Tropospheric ozone (O3) is a global air pollutant that causes negative effects on plant metabolism, physiology and growth. Because of its strong oxidative potential, O3 has a large spectrum of biocidal activities by inducing plant signal molecules that can mediate the stimulation of secondary answers at genetic and metabolic level. The objective of this work is to elucidate the potential roles of WRKY transcription factors in regulating oxidative protection and signalling in Salvia officinalis (sage, one of the most well-known aromatic herbs) exposed to a single pulse of O3 (200 ppb, 5 h day-1) in controlled environmental conditions. At the end of the treatment, leaves appeared symptomless. Minute chlorotic spots were recognizable 48 h from the beginning of the exposure and especially on the adaxial leaf surface. To identify WRKY transcriptional factors genes involved in the oxidative burst, BLASTX analysis against the current assembly of the S. miltiorrhiza sequence genome was performed using Arabidopsis WRKY protein sequences as queries. A total of 14 gene sequences were predicted for sage WRKYs. The relative expression assessment of WRKY genes were analysed by quantitative real-time reverse transcription-PCR and carried out in asymptomatic leaves. Four WRKY were highly induced by O3 at different time-points. WRKY11 and WRKY46 were significantly up-regulated after 2 h from the beginning of exposure. WRKY4 and WRKY5 have altered expression levels at the end of treatment (about 2-fold higher that controls). Only WRKY23 was significantly down-regulated by O3. No significant expression level changes were observed during the recovery period. This result suggests that WRKYs can be important components in the complex signalling processes during O3 responses. In particular, they could act as redox-responsive sequences and, consequently, as promoter elements specific for O3 perception/signal transduction. Furthermore, transcriptional and metabolic relationships will be elucidated.
Potential roles of WRKY transcription factors in regulating oxidative protection and signalling in Salvia officinalis plants exposed to ozone
Marchica A.;Papini R.;Tonelli M.;Filippi F.;Pellegrini E.;Lorenzini G.;Nali C.;Bernardi R.
2018-01-01
Abstract
Tropospheric ozone (O3) is a global air pollutant that causes negative effects on plant metabolism, physiology and growth. Because of its strong oxidative potential, O3 has a large spectrum of biocidal activities by inducing plant signal molecules that can mediate the stimulation of secondary answers at genetic and metabolic level. The objective of this work is to elucidate the potential roles of WRKY transcription factors in regulating oxidative protection and signalling in Salvia officinalis (sage, one of the most well-known aromatic herbs) exposed to a single pulse of O3 (200 ppb, 5 h day-1) in controlled environmental conditions. At the end of the treatment, leaves appeared symptomless. Minute chlorotic spots were recognizable 48 h from the beginning of the exposure and especially on the adaxial leaf surface. To identify WRKY transcriptional factors genes involved in the oxidative burst, BLASTX analysis against the current assembly of the S. miltiorrhiza sequence genome was performed using Arabidopsis WRKY protein sequences as queries. A total of 14 gene sequences were predicted for sage WRKYs. The relative expression assessment of WRKY genes were analysed by quantitative real-time reverse transcription-PCR and carried out in asymptomatic leaves. Four WRKY were highly induced by O3 at different time-points. WRKY11 and WRKY46 were significantly up-regulated after 2 h from the beginning of exposure. WRKY4 and WRKY5 have altered expression levels at the end of treatment (about 2-fold higher that controls). Only WRKY23 was significantly down-regulated by O3. No significant expression level changes were observed during the recovery period. This result suggests that WRKYs can be important components in the complex signalling processes during O3 responses. In particular, they could act as redox-responsive sequences and, consequently, as promoter elements specific for O3 perception/signal transduction. Furthermore, transcriptional and metabolic relationships will be elucidated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
