Abstract：Transcripts of chalcone synthase(CHS) gene in six lines of Arabidopsis thaliana in response to UV-B radiation and treatment of hydroxyl peroxide(H2O2), D/L-NG-monomethyl-arginine(D-NAME, L-NAME) and 2-phenyl-4,4,4,4-tetramethylimidazo- lin-1-oxyl-3-oxide(PTIO) were studied by RT-PCR method. Mutant Fah1-2 was the most sensitive and wild WS2 was the most tolerant to UV-B damage in the six lines of Arabidopsis . Accumulation of transcripts of CHS gene was markedly elevated at second hour but disappeared after 24 h of 15 μmol/m2/s UV-B. H2O2 had not effect on the transcription of CHS gene. D-NAME and L-NAME suppressed the increase of CHS transcription in response to UV-B radiation while the effect of PTIO on CHS was very weak. It appears that CHS transcription in response to UV-B radiation is not regulated by nitric oxide(NO) and H2O2.
