Two auxinic herbicides alter Brassica napus changes in transcription in a time dependent manner

The aim of this study was to investigate the molecular background by using different growth conditions under which three different auxinic herbicides were administered. These were halauxifen-methyl, and picloram at thre different harvest points after treatments (2, 48, 96 hours). Hal treatment lead to the upregulation of translational processes after 2 h, whereas auxin and hormone responses were upregulated at 48h and 96 h. Photosynthesis and mitochondrial pro-cesses were downregulated through all time points. Further, after 48 h translation was downreg-ulated. Pic treatment induced the hormone / auxin response already after 2 h, and this continued for the other time points. At 2 h and 48 h after treatment the translational processes were down-regulated and photosynthesis was downregulated after 48 h and 96 h. The more detailed analy-sis of the auxin response in the datasets indicate a role for GH3 genes, genes encoding auxin efflux proteins and confirm the upregulation of the ethylene pathway. The treatments with the auxinic herbicides halauxifen-methyl and picloram were performed at 15°C and growth stage BBCH11 (4 leaves) by pipetting the working solution onto the leaves taking care that these did not roll from the leaves. Each plant got 5 drops per treatment with a total herbicide concentration of 0.5 µg/µl Halauxifen and 2.4 µg/µl picloram. controls were treated with the solvent (1% DMSO, 0.01% Triton X-100, 0.01M NaOH). The harvest was done 2, 48 and 96 hours after application. For each treatment 3 replicates were performed.