Submitted to: American Society of Plant Physiologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2001
Publication Date: N/A
Technical Abstract: Modification of chromatin can occur by different mechanisms thought to be complementary in their ability to effect changes in the transcription rate of genes. Reversible acetylation at lysine residues within the N-termini of the core histones in nucleosomes is widely recognized as a cardinal event in transcriptional regulation. Acetylation patterns of the various histone proteins vary throughout development in animal species; however, less is known of changes during plant growth/maturation. In plants, H3 and H4 are the histones most modified by post-translational acetylation. H3 and H4 acetylation increase during salt stress and their degree of acetylation is altered during maize embryo development. Additionally, H4 acetylation changes during the cell cycle. However, nothing is known of the situation in potato tubers, where dormancy breakage, evident as sprouting of meristems, is responsible for massive losses of tubers in storage for end-users. To examine the histone makeup of tubers in various stages of dormancy, chromatin was isolated and total histones purified. H3 and H4 are the most evolutionarily-conserved histone proteins, and as such studies can employ commercially-available antibodies developed against the animal isoforms to examine acetylation in plant histones. Anti-H3 and H4 antibodies that recognize acetylated forms of these proteins were used to probe immunoblots of acetic acid-urea-Triton X-100 gels. Changes in acetylation status for these histone proteins throughout tuber dormancy breakage will be reported, as well as tissue-specific variations in these patterns.