Project description:Heterosis occurs where F1 offspring display superior characteristics to the parents. Heterosis is usually considered to result from crosses of genetically distinct (e.g. homozygous inbred) parents producing heterozygous F1 offspring. Most mechanistic models for heterosis require genetically heterozygous F1 hybrid offspring harbouring allelic diversity. Epigenetic or dosage models for heterosis could allow for heterosis effects in F1 offspring that display no allelic diversity with their parents. Reciprocal inter-ploidy crosses between diploid (2x) and tetraploid (4x) lines in the same genetic background generates genetically identical F1 triploids (3x). Such reciprocal F1 triploids differ according to whether the additional chromosome set is either maternally (maternal excess) or paternally inherited (paternal excess). Biomass accumulation and abiotic stress tolerance between the parental (2x and 4x) and reciprocal F1 triploid (3x) offspring of Arabidopsis thaliana accession C24 reveals a strong parental genome-dosage induced heterosis in the paternal-excess triploid F1 plants. In these F1 triploids, the circadian clock related genes CCA1 and TOC1, and the growth factors PIF4 and PIF5, display different expression levels compared to the non-heterotic maternal excess F1 triploid siblings. Whole transcriptome profiling reveals a paternal genome dosage effect on gene expression levels with strong enrichment for dysregulated abiotic stress-related genes in the paternal excess F1 triploids. This study demonstrates that heterosis can be triggered without allelic diversity in F1 triploid plants. Heterosis without heterozygosity in plants can be induced via an epigenetic “chromosome imprinting” like parental genome dosage effect requiring paternal transmission of an additional chromosome set
Project description:Heterosis occurs where F1 offspring display superior characteristics to the parents. Heterosis is usually considered to result from crosses of genetically distinct (e.g. homozygous inbred) parents producing heterozygous F1 offspring. Most mechanistic models for heterosis require genetically heterozygous F1 hybrid offspring harbouring allelic diversity. Epigenetic or dosage models for heterosis could allow for heterosis effects in F1 offspring that display no allelic diversity with their parents. Reciprocal inter-ploidy crosses between diploid (2x) and tetraploid (4x) lines in the same genetic background generates genetically identical F1 triploids (3x). Such reciprocal F1 triploids differ according to whether the additional chromosome set is either maternally (maternal excess) or paternally inherited (paternal excess). Biomass accumulation and abiotic stress tolerance between the parental (2x and 4x) and reciprocal F1 triploid (3x) offspring of Arabidopsis thaliana accession C24 reveals a strong parental genome-dosage induced heterosis in the paternal-excess triploid F1 plants. In these F1 triploids, the circadian clock related genes CCA1 and TOC1, and the growth factors PIF4 and PIF5, display different expression levels compared to the non-heterotic maternal excess F1 triploid siblings. Whole transcriptome profiling reveals a paternal genome dosage effect on gene expression levels with strong enrichment for dysregulated abiotic stress-related genes in the paternal excess F1 triploids. This study demonstrates that heterosis can be triggered without allelic diversity in F1 triploid plants. Heterosis without heterozygosity in plants can be induced via an epigenetic “chromosome imprinting” like parental genome dosage effect requiring paternal transmission of an additional chromosome set 4 or 5 biological replicates per ploidy level, each replicate being a single two weeks old seedling
Project description:Transcriptional profiling of A. thaliana seedlings (early development) at 7 time points We investigate biomass heterosis by scoring partial correlations of transcriptional profiles.
Project description:The goal of this project is to compare the primary metabolite profile in different tissue types of the model plant Arabidopsis thaliana. Specifically, plants were grown hydroponically under the long-day (16hr light/day) condition at 21C. Tissue samples, including leaves, inflorescences, and roots were harvest 4 1/2 weeks post sowing. Untargeted primary metabolites profiling was carried out using GCTOF.