfamily enhance seed dormancy and suppress PHS with negligible effects on shoot architecture and grain size, whereas mutations in another MIR156 subfamily modify shoot architecture and increase grain size but have minimal effects on seed dormancy. Mechanistically, mir156 mutations enhance seed dormancy by suppressing the gibberellin (GA) pathway through de-represssion of the miR156 target gene Ideal Plant Architecture 1 (IPA1), which directly regulates multiple genes in the GA pathway. These results provide an effective method to suppress PHS without compromising productivity, and will facilitate breeding elite crop varieties with ideal plant architectures.
Project description:affy_sunflower_2010_13 - affy_sunflower_2010_13 - It concerns the interaction between ROS and hormones in dormancy release in sunflower seeds. ABA is responsible for dormancy maintenance, while GA and ethylene promote seed germination. Based on our results, ROS could represent good candidate to shift from a hormone signalling to another determining the dormancy state in sunflower seeds.-We aim to understand the mechanisms controlling sunflower seed dormancy at the transcriptomic level, by the application of treatments which maintain dormancy as ABA, or alleviate dormancy as ROS and ethylene. Transcripts comparison will be performed between dormant and non-dormant sunflower embryo imbibed 24h on water, on ABA, on methylviologen, a pro-oxidant compound or on ethylene.
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:affy_sunflower_2010_13 - affy_sunflower_2010_13 - It concerns the interaction between ROS and hormones in dormancy release in sunflower seeds. ABA is responsible for dormancy maintenance, while GA and ethylene promote seed germination. Based on our results, ROS could represent good candidate to shift from a hormone signalling to another determining the dormancy state in sunflower seeds.-We aim to understand the mechanisms controlling sunflower seed dormancy at the transcriptomic level, by the application of treatments which maintain dormancy as ABA, or alleviate dormancy as ROS and ethylene. Transcripts comparison will be performed between dormant and non-dormant sunflower embryo imbibed 24h on water, on ABA, on methylviologen, a pro-oxidant compound or on ethylene. 12 arrays - SUNFLOWER; treated vs untreated comparison
Project description:Along with the inherent complexities of seed and dormancy, the use of different genotypes or mutants to study the molecular mechanisms underlying seed dormancy leads to potential biases and data misinterpretation. To provide a comprehensive insight into the actual protein activities involved in seed dormancy establishment, a SWATH-MS proteomics was performed on dormant and non-dormant developing seeds of Xanthium strumarium at five consecutive time intervals including three, 10, 20, and 30 days after burr emergence and full maturation. The amount of approximately 3.5% differentially abundant proteins (DAPs) with a ~94% stage-specificity supports considerable proteome overlap in the two seed types. More than 38% of all differentially abundant proteins were observed at the first stage, supporting the importance of this stage of seed development for seed fate determination. Rapid overrepresentation of proteins responsible for cell wall biosynthesis, cytokinesis, and seed development were detected for non-dormant seed at the first stage, while dormancy-associated proteins showed less abundance. In the middle of seed development, we identified DAPs involved in seed maturation and ABA signaling. Interestingly, higher abundant proteins in the mature non-dormant seed were mainly involved in the facilitation of seed germination. Taken together, the temporal pattern of the accumulated proteins demonstrated a delay in the initiation of active cell division, enriched response to ABA, and defect in the seed maturation in developing dormant seeds. Moreover, stored proteins in the mature dormant seed are responsible for delaying germination but not dormancy induction. Finally, assume that dormancy may be established at a stage of seed development earlier than previously thought.
Project description:Light inhibits the seed germination in the Cypriot accession (CYP) of Aethionema arabicum. Extended light illumination also induces a secondary seed dormancy that inhibits the germination even if the seeds were transferred back to darkness. This analysis aims to compare the seed transcriptome before or after the dormancy was established by light illumination (100 µmol/m2s; white light). One day light treatment (1dL) inhibits the germination but the seeds are not yet dormant. Seven day (7dL) or 14-day (14dL) long light treatment induces dormancy, and the seeds stay dormant after 7 dal-light plus 7 day-dark (7dL7dD) treatment. To understand the dormancy establishment, transcriptome was compared between non-dormant (1dL) and dormant (7dL, 14dL, 7dL7dD) seed samples.
Project description:Mother plants play an important role in the control of dormancy and dispersal characters of their progeny. In Arabidopsis seed dormancy is imposed by the embryo-surrounding tissues of the endosperm and seed coat. Here we show that VERNALIZATION5/VIN3-LIKE 3 (VEL3) maintains maternal control over progeny seed dormancy by establishing an epigenetic state in the central cell that primes the depth of primary seed dormancy later established during seed maturation. VEL3 colocalizes with MSI1 in the nucleolus and associates with a histone deacetylase complex. Furthermore, VEL3 preferentially associates with pericentromeric chromatin and is required for deacetylation and H3K27me3 deposition established in the central cell. The epigenetic state established by maternal VEL3 is retained in mature seeds, and controls seed dormancy in part through repression of programmed cell death-associated gene ORE1. Our data demonstrates a novel mechanism by which maternal control of progeny seed physiology persists post-shedding, maintaining parental control of seed behaviour.
Project description:Mother plants play an important role in the control of dormancy and dispersal characters of their progeny. In Arabidopsis seed dormancy is imposed by the embryo-surrounding tissues of the endosperm and seed coat. Here we show that the VERNALIZATION5/VIN3-LIKE 3 (VEL3) gene maintains maternal control over progeny seed dormancy by establishing an epigenetic state early in endosperm development that primes the depth of primary seed dormancy later established during seed maturation. VEL3 relocates MSI1 to the nucleolus and associates with other components of the histone deacetylase complex (HDAC). Furthermore VEL3 preferentially associates with pericentromeric chromatin and is required for deacetylation and H3K27me3 deposition and is required for gene repression via PRC2 and HDAC at pericentromeric regions established in the central cell. Interestingly, the epigenetic state established by the maternal VEL3 is retained trans-generationally in mature seeds, and controls seed dormancy in part through the repression of programmed cell death-associated gene ORE1. Our data demonstrates a novel mechanism by which maternal control of progeny seed physiology persists post-shedding, maintaining parental control of seed behaviour.
Project description:Rice is a major component of the human diet and feeds more than 50 million people across the globe. Therefore, efforts are being made to improve the nutritional quality of rice seeds in order to make a super-rice cultivar rich in antioxidants and vitamins. We previously developed two rice cultivars, Super-hongmi (red seeds) and Super-jami (black seeds), that were highly rich in antioxidants and exhibited high levels of radical scavenging activities. However, the molecular mechanism underlying the color development and accumulation of different antioxidants in these rice cultivars remains largely elusive. Here, we report the proteome profiles of mature Super-hongmi, and Super-jami seeds and compared with the Hopum (white seeds) using a label-free quantitative proteomics approach. This approach led to the identification of 5127 rice seed proteins of which 1628 showed significant changes (ANOVA, Benjamini-Hochberg FDR ≤ 0.01, fold change ≥ 1.5). Functional annotation of the differentially modulated proteins led to the identification of a phytoene desaturase (PDS3) that was highly enriched in the red seeds and was decreased in the black seeds as compared to the control white seeds. PDS3 is involved in the conversion of phytoene to ζ-carotene which may be responsible for the accumulation of red color in red seeds. Moreover, black seeds seem to accumulate higher levels of anthocyanins because of the higher abundance of dihydroflavonol 4-reductase. In addition, proteins associated with lignin and tocopherol biosynthesis were found to be highly increased in both red and black cultivars. Taken together, these data report the seed proteome of three different colored rice seeds and identify novel components associated with pigment accumulation.