Genome-wide analyses of four major histone modifications in Arabidopsis hybrids at the germinating seed stage.
Hybrid vigour (heterosis) has been used for decades in cropping agriculture, especially in the production of maize and rice, because hybrid varieties exceed their parents in plant biomass and seed yield. The molecular basis of hybrid vigour is not fully understood. Previous studies have suggested that epigenetic systems could play a role in heterosis.



In this project, we investigated genome-wide patterns of four histone modifications in Arabidopsis hybrids in germinating seeds. We found that although hybrids have similar histone modification patterns to the parents in most regions of the genome, they have altered patterns at specific loci. A small subset of genes show changes in histone modifications in the hybrids that correlate with changes in gene expression. Our results also show that genome-wide patterns of histone modifications in geminating seeds parallel those at later developmental stages of seedlings.



Ler/C24 hybrids showed similar genome-wide patterns of histone modifications as the parents at an early germination stage. However, a small subset of genes, such as FLC, showed correlated changes in histone modification and in gene expression in the hybrids. The altered patterns of histone modifications for those genes in hybrids could be related to some heterotic traits in Arabidopsis, such as flowering time, and could play a role in hybrid vigour establishment.
Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, Australian Capital Territory, 2601, Australia.|Faculty of Science, University of Technology, Sydney, New South Wales, 2007, Australia.
Anyu
A
Zhu
Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, Australian Capital Territory, 2601, Australia.
Ian K
IK
Greaves
Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, Australian Capital Territory, 2601, Australia.|Faculty of Science, University of Technology, Sydney, New South Wales, 2007, Australia.
Elizabeth S
ES
Dennis
Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, Australian Capital Territory, 2601, Australia. jim.peacock@csiro.au.|Faculty of Science, University of Technology, Sydney, New South Wales, 2007, Australia. jim.peacock@csiro.au.
W James
WJ
Peacock
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D044127:Epigenesis, Genetic; D057890:Epigenomics / Q000379:methods; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D055106:Genome-Wide Association Study; D018525:Germination / Q000235:genetics*; D006657:Histones / Q000378:metabolism*; D006823:Hybrid Vigor / Q000235:genetics*; D009154:Mutation; D036226:Seedlings / Q000235:genetics*; D012639:Seeds / Q000235:genetics*; D003313:Zea mays / Q000235:genetics
D006657:Histones
Epigenetics; Gene expression; Heterosis; Histone modification; Hybrid vigour; Seed germination