Abstract: A full-length Heat shock transcription factor（HSF）gene encoding 315 aa amino acids，belonging to HSFA2，was cloned from Lilium longiflorum‘White Heaven’by RACE（Rapid Amplification of cDNA Ends）technique. Cluster analysis showed that the putative HSFA2b was highly homologous to known OsHSFA2s and a novel member of HSFA2. Furthermore，alignment with HSFA2 from tomato，Arabidopsis，rice and lily indicated there were conserved functional domains except for an activation domain and a nuclear export signal in LlHSFA2b. Semi-quantitative RT-PCR showed that expression of this gene could be induced by heat and H2O2 exclusively. Real-time PCR revealed that LlHSFA2b transcripts were induced by heat in root，bulb and leaf without significant difference and detected earlier than that of LlHSFA2a during heat shock. These data indicate that LlHSFA2b is a novel HSF-encoding genewhich could respond to heat at an early stage.

Key words: Lilium longiflorum, heat shock transcription factor（HSF）, heat shock, thermotolerance