The molecular response of two Brassica napus cultivars to short-term hypoxia in the root zone

Waterlogging is one major stress for crops and causes multiple problems for plants, for example low gas diffusion, reducing conditions in the soil and accumulation of toxic metabolites. Brassica napus is an important oil crop with high waterlogging sensitivity, which may cause severe yield losses. Its reactions to the stress are not fully understood. In this work the transcriptional response of rapeseed to one aspect of waterlogging, hypoxia in the root zone, was analyzed, including two rapeseed cultivars from different origin, Avatar from Europe and Zhongshuang 9 from Asia. Both cultivars showed a high number of differentially expressed genes in roots after 4 and 24 h of hypoxia. The response included many well-known hypoxia-induced genes such as genes coding for glycolytic and fermentative enzymes. Leaves hardly responded to the root stress after a 24-h-stress treatment, and photosynthesis seemed to be not affected by the stress applied to roots. There was no clear difference in either gene expression or tolerance to waterlogging between the two genotypes used in this study. Overall design: two Brassica napus cultivars (Avatar, Zhongshuang 9), two timepoints (4 and 24 h), two organs (root, leaf), two treatments (aeration, nitrogen gassing), three replicates