Identification of environmental stress-inducible genes in Rhododendron aureum Georgi (Ericaceae) located on Changbai Mountain using mRNA differential display

In this study, Rhododendron aureum Georgi was scattered at four different altitudes on the north slope of Changbai Mountain in China to identify differentially expressed genes in response to environmental stress, and the differential display method was adopted to reverse transcribe the total RNA from its leaves. Four cDNA fragments were sequenced and affirmed to be up-regulated with increasing of altitudinal gradient (environmental stress), which were named ESIG4, ESIG2, ESIG10 and ESIG8, respectively. ESIG4 had 70% homology to fatty acid hydroxylase 1 (FAH1) and 74% homology to fatty acid hydroxylase 2 (FAH2), which participated in Bax inhibitor-1-mediated suppression of cell death in Arabidopsis thaliana. ESIG2 had 64% homology to mRNA sequence of sunflower under drought conditions. ESIG10 had 49% homology to response protein induced by stresses in Arabidopsis thaliana or barley. ESIG8 had 51% homology to Se-responsive gene in a Se-hyperaccumulator Astragalus racemosus. Based on these data and literatures, we discussed the stress tolerance mechanism of Rhododendron aureum Georgi located at the high altitude.