Submitted to: American Society of Plant Physiologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2000
Publication Date: July 15, 2000
Technical Abstract: Analysis of a collection of 152 expressed sequence tags (ESTs) produced using dried gametophyte tissue from the desiccation tolerant moss, Tortula ruralis revealed one cDNA clone with sequence similarity to the histone H3 family of genes. Subsequent polymerase chain reaction (PCR) amplification of moss genomic DNA using consensus primers targeted to the highly conserved H3 coding region, generated primarily a product band larger then the 260 bp predicted from cell cycle dependent H3 sequences (ccH3). Sequencing of the larger products confirmed the presence of introns, a characteristic of replacement H3 genes (rH3) whose genes are, unlike their ccH3 orthologs, active outside of the DNA replication portion of the cell cycle. Replacement histones are presumed to provide histone proteins to replace those lost or damaged during within differentiated, non-dividing cells. Preliminary data comparing H3 PCR products from related desiccation ntolerant or sensitive mosses indicates a correlation between desiccation tolerance and a high ratio of rH3 over ccH3 product. We are currently exploring the possibility that one component of desiccation tolerance is the ability to activate multiple copies of replacement histone genes in order to replace histones damaged during desiccation/rehydration.