Differential expression of ozone-induced gene duringexposures to salt stress in Polygonum sibiricum Laxm leaves, stem and underground stem

The response of plants to environmental stresses is characterized by a number of physiological and biochemical changes that ultimately result from the selective increase or decrease in the biosynthesis of a large number of distinct proteins. In this report, we describe the characterization of an ozone-induced transcript, PcOZI-1, which has been identified from Polygonum sibiricum Laxm by the rapid amplification of cDNA ends method (RACE). PcOZI-1 mRNA in untreated plants was detected at low levels in underground stem, leaves and at higher levels in stem. PcOZI-1 mRNA accumulation was transiently induced in stem 7-fold within the first 8 h of 3% NaHCO3 treatment. PcOZI-1 mRNA accumulation was also induced 22-fold in underground stem after 72 h. Sequence analysis of PcOZI-1 revealed that it encodes a 8.45 kDa basic protein that contains a putative signal peptide. Our results suggest that PcOZI-1 represents a novel stress-related protein that accumulates in response to the production of active oxygen species.