Full Length Research Paper

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

Shou-Hai Na¹, Chun-Pu Qu², Guan-Jun Liu²*, Chun Liu², Rui-Xuan Gu², Zhi-Gang Wei², Gui-Feng Liu² and Chuan-Ping Yang²

¹College of Wildlife Sciences, Northeast Forestry University, Harbin 150040, P. R. China.

²The Laboratory of Forest Genetics and Breeding and Biotechnology of Ministry of Education, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China.

*Corresponding author. E-mail: liuguanjun2010@hotmail.com.

Abbreviations: OZI, Ozone-induced gene; EST, expressed sequence tag; cDNA, complementary DNA; RACE, Rapid amplification of cDNA ends; PcOZI-1, Polygonum sibiricum Laxm ozone-induced gene transcript; PCR, polymerase chain reaction; RT-PCR, reverse transcription-PCR; ORF, open reading frame; SDS, sodium dodecyl sulfate; UTR, 5'-untranslated region.

Accepted 12 May, 2010

   Abstract

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.

Key words: Polygonum sibiricum Laxm, PcOZI-1, rapid amplification of cDNA ends, gene expression.